Efficacy of dicyclanil in the prevention of screwworm infestation (Cochliomyia hominivorax) in cattle castration wounds.
A field trial was carried out during summer 1996 in a commercial beef cattle farm located in the central area of Argentina (30 degrees 16'S, 60 degrees 30'W) to evaluate the efficacy of a new insect growth regulator material (dicyclanil) in the prevention of myiosis caused by screwworm (Cochliomyia hominivorax) larvae. Forty bull calves (Bos indicus x Bos taurus), 5 to 6 months old were allocated by ranked paris to a control (G.1) and a treated group (G.2) of the same number of animals. On day 0, all experimental animals were surgically castrated and calves of group 2 were treated topically with 20 ml as a single dose of a ready-to-use formulation containing 5% w/v dicyclanil. Inspections for screwworm larva infestation were carried out on days 4, 8, 12, 16, 19, 23 and 25 after castration. The incidence of egg masses on the scrotal wounds evidenced a similar challenge for all groups (P > 0.05 chi(2)). However, 16 animals of G.1 (80%) and only one of G.2 (5%) developed active myiosis, respectively. This difference was significant (P=0.003 X(2)).
Anziani
O S
OS
EEA INTA Rafaela, Santa Fe, Argentina.
Guglielmone
A A
AA
Schmid
H
H
D000287:Administration, Topical; D000818:Animals; D001118:Argentina; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000517:prevention & control*; D004175:Diptera / Q000187:drug effects / Q000502:physiology; D007605:Juvenile Hormones / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D009919:Orchiectomy / Q000009:adverse effects / Q000662:veterinary*; D010270:Parasite Egg Count / Q000662:veterinary; D012610:Screw Worm Infection / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D013530:Surgical Wound Infection / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*
D007605:Juvenile Hormones