Species of the family Felidae are thought to be obligate carnivores. However, detection of plants in their faeces raises questions about the role of plants in their diet. This is particularly true for the snow leopard (Panthera uncia). Our study aimed to comprehensively identify the prey and plants consumed by snow leopards. We applied DNA metabarcoding methods on 90 faecal samples of snow leopards collected in Kyrgyzstan, employing one vertebrate and four plant markers. We found that argali (Ovis ammon) was detected only from male snow leopards. Myricaraia sp. was the most consumed among 77 plant operational taxonomic units found in snow leopard samples. It frequently appeared in samples lacking any prey animal DNA, indicating that snow leopards might have consumed this plant especially when their digestive tracts were empty. We also observed differences in the patterns of plant consumption between male and female snow leopards. Our comprehensive overview of prey and plants detected in the faeces of snow leopards and other sympatric mammals will help in formulating hypotheses and guiding future research to understand the adaptive significance of plant-eating behaviour in felids. This knowledge supports the enhancement of their captive environments and the conservation planning of their natural habitats.

This study evaluated the protein quality of small mammalian prey and its body organs by analyzing amino acid (AA) composition and digestibility of wild adult rats and their body organs (skin/fur, bone, muscle, intestine, liver, kidney, spleen, brain, heart, and lung) utilizing an in vitro digestion method. The average dry matter (DM) digestibility of whole rats was 89.9%. The digestibility of total AA (TAA), total indispensable AA (TIAA), and total dispensable AA (TDAA) in whole rats was 85.6, 87.0, and 87.6%, respectively. Differences in DM digestibility were observed among rat organs, ranging from 59.0% in bone to 99.8% in muscle (P < 0.001). Highly digestible organs generally exhibited AA digestibility exceeding 90%, except for cysteine (Cys) in the intestine and kidney (83.8% and 88.9%, respectively). The digestibility of AAs in skin/fur ranged from 19.7% for Cys to 81.0% for glycine (Gly). In bone, the digestibility spanned from 56.9% for Gly to 81.1% for tyrosine (Tyr). Additionally, examining the digestible indispensable AA score (DIAAS) gives us an idea of the protein quality of small mammalian prey and their body organs. Our results complement information on AA supply and digestion during prey ingestion by felids.
As obligate carnivores, free-ranging felids consume prey and rely on nutrients from animal organs. Studies in adult carnivores such as domestic cats have demonstrated the importance of the dietary amino acid profile. Therefore, this research used rats as a small prey model to analyze the amino acid composition and digestibility of whole prey and its body organs through in vitro digestion methods. Our results add information on amino acid supply and digestion during natural food intake in felids.

For domestic cats ovaries, recommended cold-storage limit is 24 h in Phosphate Buffered Saline (PBS) or Dulbecco`s PBS (DPBS). Here, we attempted to verify wheatear cat ovaries may benefit from more complex solutions during prolonged cold-storage (>24 h). First, the preservation capabilities of extracellular (SP+), intracellular (UW) solutions and DPBS supplemented with glutathione (DPBS+GSH) were compared using ovary fragments from the same ovary (n=10). Intact ovary stored in DPBS served as a control. Ovaries were kept at 4 °C for 48 h, and 72 h. In the second experiment, first ovary was stored in DPBS, second in SP+ or UW solution for 48 h (n = 12). Ovaries pairs stored in DPBS for 24 h served as a control (n=8). Tissue samples were evaluated directly after cold-storage and after following 24 h in vitro culture. Ovarian follicle morphology, apoptosis rates (cleaved caspase-3, TUNEL), and follicular growth activation (Ki-67) were assessed. Ovary fragmentation impaired follicular morphology preservation upon cold-storage comparing to intact ovary. However, ovarian fragments stored in UW for 48 h and in SP+ for 72 h presented better morphology than DPBS+GSH group. Comparison of intact ovaries cold-storage for 48 h showed that SP+ provided superior follicular morphology over DPBS, and it was comparable to the outcome of 24-hour storage. No follicular activation after in vitro culture was observed. Nevertheless, tissue culture increased considerably caspase-3 cleavage and TUNEL detection. The ovary fragmentation prior to cold-storage is not recommended in domestic cats. Replacement of DPBS with SP+ solution for whole ovary and UW solution for ovarian tissue fragments improves follicular structure preservation during 48-hour cold-storage.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in a zoological institution were initially reported in March 2020. Since then, at least 94 peer-reviewed cases have been reported in zoos worldwide. Among the affected animals, nonhuman primates, carnivores, and artiodactyls appear to be most susceptible to infection, with the Felidae family accounting for the largest number of reported cases. Clinical symptoms tend to be mild across taxa; although, certain species exhibit increased susceptibility to disease. A variety of diagnostic tools are available, allowing for initial diagnostics and for the monitoring of infectious risk. Whilst supportive therapy proves sufficient in most cases, monoclonal antibody therapy has emerged as a promising additional treatment option. Effective transmission of SARS-CoV-2 in some species raises concerns over potential spillover and the formation of reservoirs. The occurrence of SARS-CoV-2 in a variety of animal species may contribute to the emergence of variants of concern due to altered viral evolutionary constraints. Consequently, this review emphasizes the need for effective biosecurity measures and surveillance strategies to prevent and control SARS-CoV-2 infections in zoological institutions.

