Adrenal function testing in the cat: the effect of low dose intravenous dexamethasone administration.

The plasma cortisol responses of 11 normal cats to intravenous dexamethasone at a dose rate of 0.01 mg kg-1 whole bodyweight, were evaluated. Mean plasma cortisol concentrations decreased significantly (P less than 0.01) at three hours and eight hours following dexamethasone administration. Results of this study indicate that plasma cortisol levels are significantly decreased for at least eight hours following low dose intravenous dexamethasone administration in normal cats.

Itraconazole for the treatment of cryptococcosis in cats.

Itraconazole was used in 35 cats with cryptococcosis. Treatment response was determined by comparing clinical signs before, during, and after treatment. It could not be evaluated in 7 cats because they died during treatment from causes unrelated to cryptococcosis. Of the remaining 28 cats, treatment response was classified as success in 16 cats (57%), as improvement in 8 cats (29%), and as a failure in 4 (14%). The failures were due to death or euthanasia from drug toxicity (1 cat), progressive fungal disease (2 cats), and relapse 1 year after treatment (1 cat). The cats that improved did not undergo a 1-year posttreatment evaluation because they were lost to follow-up (3 cats), died or were euthanatized for other reasons (4 cats), or had a noncompliant owner (1 cat). For the 16 cats in which treatment was successful, the median itraconazole dose was 13.8 mg/kg body weight daily (range, 10.9 to 26.7 mg/kg/d), and the median duration of treatment was 8.5 months (range, 4 to 16 months). Five of these cats had previously been treated unsuccessfully with ketoconazole.

Cryptococcal infection in cats: factors influencing treatment outcome, and results of sequential serum antigen titers in 35 cats.

The relationship between treatment outcome and location of cryptococcal infection, gender, magnitude of pretreatment cryptococcal antigen titers, results of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) serology, and serial changes in antigen titers during and after treatment were evaluated in a prospective and nonrandomized study of 35 cats with cryptococcosis. A commercial cryptococcal latex agglutination kit (CALAS; Meridian Diagnostic Inc, Cincinnati, OH) was used to detect cryptococcal antigen in sera. All cats were treated with itraconazole (Sporanox; Janssen Pharmaceutica Inc, Titusville, NJ). Pretreatment mean log titers for serum cryptococcal antigen were not influenced by location of the infection. Treatment outcome was not influenced by gender, location of the infection, or magnitude of pretreatment serum antigen titer. Treatment outcome was influenced by FeLV and FIV status; cats seropositive for FeLV or FIV had a higher likelihood of treatment failure (P = .008). The cryptococcal antigen titers of cats successfully treated decreased with significant linearity over time during treatment (r = -.64, P < .000001), whereas the corresponding titers for cats not treated successfully did not decrease with significant linearity (r = -.03, P > .9). For cats in which treatment was successful, antigen titers decreased significantly from pretreatment values by 1.3 orders of magnitude at 2 months after initiation of treatment. By 10 months after initiating treatment, log titers decreased by at least 2 orders of magnitude in all cats successfully treated, and 9 of 16 cats had undetectable titers. In contrast, in 5 of 6 cats in which treatment failed, antigen titers were unchanged or increased in magnitude even after at least 6 months of treatment.

Thyroid-stimulating hormone stimulation tests in cardiomyopathic Doberman pinschers: a retrospective study.

Thyroid-stimulating hormone (TSH) response tests were performed in 152 Doberman Pinschers. Seventy-nine dogs had cardiomyopathy (46 were in congestive heart failure [CHF] and 33 were not in CHF). Seventy-three dogs were presented for noncardiac problems (15 with skin disease, 21 with neurologic disease, 20 with internal medicine disorders, and 17 with other problems), although some may have had cardiomyopathy. The TSH response test results in the cardiomyopathic group were interpreted as normal or euthyroid-sick in 45 (57%) dogs, abnormal in 23 (29%) dogs, and equivocal in 11 (14%) dogs. The prevalence of hypothyroidism in the CHF and non-CHF cardiomyopathy groups was not different. Among the dogs presented for noncardiac problems, 27 (37%) were assessed as normal or euthyroid-sick, 29 (40%) as hypothyroid, and 17 (23%) as equivocal. No significant differences were found in the prevalence of hypothyroid test results among the subgroups of these dogs. The prevalence of hypothyroidism was not higher in the cardiomyopathic group compared to the other group, and 63 and 49% of cardiomyopathic dogs with or without CHF, respectively, tested as either euthyroid or euthyroid-sick.

