Morbidity/Mortality in the Captive Black-Footed Cats (Felis nigripes)
(submitted by Nadine Lamberski, Karen Terio and Linda Munson)

The Black-Footed cat, native to South Africa, Botswana and Namibia, is listed in Appendix 1 of
CITES. It is the smallest of the African cats weighing approximately 2 kg. Anecdotally, the
Black-Footed cat is believed to live up to 15 yr. In captivity, the average life span is only 3-5
years while free-ranging cats live approximately 5-6 yr. Because of this unusually short captive
life span, the causes of morbidity and mortality in the captive population were reviewed.

Institutional records from the past 20 years were evaluated. In 11 of these 20 years, the number
of deaths equaled or exceeded the number of births. Thirty-nine necropsy reports from
1986-1999 were reviewed. In 35/39 (87%) there was a diagnosis of renal failure/amyloidosis.
The average age at the time of death was 4.2 yr. (range 2.5-8 yr.), and there was no sex
predilection. Six of these 35 reports included a comment about enlarged adrenal glands.

Due to the high prevalence of amyloidosis, tissue samples from affected cats were analyzed by
immunohistochemistry for amyloid by Dr. Tim O’Brien. Type of amyloid was determined to be
type AA. Because this form of amyloidosis is secondary to a chronic inflammatory process, the
primary site(s) of inflammation remains to be determined.

Because of the holding institutions’ concerns regarding stress in this species and the enlarged
adrenal glands noted at necropsy, fecal cortisol concentrations were evaluated. Baseline fecal
cortisol levels from eight animals at five institutions were determined. The overall mean for these
animals was 414.5 ± 42.3 ng/gm dry feces, with a range of 106.6 to 1,386.8 ng/gm dry feces. At
one institution, feces from animals housed on and off exhibit were submitted, and there was a
significantly higher baseline concentration in the animal housed on exhibit. The results of these
preliminary studies warrant further investigation.

Ongoing and future studies include: 1) characterization of the amyloid by protein sequence
analysis; 2) identification of the primary sites of inflammation; 3) analysis of baseline fecal
cortisol concentrations in free-living Black-Footed cats; and 4) evaluation of baseline fecal
cortisol concentrations under different management conditions.