Anthrax in cheetahs (Acinonyx jubatus) in Namibia

Bacillus anthracis caused the death of five cheetahs (Acinonyx jubatus) on a farm in the Gobabis district in Namibia. The mode of infection was believed to be a freshly shot baboon (Papio ursinus) with a cutaneous anthrax lesion.     

Serosurvey of viral infections in free-ranging Namibian cheetahs (Acinonyx jubatus)

Cheetahs (Acinonyx jubatus) in captivity have unusually high morbidity and mortality from infectious diseases, a trait that could be an outcome of population homogeneity or the immunomodulating effects of chronic stress. Free-ranging Namibian cheetahs share ancestry with captive cheetahs, but their susceptibility to infectious diseases has not been investigated. The largest remaining population of free-ranging cheetahs resides on Namibian farmlands, where they share habitat with domestic dogs and cats known to carry viruses that affect cheetah health. To assess the extent to which free-ranging cheetahs are exposed to feline and canine viruses, sera from 81 free-ranging cheetahs sampled between 1992 and 1998 were evaluated for antibodies against canine distemper virus (CDV), feline coronavirus (feline infectious peritonitis virus; FCoV/ FIPV), feline herpesvirus 1 (FHV1), feline panleukopenia virus (FPV), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) and for feline leukemia virus (FeLV) antigens. Antibodies against CDV, FCoV/FIPV, FHV1, FPV, and FCV were detected in 24, 29, 12, 48, and 65% of the free-ranging population, respectively, although no evidence of viral disease was present in any animal at the time of sample collection. Neither FIV antibodies nor FeLV antigens were present in any free-ranging cheetah tested. Temporal variation in FCoV/FIPV seroprevalence during the study period suggested that this virus is not endemic in the free-ranging population. Antibodies against CDV were detected in cheetahs of all ages sampled between 1995 and 1998, suggesting the occurrence of an epidemic in Namibia during the time when CDV swept through other parts of sub-Saharan Africa. This evidence in free-ranging Namibian cheetahs of exposure to viruses that cause severe disease in captive cheetahs should direct future guidelines for translocations, including quarantine of seropositive cheetahs and preventing contact between cheetahs and domestic pets.     

Repeated use of the GnRH analogue deslorelin to down-regulate reproduction in male cheetahs (Acinonyx jubatus)

The GnRH analogue deslorelin, as a subcutaneous implant, was initially developed in Australia as an ovulation-inducing agent in mares. Its uses, for the suppression of reproduction in the domestic dog and cat and in other species, including humans, have been developed subsequently. Such implants have been used as a contraceptive modality in a variety of wild carnivores, both males and females. This paper describes the use of deslorelin implants as a contraceptive agent for cheetah males maintained in a semi-captive environment and housed in various camps together with females. Annually, male cheetahs were treated for 1 (n = 2), 2 (n = 7), 3 (n = 9), 4 (n = 3) or 5 (n = 1) consecutive years with an implant containing 4.7, 5.0 or 6.0 mg of deslorelin. On the first day of treatment and then on an annual basis, blood testosterone concentrations were analysed, testicular measurements were taken, appearance of penile spikes was determined, and semen was collected and evaluated. Pregnancy rates of mated or inseminated females were determined. A dose of 6 mg of deslorelin suppressed reproduction for at least 1 year, whereas with 4.7 and 5 mg of deslorelin, 3 of 17 males had a few non-motile spermatozoa in their ejaculates. All testosterone concentrations were basal at 1 year post-implant and no side effects were observed. We concluded that deslorelin implantation, at a dose of 6 mg, was a safe and reliable method of annual contraception in male cheetahs.     

Distribution of uterine histological changes in aged captive cheetahs (Acinonyx jubatus)

The histological effect on the felid uterus of sterilization, via ovariectomy or salpingectomy, is currently unknown. To investigate the association of ovariectomy or salpingectomy with uterine health, it is first necessary to establish if changes are distributed evenly throughout the uterus. Both laparoscopic ovariectomy and salpingectomy with concurrent sampling of the tip of the uterine horn are possible in the cheetah. Currently accepted practice for histopathological screening of the uterus utilizes four biopsy samples. It is not known whether this method accurately reflects the status of the entire uterus. In this study we histologically examined the uteri of six older cheetahs (one 7-year-old and five 10–10.5-year-old animals) via 21 tissue samples (three samples from seven different anatomical regions) per cheetah to determine overall uterine health. Although no defined lesions were detected, mild endometrial gland dilation, assumed to be of no functional consequence, was observed in multiple samples. The odds of observing this dilation was lowest in the uterine body and progressively increased in a cranial direction, being significantly higher at the tip of the uterine horns (OR = 11.5; 95% CI, 2.0-65.1; p = 0.006). This supported the reliability of sampling the tip of the uterine horn to screen for endometrial gland dilation.     