Immunosuppressive effects of cyclophosphamide, vincristine, and L-asparaginase in dogs.

The acute effects of cyclophosphamide, vincristine, and L-asparaginase on the humoral and cell-mediated immune responses in dogs were evaluated. Dogs were given a single dose of cyclophosphamide (10 mg/kg of body weight, IV), a single dose of vincristine (0.025 mg/kg, IV), a single dose of L-asparaginase (400 U/kg, IV), or a combination of these drugs at the aforementioned dosages administered simultaneously. The total number of leukocytes decreased significantly (P = less than 0.05) on posttreatment day 3 in the cyclophosphamide-treated dogs. Antibody responses and lymphocyte blastogenesis were not affected. A transient lymphopenia on posttreatment day 1 was the only response seen in the vincristine-treated dogs. Antibody responses to sheep RBC and lymphocyte blastogenesis were suppressed in the L-asparaginase-treated dogs. L-Asparaginase did not affect the antibody response to bovine serum albumin or peripheral blood leukocyte counts. Suppressed antibody responses to sheep RBC and to bovine serum albumin, depressed lymphocyte blastogenesis, and decreased numbers of all peripheral blood leukocytes were seen in dogs given the 3 drugs in combination.

Complement immunofluorescence in sera of dogs with pemphigus foliaceus.

Sera from 14 dogs with active pemphigus foliaceus were tested for the presence of circulating antiepithelial antibodies. These antibodies could not be detected in the dogs with indirect immunofluorescent staining or in vitro complement-staining methods.

Evaluation of ketoconazole and itraconazole for treatment of disseminated cryptococcosis in cats.

During the first part of a study, cats were inoculated with Cryptococcus neoformans via the following routes: intradermal, intranasal, IV, and intracisternal. Only use of the IV route of inoculation consistently induced disseminated cryptococcosis. In the second part of the study, disseminated cryptococcosis was experimentally induced in cats via IV inoculation of C neoformans. One month after inoculation, 3 cats were treated with ketoconazole (10 mg/kg of body weight/d) and 3 cats were treated with itraconazole (10 mg/kg/d) for 3 months. One of the ketoconazole-treated and 2 of the itraconazole-treated cats also had cryptococcosis of the CNS when treatment was begun. During treatment, serum cryptococcal antigen titer progressively decreased in all cats. Abnormalities in CBC values or the serum biochemical profile were not found in any cat during treatment. However, all ketoconazole-treated cats became anorectic and lost weight. Side effects were not seen in itraconazole-treated cats. During the 3-month posttreatment observation period, all cats remained healthy. At necropsy, histologic evidence of cryptococcosis was not found in the 3 ketoconazole-treated cats or in 2 of the itraconazole-treated cats. In the third itraconazole-treated cat, cryptococcal organisms were found in the kidneys.

Effect of surgery on the in vitro response of canine peripheral blood lymphocytes to phytohemagglutinin.

The effects of surgery (ovario-hysterectomy) and anesthesia on phytohemagglutinin-induced lymphocyte blastogenesis were studied in vitro in 12 dogs. Four dogs had depressed lymphocyte blastogenic responses after surgery. This suppression was transient with normal blastogenic responses occurring in cells from all dogs 24 hours after surgery. Seemingly, T-lymphocyte function may be depressed, only transiently, after surgery.

Frequency and antimicrobial susceptibility of Staphylococcus species isolated from canine pyodermas.

