Evaluation of adrenal function in small-breed dogs receiving otic glucocorticoids

The objectives of this study were to evaluate adrenal function after otic glucocorticoid [Tresaderm (dexamethasone) and Otomax (betamethasone)] therapy in small-breed dogs without evidence of otitis and to evaluate the length of time needed for resolution of adrenal suppression after discontinuation of treatment. Fourteen clinically healthy, privately owned, small-breed dogs with normal ears and normal adrenocorticotropin (ACTH) stimulation tests were assigned to one of two treatment groups, receiving one of the medications at the manufacturer's recommended dosage twice daily for 2 weeks. All of the dogs in the betamethasone treatment group had normal ACTH stimulation tests after 2 weeks of treatment. In contrast, 5/7 (71.43%) in the dexamethasone group, had suppressed adrenocortical responses to exogenous ACTH. Three of these five dogs (42%) returned to normal values 1 week after ceasing the medication and two (28.57%) returned to normal values 2 weeks after ceasing the medication. In conclusion, it appears that adrenal function can be suppressed for up to 2 weeks in dogs receiving otic dexamethasone. A follow-up study repeating this work in dogs with inflamed ears is needed before further clinical recommendations can be made.     

The cutaneous histology of dermatomyositis in collie dogs

Cutaneous lesions of 36 collie dogs affected with dermatomyositis were reviewed. The most common histologic features were follicular atrophy and perifollicular inflammation in 30 dogs, which correlated with alopecia clinically. Other less common findings included formation of colloid bodies, basal cell vacuolation, and subepidermal vesiculation. Results indicated that the most diagnostic cutaneous histologic features of dermatomyositis may be follicular atrophy and inflammation.     

Comparison of serum dexamethasone concentrations in cats after oral or transdermal administration using pluronic lecithin organogel (PLO): a pilot study

The objective of this study was to measure and compare the serum concentrations of dexamethasone after oral and transdermal administration using pluronic lecithin organogel in six healthy cats. The study was designed as a crossover, in which the cats were randomly assigned to two groups. The cats received a single dose (0.05 mg kg(-1)) of dexamethasone either orally or transdermally on the inner pinna. Blood samples were taken at 0, 5, 15, 30, 60, 90 and 120 min, and 3, 4, 6, 8, 12 and 24, 48 and 72 h post dexamethasone administration. A mean peak serum concentration of 30.1 ng mL(-1) was detected 15 min after oral administration. Serum concentrations were below detection limits by 24 h. In contrast, there was no significant increase in serum concentrations of dexamethasone after transdermal administration. In cats, transdermal administration of a single dose of dexamethasone did not result in significant serum concentrations compared to oral administration.     

Pilot study to assess the effects of early flea exposure on the development of flea hypersensitivity in cats

This pilot study was to determine if early oral flea exposure reduces the incidence of flea allergy dermatitis (FAD) in cats. Eighteen kittens, assigned to three groups, received no flea exposure, oral flea exposure or flea infestation for 12 weeks. Then all the kittens were exposed continually to fleas for 31 weeks. Sensitization was monitored using intradermal testing (IDT), in vitro measurement of anti-flea saliva immunoglobulin E (IgE) and development of FAD. There was no statistically significant difference between groups in IDT reactions, in vitro data or clinical scores. The development of FAD was not associated with the presence of anti-flea saliva IgE. However, the development of a delayed reaction to flea bite was associated with symptoms after flea exposure. Although not statistically significant, the FAD scores in the oral group were lower than in the controls. Further studies are required to determine the role of oral flea exposure in the development of FAD in cats.     

The relationship of scrotal circumference to testicular weight in rams

Scrotal circumference (SC), testicular diameter (TD) and testicular weight (TW) were measured at necropsy of 148 Merino rams of varying age (yearling: 110, 2- to 3-year-old: 5, 4-year-old: 28, greater than 7-year-old: 5). These rams, although culled from flocks in north western Queensland for poor conformation or advancing age, had no clinically palpable or gross necropsy lesions of the genitalia. Despite the fact that SC measurement was performed at necropsy on scrota with greatly varying wool cover and its diverse content of plant material (burrs and grass seeds), the correlation of SC with TW was positive, high and significant (r = 0.92, P less than 0.01). This correlation was greater than that between TD and TW (r = 0.91, P less than 0.01) even though both were measured after dissection of the scrotal contents. The clinically convenient SC measurement deserves wider application as an estimate of testicular weight and therefore fertility in rams.     

The efficacy of ivermectin jetting fluid for control of blowfly strike on sheep under field conditions

SUMMARY Seventeen trials involving 5737 sheep were conducted to test the efficacy of ivermectin jetting fluid (30 ppm in water) for the control of blowfly strike when applied to sheep either by standard hand jetting or through an automatic jetting race. Sheep were observed for up to 14 weeks after treatment and all strikes recorded. The level of fly challenge varied between trials, resulting in strike rates in untreated sheep ranging between 0 and 94%. At 12 weeks after treatment there were 93% fewer strikes in hand jetted sheep and 84% fewer strikes in machine jetted sheep when compared with untreated sheep. At this time point there was a 90%, 86% and 93% reduction in poll, body and breech strikes, respectively, when hand jetting was used, whereas machine jetting reduced poll, body, breech and pizzle strikes by 84%, 81%, 79% and 100%, respectively.     

The Queensland Poisonous Plants Committee: its history and functions

SUMMARY The Queensland Poisonous Plants Committee was established in 1937 with Professor HR Seddon as chairman. It has functioned since that year, interrupted by two periods of inactivity in 1951–9 and 1962–8. Professor Seddon, first Dean of the Queensland Veterinary School, and Dr Selwyn Everist, Queensland Government Botanist after the Second World War, provided the main impetus for committee activities in its early and middle years, respectively. The strength of the body has been its multi-disciplinary approach using contributions from veterinarians, chemists and botanists. The research work of the committee members and their associates has provided most of our current knowledge of the toxins and effects of poisonous plants in Queensland. Much of the information generated is of international significance. In equal partnership with the United States Department of Agriculture, the committee initiated a series of international symposia on plant poisoning of animals, hosting the second. This group held its 4th gathering of world authorities in the field in 1993. The committee's activities have long influenced the veterinary profession in Australia through the close involvement of its members in undergraduate and post-graduate teaching in the Queensland Veterinary School since 1951. The present committee has members from the Departments of Primary Industries, Health, and Environment and Heritage, CSIRO and the University of Queensland.