Cardiopulmonary cerebral resuscitation (CPCR, formerly abbreviated as CPR) is the treatment required to save an animal (or human) life when suffering cardiopulmonary arrest. The intent of CPCR is to provide sufficient blood flow and oxygen to the brain and vital organs to support life until more advanced medical therapy can be started. Unlike what we see on television, most patients who suffer from cardiac arrest are unable to be saved, even with CPCR. In a study from the University of California at Davis, researchers discovered that long-term survival among feline patients is extremely poor. In this study, only 2.3% of feline patients who received CPCR survived to be discharged from the hospital alive. This closely parallels findings of similar studies in human medicine.
CPCR consists of two parts: Rescue breathing and chest compressions.
These two techniques combine to keep the lungs supplied with oxygen and to keep blood circulating, carrying oxygen to the other parts of the body such as the brain and vital organs.
Basic CPCR is CPCR performed by trained bystanders at the scene of the arrest.
Advanced CPCR is CPCR performed by trained teams of professionals.
Basic CPCR is the most important for pet owners, and is described in this section.
All body tissues require a steady source of oxygen. If the source is interrupted for only a few minutes, irreversible damage may be done. If cardiopulmonary arrest occurs, basic CPCR must be initiated at the scene.
Recent research has shown that using only chest compressions was as effective as chest compressions and rescue breathing together. As long as the airway is open, compression of the chest may cause forward flow of blood and may cause adequate movement of air-at least for the first few minutes of arrest. Therefore, if only one rescuer is available to perform CPCR, it is advisable to perform only chest compressions.
Basic CPCR: Rescue Breathing (If two people are present)
Make Certain the Animal is actually Arrested and Unconscious
Talk to the pet first. Gently touch and attempt to awaken the pet. You could be seriously injured should you attempt to perform CPCR on a pet who was only sleeping heavily and was startled awake.
Ensure an Open Airway
Extend the head and neck and pull the tongue forward.
Look in the mouth and remove any saliva or vomitus. If it is too dark to see into the mouth, sweep your finger deep into the mouth and into the throat to remove any vomit or foreign body. Be aware of a hard, smooth, bone-like structure deep in the throat, which is likely to be the hyoid apparatus (Adam's apple). Serious injury could result if you pull on the hyoid apparatus.
Observe for Effective Breathing
Sometimes an animal will begin to breathe spontaneously when the head is put in the position discussed above (head and neck extended, tongue pulled forward). Watch for the rise and fall of the chest while listening closely for sounds of breathing. If no breathing is evident in 10 seconds, begin rescue breathing.
Begin Rescue Breathing
Rescue breathing is performed by covering the pet’s nose with your mouth and forcefully blowing your breath into the lungs. In cats and small dogs, you must hold the corners of the mouth tightly closed while you force the air in.
In larger dogs, the dog’s tongue should be pulled forward and the mouth and lips held shut using both hands cupped around the muzzle. Force air into the lungs until you see the chest expand. Take your mouth away when the chest has fully expended. The lungs will deflate without help. Air should be forced into the lungs until you see the chest expand.
Give 3 to 5 Full Breaths
After several breaths are given, stop for a few seconds to recheck for breathing and heart function. If the pet is still not breathing, continue rescue breathing 20 to 25 times per minute in cats or small dogs, or 12 to 20 times per minute in medium or large dogs. Push down on the stomach area every few seconds to help expel the air that may have blown into the stomach. If the stomach is allowed to distend with air, the pressure will make the rescue breathing efforts less effective. Try to coordinate breaths with chest compressions for 2-person CPCR.
If Breathing is Shallow or Non-existent
If you find that breathing is either shallow or non-existent and the pet is still unconscious, continue rescue breathing 10 to 15 times per minute and transport the pet to the nearest veterinary facility.
Basic CPCR: Chest Compressions (If one or two people are present)
After Ensuring an Open Airway, Check for a Pulse
If no pulse is detectable, begin chest compressions.
In Small Dogs or Cats
Squeeze the chest using one or both hands around the chest. Depress the rib cage circumferentially (see illustration).
Do this 100 to
150 times per minute.
In Large Dogs
Compress the chest wall with one or both hands, depending on the size of the dog and the size of the rescuer (whatever works best for you). If the dog is on her side, place your hand(s) on the side of the chest wall where it is widest. If she is on her back, place your hand(s) on the breastbone. Depress the rib cage 1.5 to 4 inches, depending on the dog's size. Do this 80 to 120 times per minute.
Coordinate Rescue Breathing and Chest Compressions
If possible, give breaths during the compressions. If it is not possible, give two breaths after every 12 compressions.
Continue CPCR until
• You become exhausted and can't continue.
• You get the animal transported to a veterinary facility and professionals can take over.
• The pulse is palpable or heartbeats are felt and they are strong and regular.
In the vast majority of cases, artificial ventilations will continue to be required for a period of time, even though heart function has returned. This is due to the nervous system depression that occurs as a result of the arrest.
All resuscitated animals should be transported to a veterinary facility for further examination and care!
Saturday, October 8, 2011
Wednesday, March 25, 2009
Canine Atopic Dermatitis Extent and Severity Index(CADESI)
Canine atopic dermatitis (CAD) severity is difficult to assess as only a few scoring systems have been developed. The most used is the Canine Atopic Dermatitis Extent and Severity Index (CADESI), adapted from the human SCORing Atopic Dermatitis (SCORAD). Despite wide use of this scoring system in clinical trials, no validation has been carried out to the authors’ knowledge. The aim of this study was to determine the reproducibility of the CADESI in clinical practice.
Initially, a set of 28 photographs taken from dogs diagnosed with CAD was scored by 6investigators for three items: erythema, lichenification and excoriation. Subsequently, 23 dogs with clinical signs compatible with CAD were graded by 2 investigators using the CADESI (erythema, lichenification and excoriation, having been assessed on 39 areas).
With the photographs, significant correlation (rS, p<0.05) was found for each combination of investigators for erythema and lichenification but only in 10/15 combinations for excoriation; interobserver agreement ranged between poor and fair (0.221
Initially, a set of 28 photographs taken from dogs diagnosed with CAD was scored by 6investigators for three items: erythema, lichenification and excoriation. Subsequently, 23 dogs with clinical signs compatible with CAD were graded by 2 investigators using the CADESI (erythema, lichenification and excoriation, having been assessed on 39 areas).
With the photographs, significant correlation (rS, p<0.05) was found for each combination of investigators for erythema and lichenification but only in 10/15 combinations for excoriation; interobserver agreement ranged between poor and fair (0.221
Oral itraconazole as a pulse therapy
The aim of this randomised, blinded, controlled study was to evaluate the efficacy of a pulse therapy with itraconazole in dogs suffering from Malassezia dermatitis. Twenty dogs presented with a generalized pruritic skin disease were included. In each case, large numbers of Malassezia spp. were demonstrated on microscopical examination of tape-strips. Dogs were randomly allocated to two groups: group A (ketoconazole 10 mg/kg/day) and group B (itraconazole 5 mg/kg twice a week). Dogs were checked after three weeks. Parameters studied were:pruritus, clinical signs (CADESI) and number of Malassezia on cytological preparations. No significant difference was observed between the two groups for any of the parameters studied. At D21, pruritus decreased by 50% (group A) to 55% (group B). CADESI markedly improved (60% in group A, 61% in group B). The mean number of Malassezia was 4.2 and 3.8 for group A and group B respectively at D0 and 0.2 and 0.1 at D21. A pulse therapy with itraconazole seems to be as effective as the daily administration of ketoconazole. This may be due to the persistence of itraconazole in the stratum corneum for long periods after discontinuation of therapy
Monday, February 23, 2009
Dog Air Travel Tips - Take your Dog Anywhere
Dog Air Travel - Tips for Traveling by Airplane with your Lovable Dog
Luckily for dog owners, these animals travel by air better than cats. If the dog is accustomed to car travel, then air travel shouldn't be a problem at all. Use the following dog air travel tips for safe and pleasant airpline travel with your best furry friend.
