Kilcoyne I, Magdesian KG, Guerra M, Dechant JE, Spier SJ, Kass PH. Prevalence of and risk factors associated with Salmonella shedding among equids presented to a veterinary teaching hospital for colic (2013-2018).
Equine Vet J 2022;
55:446-455. [PMID:
35861656 DOI:
10.1111/evj.13864]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/10/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND
Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms.
OBJECTIVES
The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic.
STUDY DESIGN
Retrospective case-control study.
METHODS
For each colic case that was positive for Salmonella (n=56), two colic cases (n=112) that tested negative for Salmonella, were enrolled as controls. Associations between variables and Salmonella shedding were identified using logistic regression. Univariate and multivariable models were developed pertaining to 1) presenting clinicopathological data and 2) clinical variables that developed during hospitalisation.
RESULTS
Of the equids presenting with colic, 1585/1917 had a sample submitted for Salmonella testing. Of these, 56 were positive for Salmonella yielding a prevalence of 3.5%. Equids shedding Salmonella were more likely to present in July (OR=7.2, 95% CI=1.63-32.13, p=0.009) and present with a history of fever (OR=53.5; 95% CI=2.57-1113.03; p=0.01), increased lactate (OR=1.6; 95% CI=1.14-2.29; p=0.007) and/or neutropenia (OR=0.79; 95% CI=0.65-0.97; p=0.02). Hospitalised equids shedding Salmonella were more likely to be febrile (OR=4.8; 95% CI=1.47-15.8; p=0.01) and 10 times more likely to develop reflux (OR=10.1; 95% CI=1.67-61.43; p=0.01) compared to colic controls.
MAIN LIMITATIONS
Retrospective nature of the study and bias inherent to the retrieval of data from medicals records cannot be discounted. Classifying Salmonella status based on a single sample may have resulted in misclassification bias.
CONCLUSIONS
The prevalence of Salmonella shedding in this colic population was low compared to earlier reports. Certain predictors such as the development of a fever or reflux in hospitalised colic cases were associated with Salmonella shedding and may help the clinician to promptly identify horses likely to shed, thus helping institute effective use of barrier nursing precautions.
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