Vocalizations and other behavioral responses of male cheetahs (Acinonyx jubatus) during experimental separation and reunion trials

In this study we assessed the extent of psychological attachment between male cheetahs living in same sex pairs in zoos by recording the behavior and vocalizations of two male coalitions (siblings and nonsiblings) during four experimental separations and reunions of each coalition. Both coalitions showed higher vocalization rates and walking rates during separations than during reunions, and during separations cheetahs spent less time resting and more time vocalizing, walking, or standing than during baseline observations. Compared to the nonsibling coalition, the sibling coalition showed a significantly higher vocalization rate during separations and more affiliative behavior during reunions. The most common calls emitted during separations were chirps, followed by eeaows and stutters. The chirps showed the highest level of individual distinctiveness. Eeaows comprised a significantly higher percentage of the calls during separations for nonsiblings that for siblings. The only vocalization heard during reunion was the stutter. We hypothesize that chirps emitted during separations communicate desire to reunite, individual identity, and have a structure that facilitates locating the caller. The results of this study suggest that male cheetahs, both sibling and nonsibling, develop strong psychological attachments to each other. The separation of existing coalitions can create stressful conditions for coalition members. We suggest that raising and maintaining coalitions of male cheetahs in coalitions in zoos is a viable husbandry technique. Zoo Biol 17:1–16, 1998. © 1998 Wiley-Liss, Inc.     

Analysis of the mitochondrial genome of cheetahs (Acinonyx jubatus) with neurodegenerative disease

The complete mitochondrial genome of Acinonyx jubatus was sequenced and mitochondrial DNA (mtDNA) regions were screened for polymorphisms as candidates for the cause of a neurodegenerative demyelinating disease affecting captive cheetahs. The mtDNA reference sequences were established on the basis of the complete sequences of two diseased and two nondiseased animals as well as partial sequences of 26 further individuals. The A. jubatus mitochondrial genome is 17,047-bp long and shows a high sequence similarity (91%) to the domestic cat. Based on single nucleotide polymorphisms (SNPs) in the control region (CR) and pedigree information, the 18 myelopathic and 12 non-myelopathic cheetahs included in this study were classified into haplotypes I, II and III. In view of the phenotypic comparability of the neurodegenerative disease observed in cheetahs and human mtDNA-associated diseases, specific coding regions including the tRNAs leucine UUR, lysine, serine UCN, and partial complex I and V sequences were screened. We identified a heteroplasmic and a homoplasmic SNP at codon 507 in the subunit 5 (MTND5) of complex I. The heteroplasmic haplotype I-specific valine to methionine substitution represents a nonconservative amino acid change and was found in 11 myelopathic and eight non-myelopathic cheetahs with levels ranging from 29% to 79%. The homoplasmic conservative amino acid substitution valine to alanine was identified in two myelopathic animals of haplotype II. In addition, a synonymous SNP in the codon 76 of the MTND4L gene was found in the single haplotype III animal. The amino acid exchanges in the MTND5 gene were not associated with the occurrence of neurodegenerative disease in captive cheetahs.     

Assessing reproductive cycles and pregnancy in cheetahs (Acinonyx jubatus) by vaginal cytology

Vaginal cytology was used to monitor ovarian cycles, two pregnancies, and three pseudopregnancies. Vaginal smears were collected two or three times per week from three adult females; smears plus blood samples were collected once per week from a fourth, adolescent female. Mean cycle lengths, based on intervals between onset of leukocyte infusions, were 11.9 ± 4.9 days (n = 43 cycles), 10.8 ± 5.1 days (n = 49), and 12.3 ± 6.3 days (n = 7) for the three females. Weekly hormone data from the adolescent female revealed a correlation between serum estradiol and percent anuclear cells, suggesting that these cells may be indicative of estrus. The fourth female experienced two sustained, 6-week increases in serum progesterone, one spontaneous and the other following follicle-stimulating hormone (FSH) administration. Leukocyte infusions continued during these periods of increased progesterone secretion. However, leukocyte infusions ceased during the two pregnancies of one adult female and during two FSH-induced pseudopregnancies of another. © 1992 Wiley-Liss, Inc.     