Certify Your Dogs Health before Air Travel
Not only is dog air travel better for your dog if the dog is healthy, but it's actually the law. Federal law requires that a dog has been certified within 10 days of the trip to be healthy, vaccinated, and free from contagious diseases. This is a very important for any pet travel, large or small.
Avoid Excessive Temperatures
Ensure the safety of your dog during air travel by never flying with your dog while temperatures are over 85 degrees or under 35 degrees, on either end of the flight. Many airliners put "heat embargos" and/or "cold embargos" on dog air travel during the summer and winter months respectively. This means that the airliners prohibit dog air travel during these times. This shouldn't be seen as a problem, because the airlines do it to prevent disease or death, and guarantee a safe flight for your dog.
Overseas Dog Air Travel May Involve Quarantine
For international dog air travel, keep in mind that some isolated countries, such as New Zealand and England, quarantine animals arriving by air. Before traveling and booking reservations, familiarize yourself with the laws, requirements, and procedures of your particular destination. Unless your flight is non-stop, remember that you may have to deal with regulations in multiple places.
Don't Tranquilize Your Dog During Air Travel
Although tranquilization may seem like a good idea during canine air travel, it isn't. Tranquilizers are the leading cause of death or sickness of dogs during air travel. A dog can't receive immediate or professional medical care during air travel, so unnecessary medications do more harm than good. In fact, many airliners reject tranquilized pets as a safety precaution.
Obedience During Dog Air Travel
Training your dog before airline travel is the best way to ensure a good flight. Unfortunately, even short air travel means hours of separation between owners and their dogs (except for service dogs). Your medium to large size dog will be confined to a shipping crate for the entire flight.
You can help relinquish the strain and discomfort on your dog by preparing him for dog air travel beforehand. Do this by getting your dog used to being inside a travel crate for extended periods of time. Also, make sure your dog works well with strangers, namely in busy, frantic, or uncomfortable environments. This will do wonders for traveling with your large furry companion.
To read the entire article on dog air travel, please visit us here.
Looking for more information regarding travel with your dog by land or air. Visit our dog air travel section at largedogbreeds.com for more breed specific information on your large canine companion.
Luckily for dog owners, these animals travel by air better than cats. If the dog is accustomed to car travel, then air travel shouldn't be a problem at all. Use the following dog air travel tips for safe and pleasant airpline travel with your best furry friend.
Certify Your Dogs Health before Air Travel
Not only is dog air travel better for your dog if the dog is healthy, but it's actually the law. Federal law requires that a dog has been certified within 10 days of the trip to be healthy, vaccinated, and free from contagious diseases. This is a very important for any pet travel, large or small.
Avoid Excessive Temperatures
Ensure the safety of your dog during air travel by never flying with your dog while temperatures are over 85 degrees or under 35 degrees, on either end of the flight. Many airliners put "heat embargos" and/or "cold embargos" on dog air travel during the summer and winter months respectively. This means that the airliners prohibit dog air travel during these times. This shouldn't be seen as a problem, because the airlines do it to prevent disease or death, and guarantee a safe flight for your dog.
Overseas Dog Air Travel May Involve Quarantine
For international dog air travel, keep in mind that some isolated countries, such as New Zealand and England, quarantine animals arriving by air. Before traveling and booking reservations, familiarize yourself with the laws, requirements, and procedures of your particular destination. Unless your flight is non-stop, remember that you may have to deal with regulations in multiple places.
Don't Tranquilize Your Dog During Air Travel
Although tranquilization may seem like a good idea during canine air travel, it isn't. Tranquilizers are the leading cause of death or sickness of dogs during air travel. A dog can't receive immediate or professional medical care during air travel, so unnecessary medications do more harm than good. In fact, many airliners reject tranquilized pets as a safety precaution.
Obedience During Dog Air Travel
Training your dog before airline travel is the best way to ensure a good flight. Unfortunately, even short air travel means hours of separation between owners and their dogs (except for service dogs). Your medium to large size dog will be confined to a shipping crate for the entire flight.
You can help relinquish the strain and discomfort on your dog by preparing him for dog air travel beforehand. Do this by getting your dog used to being inside a travel crate for extended periods of time. Also, make sure your dog works well with strangers, namely in busy, frantic, or uncomfortable environments. This will do wonders for traveling with your large furry companion.
To read the entire article on dog air travel, please visit us here.
Looking for more information regarding travel with your dog by land or air. Visit our dog air travel section at largedogbreeds.com for more breed specific information on your large canine companion.
Tuesday, November 4, 2008
Clinical Aspects, Diagnosis and Therapy of Canine Pyoderma
Clinical Aspects, Diagnosis and Therapy of Canine Pyoderma
D.N. Carlotti, DECVD
Cabinet de Dermatologie Vétérinaire
Bordeaux-Mérignac, France
Introduction
There are a large number of bacterial diseases of the skin in dogs, with different histopathological and clinical aspects. Some are superficial and benign (the basement membrane is not destroyed by the infectious process) and some are deep and severe (the basement membrane is destroyed). Pseudopyodermas are not real pyodermas since infection plays only a secondary role and anti-infectious therapy is not effective. Staphylococcus intermedius is the most common infectious agent cultured in canine pyoderma. It can multiply easily in the dog's skin, due to the thinness of the stratum corneum and the lack of sebum plug in the hair follicles. Inflammation of the skin, particularly due to allergy, is the most common cause of pyoderma, more than real immunodeficiency.
Superficial pyoderma
1. Skin fold pyoderma (intertrigo)
These lesions are seen in anatomical defects where there is an important bacterial colonization: lip, facial, vulvar, caudal, obese and mammary folds. The dermatosis is localized with erythema, exudation, suppuration and bad odour.
2. Impetigo
In juvenile impetigo, subcorneal pustules are present on the ventral side of the body, with crusting. The disease is self-limited. In adult impetigo, large pustules ("bullae") are seen all over the body. In general, adult impetigo is severe and secondary to an underlying disease (hyperadrenocorticism, glucocorticoid therapy...) or multiple traumas (e.g., during hunting).
3. Folliculitis
Juvenile folliculitis: numerous follicular pustules are present on the ventral side of the body. The condition often heals at puberty.
Short-haired dog pyoderma: there are generalized follicular pustules, epidermal collarettes and crusts, with a "moth-eaten" hair. Pruritus disappears when the lesion heal.
Secondary folliculitis: this common disease is characterized by follicular pustules, epidermal collarettes and crusts which are often generalized. Pruritus is still present after lesions healing in case of underlying pruritic dermatosis. The disease may also generate pruritus in a usually nonpruritic dermatosis (in such cases pruritus disappears when lesions heal).
"Bacterial hypersensitivity" and/or superficial spreading pyoderma: bacterial hypersensitivity is an uncommon disease based on a clinical triad: erythematous follicular pustules, target lesions/seborrhoeic plaques, haemorrhagic bullae. There is sometimes a severe pruritus. The existence of a real bacterial allergy is presumed and debatable. In superficial spreading pyoderma, nummular areas of alopecia and erythema are centrifugally expanding, with epidermal collarettes and crusts. These lesions are often associated to intact but transient follicular pustules.
