Breed and site predispositions of dogs with atopic dermatitis: a comparison of five locations in three continents.

The objectives of this multicentre study were to analyse and compare breed predispositions and lesion distributions of 552 dogs diagnosed with atopic dermatitis from five different dermatologic referral centres located in Australia, Germany (2) and the United States (2). Breeds were compared with the canine population in the respective locations. Breed predispositions varied from geographical site, although golden retrievers and German shepherd dogs were predisposed in three of five practices. Lesions were present most commonly on the paws (62%), ventrum (51%), ears (48%) and face (39%). Various breeds had specific site predilections. Based on this study, breed predispositions can vary greatly both between continents and also between different locations on the same continent. In addition, some breeds showed predispositions for certain body sites which also varied in some instances with the geographical location.

Effect of omega-3 fatty acids on canine atopic dermatitis.

Twenty-nine dogs were included in a double-blinded, placebo-controlled, randomised trial and were orally supplemented for 10 weeks with either flax oil (200 mg/kg/day), eicosapentaenoic acid (50 mg/kg/day) and docosahexaenoic acid (35 mg/kg/day) in a commercial preparation, or mineral oil as a placebo. For each dog, clinical scores were determined based on a scoring system developed prior to the trial. Total omega-6 and omega-3 intake and the ratio of omega-6:omega-3 (omega-6:3) were calculated before and after the trial. The dogs' clinical scores improved in those supplemented with flax oil and the commercial preparation, but not in the placebo group. No correlation was identified between total fatty acid intake or omega-6:3 ratio and clinical scores. Based on the results of this study, the total intake of fatty acids or the omega-6:3 ratio do not seem to be the main factors in determining the clinical response.

Zinc-responsive dermatosis in dogs: 41 cases and literature review.

Forty-one cases of zinc-responsive dermatosis in the dog are described. The Siberian husky was the predominant breed affected. Periocular crusts were the most common clinical sign and parakeratosis was noted in the skin biopsy specimens of all dogs. Treatment with oral zinc ameliorated the clinical signs in most dogs, but cases necessitating other treatments such as parenteral zinc or retinoids are reported. The authors recommend a starting dose of 2-3 mg kg-1 elemental zinc per day in the treatment of this disorder.

Clinicopathologic findings, sensitivity to house dust mites and efficacy of milbemycin oxime treatment of dogs with Cheyletiella sp. infestation.

Twenty-three dogs with positive skin scrapings for Cheyletiella sp. were treated with milbemycin oxime using a protocol approximating 2 mg kg-1 orally once weekly for three weeks. Nineteen of these dogs belonged to a household of 41 dogs and two dogs were in households with one other dog. All in-contact dogs were treated. Pre-treatment intradermal skin tests showed positive reactions to D. farinae in 13 dogs and to D. pteronyssinus in 12 dogs; these became negative post-treatment in four and seven dogs, respectively. All dogs showed a dramatic reduction in clinical signs one week after the third treatment. Eighteen dogs no longer had mites on skin scrapings, three had dead mites and two had deformed eggs. Recurrence of clinical signs necessitated two additional courses of the protocol in the multiple dog household and for a dog receiving immunosuppressive treatment for pemphigus foliaceus. Possible adverse reactions to the milbemycin (vomiting, lethargy) were noted once in two dogs.

Thiopurine methyltransferase in red blood cells of dogs, cats, and horses.

Our objective was to determine if thiopurine methyltransferase (TPMT), the enzyme important in the metabolism of azathioprine in human beings, is detectable in red blood cell lysates (RBCL) of healthy dogs, cats, and horses. Values for TPMT activity were determined from blood collected from 20 healthy dogs, cats, and horses. The TPMT activity in each animal's RBCL was determined using a radioenzymatic end point involving TPMT-facilitated metabolism of 6-mercaptopurine to 6-methylmercaptopurine (6-MMP). One unit of TPMT activity represents the formation of 1 nmol of 6-MMP per milliliter of packed red blood cells per hour of incubation at 37 degrees C. TPMT activity in RBCL was detectable in all species, with mean RBC values +/- standard deviation of 17.9 +/- 3.79 U/mL in dogs; 2.76 +/- 0.70 U/mL in cats; and 2.185 +/- 0.36 U/mL in horses. Values for TPMT in the 3 species were significantly (P < .05) different from one another. TPMT values for dogs were significantly higher than the other species, and TPMT values for cats were significantly higher than those for horses. We conclude that RBCL TPMT values are measurable in dogs. cats, and horses and that dogs have higher values than cats or horses. These findings are consistent with the lower tolerance for azathioprine in cats as compared with dogs. It remains to be determined whether RBCL TPMT values in these species correlate with TPMT activity in the liver, where most of the metabolization of azathioprine is believed to occur.