Dietary preference of cheetahs (Acinonyx jubatus) in south‐eastern Kenya

The conversion of natural ecosystems due to anthropogenic activities has led to the destruction of natural habitats and to the deterioration of habitat quality. Top predators particularly respond sensitively to changes in habitat structures, including the availability of prey. The cheetah Acinonyx jubatus prefers small‐medium‐sized, wild ungulate prey due to the cheetah''s morphological adaptations. However, the majority of the species’ population is found beyond protected areas, where habitat structures, species abundances, and community composition are highly influenced by human activities. Only few studies have analyzed the diet preference of cheetahs in relation to prey availability and abundance for rangelands beyond protected areas in Eastern Africa. The study aimed to determine cheetah prey preference in the rangelands of south‐eastern Kenya based on scat analyses. We compared dietary preference of cheetah with prey availability. For this purpose, we conducted standardized game counts. We analyzed 27 cheetah scat samples collected across the same study area where we also conducted game counts. We found that Grant''s gazelle Gazella granti contributed the highest portion of cheetah''s diet, although Thomson''s gazelle Gazella thomsonii was the most abundant medium‐sized ungulate prey in the study areas. We also recorded two primate species, yellow baboon Papio cynocephalus and vervet monkey Chlorocebus pygerythrus, as well as the rock hyrax Procavia capensis in the cheetah diet. These species have never been documented as cheetah prey before. Furthermore, our results document livestock as potential prey for cheetahs. These observations underline that cheetah use diverse prey in rangelands outside protected areas, and that the abundance of specific prey does not influence cheetah prey preference.     

High juvenile mortality in cheetahs (Acinonyx jubatus) and its consequences for maternal care

Juvenile mortality in cheetahs was found to be extremely high compared to other large mammals, with approximately 72.2% of litters dying before they emerged from the lair at eight weeks of age. An average of 83.3% of cubs alive at emergence died by adolescence at 14 months of age, thus cheetah cubs were estimated to have only a 4.8% chance of reaching independence at birth. The instantaneous rate of mortality was highest immediately after cubs emerged from the lair. Before emergence, lion predation was the major source of this mortality, although some cubs died from starvation after they were abandoned by their mothers, or as a result of grass fires and inclement weather. After emergence, predation again accounted for virtually all cub mortality, with lions and spotted hyaenas taking approximately the same proportion of cubs. Overall predation accounted for 73.2% of cheetah cub deaths in this study, with 78.2% of these being killed by lions. The extent of maternal care, in the form of vigilance and antipredator behaviour, mirrored cub susceptibility to mortality and, in the case of vigilance, possibly also starvation. The probability of a cheetah mother responding aggressively to a predator was found also to depend on the species of predator. This study highlights the importance of the influence of juvenile mortality on patterns of parental care.     

Focal palatine erosion in captive and free-living cheetahs (Acinonyx jubatus) and other felid species

We examined 1,092 skulls of captive and free-living individuals, representing 33 felid species, to determine the prevalence of focal palatine erosion (FPE). FPE was detected in 3.2% of cats evaluated, including cheetah (Acinonyx jubatus) and 14 other felid species. The prevalence of FPE between cheetah (9.4%; n = 64) and non-cheetah species (2.8%; n = 1,028) (χ(2) test; P = 0.004) and between captive (5.7%; n = 246) and free-living (2.4%; n = 824) individuals (χ(2) test; P = 0.010) were significantly different, with prevalence between captive (19%; n = 21) and free-living (2.9%; n = 34) cheetahs approaching significance (Fisher's exact test; P = 0.064). FPE was diagnosed with equal prevalence in skulls from individuals in which the lower molars did not meet the palatine bone (60.6%) and individuals in which it did (39.4%; n = 33) (χ(2) test; P = 0.139). In cheetahs with FPE, one was a captive animal in Germany, one a free-living cheetah from Mali, one captive cheetah from Kenya, and three captive cheetahs of unknown origin. Additionally, we evaluated the medical records of 49 captive cheetahs in Namibia. Of these cheetahs, 48 (98.0%) had clinical signs consistent with FPE, although only 16 of these 48 (39.6%) had perforation of the palatine bone. Based on physical examinations, FPE was diagnosed in two caracals (Caracal caracal) and one fishing cat (Prionailurus viverrinus) from a North American Zoo. Results from this study confirm FPE in cheetahs outside of Namibia, in a minimum of 15 felid species, and a higher FPE prevalence in captive individuals than free-living ones. Clinical implications of these findings and recommendations for future studies are provided.     

