Peer-reviewed veterinary case report
Generalized papillomatosis in three horses associated with a novel equine papillomavirus (EcPV8).
- Journal:
- Veterinary dermatology
- Year:
- 2018
- Authors:
- Linder, Keith E et al.
- Affiliation:
- Department of Population Health and Pathobiology · United States
- Species:
- horse
Plain-English summary
Three quarter horses were found to have a skin condition called generalized papillomatosis, which is linked to a new virus known as Equus caballus papillomavirus 8 (EcPV8). These horses developed many small, wart-like growths, mostly in areas like the armpits, groin, neck, and belly, with fewer on the face and legs. While the horses were otherwise healthy, the growths took a long time to resolve; one horse's lesions nearly disappeared after a year and a half, while another horse still had them after two years, even with treatment. Unfortunately, the oldest horse could not be followed up on. Overall, the papillomas can last for a long time, regardless of treatment.
Abstract
BACKGROUND: Currently, seven equine papillomaviruses (PV) are known and are associated with one of three different and distinct clinical presentations. HYPOTHESIS/OBJECTIVES: To report the clinical, histopathological and immunohistochemical findings in horses with generalized papillomatosis associated with a novel equine PV, Equus caballus papillomavirus 8 (EcPV8). ANIMALS: Three client-owned quarter horses. METHODS: Case report, retrospective. RESULTS: Dozens to thousands of papillomas involved the axilla, inguinal area and proximal limbs as well as the ventral and lateral neck, thorax and abdomen. Lesions were sometimes confluent in ventral areas. Fewer lesions were on the face, ears, distal limbs and genitalia. Plaque-type papillomas were small, 0.5 to 1.5 cm in diameter and hyperkeratotic. Histologically, plaque-type papillomas prominently involved follicular infundibula. Immunohistochemical findings demonstrated PV antigen in superficial keratinocyte nuclei. PCR using degenerate primers for the PV L1 gene and sequencing of amplicons revealed PV DNA sequences that were 98% identical for all three cases, but shared <70% identity to other PVs. Horses were otherwise healthy; serum immunoglobulin levels and peripheral blood lymphocyte phenotyping did not identify a known immunodeficiency syndrome. Lesions nearly completely resolved after 1.5 years in one horse and persisted for two years in another, despite intralesional human IFN-alpha treatment. The oldest horse was lost to follow-up. CONCLUSION AND CLINICAL IMPORTANCE: A novel equine papillomavirus (EcPV8) is associated with a distinct, plaque-type, generalized papillomatosis. Papillomas persisted for months to years, with or without treatment.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/28833761/