Deep folliculitis: it is the so-called acral lick dermatitis, most often a deep follicular bacterial infection with retrograde hidrosadenitis secondary to a psychogenic and/or an allergic cause.
Pyotraumatic folliculitis: some cases of folliculitis (e.g., in Labradors, Retrievers) appear as oozing suppurative plaque with pain. They are surrounded by satellite pustules of folliculitis or even furunculosis, which help to differentiate them from the "classical" pyotraumatic dermatitis.
Deep pyoderma
1 Furunculosis
Acne: papulo-pustules and pustules are seen on the face, particularly the chin, in young dogs.
Secondary furunculosis: localized or generalized pustules are associated or secondary to a folliculitis and the disease is triggered or aggravated by an excessive therapy (e.g., glucocorticosteroids).
Nasal pyoderma: pustules and crusts are present on the bridge of the nose and eyelids. There may be an unpleasant scaring. This true bacterial nasal pyoderma of unknown cause should be differentiated from the sterile eosinophilic furunculosis possibly due to arthropod bites.
2. Cellulitis
A. Localized cellulitis
Pressure points pyoderma: there are necrotizing lesions of the elbows, the rump, the stifles, the hocks and the lateral digits. They are due to permanent trauma in heavy dogs.
Various localized cellulites: These are other localized necrotizing lesions (e.g., perianal). Their cause is often unknown; they are sometimes secondary to a furunculosis.
B. Generalized cellulitis
Pyodemodicosis: There is an extensive necrotizing skin disease, which is secondary to a generalized demodicosis (an immunodeficiency status).
Various generalized cellulites: necrotizing lesions are extensive and often secondary to other immunodeficiencies.
3. The interdigital pyoderma complex
There are very numerous causes of non infectious pododermatitis with erythema, oedema, oozing and alopecia. The same lesions are present in interdigital pyoderma along with furunculosis, ulcerations, fistulae and necrosis (cellulitis). Interdigital pyoderma is often secondary.
Pseudo-pyoderma
1. Pyotraumatic dermatitis
The typical lesions have an acute onset and are characterized by alopecia, erythema, oozing, suppuration, pruritus and/or pain. These lesions are common, and most often associated to pruritic skin disease. They are poorly understood (sometimes due to vasculitis?). There is a spontaneous healing in a few days, but a short treatment is useful.
2. Juvenile pyodermas
Juvenile pyoderma of new-born puppies: crusty lesions are present on the face, thorax and dorso-lumbar area. They might be due to trauma. No treatment is required since there is a spontaneous healing.
Juvenile cellulitis: The aetiology of this disease is unknown. The typical clinical aspect is a facial oedema and furunculosis, with fistulae, crusting and a suppurative otitis externa. Adenopathy and sterile abscesses (cellulitis) are present. The onset of this uncommon disease occurs before 4 months of age in one or several puppies of a litter. There is a spontaneous healing in a few weeks with scaring but treatment is required.
Diagnosis of canine pyoderma
Diagnosis of canine pyoderma is based on history, physical examination and complementary examinations: cytology, histopathology and bacteriology.
1. Cytology
In intertrigo (skin fold pyoderma), images of "bacterial colonization" are observed, i.e., healthy neutrophils, Cocci and Bacilli in an extracellular position and degenerated neutrophils in a state of phagocytosis. In impetigo and folliculitis, impaired (degenerated) neutrophils are only found. The pictures of Cocci phagocytosis are not particularly numerous. This is an image of "bacterial invasion", i.e., the penetration of pathogenic germs into the skin. The significance of the pictures of phagocytosis differs considerably depending on whether they are observed on the surface or in a cutaneous lesion. In effect, when they are observed inside the skin (epidermis, hair follicles, dermis) one might consider that the phagocytosed germs are pathogenic and that there is a real bacterial pustulosis. In contrast, phagocytosis observed on the surface indicates multiplication of germs which are not necessarily and probably rarely pathogenic. In deep pyoderma cytology is less likely to reveal the germs and pictures of phagocytosis, although they must be looked for. Frequently there are a granulomatous reaction, eosinophils and red blood cells. Bacterial colonization is observed in pyotraumatic dermatitis as in intertrigo but it is not significant and treatment with antibiotic does not result in remission. In juvenile cellulitis, the degenerated neutrophils are very numerous, with a granulomatous reaction. No germs are seen.
2. Histopathology
This will show typical lesions, but is relatively rarely performed for the diagnosis of canine pyoderma, except in case of difficult differential diagnosis.
3. Bacteriology
This can confirm the bacterial infection and allows sensitivity testing.
Treatment of canine pyoderma
Systemic (antibiotic) and topical therapy can be used in canine pyoderma.
1. Selection of antibiotics
The criteria for the choice of an antibiotic are as follows: appropriate kinetics and good cutaneous penetration, activity against Staphylococci, activity in pus and reactive tissues, bactericidal activity rather than bacteriostatic activity particularly in severe cases, easy administration (oral, q12h or q24h), absence of secondary effects, reasonable cost. The choice can be empirical, particularly in superficial pyoderma, after cytological examination of pus from an intact pustule which shows bacterial invasion. Bacteriology and sensitivity testing must be used in case of deep pyoderma, recurrent pyoderma, when cytology shows a complex flora with rods, and in case of empirical antibiotic therapy failure. They can be repeated during therapy.
2. Dosage and duration of treatment
Ideal doses must be used and duration of treatment must be long enough (a few weeks to several months depending of extension and depth of lesions, and always beyond clinical cure). Maintenance pulse treatment (e.g., 2 to 3 days a week) can be used in chronically relapsing pyoderma but it could theoretically select resistant strains as well as the use of subminimal doses. They are both used for economical reasons but the former is preferable.
3. Antibiotics useable in canine pyoderma
Antibiotics useful in canine pyoderma are included in the following table. They all have a good cutaneous diffusion (because of their liposolubility) and can be given orally, which is useful because of long therapeutic courses (ease of administration). They are all bactericidal except macrolides which are bacteriostatic.
Class
Characteristics
Examples
Macrolides
narrow spectrum/Gram+
erythromycin : 30 to 50 mg/kg div. bid or tid
lincomycin : 40 to 50 mg/kg div. bid or tid
clindamycin : 5,5 to 11 mg/kg sid or div. Bid
tylosin : 40 mg/kg div. bid
Penicillins M
resistant to penicillinases
narrow spectrum/Gram+
oxacillin : 30 to 50 mg/kg div. bid
Penicillins A
potentiated by
clavulanic acid
resistant to penicillinases larger spectrum
amoxicillin-clavulanic acid : 25 mg/kg/div. bid
Cephalosporins
resistant to penicillinases
broad spectrum
cephalexin : 30 to 60 mg/kg div. Bid
cefadroxil : 44 to 70 mg/kg div. bid
Cephalosporin P
resistant to penicillinases
narrow spectrum/Gram+
synergy with penicillins
and erythromycin
fusidic acid (the only one of this group) :
60 mg/kg div. tid
Sulfonamides-
Diaminopyrimidines
broad spectrum
trimethoprim-sulfa : 30 mg (i.e., 5 mg
trimethoprim)/kg sid or div. Bid
baquiloprim-sulfadimethoxine : 30 mg (i.e., 5mg
baquiloprim)/kg q.48h
ormetoprim-sulfadimethoxine : 30 mg (i.e., 5mg
ormetoprim)/kg sid after a single double dose
the first day
Fluoroquinolones
broad spectrum
excellent tissue
penetration
(not to be used in puppies of giant breeds)
enrofloxacin : 5mg/kg sid of div. Bid
marbofloxacin : 2 mg/kg sid
difloxacin : 5 mg/kg sid
orbifloxacin : 2.5 mg/kg sid
Penicillin G (which is injectable) and A are sensitive to penicillinases. Aminoglycosides have a low cutaneous diffusion (they are hydrosoluble), are injectable and toxic. Chloramphenicol has a bad reputation in humans and the cat (haematologic toxicity). Tetracyclines have a very low activity against Staphylococci. These antibiotics are never or rarely used in canine pyoderma. Rifampicin is effective against Staphylococci but, as it is still used to treat human tuberculosis, it should be used when there is no other possibility (5 to 10 mg/kg SID). In addition, it should be then associated to a betalactamine to prevent the selection of resistant strains of Staphylococci. Mupirocine, a topically active bactericidal antibiotic, in a polyethylene glycol base is effective against Gram+ Cocci, is not systematically absorbed and is not chemically related to other antibiotics. It can be used in localized pyodermas (acne, pressure point pyoderma, interdigital pyoderma).
