Prevalence of hepatotoxicity and myelosuppression with alternate day use of azathioprine and glucocorticoids for treatment of dermatological conditions in dogs.

BACKGROUND: The use of azathioprine (AZA) in dogs is limited by the potential for hepatotoxicity and myelosuppression. HYPOTHESIS/OBJECTIVES: To determine the prevalence of AZA-associated hepatotoxicity in dogs with dermatological conditions receiving alternate-day AZA. The hypothesis was that dogs receiving AZA every other day (EOD) would have a lower prevalence of hepatotoxicity compared to published data for dogs receiving daily AZA. A secondary aim was to determine the prevalence of AZA-associated myelosuppression over the same time period and population. ANIMALS: Forty-one client-owned dogs with dermatological conditions treated with AZA EOD and glucocorticoids with clinical and haematological follow-up available for a minimum of two months of AZA therapy. METHODS: Retrospective analysis of data from April 1994 to July 2020. Hepatotoxicity was defined as elevation of alanine aminotransferase (ALT) at least twofold above the reference range. RESULTS: Azathioprine-associated hepatotoxicity was observed in two of 41 dogs (4.9%), with onset at 18 and 40 days, respectively. One dog receiving AZA at 1.9 mg/kg EOD had a fourfold increase in ALT. The other dog (AZA dose 2.3 mg/kg EOD) had a 30-fold increase in ALT. Azathioprine was not associated with thrombocytopenia, anaemia or neutropenia in any dogs. Lymphopenia developed in one dog (2.4%) with onset at 105 days. CONCLUSIONS AND CLINICAL RELEVANCE: Alternate-day AZA administration with tapering glucocorticoids was well-tolerated in dogs with dermatological conditions.

A double-blinded, randomized, controlled, crossover evaluation of a zinc methionine supplement as an adjunctive treatment for canine atopic dermatitis.

BACKGROUND: Zinc is important for skin health and proper immune system function. HYPOTHESIS/OBJECTIVES: A zinc methionine, essential fatty acids (EFA) and biotin product (Zn supplement) was compared to an EFA and biotin product (control) in canine atopic dermatitis (CAD). ANIMALS: Twenty seven client-owned dogs with chronic CAD receiving ciclosporin or glucocorticoids. METHODS: A 24 week, randomized, double-blinded, controlled study with crossover at week 12 and 4 week period of allergy medication reduction at weeks 8 and 20. Evaluations included Canine Atopic Dermatitis Lesion Index (CADLI), pruritus Visual Analog Scale (VAS) and cytology sampling. RESULTS: In dogs receiving the zinc supplement and ciclosporin for eight weeks, 44% (n = 7) had significantly decreased CADLI from 11.9 to 6.0 (P = 0.0002) with no significant change in pruritus VAS (P = 1.0). In dogs receiving the zinc supplement and glucocorticoids for eight weeks, 55% (n = 6) had significantly decreased CADLI from 10.9 to 5.0 (P = 0.0043) and pruritus VAS from 7.4 to 3.2 (P = 0.0166). For dogs receiving either steroids or ciclosporin there was a reduction in use of such medications, for at least four weeks, in 63% of dogs receiving the zinc supplement and 37% of dogs receiving the control. This difference was not significant (P = 0.1027). Seventy eight percent of dogs were diagnosed and treated for superficial skin infections during the study. CONCLUSIONS AND CLINICAL IMPORTANCE: This study supports a potential benefit of adjunctive zinc methionine supplementation in CAD. Dogs receiving glucocorticoids may be more likely to benefit. Further studies are needed to substantiate these initial results.

Isolation of bacterial skin flora of healthy sheep, with comparison between frequent and minimal human handling.

BACKGROUND: Few data are available regarding skin bacterial flora of healthy sheep and meticillin-resistant Staphylococcus carriage. HYPOTHESIS/OBJECTIVES: To compare skin, ear and mucosal bacterial populations between minimally and frequently handled sheep; to determine whether the frequency of meticillin-resistant Staphylococcus aureus varied between groups. ANIMALS: One hundred and three healthy feedlot and show sheep from eight farms. METHODS: Swabs were collected from the dorsum, right ear and right nostril of each sheep. Two groups from each farm were evaluated, except from one farm, which had only one group. Bacterial isolates were identified to the genus or species level using phenotypic analysis or matrix-associated laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing and spa typing were performed on isolates of S. aureus. RESULTS: Sixteen bacterial genera were identified and 11 staphylococcal species, including S. aureus. The skin and mucosal bacterial flora were compared between the groups. The only statistically significant difference in bacteria was Streptococcus spp. on the dorsum (P = 0.0088), with carriage being more common in frequently handled sheep. Antimicrobial susceptibility testing did not find meticillin-resistant S. aureus. There was no significant difference in S. aureus carriage in the ear (P = 0.33), nostril (P = 0.43) or dorsum (P = 0.053) between frequently and minimally handled sheep. The S. aureus isolates belonged to six different spa types. Three were of the ST398 lineage. CONCLUSIONS AND CLINICAL IMPORTANCE: Sheep are a potential source of livestock-associated meticillin-sensitive Staphylococcus aureus ST398.

Adverse events in 50 cats with allergic dermatitis receiving ciclosporin.

Ciclosporin is an immunosuppressive drug that has been used to treat allergies and other immune-mediated diseases in cats, dogs and humans. Information about the adverse effects of ciclosporin in cats has been limited to smaller studies and case reports. Adverse effects in dogs are mainly gastrointestinal in nature, but humans can also experience hypertension and altered renal function. The aim of this retrospective case series study was to document the occurrence and clinical appearance of adverse events in cats receiving ciclosporin to treat allergic skin disease. The medical records of 50 cats with allergic dermatitis treated with oral ciclosporin (1.9-7.3 mg/kg/day) were reviewed. Adverse events occurred in 66% (33 cats). Adverse events likely to be associated with ciclosporin included the following: vomiting or diarrhoea within 1-8 weeks of receiving ciclosporin (24%), weight loss (16%), anorexia and subsequent hepatic lipidosis (2%) and gingival hyperplasia (2%). Other adverse events less likely to be associated with ciclosporin therapy included the following: weight gain (14%), dental tartar and gingivitis (10%), otitis (4%), chronic diarrhoea (4%), inflammatory bowel disease with indolent gastrointestinal lymphoma (2%), urinary tract infection (2%), cataract (2%), elevated liver enzymes (2%), hyperthyroidism and renal failure (2%) and transient inappropriate urination (2%). Some cats experienced multiple adverse events. Case-control studies are needed to prove cause and effect of ciclosporin with regard to these adverse events.