Specimens obtained from pyogenic skin lesions of 210 dogs were culturally examined for staphylococci. A total of 215 isolates of staphylococci were biotyped, using the biochemical tests contained in a commercial staphylococcal identification system. Of 201 coagulase-positive isolates, 197 were identified as Staphylococcus intermedius, 3 as S aureus, and 1 as S hyicus. Of 14 coagulase-negative isolates, 5 were identified as S epidermidis, 5 as S xylosus, 3 as S simulans, and 1 as S hominis. Antimicrobial susceptibility tests were done on all staphylococcal isolates, using the standard disk-diffusion method. Staphylococcus intermedius isolates were susceptible to cephalothin, methicillin, and gentamicin. Resistance to ampicillin, penicillin G, and tetracycline was frequent. Antibiotic resistance was not associated with the depth of skin infection. Resistance to ampicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole was not associated with previous antibiotic use. Increased resistance to chloramphenicol, clindamycin, and erythromycin was associated with previous antibiotic therapy. Antimicrobial susceptibilities of the other Staphylococcus species isolated are reported, but the small numbers of these species precluded making meaningful comparison with S intermedius.

An evaluation of ivermectin in the treatment of sarcoptic mange in dogs.

A colony of mixed-breed dogs (n = 298) naturally infested with Sarcoptes scabiei was treated, twice, with 200 micrograms of ivermectin/kg of body weight subcutaneously at 14-day intervals. After the initial injection, positive skin scrapings from 20 treated dogs decreased from 7 to 1 and the degree of pruritus decreased. In contrast, positive skin scrapings from 22 nontreated dogs increased from 10 to 14, and there was an additional deterioration in the condition of the skin and an increase in the degree of pruritus. Complete control was noticed in all treated dogs by posttreatment day 28 (14 days after a 2nd injection) based on negative skin scrapings.

Frequency and antimicrobial susceptibility of Staphylococcus spp isolated from feline skin lesions.

Swab specimens obtained from skin lesions of 45 cats were cultured bacteriologically for staphylococci. Thirty-two staphylococcal isolates were recovered from 30 cats and were biotyped, using biochemical tests contained in a staphylococcal identification system. Of 23 isolates considered coagulase-positive, 16 were identified as Staphylococcus aureus, 5 as S intermedius, and 2 as S hyicus. Of 9 isolates considered coagulase-negative, 6 were identified as S simulans, 2 as S epidermidis, and 1 as S xylosus. Antimicrobial susceptibility tests were done on all staphylococcal isolates, using a disk-diffusion method. Staphylococcal isolates were susceptible to clavulanic acid-amoxicillin, cloxacillin, cephalothin, chloramphenicol, gentamicin, erythromycin, and trimethoprim-sulfamethoxazole. Resistance to penicillin G, ampicillin, and tetracycline was frequent.

Ketoconazole for treatment of dermatophytosis in cats.

Twelve cats with generalized dermatophytosis were treated with ketoconazole (10 mg/kg of body weight, PO, with food, q 24 h). This treatment was successful in 8 cats, with resolution of lesions and negative findings on mycologic evaluation after 2 to 10 weeks (median duration, 6 weeks). One additional cat failed to improve initially, but complete resolution was achieved after the dosage of ketoconazole was doubled. Adverse effects in 3 cats included anorexia, weight loss, vomiting, and diarrhea.

Resolution of generalized dermatophytosis without treatment in dogs.

Natural resolution of generalized dermatophytosis reportedly is common in large-animal species. In dogs with generalized dermatophytosis, antifungal treatment usually is prescribed, because the prevalence of natural resolution of dermatophytosis in dogs is not known. Five dogs, 6 to 18 months old, were diagnosed as having generalized dermatophytosis. Each dog was treated with an inert substance given orally with food, once daily. Signs of disease resolved in 3 of the dogs after 4 to 8 weeks of treatment with the inert substance. Two dogs did not improve, so treatment with ketoconazole was initiated. Resolution was achieved in these 2 dogs after 6 weeks of treatment with ketoconazole.

Food hypersensitivity in a cat.

Food hypersensitivity was diagnosed in a 4-year-old Siamese cat. Clinical signs included intense erythema, with alopecia, excoriations, erosions, and crusts involving the ventral portion of the abdomen, inguinal region, medial aspect of each thigh, and cranial and lateral aspects of all 4 limbs. The cat was intensely pruritic. Histologically, there was cutaneous mast cell hyperplasia and diffuse infiltration of eosinophils in the dermis. Blood eosinophilia also was found. Clinical signs resolved after exclusive feeding of a hypoallergenic diet.

Ivermectin for treatment of generalized demodicosis in dogs.

