The ability of biochemical and haematological tests to predict recovery in periparturient recumbent cows

Blood samples from 433 periparturient recumbent cows submitted by veterinary practitioners to Ruakura Animal Health Laboratory during 1983 and 1984 were analysed and results related to whether cows recovered, died or were euthanased. Generally cows were sampled only once and the time varied from 15 minutes to 20 days after becoming recumbent. During 1983 serum calcium, magnesium, phosphorus, creatine phosphokinase (CK), aspartate amino transferase (AST), glutamate dehydrogenase (GDH), gamma glutamyl transferase (GGT) were analysed. In 1984 serum urea, creatinine, fibrinogen and haematological examination (haemoglobin, haematocrit, total and differential white cell counts) were added to the panel. Overall 39% of cows recovered, 30% died and 32% were destroyed. Precalving cows had 111% more deaths and 7% less survivors than postcalving recumbent cows (P<0.1). There was little difference (3%) in euthanasia prevalence. Tests that were most useful in predicting a lack of recovery were serum urea and muscle enzymes. Using these tests and duration of recumbency when sampled a model was produced to predict the probability of recovery from 254 cases.     

Relative efficacy of organophosphorus insecticides against susceptible and resistant strains of the strike blowfly Lucilia cuprina (Calliphoridae) in New Zealand sheep

Four groups of five Romney lambs were treated by plunge dipping with one of four registered organophosphorus flystrike preventatives. Untreated lambs acted as controls. The sheep were challenged at weekly intervals with larval implants of organophosphate-susceptible and -resistant strains of Lucilia cuprina. All four treatments provided 19-21 weeks protection against susceptible larvae but chlorfenvinphos provided the longest protection (16-17 weeks), followed by propetamphos (15-16 weeks), dichlofenthion (10-13 weeks) and diazinon (9-13 weeks), against the resistant strain.     

Polioencephalomalacia in cattle consuming water with elevated sodium sulfate levels: A herd investigation

Polioencephalomalacia (PEM), hereafter used to refer to the specific lesion of cerebrocortical necrosis, developed in 11 of 110 mature cattle on pasture in central Saskatchewan. The primary water source contained a markedly elevated level of sodium sulfate (7200 ppm). The significant clinical findings of the herd investigation included depression, ataxia, cortical blindness, dysphagia, and death. Diagnosis of PEM was confirmed by histopathological evidence of cerebrocortical and subcortical necrosis with microvascular fibrinoid necrosis predominantly in the thalamic region of three affected cattle. The histopathology of sulfate-associated PEM observed in this herd appears to be unique and its features are presented and discussed. Mean levels for serum transketolase, copper, red blood cell transketolase activity, and thiamine (vitamin B₁) in all exposed young (n = 100) and mature (n = 99) animals did not reveal evidence of deficiencies. Although the blood thiamine status of the seven surviving, affected animals was not evaluated before treatment with exogenous thiamine, 199 members of the herd had blood thiamine levels within the reference range at the time of the outbreak. The outbreak resolved after cattle were moved to a water source containing acceptable levels of sodium sulfate.     

Determination of amphetamine by Schiff base formation and quantitative gas-liquid chromatography.

A procedure was developed to determine amphetamine salts in solid dosage forms. Amphetamine was extracted from the solid matrix with dilute hydrochloric acid and reacted with cyclohexanone in a strongly basic aqueous methanolic solution. The Schiff base reaction product was extracted with hexane for gas chromatographic determination. Reaction time and optimum conditions were studied. Phenethylamine, similarly treated, was used as an internal standard. Results compared favorably with those obtained by using USP methods.