4. Associated treatments
Topical therapy is always beneficial in canine pyoderma, particularly in superficial staphylococcal disease. Clipping can be useful and is necessary in deep pyoderma such as cellulitis. The main useful topical products are chlorhexidine (lotion and/or shampoo), povidone-iodine (lotion and/or shampoo), benzoyl-peroxide (shampoo and eventually gel), ethyl-lactate (shampoo). They should be used frequently, e.g., once a day, at the beginning of therapy. Later, frequency of application may decrease. Each shampoo should be followed by the application of an appropriate humectant. Topical or systemic glucocorticoids should never be used in true canine pyoderma, even in case of pruritus, because they cause severe relapses ("rebound effect"). In contrast they can be used and are effective in pseudo-pyoderma (e.g., oral prednisolone: 1 mg/kg/day for pyotraumatic dermatitis and 2 mg/kg/day for juvenile cellulitis).
Conclusion
Canine pyoderma is a group of various skin diseases and an accurate diagnosis is mandatory. An appropriate antibacterial therapy is required in most cases of canine pyoderma, in association with topical therapy. Antibiotics must be selected carefully and used with appropriate dosage and duration of treatment.
D.N. Carlotti, DECVD
Cabinet de Dermatologie Vétérinaire
Bordeaux-Mérignac, France
Introduction
There are a large number of bacterial diseases of the skin in dogs, with different histopathological and clinical aspects. Some are superficial and benign (the basement membrane is not destroyed by the infectious process) and some are deep and severe (the basement membrane is destroyed). Pseudopyodermas are not real pyodermas since infection plays only a secondary role and anti-infectious therapy is not effective. Staphylococcus intermedius is the most common infectious agent cultured in canine pyoderma. It can multiply easily in the dog's skin, due to the thinness of the stratum corneum and the lack of sebum plug in the hair follicles. Inflammation of the skin, particularly due to allergy, is the most common cause of pyoderma, more than real immunodeficiency.
Superficial pyoderma
1. Skin fold pyoderma (intertrigo)
These lesions are seen in anatomical defects where there is an important bacterial colonization: lip, facial, vulvar, caudal, obese and mammary folds. The dermatosis is localized with erythema, exudation, suppuration and bad odour.
2. Impetigo
In juvenile impetigo, subcorneal pustules are present on the ventral side of the body, with crusting. The disease is self-limited. In adult impetigo, large pustules ("bullae") are seen all over the body. In general, adult impetigo is severe and secondary to an underlying disease (hyperadrenocorticism, glucocorticoid therapy...) or multiple traumas (e.g., during hunting).
3. Folliculitis
Juvenile folliculitis: numerous follicular pustules are present on the ventral side of the body. The condition often heals at puberty.
Short-haired dog pyoderma: there are generalized follicular pustules, epidermal collarettes and crusts, with a "moth-eaten" hair. Pruritus disappears when the lesion heal.
Secondary folliculitis: this common disease is characterized by follicular pustules, epidermal collarettes and crusts which are often generalized. Pruritus is still present after lesions healing in case of underlying pruritic dermatosis. The disease may also generate pruritus in a usually nonpruritic dermatosis (in such cases pruritus disappears when lesions heal).
"Bacterial hypersensitivity" and/or superficial spreading pyoderma: bacterial hypersensitivity is an uncommon disease based on a clinical triad: erythematous follicular pustules, target lesions/seborrhoeic plaques, haemorrhagic bullae. There is sometimes a severe pruritus. The existence of a real bacterial allergy is presumed and debatable. In superficial spreading pyoderma, nummular areas of alopecia and erythema are centrifugally expanding, with epidermal collarettes and crusts. These lesions are often associated to intact but transient follicular pustules.
Deep folliculitis: it is the so-called acral lick dermatitis, most often a deep follicular bacterial infection with retrograde hidrosadenitis secondary to a psychogenic and/or an allergic cause.
Pyotraumatic folliculitis: some cases of folliculitis (e.g., in Labradors, Retrievers) appear as oozing suppurative plaque with pain. They are surrounded by satellite pustules of folliculitis or even furunculosis, which help to differentiate them from the "classical" pyotraumatic dermatitis.
Deep pyoderma
1 Furunculosis
Acne: papulo-pustules and pustules are seen on the face, particularly the chin, in young dogs.
Secondary furunculosis: localized or generalized pustules are associated or secondary to a folliculitis and the disease is triggered or aggravated by an excessive therapy (e.g., glucocorticosteroids).
Nasal pyoderma: pustules and crusts are present on the bridge of the nose and eyelids. There may be an unpleasant scaring. This true bacterial nasal pyoderma of unknown cause should be differentiated from the sterile eosinophilic furunculosis possibly due to arthropod bites.
2. Cellulitis
A. Localized cellulitis
Pressure points pyoderma: there are necrotizing lesions of the elbows, the rump, the stifles, the hocks and the lateral digits. They are due to permanent trauma in heavy dogs.
Various localized cellulites: These are other localized necrotizing lesions (e.g., perianal). Their cause is often unknown; they are sometimes secondary to a furunculosis.
B. Generalized cellulitis
Pyodemodicosis: There is an extensive necrotizing skin disease, which is secondary to a generalized demodicosis (an immunodeficiency status).
Various generalized cellulites: necrotizing lesions are extensive and often secondary to other immunodeficiencies.
3. The interdigital pyoderma complex
There are very numerous causes of non infectious pododermatitis with erythema, oedema, oozing and alopecia. The same lesions are present in interdigital pyoderma along with furunculosis, ulcerations, fistulae and necrosis (cellulitis). Interdigital pyoderma is often secondary.
Pseudo-pyoderma
1. Pyotraumatic dermatitis
The typical lesions have an acute onset and are characterized by alopecia, erythema, oozing, suppuration, pruritus and/or pain. These lesions are common, and most often associated to pruritic skin disease. They are poorly understood (sometimes due to vasculitis?). There is a spontaneous healing in a few days, but a short treatment is useful.
2. Juvenile pyodermas
Juvenile pyoderma of new-born puppies: crusty lesions are present on the face, thorax and dorso-lumbar area. They might be due to trauma. No treatment is required since there is a spontaneous healing.
