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).
Yazwinski
T A
TA
Department of Animal Science, University of Arkansas, Fayetteville, AR 72701, USA. yazwinsk@uark.edu
Williams
J C
JC
Smith
L L
LL
Tucker
C
C
Loyacano
A F
AF
Derosa
A
A
Peterson
P
P
Bruer
D J
DJ
Delay
R L
RL
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