Spatial associations among density of cattle, abundance of wild canids, and seroprevalence to Neospora caninum in a population of beef calves
- 1 November 2000
- journal article
- Published by American Veterinary Medical Association (AVMA) in Journal of the American Veterinary Medical Association
- Vol. 217 (9), 1361-1365
- https://doi.org/10.2460/javma.2000.217.1361
Abstract
Objective—To determine the epidemiologic plausibility of a sylvatic transmission cycle for Neospora caninum between wild canids and beef cattle. Design—Spatial analysis study. Animals—1,009 weaned beef steers from 94 beef herds in Texas. Procedure—Calves were grouped on the basis of seroprevalence for N caninum and ecologic region in Texas. The Morans I test was used to evaluate spatial interdependence for adjusted seroprevalence by ecologic region. Cattle density (Number of cattle/259 km2 [Number of cattle/100 mile2] of each ecologic region) and abundance indices for gray foxes and coyotes (Number of animals/161 spotlight-transect [census] km [Number of animals/100 census miles] of each ecologic region) were used as covariates in spatial regression models, with adjusted seroprevalence as the outcome variable. A geographic information system (GIS) that used similar covariate information for each county was used to validate spatial regression models. Results—Spatial interdependence was not detected for ecologic regions. Three spatial regression models were tested. Each model contained a variable for cattle density for the ecologic regions. Results for the 3 models revealed that seroprevalence was associated with cattle density and abundances of gray foxes, coyotes, or both. Abundances of gray foxes and coyotes were collinear. Results of a GIS-generated model validated these spatial models. Conclusions and Clinical Relevance—In Texas, beef cattle are at increased risk of exposure to N caninum as a result of the abundance of wild canids and the density of beef cattle. It is plausible that a sylvatic transmission cycle for neosporosis exists. (J Am Vet Med Assoc 2000;217:1361–1365)This publication has 17 references indexed in Scilit:
- Oral infection of calves with Neospora caninum oocysts from dogs: humoral and cellular immune responsesInternational Journal for Parasitology, 1999
- High prevalence of antibodies to Neospora caninum in white-tailed deer (Odocoileus virginianus)International Journal for Parasitology, 1999
- Confirmation that the dog is a definitive host for Neospora caninumVeterinary Parasitology, 1999
- Rapid communicationInternational Journal for Parasitology, 1998
- Direct agglutination test for serologic diagnosis of Neospora caninum infectionZeitschrift Fur Parasitenkunde-Parasitology Research, 1997
- Examination of red foxes (Vulpes vulpes) from Belgium for antibody to Neospora caninum and Toxoplasma gondiiVeterinary Record, 1997
- A review of Neospora caninum and neosporosisVeterinary Parasitology, 1996
- Systemic Neosporosis in a California Black-Tailed Deer (Odocoileus Hemionus Columbianus)Journal of Veterinary Diagnostic Investigation, 1994
- Neosporosis-Like Abortions in a Herd of Dairy CattleJournal of Veterinary Diagnostic Investigation, 1989
- Spatial Data Analysis of Regional CountsBiometrical Journal, 1989