Ultrasonographic and laparoscopic evaluation of the reproductive tract in older captive female cheetahs (Acinonyx jubatus)

The study uniquely described the clinical value of transabdominal ultrasonography for monitoring features characterizing the estrous cycle in female cheetahs (Acinonyx jubatus). The reproductive tracts of 21 female, nulliparous, and relatively aged (median: 11 and interquartile range: 9.25–14 years) captive cheetahs resident on two sites in Namibia were assessed by transabdominal ultrasound. Subsequently, the ovarian findings on ultrasound were compared with direct visualization while performing laparoscopic sterilization. A combination of these observations supported by concurrent sampling for vaginal cytology and serum progesterone concentrations defined the estrous status of individual animals. At one site, six cheetahs had been implanted with the GnRH agonist, deslorelin as a contraceptive at least once within the preceding 11 years. On ultrasound, 31 uterine horns and 35 ovaries with discernible structures on 28 (86%) were visualized in the 21 cheetahs. The uterine body was difficult to visualize because of its intrapelvic location. Eleven of 19 uteri (58%) visualized showed endometrial edema suggestive of estrogenization. The uteri of four cheetahs (19%) showed evidence of mild cystic endometrial hyperplasia. Paraovarian cysts were seen on ultrasound (n = 21) and laparoscopy (n = 26) in 16 (76.2%) and 18 (85.7%) cheetahs, respectively. Ovarian volumes obtained from ultrasonographically determined dimensions predicted cyclic activity. Laparoscopy showed that 19 ovaries had discernible follicular structures. In the study population, 10 (47.6%) cheetahs were in proestrus or estrus; none in the luteal phase; and 11 (52.4%) in anestrus. Transabdominal ultrasound, in combination with serum progesterone concentrations and vaginal cytology, was used with acceptable accuracy to assess cyclic ovarian activity in captive cheetahs. A considerable proportion of this aged population showed ovarian activity and the prevalence of paraovarian cysts was notable. A history of prior deslorelin treatment was not associated with either reproductive activity or uterine pathology.     

Cryopreservation of spermatozoa from wild-born Namibian cheetahs (Acinonyx jubatus) and influence of glycerol on cryosurvival

Sperm cryopreservation is a valuable tool for the genetic management of ex situ populations. This study was conducted to assess: (1) semen characteristics of wild-born cheetahs; and (2) the impact of three types of glycerol influence (duration of exposure, temperature, and method of addition) on sperm cryosensitivity. To evaluate the impact of duration of glycerol exposure, spermatozoa were incubated in Test Yolk Buffer (TYB) with 4% glycerol at ambient temperature (approximately 22 degrees C) for 15 vs. 60 min before cryopreservation. To evaluate the influence of temperature and method of glycerol addition, spermatozoa were resuspended at ambient temperature either in TYB with 0% glycerol followed by addition of 8% glycerol (1:1 v/v; at ambient temperature vs. 5 degrees C) or directly in TYB with 4% glycerol. All samples were cryopreserved in straws over liquid nitrogen vapor and evaluated for sperm motility and acrosomal integrity after thawing. Semen samples (n = 23; n = 13 males) contained a high proportion (78%) of pleiomorphic spermatozoa. Ejaculates also contained a high proportion of acrosome-intact (86%) and motile spermatozoa (78%). Immediately after thawing, a significant proportion of spermatozoa retained intact acrosomes (range, 48-67%) and motility (range, 40-49%). After thawing, incubation in glycerol for 60 min at ambient temperature before freezing decreased (p < 0.05) sperm motility and acrosomal integrity at one time-point each (pre-centrifugation and post-centrifugation, respectively). However, method or temperature of glycerol addition had no (p > 0.05) impact on sperm cryosurvival. In summary, (1) wild-born cheetahs produce high proportions of pleiomorphic spermatozoa but with a high proportion of intact acrosomes; and (2) resuspension in 4% glycerol, followed by exposure for up to 60 min at ambient temperature, had minimal effect on sperm motility and acrosomal integrity after cryopreservation. Results indicate the feasibility of cryopreserving cheetah spermatozoa under field conditions, providing a user-friendly method to capture and store gametes to enhance genetic management.     

