Abstract: Noninvasive fecal assays were used to study steroid metabolism and ovarian activity in several felid species. Using the domestic cat (Felis catus) as model, the excretory products of injected [14C]estradiol (E2) and [14C]progesterone (P4) were determined. Within 2 days, 97.0 +/- 0.6% and 96.7 +/- 0.5% of recovered E2 and P4 radioactivity, respectively, was found in feces. E2 was excreted as unconjugated estradiol and estrone (40%) and as a non-enzyme- hydrolyzable conjugate (60%). P4 was excreted primarily as non-enzyme- hydrolyzable, conjugated metabolites (78%) and as unconjugated pregnenolone epimers. A simple method for extracting fecal steroid metabolites optimized extraction efficiencies of the E2 and P4 excretion products (90.1 +/- 0.8% and 87.2 +/- 1.4%, respectively). Analysis of HPLC fractions of extracted fecal samples from the radiolabel-injected domestic cats revealed that E2 immunoreactivity coincided primarily with the unconjugated metabolized [14C]E2 peak, whereas progestogen immunoreactivity coincided with a single conjugated epimer and multiple unconjugated pregnenolone epimers. After HPLC separation, similar immunoreactive E2 and P4 metabolite profiles were observed in the leopard cat (F. bengalensis), cheetah (Acinonyx jubatus), clouded leopard (Neofelis nebulosa), and snow leopard (Panthera uncia). Longitudinal analyses demonstrated that changes in fecal E2 and P4 metabolite concentrations reflected natural or artificially induced ovarian activity. For example, severalfold increases in E2 excretion were associated with overt estrus or exogenous gonadotropin treatment, and elevated fecal P4 metabolite concentrations occurred during pregnant and nonpregnant (pseudopregnant) luteal phases. Although overall concentrations were similar, the duration of elevated fecal P4 metabolites during pseudopregnancy was approximately half that observed during pregnancy. In summary, steroid metabolism mechanisms appear to be conserved among these physically diverse, taxonomically related species. Results indicate that this hormone-monitoring approach will be extremely useful for elucidating the hormonal regulatory mechanism associated with the reproductive cycle, pregnancy, and parturition of intractable and endangered felid species.

Abstract: Dissections were made of the larynges of 14 species of the cat family, with representative specimens from all genera. It was found that the vocal folds of the larynx of genus Panthera (with the exception of the snow leopard) form the basic structure of a sound generator well- designed to produce a high acoustical energy. Combined with an efficient sound radiator (vocal tract) that can be adjusted in length, a Panthera can use its vocal instrument literally to blow its own horn with a 'roar'. Also, it is proposed that laryngeal morphology can be used as an anatomical character in mammalian taxonomy.

Abstract: The annual reproductive cycle of the male snow leopard (Panthera uncia) was characterized by evaluating seminal and endocrine traits monthly. Testicular volume was greatest (P < 0.05) during the winter months when the quality of ejaculate was optimal. Ejaculate volume, total sperm concentration ml-1, motile sperm concentration per ejaculate, sperm morphology and sperm motility index were lowest during the summer and autumn months compared with the winter and spring. Peripheral LH, FSH and testosterone concentrations were also lowest during the summer months, increasing during the autumn just before the increase in semen quality, and were maximal during the winter months. There was a direct relationship (P < 0.01) between: (1) testosterone and testicular volume, total sperm concentration ml-1, motile sperm concentration per ejaculate and ejaculate volume, and (2) LH and testicular volume and motile sperm concentration per ejaculate. In summary, although spermatozoa were recovered throughout the year, optimal gamete quality was observed during the winter and spring. Although previous studies in felids have demonstrated seasonal effects on either seminal or endocrine traits, this is the first study to demonstrate a distinct effect of season on both pituitary and testicular function.