Bartonella henselae is a primary zoonotic agent, having cats as asymptomatic reservoirs. In humans, it causes cat scratch disease. Here, we report the whole genome sequences of 16 strains isolated from cats in Valdivia city, Southern Chile. Strains showed little variability in the multilocus sequence typing profiles.

A relationship exists between mechanical loading and bone morphology. Although studies show a relationship between trabecular bone morphology and locomotor strategy in mammals, none of them have studied trabecular bone morphology in felid species occupying disparate and overlapping habitats. We investigate trabecular bone volume fraction (BVF) in the femoral and humeral heads, and distal tibia of four felid species (mountain lions, jaguars, cheetahs, and leopards) to identify whether there is a relationship between BVF and locomotor behavior. This study\'s goals are to identify whether felid species with high daily travel distance or large home range size have greater BVF compared with those with small daily travel distance or home range size, and whether BVF is correlated among the three elements of the fore and hindlimb studied. We quantified BVF in micro- and peripheral computed tomography images and found no significant differences across species in the femoral and humeral head (p > 0.05). However, in the distal tibia, results showed that leopards, mountain lions, and cheetahs have significantly greater (p < 0.05) BVF than jaguars. Despite differences in home range size and daily travel distance, the proximal elements did not reflect differences in BVF; however, the distal-most element did, suggesting decreased loading among jaguars. These findings suggest that the observed pattern of trabecular bone morphology is potentially due to the diversity in locomotor strategy of the forelimb. Additionally, these results imply that neither home range size nor daily travel distance are clear indicators of activity levels. A cautious approach is warranted in studying how loading influences trabecular morphology.

The mammalian Leukocyte Receptor Complex (LRC) chromosomal region may contain gene families for the killer cell immunoglobulin-like receptor (KIR) and/or leukocyte immunoglobulin-like receptor (LILR) collections as well as various framing genes. This complex region is well described in humans, mice, and some domestic animals. Although single KIR genes are known in some Carnivora, their complements of LILR genes remain largely unknown due to obstacles in the assembly of regions of high homology in short-read based genomes.
As part of the analysis of felid immunogenomes, this study focuses on the search for LRC genes in reference genomes and the annotation of LILR genes in Felidae. Chromosome-level genomes based on single-molecule long-read sequencing were preferentially sought and compared to representatives of the Carnivora.
Seven putatively functional LILR genes were found across the Felidae and in the Californian sea lion, four to five genes in Canidae, and four to nine genes in Mustelidae. They form two lineages, as seen in the Bovidae. The ratio of functional genes for activating LILRs to inhibitory LILRs is slightly in favor of inhibitory genes in the Felidae and the Canidae; the reverse is seen in the Californian sea lion. This ratio is even in all of the Mustelidae except the Eurasian otter, which has a predominance of activating LILRs. Various numbers of LILR pseudogenes were identified.
The structure of the LRC is rather conservative in felids and the other Carnivora studied. The LILR sub-region is conserved within the Felidae and has slight differences in the Canidae, but it has taken various evolutionary paths in the Mustelidae. Overall, the process of pseudogenization of LILR genes seems to be more frequent for activating receptors. Phylogenetic analysis found no direct orthologues across the Carnivora which corroborate the rapid evolution of LILRs seen in mammals.