Juvenile cellulitis: The aetiology of this disease is unknown. The typical clinical aspect is a facial oedema and furunculosis, with fistulae, crusting and a suppurative otitis externa. Adenopathy and sterile abscesses (cellulitis) are present. The onset of this uncommon disease occurs before 4 months of age in one or several puppies of a litter. There is a spontaneous healing in a few weeks with scaring but treatment is required.
Diagnosis of canine pyoderma
Diagnosis of canine pyoderma is based on history, physical examination and complementary examinations: cytology, histopathology and bacteriology.
1. Cytology
In intertrigo (skin fold pyoderma), images of "bacterial colonization" are observed, i.e., healthy neutrophils, Cocci and Bacilli in an extracellular position and degenerated neutrophils in a state of phagocytosis. In impetigo and folliculitis, impaired (degenerated) neutrophils are only found. The pictures of Cocci phagocytosis are not particularly numerous. This is an image of "bacterial invasion", i.e., the penetration of pathogenic germs into the skin. The significance of the pictures of phagocytosis differs considerably depending on whether they are observed on the surface or in a cutaneous lesion. In effect, when they are observed inside the skin (epidermis, hair follicles, dermis) one might consider that the phagocytosed germs are pathogenic and that there is a real bacterial pustulosis. In contrast, phagocytosis observed on the surface indicates multiplication of germs which are not necessarily and probably rarely pathogenic. In deep pyoderma cytology is less likely to reveal the germs and pictures of phagocytosis, although they must be looked for. Frequently there are a granulomatous reaction, eosinophils and red blood cells. Bacterial colonization is observed in pyotraumatic dermatitis as in intertrigo but it is not significant and treatment with antibiotic does not result in remission. In juvenile cellulitis, the degenerated neutrophils are very numerous, with a granulomatous reaction. No germs are seen.
2. Histopathology
This will show typical lesions, but is relatively rarely performed for the diagnosis of canine pyoderma, except in case of difficult differential diagnosis.
3. Bacteriology
This can confirm the bacterial infection and allows sensitivity testing.
Treatment of canine pyoderma
Systemic (antibiotic) and topical therapy can be used in canine pyoderma.
1. Selection of antibiotics
The criteria for the choice of an antibiotic are as follows: appropriate kinetics and good cutaneous penetration, activity against Staphylococci, activity in pus and reactive tissues, bactericidal activity rather than bacteriostatic activity particularly in severe cases, easy administration (oral, q12h or q24h), absence of secondary effects, reasonable cost. The choice can be empirical, particularly in superficial pyoderma, after cytological examination of pus from an intact pustule which shows bacterial invasion. Bacteriology and sensitivity testing must be used in case of deep pyoderma, recurrent pyoderma, when cytology shows a complex flora with rods, and in case of empirical antibiotic therapy failure. They can be repeated during therapy.
2. Dosage and duration of treatment
Ideal doses must be used and duration of treatment must be long enough (a few weeks to several months depending of extension and depth of lesions, and always beyond clinical cure). Maintenance pulse treatment (e.g., 2 to 3 days a week) can be used in chronically relapsing pyoderma but it could theoretically select resistant strains as well as the use of subminimal doses. They are both used for economical reasons but the former is preferable.
3. Antibiotics useable in canine pyoderma
Antibiotics useful in canine pyoderma are included in the following table. They all have a good cutaneous diffusion (because of their liposolubility) and can be given orally, which is useful because of long therapeutic courses (ease of administration). They are all bactericidal except macrolides which are bacteriostatic.
Class
Characteristics
Examples
Macrolides
narrow spectrum/Gram+
erythromycin : 30 to 50 mg/kg div. bid or tid
lincomycin : 40 to 50 mg/kg div. bid or tid
clindamycin : 5,5 to 11 mg/kg sid or div. Bid
tylosin : 40 mg/kg div. bid
Penicillins M
resistant to penicillinases
narrow spectrum/Gram+
oxacillin : 30 to 50 mg/kg div. bid
Penicillins A
potentiated by
clavulanic acid
resistant to penicillinases larger spectrum
amoxicillin-clavulanic acid : 25 mg/kg/div. bid
Cephalosporins
resistant to penicillinases
broad spectrum
cephalexin : 30 to 60 mg/kg div. Bid
cefadroxil : 44 to 70 mg/kg div. bid
Cephalosporin P
resistant to penicillinases
narrow spectrum/Gram+
synergy with penicillins
and erythromycin
fusidic acid (the only one of this group) :
60 mg/kg div. tid
Sulfonamides-
Diaminopyrimidines
broad spectrum
trimethoprim-sulfa : 30 mg (i.e., 5 mg
trimethoprim)/kg sid or div. Bid
baquiloprim-sulfadimethoxine : 30 mg (i.e., 5mg
baquiloprim)/kg q.48h
ormetoprim-sulfadimethoxine : 30 mg (i.e., 5mg
ormetoprim)/kg sid after a single double dose
the first day
Fluoroquinolones
broad spectrum
excellent tissue
penetration
(not to be used in puppies of giant breeds)
enrofloxacin : 5mg/kg sid of div. Bid
marbofloxacin : 2 mg/kg sid
difloxacin : 5 mg/kg sid
orbifloxacin : 2.5 mg/kg sid
Penicillin G (which is injectable) and A are sensitive to penicillinases. Aminoglycosides have a low cutaneous diffusion (they are hydrosoluble), are injectable and toxic. Chloramphenicol has a bad reputation in humans and the cat (haematologic toxicity). Tetracyclines have a very low activity against Staphylococci. These antibiotics are never or rarely used in canine pyoderma. Rifampicin is effective against Staphylococci but, as it is still used to treat human tuberculosis, it should be used when there is no other possibility (5 to 10 mg/kg SID). In addition, it should be then associated to a betalactamine to prevent the selection of resistant strains of Staphylococci. Mupirocine, a topically active bactericidal antibiotic, in a polyethylene glycol base is effective against Gram+ Cocci, is not systematically absorbed and is not chemically related to other antibiotics. It can be used in localized pyodermas (acne, pressure point pyoderma, interdigital pyoderma).
4. Associated treatments
Topical therapy is always beneficial in canine pyoderma, particularly in superficial staphylococcal disease. Clipping can be useful and is necessary in deep pyoderma such as cellulitis. The main useful topical products are chlorhexidine (lotion and/or shampoo), povidone-iodine (lotion and/or shampoo), benzoyl-peroxide (shampoo and eventually gel), ethyl-lactate (shampoo). They should be used frequently, e.g., once a day, at the beginning of therapy. Later, frequency of application may decrease. Each shampoo should be followed by the application of an appropriate humectant. Topical or systemic glucocorticoids should never be used in true canine pyoderma, even in case of pruritus, because they cause severe relapses ("rebound effect"). In contrast they can be used and are effective in pseudo-pyoderma (e.g., oral prednisolone: 1 mg/kg/day for pyotraumatic dermatitis and 2 mg/kg/day for juvenile cellulitis).
Conclusion
Canine pyoderma is a group of various skin diseases and an accurate diagnosis is mandatory. An appropriate antibacterial therapy is required in most cases of canine pyoderma, in association with topical therapy. Antibiotics must be selected carefully and used with appropriate dosage and duration of treatment.
The Efficacy of Ibafloxacin Tablets and Gel in the Treatment of Canine Pyoderma
The Efficacy of Ibafloxacin Tablets and Gel in the Treatment of Canine Pyoderma
*L. J. I. Horspool, R. van den Bos, P. van Laar
*Intervet International bv
Boxmeer, NL
Linda.Horspool@intervet.com
OBJECTIVES
Canine pyoderma is an inflammatory skin disease that is commonly encountered in clinical practice. Staphylococcus intermedius is the primary cause of pyoderma in dogs. However a number of underlying causes (such as seborrhea, parasites, immune incompetence (corticosteroid use), endocrine imbalance) can predispose to the development of canine pyoderma.