Pharmacokinetics of exogenous corticotropin in normal dogs, hospitalized dogs with non adrenal illness and adrenopathic dogs.

Corticotropin (ACTH) pharmacokinetics was assessed in 10 normal dogs receiving exogenous ACTH (0.5 U/kg, i.v.). A two-compartment open model was most appropriate for description of exogenous ACTH pharmacokinetics. The apparent distribution and elimination rate constants (alpha and beta) were 7.4 +/- 2.7 x 10(-2) min(-1) and 5.5 +/- 3.8 x 10(-3) min(-1), respectively. Area under the concentration-time curve (AUC) was 2.91 +/- 0.78 x 10(4) pg x min/mL, mean residence time (MRT) was 45.0 +/- 12.2 min, the distribution half-life (t1/2alpha) was 9.4 min (harmonic mean), and the elimination half-life (t1/2beta) was 128 min (harmonic mean). The total body clearance of ACTH (ClB) was 1.83 +/- 0.46 x 10(4) mL x min/kg and volume of distribution (Vd(area)) was 30 +/- 15 L/kg. Corticotropin pharmacokinetics was also assessed in 12 client owned dogs, six dogs with non adrenal illness (NAI) and six dogs with hyperadrenocorticism (HAC), receiving exogenous ACTH (0.5 U/kg, i.v.). For these patients, data was best fitted to a one-compartment open model. In dogs with NAI, the AUC was 6.23 +/- 0.62 x 10(5) pg x min/mL, MRT was 38.7 +/- 12 min, the apparent elimination rate constant (k(el)) was 0.26 +/- 0.0017 min(-1) elimination half-life was 26.7 min, ClB was 0.84 +/- 0.1 x 10(4) mL/min/kg, and Vd(area) was 31.9 +/- 5.7 L/kg. In dogs with HAC, AUC was 4.74 +/- 0.23 x 10(5) pg x min/mL, MRT was 20.4 min, k(el) was 0.034 +/- 0.009 min(-1), half-life was 20.4 min, CIB was 1.06 +/- 6.0 x 10(4) mL/min/kg and Vd(area) was 29.7 +/- 6.7 L/kg. Dogs with pituitary-dependent hyperadrenocorticism showed more rapid elimination and clearance of exogenous corticotropin than dogs with NAI.

The effect of levothyroxine treatment on resting energy expenditure of hypothyroid dogs.

Thirty adult, client-owned dogs were diagnosed with hypothyroidism based on history, physical examination findings, hematologic and biochemical abnormalities, thyrotropin (TSH) response testing, endogenous canine thyrotropin (cTSH) concentration, or both, and total serum thryoxine concentration. All dogs received levothyroxine (L-thyroxine) at an initial dose of 22 micrograms/kg PO sid in either a tablet (13 dogs) or chewable form (17 dogs). Energy expenditure of each dog during apparent rest was estimated with an open-flow indirect calorimetry system by determining the rates of carbon dioxide production and oxygen consumption. Energy expenditure of apparent rest (EE) was lower in untreated hypothyroid dogs compared with reference values for EE. After treatment with L-thyroxine, EE of the hypothyroid dogs was significantly (P < .05) higher than pretreatment values.

Primary cutaneous coccidioidomycosis and subsequent drug eruption to itraconazole in a dog.

Three weeks after traveling to Arizona, a 13-month-old, female Labrador retriever developed draining tracts in the right hind limb. Primary cutaneous coccidioidomycosis was diagnosed. Initial treatment with itraconazole resulted in exacerbation of clinical signs. Histopathology was suggestive of a cutaneous drug eruption. Discontinuation of the itraconazole caused resolution of the drug eruption. Successful treatment of the fungal infection was achieved using ketoconazole.

