Detection of bicarbonate administration (milkshake) in Standardbred horses

SUMMARY Total plasma carbon dioxide (TCO₂) concentrations were measured in Standardbred horses to determine criteria to discriminate between normal horses and horses with excessive TCO₂ concentrations on raceday. TCO₂ concentrations from stabled horses were distributed normally with a mean of 30.2 mmol/L and a standard deviation of 1.2 (n = 192) while pre-race TCO₂ concentrations were not normally distributed. The results indicate that about 50 horses per million are likely to have TCO₂ concentrations greater than or equal to 35 mmol/L and that it is extremely unlikely that a normal horse would have a resting TCO₂ concentration above 36 mmol/L. These values were associated with sensitivities of 67% and 59%, respectively, and with a specificity of 100%. TCO₂ concentrations were relatively stable in blood samples stored at 4°C for 4 days, whereas the TCO₂ in specimens stored at room temperature (25°C) and at ambient temperature (16–28°C) declined progressively over 5 days. The accuracy and precision of the Beckman EL-ISE Auto Analyser were acceptable and within the manufacturers specified range. Paired specimens analysed using a Beckman EL-ISE Auto Analyser and a Kodak Dry Chemistry Analyser were not significantly different. However, the measurements made using the Kodak Dry Chemistry Analyser averaged 0.5 mmol/L higher than those analysed on the Beckman EL-ISE. The significance of these sources of variation in TCO₂ concentration in relation to the testing of horses for ‘milkshake’ administration are discussed.     

Toxicity of Saskatoon Serviceberry to Cattle

Saskatoon serviceberry (Amelanchier alnifolia) twigs were administered to cattle in feed rations and by intraruminal dosing to determine the toxicity of the cyanogenic shrub. When chopped twigs were fed as 75% of the diet, cattle exhibited restlessness, shivering, loss of weight, scours and shortness of breath. Low level dosing experiments indicated a rapid turnover of hydrogen cyanide in the rumen. When potential doses were increased to 5 mg hydrogen cyanide/kg (body weight) progressive stages of poisoning developed rapidly, rumen hydrogen cyanide levels were elevated for at least three hours and the increase in heart rate correlated with the rise in blood hydrogen cyanide concentration.     

BSAVA Manual of Canine and Feline Musculoskeletal Imaging

BSAVA Manual of Canine and Feline Musculoskeletal Imaging
Edited by Frances J. Barr and Robert M. Kirberger
Published by the BSAVA, 2006, paperback, 220 pages, Price £70.00, ISBN‐10: 0905214862, ISBN‐13: 978‐0905214863     

Ligneous conjunctivitis secondary to a congenital plasminogen deficiency in a dog

CASE DESCRIPTION: A 7-month-old 16.6-kg (36.5-lb) sexually intact female Golden Retriever was evaluated because of progressive severe bilateral membranous conjunctivitis, oral lesions, nasal discharge, and cough. CLINICAL FINDINGS: Histologic examination of conjunctival biopsy specimens revealed findings consistent with ligneous conjunctivitis. Circulating plasminogen activity was repeatedly low, and congenital plasminogen deficiency was identified as the underlying cause of the ocular, oral, and respiratory lesions. TREATMENT AND OUTCOME: Topical and subconjunctival administrations of fresh frozen plasma (FFP), topical administration of cyclosporine, and oral administration of azathioprine had no effect on the conjunctival membranes. Excision of the membranes followed by intensive treatment with topical applications of heparin, tissue plasminogen activator, corticosteroid, and FFP and IV administration of FFP prevented membrane regrowth. Intravenous administration of FFP increased plasma plasminogen activity to within reference limits, improved respiratory and oral lesions, and resulted in weight gain; discontinuation of this treatment resulted in weight loss, signs of depression, and worsening of lesions. After euthanasia because of disease progression, necropsy findings included mild hydrocephalus; multifocal intestinal hemorrhages; and fibrinous plaques in the oral cavity, nasopharynx, trachea, esophagus, and pericardium. Microscopically, the plaques were composed of fibrin and poorly organized granulation tissue. Fibrin thrombi were present within vessels in the lungs, oral cavity, and trachea. CLINICAL RELEVANCE: In dogs, congenital plasminogen deficiency can occur and may be the underlying cause of ligneous conjunctivitis. A combination of surgical and medical treatments may improve conjunctival membranes, and administration of FFP IV appears to be effective in treating nonocular signs of plasminogen deficiency.     

Improved chemical control of Conyza bonariensis in wheat limits problems in the following fallow

Conyza bonariensis is a major weed infesting zero‐tilled cropping systems in subtropical Australia, particularly in wheat and winter fallows. Uncontrolled C. bonariensis survives to become a problem weed in the following crops or fallows. As no herbicide has been registered for C. bonariensis in wheat, the effectiveness of 11 herbicides, currently registered for other broad‐leaved weeds in wheat, was evaluated in two pot and two field experiments. As previous research showed that the age of C. bonariensis, and to a lesser extent, the soil moisture at spraying affected herbicide efficacy, these factors also were investigated. The efficacy of the majority of herbicide treatments was reduced when large rosettes (5–15 cm diameter) were treated, compared with small rosettes (<5 cm diameter). However, for the majority of herbicide treatments, the soil moisture did not affect the herbicide efficacy in the pot experiments. In the field, a delay in herbicide treatment of 2 weeks reduced the herbicide efficacy consistently across herbicide treatments, which was related to weed age but not to soil moisture differences. Across all the experiments, four herbicides controlled C. bonariensis in wheat consistently (83–100%): 2,4‐D; aminopyralid + fluroxypyr; picloram + MCPA + metsulfuron; and picloram + high rates of 2,4‐D. Thus, this problem weed can be effectively and consistently controlled in wheat, particularly when small rosettes are treated, and therefore C. bonariensis will have a less adverse impact on the following fallow or crop.