In the present study, the efficacy of the tablet formulation of the novel fluoroquinolone ibafloxacin was compared with a new gel formulation containing ibafloxacin in a multicentre, randomised, non-blinded, controlled clinical study on canine pyoderma in The Netherlands, Germany and Italy.
MATERIALS
Dogs with pyoderma were administered ibafloxacin (Ibaflin®, Intervet International bv) orally, at a dose rate of 15 mg/kg bodyweight, as tablets (Group 1, n=94) or gel (Group 2, n=93) for 21-91 days. Clinical examinations were carried out on Days 0, 7 and 21 and then every 14 days until treatment was stopped. Bacterial culture was performed on Day 0. The response to treatment was evaluated using the number of treatment failures (lack of improvement by Day 7 or 21) and the improvement in general condition and pyoderma lesion scores. The overall response to treatment was based on clinical examinations 7 and 28 days after treatment was stopped.
RESULTS
Staphylococcus intermedius was cultured from 82% of Group 1 and 88% of Group 2. The pyoderma was considered to be superficial in 58% and deep in 42% of the dogs in the present study. The mean duration of treatment was 5-6 weeks in both groups. The number of treatment failures and the improvement in general condition or specific disease scores did not differ significantly between the two groups. Seven days after the last treatment, 80% of Group 1 and 84% of Group 2 were classed as having responded to treatment (P>0.05). Mild suspected adverse reactions to treatment (dullness, polydipsia) were reported for 2 dogs in Group 1 (2.1%) and 1 dog in Group 2 ((1.1%).
CONCLUSION
The present study was designed so that all dogs would be treated for at least 3 weeks (suitable for superficial pyoderma). Deep pyoderma requires longer treatment (at least 6 weeks) and is more difficult to manage, thus dogs in the present study could be treated for up to 13 weeks. Fluoroquinolones have a broad spectrum of activity, are widely distributed in the body and can be administered orally once daily, making them ideal for the treatment of canine pyoderma. In the present study, ibafloxacin was equally effective in the treatment of canine pyoderma when formulated as conventional tablets or as gel for oral administration. In addition, suspected adverse reactions to treatment with ibafloxacin tablets or gel occurred at a similar low rate even during prolonged treatment.
*L. J. I. Horspool, R. van den Bos, P. van Laar
*Intervet International bv
Boxmeer, NL
Linda.Horspool@intervet.com
OBJECTIVES
Canine pyoderma is an inflammatory skin disease that is commonly encountered in clinical practice. Staphylococcus intermedius is the primary cause of pyoderma in dogs. However a number of underlying causes (such as seborrhea, parasites, immune incompetence (corticosteroid use), endocrine imbalance) can predispose to the development of canine pyoderma.
In the present study, the efficacy of the tablet formulation of the novel fluoroquinolone ibafloxacin was compared with a new gel formulation containing ibafloxacin in a multicentre, randomised, non-blinded, controlled clinical study on canine pyoderma in The Netherlands, Germany and Italy.
MATERIALS
Dogs with pyoderma were administered ibafloxacin (Ibaflin®, Intervet International bv) orally, at a dose rate of 15 mg/kg bodyweight, as tablets (Group 1, n=94) or gel (Group 2, n=93) for 21-91 days. Clinical examinations were carried out on Days 0, 7 and 21 and then every 14 days until treatment was stopped. Bacterial culture was performed on Day 0. The response to treatment was evaluated using the number of treatment failures (lack of improvement by Day 7 or 21) and the improvement in general condition and pyoderma lesion scores. The overall response to treatment was based on clinical examinations 7 and 28 days after treatment was stopped.
RESULTS
Staphylococcus intermedius was cultured from 82% of Group 1 and 88% of Group 2. The pyoderma was considered to be superficial in 58% and deep in 42% of the dogs in the present study. The mean duration of treatment was 5-6 weeks in both groups. The number of treatment failures and the improvement in general condition or specific disease scores did not differ significantly between the two groups. Seven days after the last treatment, 80% of Group 1 and 84% of Group 2 were classed as having responded to treatment (P>0.05). Mild suspected adverse reactions to treatment (dullness, polydipsia) were reported for 2 dogs in Group 1 (2.1%) and 1 dog in Group 2 ((1.1%).
CONCLUSION
The present study was designed so that all dogs would be treated for at least 3 weeks (suitable for superficial pyoderma). Deep pyoderma requires longer treatment (at least 6 weeks) and is more difficult to manage, thus dogs in the present study could be treated for up to 13 weeks. Fluoroquinolones have a broad spectrum of activity, are widely distributed in the body and can be administered orally once daily, making them ideal for the treatment of canine pyoderma. In the present study, ibafloxacin was equally effective in the treatment of canine pyoderma when formulated as conventional tablets or as gel for oral administration. In addition, suspected adverse reactions to treatment with ibafloxacin tablets or gel occurred at a similar low rate even during prolonged treatment.
The Approach to Canine Recurrent Pyoderma
The Approach to Canine Recurrent Pyoderma
Richard EW Halliwell, MA VetMB PhD MRCVS DECVD
Professor, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Summerhall
Edinburgh, UK
THE DEVELOPMENT OF PYODERMA
It is believed that staphylococcal pyoderma develops following surface spread from the carrier sites. Factors that ordinarily prevent the development of pyoderma are:
1. The physical barrier of the intact skin. Normal desquamation is extremely important in preventing niches in which pathogenic bacteria could become established.
2. Antibacterial substances present in normal sebum, and secreted onto the skin surface from apocrine secretions. This would include immunoglobulin, and other non-specifically acting substances such as those produced by resident bacteria.
3. The bacterial barrier. If non-pathogenic bacteria occupy all available colonization sites, pathogens will not become established.
There is thus a dynamic balance between the host defenses, the virulence of any potential pathogens and their ability to gain access, and the host defenses that are brought into play in a damage limitation exercise.
FACTORS THAT PREDISPOSE TO RECURRENT PYODERMAS
Pyoderma is likely to prove recurrent in a number of situations
1. Where there is a tendency to surface colonization:
a. Seborrhoea, of whatever cause, is likely to lead to colonization with Staph intermedius.
b. Atopic disease. In this condition it has been shown that Stratum corneum cells of atopics have a greater tendency to adhere to the organism than do cells from normals.
2. Where the integrity of the skin barrier is impaired:This may occur secondarily to any inflammatory skin disease, or one that leads to self-trauma from pruritus. Flea allergy is a rather special case. The secondary infection in such cases is often minor, and does not necessitate antibiotic therapy. However a minority of animals will break with a staphylococcal infection whenever they acquire an infestation. In demodicosis, a recurrence of the infection is often the first sign of recurrence of the mite population.
3. In the immunocompromised animal: This is generally limited to deficiencies in non-specific defenses or in cell-mediated immunity, as antibody response is always evident.
a. Congenital non-specific immune defects. Delayed intracellular killing by neutrophils has been noted in weimaraners and dobermans. Irish setters have been reported with a severe, intracellular killing defect, but this is exceedingly rare. However, absence of the neutrophil complement receptors CD11b and CD18, which aid attachment prior to engulfment, is quite common in Irish setters in the UK and Scandinavia. Such animals would be expected to have difficulties in handling infections of all types.
b. Impaired cell-mediated immunity. It has been documented that atopic dogs have impaired cell-mediated immunity. In animals with impaired cell-mediated immunity from other causes has also been documented. Some animals with recurrent pyoderma have impaired cell-mediated immunity- where their lymphocytes appear to have an inbuilt defect, or where there are serum immunosuppressive factors present. This seems to be an excellent way by which the infection can be potentiated.