Blood values of adult captive cheetahs (Acinonyx jubatus) fed either supplemented beef or whole rabbit carcasses

This study evaluated nutrient intake and relevant blood parameters of 14 captive cheetahs, randomly assigned to a meat‐only diet (supplemented beef, SB) or a whole prey diet (whole rabbit, WR) for 4 weeks each. Despite a higher food intake, daily metabolizable energy intake was lower when fed WR (308 kJ BW^?1) compared with SB (347 kJ BW^?1) (P = 0.002). The ratio of protein to fat was markedly lower for WR (2.3:1) compared with SB (8.8:1), which was reflected in higher serum urea levels when fed SB (P = 0.033), and a tendency for elevated cholesterol levels when fed WR (P = 0.055). Taurine intake of cheetahs fed WR was low (0.06% on DM basis); however, analytical error during taurine analysis cannot be ruled out. Feeding WR resulted in a well‐balanced mineral intake, in contrast to SB. The latter provided a low calcium:phosphorus ratio (1:2.3), thereby increasing the risk of metabolic bone disease. The high zinc content of SB (200 mg/kg DM), compared with WR (94 mg/kg DM), was reflected in higher serum zinc concentrations (P = 0.011). Feeding WR resulted in an increase in serum vitamin A (P = 0.011). Therefore, the risk of hypervitaminosis A in captive cheetahs when fed WR exclusively on a long‐term basis should be evaluated. Our findings suggest that neither diet is likely to provide appropriate nutrition to captive cheetahs when fed exclusively. Zoo Biol 31:629‐641, 2012. © 2011 Wiley Periodicals, Inc.     

Prevalence and implications of feline coronavirus infections of captive and free-ranging cheetahs (Acinonyx jubatus).

The extent and progression of exposure to feline infectious peritonitis (FIP) virus in the cheetah, Acinonyx jubatus, was monitored by a world-wide serological survey with indirect fluorescent antibody titers to coronavirus. The indirect fluorescent antibody assay was validated by Western blots, which showed that all indirect fluorescent antibody-positive cheetah sera detected both domestic cat and cheetah coronavirus structural proteins. There was a poor correlation between indirect fluorescent antibody results and the presence of coronaviruslike particles in cheetah feces, suggesting that electron microscopic detection of shed particles may not be an easily interpreted diagnostic parameter for FIP disease. Low, but verifiable (by Western blots [immunoblots]) antibody titers against coronavirus were detected in eight free-ranging cheetahs from east Africa as well as from captive cheetahs throughout the world. Of 20 North American cheetah facilities screened, 9 had cheetahs with measurable antibodies to feline coronavirus. Five facilities showed patterns of an ongoing epizootic. Retrospective FIP virus titers of an FIP outbreak in a cheetah-breeding facility in Oregon were monitored over a 5-year period and are interpreted here in terms of clinical disease progression. During that outbreak the morbidity was over 90% and the mortality was 60%, far greater than any previously reported epizootic of FIP in any cat species. Age of infection was a significant risk factor in this epizootic, with infants (less than 3 months old) displaying significantly higher risk for mortality than subadults or adults. Based upon these observations, empirical generalizations are drawn which address epidemiologic concerns for cheetahs in the context of this lethal infectious agent.     

Daily fecal sex steroid hormonal changes and mating success in captive female cheetahs (Acinonyx jubatus) in Japan

Daily fecal estrogen and progestin concentrations were measured by enzyme immunoassay in five female cheetahs (Acinonyx jubatus) for 4-6 months. The animals were housed under different conditions: (1) a female always housed in a group including one or more males; (2) two females isolated individually for short or long periods; (3) the other two females housed together. These females were separately housed with males for mating around the time of the estrogen peaks. The hormone profiles were similar in all five females regardless of the housing conditions. However, only the female that had been isolated from other cheetahs for over a year mated and reproduce cubs successfully, whereas the remaining four did not (one was isolated for only 6 weeks, another was always housed with males and the other two were housed together). In all females, the estrogen peaks were obtained at regular intervals of approximately 8-15 days. Unlike estrogen, the progestin concentrations were always low in all females except during pregnancy and they did not increase following the estrogen surges. These results showed that female cheetahs are typically reflex ovulators and female receptiveness may not be reflected to her hormonal states. It was also suspected that individual housing and long-term separation are advantageous for breeding this wild cat in captivity, mimicking the ecological/behavioral patterns in the wild, though housing condition might have no effect on the estrous cycle.