MAGNETIC RESONANCE IMAGING FEATURES OF EQUINE NIGROPALLIDAL ENCEPHALOMALACIA

Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encephalomalacia. Lesions were seen on T1-weighted, T2-weighted and proton density images. There was no contrast enhancement following Gd-DTPA administration. Lesions seen on MR were confirmed at necropsy. Using MR to confirm a diagnosis of equine nigropallidal encephalomalacia will prevent unnecessary suffering of horses and expense to owners that would otherwise incur, while further diagnostics are performed.     

Has bovine somatotropin (BST) an effect upon drug disposition? Comparative studies in goats and cattle with sulphadimidine and antipyrine after parenteral administration of BST,zeranol and proligestone

Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.     

Pharmaco-epidemiology and -economics should be developed more extensively in veterinary medicine

Pharmaco-epidemiology, which has emerged within the last 20 years as a new discipline in human medicine, deals with the quantities of drugs consumed and their effects on populations in terms of epidemiological concepts and tools. To a lesser extent, it is also practised in veterinary medicine. The applications presented in this review are illustrative of pharmaco-epidemiological and -economical concepts. Assessment of drug consumption, the study of adverse drug effects, and the economic implications of drug use are the three main fields considered. Developments can be expected in veterinary medicine within the next few years relative to novel areas of interest such as antimicrobial resistance and new therapeutic class uses. These applications will require methodological progress and the elimination of current gaps. Pharmaco-epidemiological methods need to be developed, which implies close co-operation between statisticians, pharmacologists, veterinary practitioners and epidemiologists. A greater use of the term 'pharmaco-epidemiology' as a keyword in literature would facilitate recognition of this domain which associates closely epidemiology and pharmacology.     

Investigating Intraspecific Variation of Acidovorax avenae subsp. citrulli Using DNA Fingerprinting and Whole Cell Fatty Acid Analysis

ABSTRACT To assess the diversity of Acidovorax avenae subsp. citrulli, 121 strains from watermelon, cantaloupe, and pumpkin were compared using pulse field gel electrophoresis of SpeI-digested DNA and gas chromatographic analysis of fatty acid methyl esters. Twenty-nine unique DNA fragments resulted from DNA digestion, and 14 distinct haplotypes were observed. Based on cluster analysis, two subgroups, I and II, were recognized, which accounted for 84.8% (eight haplotypes) and 15.2% (six haplotypes) of the strains, respectively. Results of cellular fatty acid analysis varied quantitatively and qualitatively for the A. avenae subsp. citrulli strains and supported the existence of the two subgroups. Group I includes strains from cantaloupe and pumpkin as well as the ATCC type strain, which was first described in the United States in 1978, whereas group II represents the typical watermelon fruit blotch-causing strains that appeared in the mainland United States in 1989. Knowledge of the two A. avenae subsp. citrulli groups may be useful in screening for watermelon fruit blotch resistance.     

Effect of prepubertal versus postpubertal castration on sexual and aggressive behavior in male horses

Males horses castrated prepubertally occasionally display stallion-like sexual and aggressive behavior as adults. A retrospective survey of 140 horse owners was undertaken to compare the effectiveness of prepubertal versus postpubertal castration on objectionable sexual and aggressive behavior. Of 94 geldings that had been castrated prepubertally (before 2 years of age), 20% to 30% displayed stallion-like sexual behavior and aggression toward horses, and 5% were aggressive toward people in a stallion-like manner. This occurrence of problem behavior was not significantly different from the occurrence of these behavioral patterns in 46 geldings that had been castrated as stallions (over 3 years of age). When castration was examined as a therapeutic measure to eliminate sexual and aggressive behavior in stallions in which the behavior had become objectionable, it was found that the operation was effective on sexual behavior and aggression toward people in 60% to 70% of horses and on aggression toward horses in 40% of horses.