Bovine papillomavirus DNA in neoplastic and nonneoplastic tissues obtained from horses with and without sarcoids in the western United States.
OBJECTIVE
To determine the incidence of bovine papillomavirus (BPV) type 1 or 2 in sarcoids and other samples of cutaneous tissues collected from horses in the western United States.


METHODS
55 horses with sarcoids and 12 horses without sarcoids.


METHODS
Tissue samples (tumor and normal skin from horses with sarcoids and normal skin, papillomas, and nonsarcoid cutaneous neoplasms from horses without sarcoids) were collected. Tissue samples were analyzed for BPV-1 or -2 DNA, using a polymerase chain reaction (PCR) and restriction fragment length polymorphism. The PCR products from 7 sarcoid-affected horses were sequenced to evaluate percentage homology with expected sequences for BPV-1 or-2.


RESULTS
Most (94/96, 98%) sarcoids contained BPV DNA. Sixty-two percent of the tumors examined had restriction enzyme patterns consistent with BPV-2. Thirty-one of 49 (63%) samples of normal skin obtained from horses with sarcoids contained BPV DNA. All samples subsequently sequenced had 100% homology with the expected sequences for the specific viral type. All tissues from healthy horses, nonsarcoid neoplasms, and papillomas were negative for BPV DNA.


CONCLUSIONS
Bovine papillomaviral DNA was detected in essentially all sarcoids examined. There appears to be regional variation in the prevalence of viral types in these tumors. The fact that we detected viral DNA in normal skin samples from horses with sarcoids suggests the possibility of a latent viral phase. Viral latency may be 1 explanation for the high rate of recurrence following surgical excision of sarcoids.
Carr
E A
EA
Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616, USA.
Théon
A P
AP
Madewell
B R
BR
Griffey
S M
SM
Hitchcock
M E
ME
D000818:Animals; D052688:Bovine papillomavirus 1 / Q000235:genetics* / Q000254:growth & development; D002417:Cattle; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D006651:Histocytochemistry; D006734:Horse Diseases / Q000473:pathology / Q000821:virology*; D006736:Horses; D030361:Papillomavirus Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D012507:Sarcoidosis / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D012878:Skin Neoplasms / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D014412:Tumor Virus Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D014481:United States
D004279:DNA, Viral