OBJECTIVE: To evaluate the efficacy of daily administration of ivermectin in the treatment of dogs with amitraz-resistant generalized demodicosis. DESIGN: Prospective, clinical trial. ANIMALS: Twelve privately owned dogs with juvenile-onset or adult-onset generalized demodicosis that had failed to respond to biweekly or weekly applications of 0.025% amitraz solution. PROCEDURE: All dogs were treated with undiluted ivermectin at a dosage of 0.6 mg/kg of body weight, PO, every 24 hours. There was no other parasiticidal agent given topically or systemically. A physical examination and multiple skin scrapings were performed every 2 to 4 weeks while dogs were receiving ivermectin. Skin scrapings were performed at approximately the same sites at every examination. After no mites were seen, treatment was continued for at least 2 more weeks and then stopped. Dogs were reexamined, and skin scrapings were repeated if any skin lesions developed. For dogs that remained clinically normal, follow-up information was obtained by telephone. Dogs that were free of clinical signs of demodicosis 12 months after ivermectin administration was discontinued were considered cured. RESULTS: Ten of 12 dogs were cured. Median duration of treatment for these dogs was 10 weeks (range, 6 weeks to 5 months). Two dogs were failures, relapsing 10 months and 11.5 months after treatment was stopped. One of these dogs was successfully treated with a second course of ivermectin. Mild ivermectin toxicosis developed in 1 dog after 6 weeks of treatment; side effects resolved shortly after the treatment was stopped. CLINICAL IMPLICATIONS: Daily use of ivermectin, at a dosage of 0.6 mg/kg, PO, was found to be effective in the treatment of generalized demodicosis in dogs.

Cutaneous cryptococcosis in three cats.

Cutaneous cryptococcosis was diagnosed in 3 cats. No other organ involvement was found. One cat has remained healthy after surgical excision of the cryptococcal skin lesion. One cat was euthanatized after diagnosis. The third cat was treated successfully with a 5-month course of ketoconazole.

Clinical evaluation of a cryptococcal antigen latex agglutination test for diagnosis of cryptococcosis in cats.

A commercial cryptococcal antigen latex agglutination test was used to evaluate sera from 20 cats with cryptococcosis and 184 cats without cryptococcosis. Cryptococcal antigen was detected in the sera from 19 of 20 cats with cryptococcosis. Antigen was not detected in sera from any of the cats without cryptococcosis. The test had sensitivity of 95% and specificity of 100%.

Comparison of procedures for assessing adequacy of dog foods.

Dog foods with similar claims for nutritional adequacy were tested by chemical analysis and the American Association of Feed Control Officials' growth trial. All foods tested were similar chemically, however, dogs given one regionally marketed food had lower growth rate and food efficiency as well as suboptimal PCV and hemoglobin values during the growth trial. Pups fed this diet also had clinical signs typical of zinc and copper deficiencies. We concluded that American Association of Feed Control Officials' approved feeding tests provide valid assessment of pet food quality, and procedures involving only chemical analysis or calculated values may not.

Recently described feline dermatoses.

This article discusses the etiology, clinical signs, diagnosis, and treatment of several diseases. Feline immunodeficiency, virus infection, cryptococcosis, dermatophyte pseudomycetomas, demodicosis, Sézary-like syndrome, and discoid lupus erythematosus in cats are reviewed.

Efficacy of daily amitraz on generalised demodicosis in dogs.

Fifty dogs with generalised demodicosis were treated with daily applications of 0.125 per cent amitraz solution over half the body. This was applied once a day, alternating the body half treated. Nine dogs were lost to follow-up; the remaining dogs were classified as either a success (25 dogs, 61 per cent) or a failure (16 dogs, 39 per cent) according to their response to treatment. Eight of the failures were due to persistent demodicosis and eight relapsed within one year after treatment. All eight of the relapsed dogs were cured after a second course of daily amitraz treatment. For the 25 dogs considered treatment successes, the median duration of treatment was 6.5 weeks (range, three weeks to nine months), and the median interval from completion of treatment to last post treatment evaluation was 3.4 years (range, two to four-and-a-half-years). Including the eight dogs that were cured after retreatment, the daily amitraz applications were curative in 33 of 41 dogs (80 per cent) with generalised demodicosis.