Epigenetic clock and methylation studies in cats.

Human DNA methylation profiles have been used successfully to develop highly accurate biomarkers of aging ("epigenetic clocks"). Although these human epigenetic clocks are not immediately applicable to all species of the animal kingdom, the principles underpinning them appear to be conserved even in animals that are evolutionarily far removed from humans. This is exemplified by recent development of epigenetic clocks for mice and other mammalian species. Here, we describe epigenetic clocks for the domestic cat (Felis catus), based on methylation profiles of CpGs with flanking DNA sequences that are highly conserved between multiple mammalian species. Methylation levels of these CpGs are measured using a custom-designed Infinium array (HorvathMammalMethylChip40). From these, we present 3 epigenetic clocks for cats; of which, one applies only to blood samples from cats, while the remaining two dual-species human-cat clocks apply both to cats and humans. We demonstrate that these domestic cat clocks also lead to high age correlations in cheetahs, tigers, and lions. It is expected that these epigenetic clocks for cats possess the potential to be further developed for monitoring feline health as well as being used for identifying and validating anti-aging interventions.

Epigenetic models developed for plains zebras predict age in domestic horses and endangered equids.

Effective conservation and management of threatened wildlife populations require an accurate assessment of age structure to estimate demographic trends and population viability. Epigenetic aging models are promising developments because they estimate individual age with high accuracy, accurately predict age in related species, and do not require invasive sampling or intensive long-term studies. Using blood and biopsy samples from known age plains zebras (Equus quagga), we model epigenetic aging using two approaches: the epigenetic clock (EC) and the epigenetic pacemaker (EPM). The plains zebra EC has the potential for broad application within the genus Equus given that five of the seven extant wild species of the genus are threatened. We test the EC's ability to predict age in sister taxa, including two endangered species and the more distantly related domestic horse, demonstrating high accuracy in all cases. By comparing chronological and estimated age in plains zebras, we investigate age acceleration as a proxy of health status. An interaction between chronological age and inbreeding is associated with age acceleration estimated by the EPM, suggesting a cumulative effect of inbreeding on biological aging throughout life.

Tick paralysis in a free-ranging bobcat (Lynx rufus).

CASE DESCRIPTION: A free-ranging male bobcat (Lynx rufus) was evaluated because of signs of pelvic limb paralysis. CLINICAL FINDINGS: Physical examination of the anesthetized animal revealed tick infestation, normal mentation, and a lack of evidence of traumatic injuries. Radiography revealed no clinically relevant abnormalities. Hematologic analysis results were generally unremarkable, and serologic tests for exposure to feline coronavirus, FeLV, FIV, and Toxoplasma gondii were negative. Results of PCR assays for flea- and common tick-borne organisms other than Bartonella clarridgeiae were negative. TREATMENT AND OUTCOME: Ticks were manually removed, and the patient received supportive care and fipronil treatment. The bobcat made a full recovery within 72 hours after treatment for ticks, and a presumptive diagnosis of tick paralysis was made. Identified tick species included Dermacenter variabilis, Amblyomma americanum, and Ixodes scapularis. CLINICAL RELEVANCE: To the authors' knowledge, tick paralysis has not previously been reported in felids outside Australia. This disease should be considered a differential diagnosis in felids, including exotic cats, with signs of neuromuscular disease of unknown etiopathogenesis.