Monoclonal gammopathy in a dog with chronic pyoderma.

A monoclonal gammopathy composed of immunoglobulin G, with concurrent light-chain proteinuria and generalized lymph node plasmacytosis, was associated with chronic pyoderma in a dog. A uniform population of plasma cells was observed cytologically and histologically in multiple lymph node specimens. A diagnosis of monoclonal gammopathy of unknown significance was eventually made by exclusion of other known causes of monoclonal gammopathy, resolution after antibiotic therapy, and no evidence of lymphoproliferative disease after 11 months of follow-up and subsequent necropsy. This report expands the diagnostic considerations for monoclonal gammopathies in the dog.

Sebaceous adenitis in dogs and results of treatment with isotretinoin and etretinate: 30 cases (1990-1994).

Medical records of 30 dogs with histologically confirmed sebaceous adenitis that were treated with isotretinoin or etretinate were reviewed. Akitas and Standard Poodles were overrepresented, compared with the general hospital population. Thirteen dogs had concurrent pyoderma. The retinoids were administered for a minimum of 2 months. Dosage for the 13 dogs treated with isotretinoin only ranged from 0.8 to 3.5 mg/kg of body weight/d (mean, 1.4 mg/kg/d). Dosage for the 10 dogs treated with etretinate only ranged from 0.7 to 1.8 mg/kg/d (mean, 1.1 mg/kg/d). Two dogs were first given isotretinoin (mean dosage, 1.5 mg/kg/d) and, when they did not respond, were subsequently given etretinate (mean dosage, 0.85 mg/kg/d). Five dogs were first given etretinate (mean dosage, 1 mg/kg/d) and, when they did not respond, were subsequently given isotretinoin (mean dosage, 1.6 mg/kg/d). For the 20 dogs treated with isotretinoin, 1 was lost to follow-up; 9 of the remaining 19 had a successful outcome (> 50% reduction in severity of scaling and extent of alopecia, compared with pretreatment appearance). For the 17 dogs treated with etretinate, 9 had a successful outcome. Outcome could not be predicted on the basis of clinical signs or histologic findings, and a prognosis could not be determined on the basis of whether sebaceous glands were evident histologically.

Management of otitis externa.

Otitis externa represents one of the most common reasons that pets are presented for veterinary attention. They are also some of the more frustrating entities practitioners are called on to deal with. Successful management depends on an understanding of the primary, predisposing, and perpetuating factors involved in the pathogenesis of otitis externa. Emphasis is then placed on establishing a diagnosis through physical examination, cytologic examination, culture and sensitivity testing, radiographs and biopsies. The general goals of management are to resolve, remove, or control primary factors, clean and dry the ear, reduce inflammation and resolve secondary infections. These goals are achieved through various cleaning techniques, topical, and systemic therapies. Therapeutic alternatives are given for otitis involving bacteria, Malassezia, otodectes, demodex, allergies, ceruminous disorders, the idiopathic inflammatory/hyperplastic otitis externa of cocker spaniels, "Swimmer's Ear", contact/irritant reactions, overtreatment, and concurrent otitis media.

Llama dermatology.

The purpose of this article is to add information to the many dermatologic topics initially discussed in the 1989 issue on llama medicine (normal anatomy; bacterial, fungal, ectoparasitic, immune-mediated, and zinc-responsive disease) and make mention of newly recognized diseases. Since 1989, it appears that one of the most common and perplexing groups of dermatoses seen at Colorado State University are hyperkeratotic/inflammatory dermatoses. These remain poorly understood. Idiopathic hyperkeratosis (zinc-responsive dermatosis) may be a true zinc deficiency or a keratinizing disorder responsive to supraphysiologic dosages of zinc supplementation. Idiopathic nasal/perioral hyperkeratotic/ inflammatory dermatosis (munge) and idiopathic necrolytic/neutrophilic/hyperkeratotic dermatosis bear clinical, histologic, and therapeutic similarities, and may be subsets of the same disease. Further studies (e.g., looking for metabolic derangements) are necessary to better answer these questions.