Abstract: Liver tissues from 126 captive cheetah were evaluated by light microscopy and histochemistry; eight animals were evaluated by electron microscopy. The main hepatic lesion, a vascular lesion resembling veno- occlusive disease (VOD) of the liver and characterized by subendothelial fibrosis and proliferation of smooth muscle-like cells in the central veins, was seen in 60% of the sexually mature cheetah. Although this hepatic vascular lesion was seen in cheetah as young as 1 year of age, the most severe lesions, usually associated with liver failure, were found in cheetah between the ages of 6 and 11. There was no sex predisposition, and in approximately 40% of the VOD cases, liver disease was not suspected clinically or at necropsy. VOD was found in other felidae, especially in the snow leopard. High levels of vitamin A in livers, as well as in diets of the cheetah, could be a contributing factor in the development of VOD in some groups of cheetah.

Abstract: A 5-mo-old male snow leopard (Panthera uncia) was presented for mild rear leg lameness. Osteomyelitis was suspected on the basis of radiographic changes and confirmed by histopathology of a biopsy sample from the affected bone. Aerobic cultures of the biopsies repeatedly grew Klebsiella oxytoca. Repeated anaerobic and fungal cultures did not result in growth. The leopard was treated unsuccessfully with cefadroxil, chloramphenicol, and trimethoprim/sulfadiazine despite apparent in vitro sensitivity to these antibiotics. Successful resolution was eventually achieved with enrofloxacin, 7.5 mg/kg p.o. b.i.d. for 60 days. The number of bones involved (right humerus, right and left ulna, right and left radius, right and left femur, right and left tibia, mandible, right metatarsus) made this an unusual presentation of osteomyelitis.

Abstract: An extraction and assay procedure to measure fecal estradiol-17-beta and progestin concentrations in several cat species was developed and validated for use for noninvasive monitoring of ovarian function. Fecal samples were collected over a range of 3-20 months from female tigers (three), lions (three), snow leopards (three), cheetahs (two), caracals (two), and domestic cats (five). Samples were extracted with 90% methanol, lipids removed with petroleum ether, and the estradiol and progestins in the methanol measured by radioimmunoassay (RIA). High Performance Liquid Chromatography (HPLC) fractionation and subsequent RIA of the fractions indicated that the estradiol-17-beta antiserum cross-reacted primarily with estradiol-17-beta in the feces of lions and tigers and was assumed to be specific for estradiol-17-beta in the feces of other species as well. However, there were several immunoreactive compounds, presumably progesterone metabolites, excreted in the feces which varied both quantitatively and qualitatively among species. The behavior of tigers, lions, cheetahs, and caracals was visually monitored during the collection period and frequency of sexual behaviors was positively correlated with increases in fecal estradiol in all species observed. The mean fecal estradiol-17-beta peaks were as follows: tigers, 128.0 +- 13.1; lions, 186.0 +- 14.8; snow leopards, 136.7 +- 15.9; cheetahs, 140.9 +- 9.0; caracals, 24.5 +- 4.0; and domestic cats 158.9 +- 19.3 ng/gm. Fecal progestin concentrations rose significantly (P lt 0,001) only after breeding or during pregnancy and were as follows: tigers, 5.6 +- 0.6; lions, 1.9 +- 0.1; cheetahs, 8.4 +- 1.1; and caracals, 2.4 +- 0.4 mu-g/gm. Fecal progestins were elevated for one-half to two-thirds of the gestation length during presumed pseudopregnancy but remained elevated throughout successful pregnancies. These results suggest that ovarian function can be monitored noninvasively in the family Felidae by the measurement of fecal estradiol-17-beta and progestin concentrations.

Abstract: A snow leopard project is underway to study snow leopards in Mongolia. The project, called the Mongolian-American Snow Leopard Project, involves the Wildlife Conservation Society, the Mongolian Association for the Conservation of Nature and Environment, the National Geographic Society, the Mongolian Ministry of Nature and the Environment, the U.S. National Biological Service, and the International Snow Leopard Trust. The objective of the study is to survey the distribution and status of Mongolia's snow leopards, including those living in the Gobi Desert. klf.