Topical use of 5-fluorouracil for treatment of squamous cell carcinoma of the external genitalia of horses: 11 cases (1988-1992)
Fortier, L.A.; Mac Harg, M.A.
Journal of the American Veterinary Medical Association 205(8): 1183-1185
1994
ISSN/ISBN: 0003-1488 PMID: 7890581 Document Number: 430097
Topical administration of 5-fluorouracil (5-FU), in conjunction with surgical debulking in advanced cases, was assessed as a treatment for penile and vulvular squamous cell carcinoma in horses. Three mares, 7 geldings, and 1 stallion were treated. Daily 5-FU application was necessary to maintain therapeutic concentrations in the females, whereas males required treatments only every 14 days, presumably because of drug retention in the penile sheath. The mean number of months of treatment required for clinical remission in the females was 3.7 (range, 1 to 8 months). Males obtained remission with a mean of 5 treatments (range, 2 to 7). All horses that completed the treatment protocol obtained and sustained clinical remission (n = 10), with follow-up periods of 5 to 52 months.