Abstract: The structure of the foramen ovale from 16 species representing 4 carnivore families, the Felidae, Canidae, Ursidae and Hyaenidae, was studied using the scanning electron microscope. The Felidae were represented by 9 domestic cat fetuses (Felis catus), 2 snow leopard neonates (Uncia uncia), an ocelot neonate (Leopardus pardalis), 2 lion neonates (Panthera leo), a panther neonate (Panthera pardus) and 3 tigers (Neofelis tigris), comprising 2 fetuses and a neonate. The Canidae were represented by a golden jackal neonate (Canis aureus), a newborn wolf (Canis lupus), 8 domestic dog fetuses (Canis familiaris), 3 red fox neonates (Vulpes vulpes) and a dhole neonate (Cuon alpinus). The Ursidae were represented by a brown bear neonate (Ursus arctos), a day-old grizzly bear cub (Ursus arctos horribilis), a polar bear neonate (Ursus maritimus), and 2 additional bear fetuses (species unknown). The Hyaenidae were represented by a striped hyaena neonate (Hyaena hyaena). In each species, the foramen ovale, when viewed from the terminal part of the caudal vena cava, had the appearance of a short tunnel. A thin fold of tissue, the developed remains of the embryonic septum primum, extended from the distal end of the caudal vena cava for a variable distance into the lumen of the left atrium and contributed towards the 'tunnel' appearance in all specimens. It constituted a large proportion of the tube, and its distal end was straight-edged. There was fibrous material underlying the endothelium of the flap, the apparent morphology of which suggested that it comprised cardiac muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Melengestrol acetate (MGA) is the most widely used contraceptive in zoo felids, but the mechanism of contraception and the pathologic effects have not been investigated. For this study, the effects of MGA on folliculogenesis were assessed, and the association of MGA with ovarian lesions was evaluated. Comparisons were made among the histopathologic findings in the ovaries from 88 captive wild felids (representing 15 species) divided into three groups: 37 currently contracepted with MGA, eight previously exposed to MGA, and 43 never contracepted. Ninety-one percent of the felids evaluated had tertiary follicles, and no differences were noted between contracepted and uncontracepted cats. Some MGA-contracepted cats also had corpora lutea indicating recent ovulation. These results indicate that folliculogenesis is not suppressed by current doses of MGA and ovulation occurred in some cats. Therefore, the contraceptive actions of MGA do not occur by suppressing folliculogenesis, and MGA-contracepted felids likely have endogenous estrogens that may confound progestin effects on the uterus. Cystic rete ovarii was the most common pathologic finding, but they were not more prevalent in MGA-contracepted cats. These findings indicate that MGA is not associated with ovarian disease, including ovarian cancer, in contrast to the uterine lesions noted in MGA-treated cats.

Abstract: Because of their low densities, sparse distribution, elusive behavior, and the precipitous habitat they occupy, snow leopards (Uncia uncia) have been the subject of limited study. This study contributes to that limited database with an investigation of the winter home range of 3 radio-collared snow leopards (2 females and 1 male) in the Annapurna Conservation Area, Nepal. Winter home ranges varied from 13.9-22.3 km2 (x = 19.1). Home ranges overlapped extensively within and between sexes, and an area of 8.1 km2 in the core study site was shared by all three leopards.

Abstract: Przewalski's gazelle Procapra przewalskii is endemic to China and is classified as Critically Endangered by IUCN-The World Conservation Union. Historically, the species occurred in parts of the provinces of Gansu, Inner Mongolia, Ningxia and Qinghai but now appears to be restricted to three populations around Qinghai Lake. These three populations-Bird Island, Hudong-Ketu and Yuanzhe-have all declined since 1988. The populations have been monitored since 1994 and the smallest, on Bird Island, appears to be on the brink of extinction, with only seven individuals being recorded in 1998. In the same year, the Hudong- Ketu population comprised 56 individuals (29.4 per cent males, 50 per cent females and 21 per cent juveniles) and the Yuanzhe population 51 individuals (29.4 per cent males, 43.1 per cent females and 27.5 per cent juveniles). The causes of the declines vary for each population but include loss of habitat as a result of desertification, poaching and, possibly, wolf predation. Human activity and high juvenile mortality are major threats to the continued survival of the gazelle. Conservation measures proposed are: (i) the establishment of a special reserve for Przewalski's gazelle; (ii) a study of the wolf-gazelle relationship and control of the number of wolves if necessary; (iii) a search for remnant populations of Przewalski's gazelle in other regions in their historical range and the identification of suitable sites for translocation and establishment of new populations.