Efficacy of a pour-on formulation of doramectin against lice, mites, and grubs of cattle.
OBJECTIVE
To determine effectiveness of a pour-on formulation of doramectin against Damalinia bovis, Haematopinus eurysternus, Linognathus vituli, Solenopotes capillatus, Chorioptes bovis, Sarcoptes scabiei, Hypoderma bovis, and Hypoderma lineatum.


METHODS
Cattle of various ages with naturally acquired or artificial infestations with 1 or more species of lice, mites, or grubs.


METHODS
In 10 louse and 6 mite studies, cattle were treated with doramectin (500 microg/kg, topically) on day 0, and parasite counts were performed approximately weekly from days 0 to 35. In 6 grub studies, cattle expected to harbor Hypoderma spp were treated before emergence of warbles. After warbles began to emerge, they were counted every 2 weeks, and grubs were collected and identified by species.


RESULTS
Burdens of D bovis, H eurystemus, L vituli, and S capillatus on doramectin-treated cattle were 0 by 28 days after treatment. Burdens of C bovis and S scabiei decreased to 0 in naturally infested cattle and approximately 0 in artificially infested cattle by day 14 to 15. In grub studies, 107 of 136 control cattle had warbles, whereas 2 of 136 doramectin-treated cattle had 1 warble each, which represented a cure rate of 98.5%.


CONCLUSIONS
One topical application of doramectin was highly efficacious against common species of lice, mites, and grubs known to affect performance, health, and appearance of cattle.
Rooney
K A
KA
Pfizer Central Research, Groton, CT 06340, USA.
Illyes
E F
EF
Sunderland
S J
SJ
Sarasola
P
P
Hendrickx
M O
MO
Keller
D S
DS
Meinert
T R
TR
Logan
N B
NB
Weatherley
A J
AJ
Conder
G A
GA
D000287:Administration, Topical; D000818:Animals; D000854:Anoplura; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000469:parasitology; D004175:Diptera; D005260:Female; D007000:Hypodermyiasis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D007306:Insecticides / Q000008:administration & dosage / Q000627:therapeutic use*; D007559:Ivermectin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010373:Lice Infestations / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D008924:Mite Infestations / Q000188:drug therapy / Q000662:veterinary*; D008003:Phthiraptera; D012520:Sarcoptes scabiei; D016896:Treatment Outcome
D000871:Anthelmintics; D007306:Insecticides; D007559:Ivermectin; C084101:doramectin