The prevalence of resistance found in this study was higher than that reported previously, suggesting that anthelmintic resistance in equine cyathostomes is becoming a major problem. Furthermore, data from these 5 southern states, which are geographically and physiographically distinct, were remarkably similar. This suggests that drug resistance in cyathostomes is highly prevalent throughout the entire southern United States and probably nationwide.

Skull characters of wildcats (Felis silvestris), classed as ‘old’, ‘recent’ or ‘modern’, depending on collection date, were compared with those of domestic cats (F. catus) and hybrids, using Fisher Linear Discriminant Functions, Principal Component Analyses and Canonical Variates. A key is derived for classification of individual (unknown) skulls. All analyses indicate that ‘recent’ and ‘modern’ wildcats were different from those collected earlier, and implied marked changes in the rate of hydridization during this century. We suggest that the older wildcat populations were a relatively ‘pure’ form but more recent populations contain a significant hybrid component. Although there may be a trend towards re‐establishment of the earlier type, an alternative conclusion is that the ‘pure’ form of wildcat is effectively extinct in Scotland.

Jejunal hemorrhage syndrome (JHS) is an acute, highly fatal enterotoxemic disorder in dairy cattle that has been reported during the last few decades. No specific cause of this syndrome has been identified; however, several studies have revealed a strong association between JHS and infection with Clostridium perfringens type A. A common mold, Aspergillus fumigatus, has also been implicated as a potential causative agent in this disease syndrome. Clinical signs of JHS (including sudden decreases in feed intake and milk production, rapid loss of condition, a right-sided ping audible during simultaneous auscultation and percussion of the abdomen, abdominal distension, and melena or bloody feces) usually develop early during lactation when cattle receive rations that are high in energy and low in fiber. Appropriate preventive strategies have not yet been determined, and intensive medical management with or without surgical intervention is rarely successful. The use of commercially available vaccines that are directed against C perfringens types C and D is of questionable efficacy and not likely to be helpful as a preventative measure. This article highlights the potential etiologic and risk factors, describes common clinical signs, outlines relevant diagnostic testing, and summarizes treatment options and their outcomes.

Prey populations, patterns of availability, and dispersion of prey can have farreaching effects on numbers and range-sizes of terrestrial Carnivora (Macdonald, 1983; Kruuk & Parish, 1982; Kruuk & Macdonald, 1985). These parameters may therefore also affect populations of otters Lutra lutra, living in the sea around Shetland, U.K., as well as populations of fish-eating birds there. This paper presents observations on fluctuations in numbers and activity of several species of demersal fish, over a 3½ year period, along a coast in Shetland. It aims to provide information on the distribution and availability of these species to some predators, especially to the otter, but also to the heron Ardea cinerea, the black guillemot Cepphus grylle and others.

Five lighthorse mares were actively immunized against gonadotropin releasing hormone (GnRH) to determine the relative importance of this hypothalamic hormone in the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Five mares immunized against the conjugation protein served as controls. Mares were initially immunized in November and received secondary immunizations 4 wk later, and then at 6-wk intervals until ovariectomy in June. All mares immunized against GnRH exhibited an increase (p less than 0.01) in the binding of tritiated GnRH by plasma, an indication that antibodies against this hormone had been elicited. Concentrations of LH, FSH and progesterone in weekly blood samples were lower (p less than 0.05) in GnRH-immunized mares than in controls after approximately 4 mo of immunization. However, the LH concentrations were affected to a greater degree than were FSH concentrations. All five control mares exhibited normal cycles of estrus and diestrus in spring, whereas no GnRH-immunized mare exhibited cyclic displays of estrus up to ovariectomy. All mares were injected intravenously with a GnRH analog (which cross-reacted less than 0.1% with the anti-GnRH antibodies) in May, after all control mares had displayed normal estrous cycles, to characterize the response of LH and FSH in these mares; two days later, the mares were injected with GnRH. The LH response to the analog, which was assessed by net area under the curve, was lower (p less than 0.01) by approximately 99% in mares immunized against GnRH than in control mares. In contrast, the FSH response to the analog was similar for both groups.(ABSTRACT TRUNCATED AT 250 WORDS)