Use of isotretinoin and etretinate for the treatment of benign cutaneous neoplasia and cutaneous lymphoma in dogs.

The purpose of this study was to evaluate the synthetic retinoids isotretinoin and etretinate to treat dogs with intracutaneous cornifying epitheliomas (ICE), other benign skin neoplasias, and cutaneous lymphoma. Twenty-four dogs were used. All tumors were diagnosed by histologic examination. Ten dogs with multiple (at least 5) benign skin tumors (7 with ICE, 1 each with inverted papillomas, sebaceous adenomas and epidermal cysts) were treated with isotretinoin (n = 7) and/or etretinate (n = 5). Twelve dogs with cutaneous lymphoma were treated with isotretinoin, and 2 dogs with cutaneous lymphoma were initially treated with etretinate. Successful treatment with isotretinoin was achieved in 1 dog with ICE, 1 with inverted papillomas, and 1 with epidermal cysts. Partial improvement with isotretinoin was seen in 2 dogs with ICE. Successful treatment was achieved with etretinate in 4 dogs with ICE (Norwegian Elkhound was the predominant breed with ICE). Remission was achieved in 6 of the 14 dogs with cutaneous lymphoma. Adverse effects developed in 7 of the 24 dogs, so treatment was stopped in 2 dogs.

Feline gingivitis-stomatitis-pharyngitis.

Inflammatory conditions of the feline mouth are commonly encountered in small animal practice. Although the majority can be attributed to dental disease and a small percentage are due to autoimmune diseases, the eosinophilic granuloma complex, neoplasia, and other miscellaneous syndromes, many cases appear to be due to a gingivitis-stomatitis-pharyngitis complex, which is likely multifactorial in origin. Viruses, bacterial infection, diet, dental disease, oral conformation, genetic predisposition, hypersensitivities, immunoinsufficiencies, and other defects in oral defense mechanisms may all be contributory. The complexities of this syndrome have made it one of the most challenging diagnostic and therapeutic problems in feline medicine.

Investigation of antibodies to extractable nuclear antigens in dogs.

Determination of antibodies to specific nuclear antigens, termed extractable nuclear antigen (ENA), was investigated in healthy dogs and in dogs with autoimmune, inflammatory, and neoplastic diseases. Using a counterimmunoelectrophoresis method, the dogs' sera were tested for antibodies against the nuclear antigens single-stranded DNA, Sm, Ro, La, ribonucleoprotein, Scl, and proliferating cell nuclear antigen. Antibodies to the Ro antigen were found in 1 dog with discoid lupus erythematosus, in 1 dog with pemphigus erythematosus, and in 1 dog with facial pyoderma and chronic superficial keratitis. In 15 dogs, antibodies were detected to ENA, but the precipitin lines were too weak to identify the specific ENA. These antibodies were found in some dogs with systemic lupus erythematosus, discoid lupus erythematosus, pemphigus erythematosus, dermatomyositis, vitiligo, lymphoma; in the dog with facial pyoderma and chronic superficial keratitis; and in 1 healthy dog. The highest percentage of dogs with antibodies to ENA in a large series (greater than 8) of this study was in dogs with systemic lupus erythematosus (4 of 13; 31%).

Use of tetracycline and niacinamide for treatment of autoimmune skin disease in 31 dogs.

A combination of niacinamide and tetracycline was used to treat 31 dogs with various autoimmune skin diseases (discoid lupus erythematosus, pemphigus foliaceus, pemphigus erythematosus, and bullous pemphigoid). Of the 20 dogs with discoid lupus erythematosus, 70% had excellent or good response to treatment. Serious side effects were not noticed in any dog.

Plasma cell stomatitis-pharyngitis in cats: 40 cases (1973-1991).

Clinical signs, laboratory findings, and treatment results of 40 cats with the histologic diagnosis of plasma cell stomatitis-pharyngitis are discussed. Median age was 7.1 years, with no discernable sex predilection. Anorexia and difficulty prehending food were the most common clinical signs. Hyperproteinemia with associated hyperglobulinemia was the most common laboratory finding. Of various treatments, administration of corticosteroids or injectable gold (aurothioglucose) proved most effective in controlling the clinical signs.

