Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Clinical Science
Non Technical Summary
Salmonella is a leading cause of equine colitis affecting both mature horses and foals. In neonatal foals, Salmonella infection often results in life threatening septicemia in addition to diarrhea. Individual cases of salmonellosis with severe gastrointestinal and systemic disease have been described in camelids but to date, no outbreaks have been documented in North American camelid populations. Importantly, Salmonella is a zoonotic agent causing serious gastrointestinal illness, especially in immuno-compromised people, the elderly and infants. Nosocomial infections with Salmonella spp. have been described among hospitalized equine populations more frequently than any other agent and occurred in the Cornell University Hospital for Animal Equine Farm Animal Hospital (CUHA EFAH) during 2007 and 2008. Nosocomial infections are a serious threat to optimum patient care and can have far-reaching consequences for the personnel and the financial aspects of the hospital. Salmonella organisms are shed in high numbers in the feces of an infected patient. However, there is also the ?carrier state?, where an animal is clinically normal but may be shedding Salmonella in its feces and be infective to other animals and people. In the past, the prevalence of sub-clinical Salmonella shedding in the general US equine population has been estimated at between 1 and 5%. Salmonella ?carrier states? and outbreaks in camelids have not previously been published. In other geographical areas (California and Oregon), prevalence has been found to be very low to zero. However, from our medical records during 2007, several camelids were positive for Salmonella, both asymptomatic and those affected with gastrointestinal illness. We wish to build upon the preliminary information stated above. To the authors? knowledge, the prevalence of Salmonella infection in foals, crias and their respective dams in New York State and the surrounding area has not been previously investigated. Firstly, in light of the recent Salmonella ?outbreak? in the CUHA EFAH, our objective is to screen animals in their home environments to investigate the prevalence of Salmonella positive foals, crias and their dams in the region. In completing this study, we also aim to identify any farms with Salmonella positive animals. Identification of risk factors associated with these farms would help advise owners and managers about changes that could be made to reduce the risk of Salmonella infections. Short-term goals are firstly to improve the control of Salmonella among these species via identification of prevalence and potential risk factors in the study population. Long-term we aim to be able to generalize these results to broader external populations. Future studies anticipated include characterizing the molecular epidemiology via genotyping of Salmonella isolates obtained. This may highlight transmission patterns and potential zoonotic relationships. Both fecal samples and Salmonella isolates will be banked for future PCR and genotyping.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The objectives of this study are to: 1) determine the frequency of Salmonella infections, 2) describe its occurrence, and 3) elucidate risk factors so that control measures can be recommended to equine and camelid owners.
Project Methods
A. Experimental design: An observational cross-sectional study. 1.Identify broodmare and alpaca breeding farms in New York State. 2.Generate a questionnaire to establish potential risk factors associated with Salmonella infection. 3.Collect fecal samples from foals, crias and their respective dams from the selected farms. 4.Perform Salmonella fecal cultures on these samples at the New York State Animal Health Diagnostic Center (New York State AHDC). 5.Determine the best estimate for the proportion of horses and camelids in New York State with Salmonella positive fecal samples. 6.Determine any relationship of Salmonella positive animals to risk factors identified e.g. frequent on and off farm animal, farm biosecurity practices. B. Experimental methods: 1. Case selection. a) Foals and Crias 1 - 30 days of age and their respective dams. i) Health would be determined by owner questionnaire and a physical examination performed by Dr Burton or Dr Mitchell. ii) Farms will be selected from the CUHA EFAH client and referring veterinarian database, local contacts and breeder association directories (e.g. New York Breeding and Racing Program, Standardbred Owners Association of New York, New York State Horse Breeders Association, Empire Alpaca Association). iii) Total samples collected and cultures will be 250 each species (125 foals plus 125 mares and 125 crias plus 125 dams). 3. Sample procurement: sample from crias and foals will be obtained directly by digital rectal stimulation, as it is often difficult to identify the manure of young foals and crias in stall bedding. Samples from the adult dams will be obtained fresh from the ground of the individual stall environment. As Salmonella and other pathogens in feces are zoonotic, examination gloves will be worn when fecal samples are collected and the samples securely contained. 4. Salmonella culture: Will be performed at the New York State AHDC laboratory, which has extensive experience with culturing feces for Salmonella spp. 5. Statistical analysis: We will carry out a fecal shedding prevalence survey using a two-stage probability proportional to size sampling design. A two-stage design will be used because an adequate sampling frame at the individual foal/cria level does not exist in NYS. The NYS Department of Agriculture and Markets does however keep a census of horse farms that will enable us to create a sampling frame at the herd level from which we well attempt to choose our sample randomly, but will likely also include some convenience sampling. In the first stage, a sample of the brood mare farms in NYS will be selected proportional to the number of mares - one with a greater number of horses being more likely to be selected. In the second stage, a fixed number of foals/crias and mares/dams from each herd will be selected by simple random sampling. This is possible because we will contact the farms selected from the first stage to obtain a listing of their eligible animals. This design will allow for a more accurate estimate of the fecal shedding prevalence than other designs for a given sample size.