BACKGROUND: Considering animals as individuals and not as species is becoming increasingly essential to animal welfare management in captive settings. Recent studies on big cat personalities and coping strategies suggest personality can help big cats cope in their surroundings. Yet a large portion of the published literature focuses on understanding either the personality or stress physiology of big cats. Our research shows how integrating an improved understanding of the personality of big cats with stress physiology may enhance welfare, especially for endangered species like African lions. By using a wild cat personality checklist, this study compared the key personality dimensions of 22 African lions with its faecal glucocorticoids and assessed factors influencing their personality and stress physiology.
RESULTS: We found two reliable personality dimensions for African lions (dominance and agreeableness) and identified key factors (sex, age and location) that may influence their personality. Further, on testing if these factors influenced the stress physiology through variations in glucocorticoid levels, there was no significant difference. However, there was a strong negative association between agreeableness and glucocorticoid levels. These results suggest that the behavioural traits loading positively and higher for agreeableness are associated with lower glucocorticoid stress levels, which may assist a lion to cope with stressors in its surroundings.
CONCLUSIONS: Our findings highlight this integrated approach of linking personality and stress physiology of big cats can be beneficial for caretakers. For example, during stressful veterinary procedures or in reintroduction programs, recognizing the personality of lions can help in designing or providing them with resources that will alleviate stress. Thus, there is a need for more interdisciplinary approaches that will contribute towards enhancing the individual and overall welfare of big cats.

Zookeepers working with felids were asked to complete an online survey to examine their perceptions of animal welfare. A total of 121 zookeepers in an AZA-accredited zoo completed the survey. Results from this study suggest that institutional offerings of professional development programming in animal welfare have the greatest potential to influence zookeeper perceptions of animal welfare. Participants also identified four areas of improvement for felid welfare, including 1) larger and more dynamic spaces, 2) increased attention to behavioral husbandry, 3) more unique diet presentations, and 4) the ability for the animal to remain out of the view of the public. In addition, there appear to be differences in perception between traditionally described \"small cat\" and \"large cat\" keepers in terms of the ability to deliver the Five Freedoms.

The puma population is constantly decreasing, and cloning by somatic cell nuclear transfer can be used to conserve the species. One of the factors determining the success of the development of cloned embryos is the cell cycle stage of the donor cells. We evaluated the effects of full confluency (~100%), serum starvation (0.5% serum), and roscovitine (15 µM) treatments on the cell cycle synchronization in G0/G1 of puma skin-derived fibroblasts by flow cytometric analysis. Also, we assessed the effects of these synchronization methods on morphology, viability, and apoptosis levels using microscopy tools. The results showed that culturing the cells to confluence for 24 h (84.0%), 48 h (84.6%), and 72 h (84.2%) and serum starvation for 96 h (85.4%) yielded a significantly higher percentage of cells arrested in the G0/G1 (P 0.05) phase than cells not subjected to any cell cycle synchronization method (73.9%). Nevertheless, while serum starvation reduced the percentage of viable cells, no difference was observed for the full confluence and roscovitine treatments (P 0.05). Moreover, roscovitine for 12 h (78.6%) and 24 h (82.1%) was unable to synchronize cells in G0/G1 (P 0.05). In summary, full confluency induces puma fibroblast cell cycle synchronization at the G0/G1 stage without affecting cell viability. These outcomes may be valuable for planning donor cells for somatic cell nuclear transfer in pumas.