4. Food allergy:Typically, affected animals are less pruritic when on antibiotics with their pyoderma controlled, but relapse occurs either immediately on cessation of therapy or within 2-3 weeks. In other cases the pruritus is fully controlled by antibiotic therapy, and the animal appears to be suffering from a food allergy which is sub clinical as far as the pruritus is concerned.
5. In cases of hypersensitivity to staphylococcal antigens:It is well documented in experimental animals that development of hypersensitivity renders the animal much easier to infect. This has been shown also to be true in dogs.
6. Hypothyroidism:This is well recognized as a cause of recurrent staphylococcal infection, but it is not clear whether it results from the accompanying seborrhea, or to impaired defenses that may accompany the condition.
7. Iatrogenic:
a. Improper use of antibiotics. These must be given in full doses for the full length of time.
b. Use of corticosteroids. Although these may appear to produce an improvement, merely from their anti-inflammatory action, in the long term they are working against our best interests as they (a), tend to dry the skin inducing scaling and thus favoring colonization, and (b), they may further impair cell-mediated immunity.
Antibiotic selection
Suitable antibiotics are directed at the Staph. intermedius. Where there is secondary infection with gram-negatives, these will disappear once the Staph. is controlled unless the animal is severely immunodeficient, or there is an overwhelming infection.
1. Macrolides.Erythromycin and lincomycin are good, first choice bacteriostatic antibiotics. Clindamycin does not appear to offer any major advantages over the other, cheaper, products. The vomiting with erythromycin can be obviated by feeding an anti-emetic 30 minutes prior to each dose for the first two days. There is cross-resistance between the two drugs. The dose for erythromycin is 10-15mg/kg TID, and for lincomycin 20mg/kg BID.
2. Potentiated sulphonamides. Trimethoprim-sulphadiazine (or sulphamethoxazole), ormetoprim-sulphadimethoxine and bacquiloprim-sulphadimethoxine are very useful antibiotics for pyodermas. The dose for the first is 30mg/kg given twice daily, although some clinicians are comfortable with SID dosage. The dose for ormetoprim is 55mg/kg for the first day, and then 27.5mg/kg once daily thereafter. Drug reactions are not uncommon with trimethoprim sulphur, and result from the sulphadiazine, which also has the propensity to induce a transient arthropathy, especially in Dobermans. The tendency to induce keratoconjunctivitis sicca must be watched.
3. Cephalosporins. Cephadroxyl and cephalexin are excellent for the treatment of pyodermas. Although they are broader spectrum than is oxacillin, they do not classify as broad-spectrum drugs, and are perfectly acceptable for the routine treatment of canine pyoderma. Drug reactions are seen, but probably with less frequency than with the sulphonamides. They are bactericidal. Doses are 20-25mg/kg BID.
4. Oxacillin. This is an excellent, narrow spectrum bactericidal antibiotic to which resistance is extremely rare. Unfortunately there are no veterinary preparations. The dose is 20mg/kg TID.
5. Amoxacillin/clavulonic acid. This broad-spectrum bactericidal antibiotic is very useful. Doses used range from 15-20mg/kg BID.
6. Fluoroquinolones. These are very broad spectrum, bactericidal antibiotics. It would be indicated where there is a significant involvement of gram negatives. Recommended doses are 2.5mg/kg BID (or 5mg SID) for enrofloxacin, 2.0mg/kg SID for marbofloxacin. 2.5mg/kg SID for orbofloxacin and 5-10 mg/kg BID for difloxacin. They are, however, not indicated for routine use in dermatology, due to the possibility of inducing resistance in Pseudomonas.
Topical therapy
Antibacterial shampoos using products containing benzoyl peroxide (2-3%), clorhexidene (2-4%) or ethyl lactate (10%) form a most valuable supplementary treatment. Chitosanide, which is contained in the new spherulite-based shampoos of Virbac, also has antibacterial properties. Shampoos can be used 1-2 times weekly therapeutically, and are also useful as part of a preventative maintenance strategy.
In the case of deep pyodermas, antibacterial soaks employing povidone iodine are a valuable aid, and can be done twice weekly in the initial stages of treatment. In the case of localised deep pyodermas, benzoyl peroxide gels are of value. Also, where there is evidence of ingrown hairs forming foreign body reactions, these should be gently massaged out in warm water soaks.
THE APPROACH TO THE RECURRENT INFECTION
1. Search for a predisposing cause.
a. Evaluate for seborrhea. If this is evident, look for a cause of the seborrhea.
b. Evaluate for evidence of ectoparasitic disease. Be sure to search repeatedly for demodex in any case of recurrent deep pyoderma, particularly pododermatitis. Biopsies are sometimes necessary to demonstrate mites in such cases.
c. Check for thyroid function, even in animals that are not overtly seborrheic.
d. Skin test, or undertake in vitro tests for atopy, even if animals are not pruritic when their pyoderma is controlled.
e. Do an elimination diet for food allergy, again, even if the animal is not pruritic when the pyoderma is controlled.
f. Unfortunately, work-up for immunological defects is not generally available, but should be pursued if possible if all of the above are negative.
2. Therapy for the recurrent case with no apparent cause.
a. Be sure to use the appropriate antibiotic therapy supported by results of in vitro sensitivity tests. Bactericidal therapy is preferred in recurrent cases.
b. Use good supporting antibacterial shampoos. These may be alternated with antiseborrhoeic shampoos if seborrhoea is evident.
c. Consider using immunotherapy with a staphylococcal product e.g., Staph Phage Lysate (Delmont Labs, Swarthmore, PA, USA).
d. As a last resort some clinicians advocate:
i. Continued antibiotic therapy in normal doses,
ii. Intermittent full courses at full dosage with one month on and one month off.
iii. Intermittent full dose therapy on, say, two consecutive days each week.
iv. Continual low dose therapy, which seems conceptually the least desirable approach.
Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)
Richard EW Halliwell, MA, VetMB, PhD, MRCVS, DECVD
Professor, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Summerhall
Edinburgh, UK
Richard EW Halliwell, MA VetMB PhD MRCVS DECVD
Professor, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Summerhall
Edinburgh, UK
THE DEVELOPMENT OF PYODERMA
It is believed that staphylococcal pyoderma develops following surface spread from the carrier sites. Factors that ordinarily prevent the development of pyoderma are:
1. The physical barrier of the intact skin. Normal desquamation is extremely important in preventing niches in which pathogenic bacteria could become established.
2. Antibacterial substances present in normal sebum, and secreted onto the skin surface from apocrine secretions. This would include immunoglobulin, and other non-specifically acting substances such as those produced by resident bacteria.
3. The bacterial barrier. If non-pathogenic bacteria occupy all available colonization sites, pathogens will not become established.
There is thus a dynamic balance between the host defenses, the virulence of any potential pathogens and their ability to gain access, and the host defenses that are brought into play in a damage limitation exercise.
FACTORS THAT PREDISPOSE TO RECURRENT PYODERMAS
Pyoderma is likely to prove recurrent in a number of situations
1. Where there is a tendency to surface colonization:
a. Seborrhoea, of whatever cause, is likely to lead to colonization with Staph intermedius.
b. Atopic disease. In this condition it has been shown that Stratum corneum cells of atopics have a greater tendency to adhere to the organism than do cells from normals.
