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Steven J. Sweeney

Publications and source records attributed to Steven J. Sweeney.

5 recordsLinked to original sources

Risk factors and productivity losses associated with Mycoplasma ovipneumoniae infection in United States domestic sheep operations

Association of Mycoplasma ovipneumoniae with pneumonia in domestic small ruminants has been described in Europe, Asia, and New Zealand but has received less attention in the United States. In 2011, the US Department of Agriculture’s National Animal Health Monitoring Survey detected M. ovipneumoniae shedding in 88% of 453 domestic sheep operations tested in 22 states that accounted for 85.5% of US ewe inventory in 2001. We evaluated factors associated with M. ovipneumoniae infection presence and prevalence, and we compared health, lamb production, and ewe losses in in-fected and uninfected operations. M. ovipneumoniae detection was more common in larger opera-tions than in smaller operations. Both likelihood of detection (at the operation level) and within-operation prevalence were higher in operations with more open management practices than in oper-ations with more closed management practices. M. ovipneumoniae-positive operations showed sig-nificantly lower lambing rates and lower rates of lamb survival to weaning after accounting for dif-ferences in operation size and management practice. While its effect on any single rate was not par-ticularly large, in aggregate we estimated that M. ovipneumoniae presence was associated with an approximately 4.3% reduction in annual lamb production.

Preventive Veterinary Medicine

Cross-species transmission potential between wild pigs, livestock, poultry, wildlife, and humans: Implications for disease risk management in North America

Cross-species disease transmission between wildlife, domestic animals and humans is an increasing threat to public and veterinary health. Wild pigs are increasingly a potential veterinary and public health threat. Here we investigate 84 pathogens and the host species most at risk for transmission with wild pigs using a network approach. We assess the risk to agricultural and human health by evaluating the status of these pathogens and the co-occurrence of wild pigs, agriculture and humans. We identified 34 (87%) OIE listed swine pathogens that cause clinical disease in livestock, poultry, wildlife, and humans. On average 73% of bacterial, 39% of viral, and 63% of parasitic pathogens caused clinical disease in other species. Non-porcine livestock in the family Bovidae shared the most pathogens with swine (82%). Only 49% of currently listed OIE domestic swine diseases had published wild pig surveillance studies. The co-occurrence of wild pigs and farms increased annually at a rate of 1.2% with as much as 57% of all farms and 77% of all agricultural animals co-occurring with wild pigs. The increasing co-occurrence of wild pigs with livestock and humans along with the large number of pathogens shared is a growing risk for cross-species transmission.

Scientific Reports

Tolazoline reversal of xylazine in bison (Bison bison): Mitigation of adverse effects

Tolazoline is a mixed alpha-1 and -2 adrenergic antagonist used to reverse the sedative, analgesic and muscle-relaxing effects of xylazine, a potent alpha adrenergic agonist. Tolazoline has been used in cattle and is superior to yohimbine, another alpha adrenergic antagonist, in this species. In white-tailed deer, tolazoline shortened recovery times and reversed xylazine-induced bradycardia, respiratory depression, and bloat following xylazine-ketamine anesthesia (Kreeger et al. 1986). We have used it for a number of years in moose without any detected adverse reactions. Caulkett et al. (2000) used tolazoline in wood bison to reverse the xylazine-induced effects of xylazine-tiletamine/zolazepam anesthesia and did not report any ill effects. However, the reported side effects of tolazoline in horses (species for which the drug was developed and is labeled) include abdominal discomfort, gastrointestinal hypermotility, diarrhea, tachycardia, ventricular dysrhythmia, hypertension and apprehensiveness.

Conference Paper

Effectiveness of Brucella abortus Strain 19 single calfhood vaccination in elk (Cervus elaphus)

Brucellosis in Greater Yellowstone Area (GYA) bison and elk has been a source of controversy and focus of the Greater Yellowstone Interagency Brucellosis Committee (GYIBC) for years. Brucellosis has been eradicated from cattle in the 3 states of Wyoming, Montana, and Idaho and all three states currently are classified as “brucellosis free” with regard to livestock. Yet free-ranging elk that attend feedgrounds in the GYA, and bison in Yellowstone and Grand Teton National Parks, still have high seroprevalence to the disease and are viewed as a threat to the state-federal cooperative national brucellosis eradication program. Recently, cattle in eastern Idaho were found infected with brucellosis and transmission was apparently from fed elk. The GYIBC, formed of state and federal agencies involved in wildlife and livestock management in the 3 states, has committed to eventual elimination of the disease from wildlife. Management tools to control or eliminate the disease are limited; however, wildlife vaccination is one of the methods currently employed. Effective wildlife vaccination depends on dose efficacy, deliverability, and safety to non-targeted species. We commenced a single-dose efficacy study of vaccine Brucella abortus strain 19 (S19) in elk in 1999.

Wyoming

Cloning, sequencing, and expression of interferon-γ from elk in North America

Eradication of Mycobacterium bovis relies on accurate detection of infected animals, including potential domestic and wildlife reservoirs. Available diagnostic tests lack the sensitivity and specificity necessary for accurate detection, particularly in infected wildlife populations. Recently, an in vitro diagnostic test for cattle which measures plasma interferon-gamma (IFN-γ) levels in blood following in vitro incubation with M. bovis purified protein derivative has been enveloped. This test appears to have increased sensitivity over traditional testing. Unfortunately, it does not detect IFN-γ from Cervidae. To begin to address this problem, the IFN-γ gene from elk ( Cervus elaphus ) was cloned, sequenced, expressed, and characterized. cDNA was cloned from mitogen stimulated peripheral blood mononuclear cells. The predicted amino acid (aa) sequence was compared to known sequences from cattle, sheep, goats, red deer ( Cervus elaphus ), humans, and mice. Biological activity of the recombinant elk IFN-γ (rElkIFN-γ) was confirmed in a vesicular stomatitis virus cytopathic effect reduction assay. Production of monoclonal antibodies to IFN-γ epitopes conserved between ruminant species could provide an important tool for the development of reliable, practical diagnostic assays for detection of a delayed type hypersensitivity response to a variety of persistent infectious agents in ruminants, including M. bovis and Brucella abortus . Moreover, development of these reagents will aid investigators in studies to explore immunological responses of elk that are associated with resistance to infectious diseases.

Journal of Wildlife Diseases