Effects of oral administration of controlled-ileal-release budesonide and assessment of pituitary-adrenocortical axis suppression in clinically normal dogs

OBJECTIVE: To evaluate the effects of oral administration of controlled-ileal-release (CIR) budesonide on the pituitary-adrenal axis in dogs with a normal gastrointestinal mucosal barrier. ANIMALS: 10 healthy dogs. PROCEDURES: 5 dogs received CIR budesonide orally once daily for days 1 through 28, and 5 dogs received placebo. Treatment group dogs that weighed < 18 kg received 2 mg of CIR budesonide; treatment group dogs that weighed > or = 18 kg received 3 mg of CIR budesonide. In the treatment and placebo groups, there were 3 and 2 dogs, respectively, that weighed > 18 kg. Plasma cortisol concentration before and after ACTH stimulation, basal plasma endogenous ACTH concentration, and body weight were measured on days 0, 7, 14, 21, 28, and 35. Serum biochemical analysis, CBC determination, and urinalysis were performed on days 0, 28, and 35. On days 7, 14, and 21, serum ALP and ALT activities, serum glucose concentration, and urine specific gravity were obtained in lieu of a full hematologic evaluation and urinalysis. RESULTS: Basal and post-ACTH stimulation plasma cortisol concentrations and plasma endogenous ACTH concentration were significantly suppressed by treatment. No other variables were altered over the course of the study. CONCLUSIONS AND CLINICAL RELEVANCE: Budesonide suppresses pituitary-adrenal function in dogs with normal gastrointestinal integrity, whereas other variables often affected by glucocorticoids were not altered by a 4-week treatment course. Budesonide may be a good alternative to traditional cortico-steroids if used short-term for acute exacerbations of inflammatory bowel disease.     

Serum 17-alpha-hydroxyprogesterone and corticosterone concentrations in dogs with nonadrenal neoplasia and dogs with suspected hyperadrenocorticism

OBJECTIVE: To assess serum 17-alpha-hydroxyprogesterone (17OHP) and corticosterone concentrations in dogs with nonadrenal neoplasia and dogs being screened for hyperadrenocorticism. DESIGN: Prospective study. ANIMALS: 16 clinically normal dogs, 35 dogs with nonadrenal neoplasia, and 127 dogs with suspected hyperadrenocorticism. PROCEDURE: ACTH stimulation tests were performed in all dogs. Baseline serum cortisol and corticosterone concentrations were measured in the healthy dogs; baseline serum cortisol concentration and ACTH-stimulated cortisol, corticosterone, and 17OHP concentrations were measured in all dogs. Endogenous plasma ACTH concentration was also measured before administration of ACTH in dogs with neoplasia. RESULTS: In 35 dogs with neoplasia, 31.4% had high serum 17OHP concentration and 22.9% had high serum corticosterone concentration. Of the 127 dogs with suspected hyperadrenocorticism, 59 (46.5%) had high ACTH-stimulated cortisol concentrations; of those, 42 of 59 (71.2%) and 32 of 53 (60.4%) had high serum 17OHP and corticosterone concentrations, respectively. Of dogs with serum cortisol concentration within reference range after ACTH administration, 9 of 68 (13.2%) and 7 of 67 (10.4%) had high serum 17OHP and corticosterone concentrations, respectively. In the dogs with neoplasia and dogs suspected of having hyperadrenocorticism, post-ACTH serum hormone concentrations were significantly correlated. CONCLUSIONS AND CLINICAL RELEVANCE: Serum concentrations of 17OHP or corticosterone after administration of ACTH may be high in dogs with nonadrenal neoplasia and no evidence of hyperadrenocorticism. Changes in serum 17OHP or corticosterone concentrations after administration of ACTH are proportionate with changes in cortisol concentration.     

Significance for exercise capacity of some electrocardiographic findings in racehorses

Summary Various cardiorespiratory and metabolic indices were assessed during treadmill exercise in Thoroughbred and Standardbred racehorses with T wave changes in 4 or more leads on the electrocardiogram or second-degree atrio-ventricular (AV) block, and in horses that had no abnormalities on clinical examination, resting electrocardiography or upper respiratory tract endoscopy. No significant differences in heart rate, plasma lactate concentration, arterial blood gases, oxygen uptake, run time, peak velocity, or blood and red cell volumes were found between normal horses and horses with T wave changes or second-degree AV block. These results indicate that some electrocardiographic findings that are considered by some clinicians to indicate cardiac dysfunction, may have little effect on exercise capacity.     

Evaluation of ear tags impregnated with cypermethrin for the control of sheep body lice (Damalinia ovis)

The application of polymer matrix ear tags impregnated with 8.5% w/w cypermethrin to 6 wethers following shearing reduced lice to non-detectable levels on 4 of them at 29 weeks after tagging. At the conclusion of the study at 45 weeks the mean count of lice on tagged wethers was 3 per sheep compared to 158 on untreated wethers. In a second experiment, 6 non-infected sheep were treated at shearing with cypermethrin tags, 6 with 25 g/l cypermethrin backline formulation, 6 with tags plus backline and 6 were left untreated. Each group was exposed to 6 sheep with moderate to heavy infestations of lice. Compared to controls, all treatments delayed infestation, but cypermethrin tags gave no longer protection than backline treatment. All sheep were infested by 17 weeks after commencement of the study. At 45 weeks mean counts of lice were 38, 27, 20 and 74 respectively for sheep treated with tags, backline formulation, backline plus tags and untreated. Possible reasons for the better effect observed from applying tags to infested sheep than to sheep which were not infected at application but which were subsequently exposed to infested sheep are discussed.     

Adrenocortical suppression in the dog given a single intramuscular dose of prednisone or triamcinolone acetonide

Adrenocortical function was assessed in dogs given a single intramuscular dose of either prednisone or triamcinolone acetonide (TCA; or saline solution to controls) to determine the duration of adrenocortical suppression caused by 2 commonly used glucocorticoids. The glucocorticoids were administered at recommended therapeutic doses; therefore, dogs given prednisone received a greater amount of glucocorticoid activity than did in dogs given TCA. Basal and ACTH-stimulated plasma cortisol concentrations, as determined by radioimmunoassay, were obtained once a week. Total intravascular eosinophil concentration and skin responses to intradermally injected histamine phosphate were quantitated. Dogs given TCA showed suppressed basal and ACTH-stimulated plasma cortisol concentrations 1 week after injection; the latter change persisted 2 weeks after injection. Adrenocortical function in 1 of 4 dogs given TCA remained suppressed for 4 weeks. In contrast, prednisone did not significantly alter adrenocortical function. Although intravascular eosinophil concentrations did not vary among groups, skin responses to intradermally injected histamine phosphate were reduced 6 days after prednisone and TCA were given.     

Nutrient intake of horses in Thoroughbred and Standardbred stables

SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work.