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  • Author or Editor: Michael B. Hildreth x
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Objective—To assess the effect of subclinical, naturally acquired gastrointestinal nematode infestation on weight gain in yearling cattle kept on pasture.

Design—Prospective study.

Animals—799 Bos taurus yearlings kept on pasture with 2,805 herd mates in eastern and central South Dakota.

Procedure—11 trials were initiated at 9 sites from 1999 through 2001. For each trial, approximately 10% of cattle in each site's pasture group were identified, weighed, and administered a bolus of ivermectin (sustained-release formulation) prior to turnout. A similar subgroup of nontreated control cattle was identified and weighed prior to turnout. For each trial, treated and control groups remained with the larger pasture group throughout the entire grazing season. At the end of the grazing season, weight measurements and fecal samples were obtained from all treated and control cattle; average daily grazing gain was calculated and compared between these 2 groups.

Results—Treatment of grazing cattle with ivermectin increased average daily gain by 0.0459 ± 0.01 kg/head/d (mean ± SEM; 0.1 ± 0.02 lb/head/d), compared with that achieved in control cattle. Control cattle had significantly greater fecal egg counts at grazing season end than treated cattle.

Conclusions and Clinical Relevance—Compared with anthelmintic-treated cattle, yearling cattle with naturally occurring gastrointestinal nematode infestations kept on pasture in the US Northern Plains had a decreased average daily gain equivalent to 6.6 kg (14.5 lb) less gain in a 143-day grazing season. Strategies for control of nematode populations in pastures should be considered to ameliorate this production loss. (J Am Vet Med Assoc 2005;226:779–783)

Full access
in Journal of the American Veterinary Medical Association


Objective—To determine the spatiotemporal gait characteristics and associated covariates of clinically normal dogs and dogs with spinal cord disease.

Animals—42 clinically normal dogs and 24 dogs with myelopathy at spinal cord segment T3-L3.

Procedures—Gait was analyzed for velocity, stride length, stride time, stance time, and swing time and compared between groups with consideration of covariates, including height, weight, velocity, sex, and age.

Results—By use of multivariate regression, dogs with neurologic signs, compared with clinically normal dogs, had decreased stride time, stance time, and stride length in the forelimbs and increased swing time in the hind limbs.

Conclusions and Clinical Relevance—Use of spatiotemporal gait characteristics appears to have potential for use as an outcome measure for dogs with neurologic disease.

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in American Journal of Veterinary Research


To evaluate effectiveness of an allicin-based product in neonatal calves inoculated with Cryptosporidium parvum.


Randomized controlled study.


43 neonatal calves.


Calves were inoculated with 1.5 × l06 or 7.5 × 105 C parvum oocysts within 2 days after birth. Calves were given an allicin-based product once after inoculation or daily for 7 days after inoculation or were not treated. Calves that developed diarrhea were treated by administration of the product. Fecal consistency scores and weight gains were statistically evaluated.


Mean daily weight gain and severity of diarrhea in calves 4 to 21 days old were unaffected by prophylactic use of the product. However, intensive prophylactic administration may have delayed onset of C parvum-induced diarrhea in calves inoculated with the lower dose of oocysts.

Clinical Implications

Administration of an allicin-based product did not alter duration of C parvum-induced diarrhea or enhance weight gain in neonatal calves. However, intensive prophylactic administration of an allicin-based product may delay onset of diarrhea in calves exposed to C parvum oocysts. (J Am Vet Med Assoc 1998;212:987–990)

Free access
in Journal of the American Veterinary Medical Association