Dose determination of the persistent activity of moxidectin long-acting injectable formulations against various nematode species in cattle.
The effectiveness, safety and production-enhancing benefit (improved weight gains) of moxidectin long-acting injection given subcutaneously in the ear at the rates of 0.75, 1.0 and 1.5mg/kg bw were evaluated in three studies under common protocol. The only adverse reaction to treatment was a mild (<2 tablespoons in volume), and for the most part transient (<28 days for the treatment rate of 1.0mg/kg bw) injection site swelling as noted in a minority of the animals (12.2% of the animals treated at the rate of 1.0mg/kg bw). Regardless of study site, post-treatment interval or dose rate, average daily gains were improved over control cattle by approximately 33%. Reductions in strongyle EPG counts relative to controls were > or = 90% for all dose rates of moxidectin for a post-treatment period of 42 days (Wisconsin), 84 days (Arkansas) and 140 days (Louisiana). In Arkansas and Louisiana, the majority (>80%) of post-treatment strongyle eggs, as determined by coproculture, were Cooperia spp. As determined by sequential necropsies, periods of continuous, post-treatment protection (> or = 90% efficacy in at least two out of three studies) for moxidectin long-acting injection given at the rate of 1.0 mg/kg bw were 90 days (adult Haemonchus spp.), 120 days (Dictyocaulus viviparus and adult Ostertagia and Oesophagostomum) and 150 days (Ostertagia spp. EL4).
Department of Animal Science, University of Arkansas, Fayetteville, AR 72701, USA. yazwinsk@uark.edu
T A
TA
Yazwinski
J C
JC
Williams
L L
LL
Smith
C
C
Tucker
A F
AF
Loyacano
A
A
Derosa
P
P
Peterson
D J
DJ
Bruer
R L
RL
Delay
D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000469:parasitology; D004305:Dose-Response Relationship, Drug; D005243:Feces / Q000469:parasitology; D006374:Helminthiasis, Animal / Q000188:drug therapy* / Q000469:parasitology; D006376:Helminths / Q000302:isolation & purification; D007279:Injections, Subcutaneous / Q000662:veterinary; D018942:Macrolides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D010270:Parasite Egg Count / Q000662:veterinary; D011897:Random Allocation; D013323:Strongylus / Q000302:isolation & purification; D016896:Treatment Outcome; D015430:Weight Gain / Q000187:drug effects*
D000871:Anthelmintics; D018942:Macrolides; C027837:moxidectin