A high prevalence of systemic amyloidosis was documented in the black-footed cat (Felis nigripes) based on a retrospective review of necropsy tissues (n = 38) submitted as part of ongoing disease surveillance. Some degree of amyloid deposition was present in 33 of 38 (87%) of the examined cats, and amyloidosis was the most common cause of death (26/38, 68%). Amyloid deposition was most severe in the renal medullary interstitium (30/33, 91%) and glomeruli (21/33, 63%). Other common sites included the splenic follicular germinal centers (26/31, 84%), gastric lamina propria (9/23, 39%), and intestinal lamina propria (3/23, 13%). Amyloid in all sites stained with Congo red, and in 13 of 15 (87%) cats, deposits had strong immunoreactivity for canine AA protein by immunohistochemistry. There was no association with concurrent chronic inflammatory conditions (P = .51), suggesting that amyloidosis was not secondary to inflammation. Adrenal cortical hyperplasia, a morphologic indicator of stress that can predispose to amyloid deposition, was similarly not associated (P = .09) with amyloidosis. However, adrenals were not available from the majority of cats without amyloidosis; therefore, further analysis of this risk factor is warranted. Heritability estimation suggested that amyloidosis might be familial in this species. Additionally, tissues from a single free-ranging black-footed cat had small amounts of amyloid deposition, suggesting that there could be a predilection for amyloidosis in this species. Research to identify the protein sequence of serum amyloid A (SAA) in the black-footed cat is needed to further investigate the possibility of an amyloidogenic SAA in this species.
Bibliographical noteFunding Information:
The authors thank Gea Olbricht, Drs. Alex Sliwa and Lorna Bolton, and the following institutions for submitting material: Central Florida Zoo, Sanford, FL; Cincinnati Zoo & Botanical Garden, Cincinnati, OH; Happy Hollow Zoo, San Jose, CA; Johannesburg Zoo, Johannesburg, South Africa; The Living Desert Palm Desert, CA; Riverbanks Zoo and Garden, Columbia, SC; Sacramento Zoo, Sacramento, CA; San Antonio Zoo, San Antonio, TX; Zoo of Wuppertal, Wuppertal, Germany; and Zoological Society of San Diego, San Diego, CA. We also thank Drs. Sliwa and Jennifer Landolfi for critical review of this manuscript. This study was funded by a grant from the American Association of Zoo Veterinarians Mazuri Fund.
- AA amyloid
- Black-footed cat
- Felis nigripes