2. Where the integrity of the skin barrier is impaired:This may occur secondarily to any inflammatory skin disease, or one that leads to self-trauma from pruritus. Flea allergy is a rather special case. The secondary infection in such cases is often minor, and does not necessitate antibiotic therapy. However a minority of animals will break with a staphylococcal infection whenever they acquire an infestation. In demodicosis, a recurrence of the infection is often the first sign of recurrence of the mite population.
3. In the immunocompromised animal: This is generally limited to deficiencies in non-specific defenses or in cell-mediated immunity, as antibody response is always evident.
a. Congenital non-specific immune defects. Delayed intracellular killing by neutrophils has been noted in weimaraners and dobermans. Irish setters have been reported with a severe, intracellular killing defect, but this is exceedingly rare. However, absence of the neutrophil complement receptors CD11b and CD18, which aid attachment prior to engulfment, is quite common in Irish setters in the UK and Scandinavia. Such animals would be expected to have difficulties in handling infections of all types.
b. Impaired cell-mediated immunity. It has been documented that atopic dogs have impaired cell-mediated immunity. In animals with impaired cell-mediated immunity from other causes has also been documented. Some animals with recurrent pyoderma have impaired cell-mediated immunity- where their lymphocytes appear to have an inbuilt defect, or where there are serum immunosuppressive factors present. This seems to be an excellent way by which the infection can be potentiated.
4. Food allergy:Typically, affected animals are less pruritic when on antibiotics with their pyoderma controlled, but relapse occurs either immediately on cessation of therapy or within 2-3 weeks. In other cases the pruritus is fully controlled by antibiotic therapy, and the animal appears to be suffering from a food allergy which is sub clinical as far as the pruritus is concerned.
5. In cases of hypersensitivity to staphylococcal antigens:It is well documented in experimental animals that development of hypersensitivity renders the animal much easier to infect. This has been shown also to be true in dogs.
6. Hypothyroidism:This is well recognized as a cause of recurrent staphylococcal infection, but it is not clear whether it results from the accompanying seborrhea, or to impaired defenses that may accompany the condition.
7. Iatrogenic:
a. Improper use of antibiotics. These must be given in full doses for the full length of time.
b. Use of corticosteroids. Although these may appear to produce an improvement, merely from their anti-inflammatory action, in the long term they are working against our best interests as they (a), tend to dry the skin inducing scaling and thus favoring colonization, and (b), they may further impair cell-mediated immunity.
Antibiotic selection
Suitable antibiotics are directed at the Staph. intermedius. Where there is secondary infection with gram-negatives, these will disappear once the Staph. is controlled unless the animal is severely immunodeficient, or there is an overwhelming infection.
1. Macrolides.Erythromycin and lincomycin are good, first choice bacteriostatic antibiotics. Clindamycin does not appear to offer any major advantages over the other, cheaper, products. The vomiting with erythromycin can be obviated by feeding an anti-emetic 30 minutes prior to each dose for the first two days. There is cross-resistance between the two drugs. The dose for erythromycin is 10-15mg/kg TID, and for lincomycin 20mg/kg BID.
2. Potentiated sulphonamides. Trimethoprim-sulphadiazine (or sulphamethoxazole), ormetoprim-sulphadimethoxine and bacquiloprim-sulphadimethoxine are very useful antibiotics for pyodermas. The dose for the first is 30mg/kg given twice daily, although some clinicians are comfortable with SID dosage. The dose for ormetoprim is 55mg/kg for the first day, and then 27.5mg/kg once daily thereafter. Drug reactions are not uncommon with trimethoprim sulphur, and result from the sulphadiazine, which also has the propensity to induce a transient arthropathy, especially in Dobermans. The tendency to induce keratoconjunctivitis sicca must be watched.
3. Cephalosporins. Cephadroxyl and cephalexin are excellent for the treatment of pyodermas. Although they are broader spectrum than is oxacillin, they do not classify as broad-spectrum drugs, and are perfectly acceptable for the routine treatment of canine pyoderma. Drug reactions are seen, but probably with less frequency than with the sulphonamides. They are bactericidal. Doses are 20-25mg/kg BID.
4. Oxacillin. This is an excellent, narrow spectrum bactericidal antibiotic to which resistance is extremely rare. Unfortunately there are no veterinary preparations. The dose is 20mg/kg TID.
5. Amoxacillin/clavulonic acid. This broad-spectrum bactericidal antibiotic is very useful. Doses used range from 15-20mg/kg BID.
6. Fluoroquinolones. These are very broad spectrum, bactericidal antibiotics. It would be indicated where there is a significant involvement of gram negatives. Recommended doses are 2.5mg/kg BID (or 5mg SID) for enrofloxacin, 2.0mg/kg SID for marbofloxacin. 2.5mg/kg SID for orbofloxacin and 5-10 mg/kg BID for difloxacin. They are, however, not indicated for routine use in dermatology, due to the possibility of inducing resistance in Pseudomonas.
Topical therapy
Antibacterial shampoos using products containing benzoyl peroxide (2-3%), clorhexidene (2-4%) or ethyl lactate (10%) form a most valuable supplementary treatment. Chitosanide, which is contained in the new spherulite-based shampoos of Virbac, also has antibacterial properties. Shampoos can be used 1-2 times weekly therapeutically, and are also useful as part of a preventative maintenance strategy.
In the case of deep pyodermas, antibacterial soaks employing povidone iodine are a valuable aid, and can be done twice weekly in the initial stages of treatment. In the case of localised deep pyodermas, benzoyl peroxide gels are of value. Also, where there is evidence of ingrown hairs forming foreign body reactions, these should be gently massaged out in warm water soaks.
THE APPROACH TO THE RECURRENT INFECTION
1. Search for a predisposing cause.
a. Evaluate for seborrhea. If this is evident, look for a cause of the seborrhea.
b. Evaluate for evidence of ectoparasitic disease. Be sure to search repeatedly for demodex in any case of recurrent deep pyoderma, particularly pododermatitis. Biopsies are sometimes necessary to demonstrate mites in such cases.
c. Check for thyroid function, even in animals that are not overtly seborrheic.
d. Skin test, or undertake in vitro tests for atopy, even if animals are not pruritic when their pyoderma is controlled.
e. Do an elimination diet for food allergy, again, even if the animal is not pruritic when the pyoderma is controlled.
f. Unfortunately, work-up for immunological defects is not generally available, but should be pursued if possible if all of the above are negative.
2. Therapy for the recurrent case with no apparent cause.
a. Be sure to use the appropriate antibiotic therapy supported by results of in vitro sensitivity tests. Bactericidal therapy is preferred in recurrent cases.
b. Use good supporting antibacterial shampoos. These may be alternated with antiseborrhoeic shampoos if seborrhoea is evident.
c. Consider using immunotherapy with a staphylococcal product e.g., Staph Phage Lysate (Delmont Labs, Swarthmore, PA, USA).
d. As a last resort some clinicians advocate:
i. Continued antibiotic therapy in normal doses,
ii. Intermittent full courses at full dosage with one month on and one month off.
iii. Intermittent full dose therapy on, say, two consecutive days each week.
iv. Continual low dose therapy, which seems conceptually the least desirable approach.
Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)
Richard EW Halliwell, MA, VetMB, PhD, MRCVS, DECVD
Professor, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Summerhall
Edinburgh, UK
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