Effects of flunixin and flunixin plus prednisone on the gastrointestinal tract of dogs.

Flunixin meglumine has been reported to induce gastrointestinal lesions in dogs when administered at therapeutic dosages. We administered flunixin meglumine to dogs daily for 10 days to assess the effect of this drug on the gastrointestinal tract. We also evaluated the possibility of corticosteroid potentiation of gastrointestinal toxicosis by concurrent administration of prednisone to 1 group of dogs. Dogs were monitored for gastrointestinal toxicosis by means of serial endoscopic evaluation, measurement of fecal occult blood, PCV, and total solid concentration, and by physical examination. There were 3 treatment groups of 5 dogs each. Group-1 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses IM; group-2 dogs were given 4.4 mg of flunixin meglumine/kg daily, in 2 divided doses IM; and group-3 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses IM plus 1.1 mg of prednisone/kg/d orally, in 2 divided doses. A fourth group of 5 dogs served as a control group. Endoscopically visible gastric mucosal lesions developed in all treated dogs within 4 days of initiating treatment. Lesions first developed in the gastric pylorus and antrum and lesions at these sites were more severe than those observed elsewhere. Dogs treated with flunixin meglumine plus prednisone developed the earliest and most severe lesions; lesion scores in group-2 dogs were higher than those in group-1 dogs. All dogs treated had occult blood in their feces by day 5 and its presence appeared to correlate more closely with endoscopic findings than did physical examination findings or changes in values for PCV or total solids.(ABSTRACT TRUNCATED AT 250 WORDS)

Juvenile cellulitis in dogs: 15 cases (1979-1988).

The records of 15 dogs diagnosed as having juvenile cellulitis (juvenile pyoderma, puppy strangles) were evaluated for clinical, laboratory, and therapeutic results. Mandibular lymphadenopathy was observed in 14 dogs, and was not associated with skin lesions in 5 dogs. Edema, pustules, papules, or crusts were noticed periorally, periocularly, on the chin or muzzle, or in the ears of those dogs with skin lesions. Eight dogs were lethargic; fever and anorexia were inconsistent findings. Four dogs had signs of pain on manipulation of their joints. Complete blood counts revealed leukocytosis with neutrophilia in 4 dogs, and normocytic, normochromic anemia in 6 dogs. Three dogs had suppurative lymphadenitis with many neutrophils. Cytology of the aspirate of pustules or abscesses in 6 dogs revealed many neutrophils without bacteria. Coagulase-positive Staphylococcus spp were isolated from draining lesions in 2 dogs. Intact abscesses and lymph nodes were negative for bacterial growth in 4 dogs. Three of these dogs were being administered antibiotics at the time of bacterial culturing. Cytology of the aspirates of joints in 3 of the 4 dogs with joint pain revealed suppurative arthritis with no bacteria, and the aspirates were negative for bacterial growth on culturing, although all 3 dogs were being administered antibiotics at the time of culturing. Of 12 dogs initially treated with antibiotics, only 4 (33%) responded favorably; the other 8 dogs were then given antibiotics and corticosteroids. Three dogs were initially given antibiotics and corticosteroids. All dogs treated concurrently with antibiotics and corticosteroids responded favorably. One of these dogs had a relapse after treatment was discontinued. The concurrent arthritis in 4 of the dogs resolved with treatment of the juvenile cellulitis and did not redevelop once the medication was discontinued. Concurrent treatment with antibiotics (cephalosporins) and prednisone (2.2 mg/kg of body weight/day) was the most consistently effective treatment in the dogs in this study.

Pulmonary thromboembolism associated with immune-mediated hemolytic anemia in dogs: ten cases (1982-1987).

Pulmonary thromboembolism was confirmed at necropsy in 10 (32.2%) of 31 dogs treated for immune-mediated hemolytic anemia. Radiographic findings associated with thromboembolism included pronounced interstitial lung pattern and small amounts of pleural effusion. Variables associated with significantly higher incidence of pulmonary thromboembolism included hyperbilirubinemia (P = 0.023), negative Coombs test result (P = 0.032), and presence of an indwelling catheter (P = 0.04). There was a tendency (P = 0.06) for association of higher number of whole blood transfusions with pulmonary thromboembolism.