Search Results

You are looking at 21 - 26 of 26 items for

  • Author or Editor: Michael P. Ward x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

A method of extracting bacterial dna from swine feces was developed and used in a molecular assay for the presence of ileal symbiont (is) intracellularis, formerly known as the Campylobacter-like organism associated with swine with proliferative enteritis. Hybridization with a digoxigenin-labeled, is intracellularis-specific probe detected the presence of is intracellularis at a concentration of 107 organisms/g of feces. This method was sufficient to detect is intracellularis in the feces of swine with experimentally induced and naturally acquired infection. Results of the hybridization were in agreement with those from histologic postmortem examination.

Free access
in American Journal of Veterinary Research

Summary

In an abattoir-based case-control study, histologic, and macroscopic examination of porcine intestines at slaughter and 2 molecular assays were compared for use as diagnostic tests of proliferative enteritis (pe). Fecal samples and intestinal specimens were collected from pigs with grossly thick ileum and from clinically normal pigs at slaughter. Tissue specimens were fixed in neutral buffered 10% formalin, and sectioned. Sections stained with H&E were examined for proliferative lesions by a pathologist unaware of the group to which the pig had been assigned on the basis of results of gross examination. Adjacent tissue sections, stained with Warthin-Starry (silver) stain, were examined for presence of the intracellular bacterium of pe, ileal symbiont (is)-intracellularis, in the enterocytes of the intestinal crypts by the senior author, who was unaware either of the group to which the pig had been assigned or diagnosis by the pathologist. Bacterial DNA was extracted from the fecal samples and assayed by dot-blot hybridization and polymerase chain reaction (pcr) for presence of is-intracellularis dna, without knowledge of results of the other examinations. The pcr assay for is-intracellularis was a specific and sensitive diagnostic test for pe, and dot-blot hybridization was sensitive, but was less specific. Macroscopic examination of intestines at slaughter was a sensitive, but not specific, test.

Association between is-intracellularis and proliferative lesions was statistically examined in the same study. There was a highly significant (P = 0.0078) association between presence of naturally acquired proliferative lesions and intracellular infection induced by is-intracellularis. The odds ratio of ≥ 14 and estimated attributable fraction of ≥ 92% indicate that is-intracellularis may be a necessary cause of pe.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To describe an outbreak of encephalomyelitis caused by West Nile virus (WNV) in horses in northern Indiana.

Design—Case series.

Animals—170 horses.

Procedure—Horses with clinical signs suggestive of encephalomyelitis caused by WNV were examined. Date, age, sex, breed, and survival status were recorded. Serum samples were tested for anti-WNV antibodies, and virus isolation was attempted from samples of brain tissue. Climate data from local weather recording stations were collected. An epidemic curve was constructed, and case fatality rate was calculated.

Results—The most common clinical signs were ataxia, hind limb paresis, and muscle tremors and fasciculations. Eight horses had been vaccinated against WNV from 2 to 21 days prior to the appearance of clinical signs. West Nile virus was isolated from brain tissue of 2 nonvaccinated horses, and anti-WNV IgM antibodies were detected in 132 nonvaccinated horses; in 2 other nonvaccinated horses, anti-WNV antibodies were detected and WNV was also isolated from brain tissue. Thirty-one (22.8%) horses died or were euthanatized. The peak of the outbreak occurred on September 6, 2002. Ambient temperatures were significantly lower after the peak of the outbreak, compared with prior to the peak.

Conclusions and Clinical Relevance—The peak risk period for encephalomyelitis caused by WNV in northern Indiana was mid-August to mid-September. Reduction in cases coincided with decreasing ambient temperatures. Because of a substantial case fatality rate, owners of horses in northern Indiana should have their horses fully protected by vaccination against WNV before June. In other regions of the United States with a defined mosquito breeding season, vaccination of previously nonvaccinated horses should commence at least 4 months before the anticipated peak in seasonal mosquito numbers, and for previously vaccinated horses, vaccine should be administered no later than 2 months before this time. (J Am Vet Med Assoc 2004;225:84–89)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine incidence rates and potential risk factors for vaccine-associated adverse events (VAAEs) diagnosed within 3 days of administration in dogs.

Design—Retrospective cohort study.

Animals—1,226,159 dogs vaccinated at 360 veterinary hospitals.

Procedure—Electronic records from January 1, 2002, through December 31, 2003, were searched for possible VAAEs (nonspecific vaccine reaction, allergic reaction, urticaria, or anaphylaxis) diagnosed within 3 days of vaccine administration. Information included age, weight, sex, neuter status, and breed. Specific clinical signs and treatments were reviewed in a random sample of 400 affected dogs. The association between potential risk factors and a VAAE was estimated by use of multivariate logistic regression.

Results—4,678 adverse events (38.2/10,000 dogs vaccinated) were associated with administration of 3,439,576 doses of vaccine to 1,226,159 dogs. The VAAE rate decreased significantly as body weight increased. Risk was 27% to 38% greater for neutered versus sexually intact dogs and 35% to 64% greater for dogs approximately 1 to 3 years old versus 2 to 9 months old. The risk of a VAAE significantly increased as the number of vaccine doses administered per office visit increased; each additional vaccine significantly increased risk of an adverse event by 27% in dogs ≤ 10 kg (22 lb) and 12% in dogs > 10 kg.

Conclusions and Clinical Relevance—Young adult small-breed neutered dogs that received multiple vaccines per office visit were at greatest risk of a VAAE within 72 hours after vaccination. These factors should be considered in risk assessment and risk communication with clients regarding vaccination. (J Am Vet Med Assoc 2005;227:1102–1108)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate clinical findings, complications, and outcome of horses and foals with third metacarpal, third metatarsal, or phalangeal fractures that were treated with transfixation casting.

Design—Retrospective case series.

Animals—29 adult horses and 8 foals with fractures of the third metacarpal or metatarsal bone or the proximal or middle phalanx.

Procedures—Medical records were reviewed, and follow-up information was obtained. Data were analyzed by use of logistic regression models for survival, fracture healing, return to intended use, pin loosening, pin hole lysis, and complications associated with pins.

Results—In 27 of 35 (77%) horses, the fracture healed and the horse survived, including 10 of 15 third metacarpal or metatarsal bone fractures, 11 of 12 proximal phalanx fractures, and 6 of 8 middle phalanx fractures. Four adult horses sustained a fracture through a pin hole. One horse sustained a pathologic unicortical fracture secondary to a pin hole infec-tion. Increasing body weight, fracture involving 2 joints, nondiaphyseal fracture location, and increasing duration until radiographic union were associated with horses not returning to their intended use. After adjusting for body weight, pin loosening was associated with di-aphyseal pin location, pin hole lysis was associated with number of days with a transfixation cast, and pin complications were associated with hand insertion of pins.

Conclusions and Clinical Relevance—Results indicated that transfixation casting can be successful in managing fractures distal to the carpus or tarsus in horses. This technique is most suitable for comminuted fractures of the proximal phalanx but can be used for third metacarpal, third metatarsal, or middle phalanx fractures, with or without internal fixation.

Full access
in Journal of the American Veterinary Medical Association