Sarcoids in Captive Zebras (Equus Burchellii): Association With Bovine Papillomavirus Type 1 Infection

Abstract

Sarcoids were diagnosed in two captive zebras from different facilities. Zebra 1 (Equus burchellii boehmi) was a 4.5-yr-old, captive-born male that presented with a 9- by 7-cm inguinal mass. Seven months after surgical excision of the inguinal mass, the zebra presented with a similar lesion in the right upper eyelid that has relapsed repeatedly and has not responded to treatment including local cisplatin injections and cryosurgery. Zebra 2 (of undetermined taxon) was housed at a private wild animal farm. The zebra presented with a single, raised, 2.5- by 2.0- by 2.0-cm, ulcerated mass on the nose, and surgical excision was curative. Histologically, the three masses consisted of a dermal, compact, nonencapsulated, poorly demarcated neoplasm composed of well-differentiated spindle cells arranged in streams and whorls and accompanied by moderate epidermal hyperplasia with long rete pegs. On the basis of the morphologic resemblance to the unique equine cutaneous neoplasm, "sarcoid" was diagnosed. This is the first description of sarcoids in captive zebras. Association with bovine papillomavirus (BPV) type 1, as it occurs in horses, was demonstrated by polymerase chain reaction, nucleic acid sequencing, and in situ hybridization (ISH) on paraffin-embedded tissues from the inguinal mass of zebra 1. Sequencing revealed 98% identity of the 244-bp fragment with BPV type 1. The ISH for BPV type 1 DNA intensely stained the nuclei of neoplastic mesenchymal spindle cells. The sites and the clinical behavior of the sarcoids in these zebras are similar to those described in horses.

Transcriptional Changes Induced by Bovine Papillomavirus Type 1 in Equine Fibroblasts

“…BPV DNA has not been detected in other equine tumors, including melanomas, papillomas, and squamous cell carcinomas (15), although we and others have shown that BPV-1/BPV-2 DNA can be detected in some cases of equine inflammatory skin disease (3,15,68). BPV DNA is localized to the fibroblast nuclei (37,60) and is maintained as a high-copynumber episome, and infection results in the expression of viral genes (2,10,15,49,67). We have recently shown that BPV-1 transforms primary equine fibroblasts (69).…”

Comparative Genetics of Sarcoid Tumour-Affected and Non-Affected Mountain Zebra (Equus zebra) Populations

“…Comparing levels of average heterozygosity, mean number of alleles per loci, effective number of alleles, mean range of microsatellite repeats and microsatellite variance estimates between a population of interest and its free-ranging counterpart are useful to determine loss of genetic variation. The appearance of sarcoid tumours in equids has been correlated with specific genetic haplotypes (Chambers et al 2003) with the involvement of BPV in the formation of sarcoid tumour in equids proven (Lohr et al 2005;Brandt et al 2008) and correlated with down-regulation of immune system genes (Ashrafi et al 2006;Yuan et al 2008). The only previous epizootic of sarcoid tumour reported was in horses, with four of the five affected individuals being members of a highly inbred herd (Ragland et al 1966).…”

Detomidine and Butorphanol for Standing Sedation in a Range of Zoo-Kept Ungulate Species

“…At a minimum, the skin should be checked for parasites and sarcoids (the most common tumor in zebras), 11 the joints flexed, the hooves inspected, and the oral cavity and mucous membranes visualized. The examination should be efficient without unduly prolonging the anesthesia.…”