Prevalence and Risk Factors for Cardiac Diseases in a Hospital‐Based Population of 3,434 Horses (1994–2011)

Abstract

Background: Risk factors for cardiac diseases in horses have not been explored in a large population of animals. Objectives: To describe risk factors for various cardiac diseases in a hospital-based population of horses. Animals: Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease.Methods: Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chisquare test) or sex, age, body weight (BW), and other cardiac diseases (logistic regressions) were risk factors (p < .05 significant).Results: Mitral regurgitation (MR, 4.4%), atrial fibrillation (AF, 2.3%), aortic regurgitation (AR, 2.1%), and tricuspid regurgitation (TR, 1.7%) were the most common cardiac abnormalities detected. Determinants were male sex and increasing age for AR (OR = 2.03, CI = 1.07-4.94), racehorses breed and middle-age for TR (OR = 4.36; CI = 1.10-17.24), and high BW for AF (OR = 3.54; CI = 1.67-7.49). MR was the most common valvular disease associated with AF, clinically important ventricular arrhythmia, pulmonary regurgitation (PR), and congestive heart failure (CHF). TR was also associated with AF, PR, and CHF; AR was not associated with CHF.Conclusions and Clinical Importance: Several previously suspected risk factors for a variety of equine cardiac diseases are statistically confirmed and other risk factors are highlighted in the studied hospital-based population. These observations should be taken into account in health and sport's monitoring of horses presenting predisposing factors.

Horse: anaesthetic management for open castration of a Belgian draught horse with interventricular septum defect, aortic regurgitation and ventricular premature depolarisations

“…On the other hand, conditions such as hypocapnia, alkalaemia, spontaneous ventilation or deep anaesthesia can decrease pulmonary vascular resistance (PVR), which will increase the shunt fraction (Perkowski and Oyama 2015). Often, as in the current case, the functional size of the VSD is reduced by prolapse of the aortic valve into the defect, leading to aortic regurgitation (Leroux and others 2013, Reef and others 2014). This condition may lead to chronic left ventricular volume overload, which can result in myocardial hypoxaemia and arrhythmias.…”

Diagnostic value of noninvasive pulse pressure measurements in Warmblood horses with aortic regurgitation

“…Older horses were overrepresented in the AR group; similar results have been reported in previous studies investigating the epidemiology of AR in horses. 2,3,6 The effect of age (independent of AR) on PP is unknown in horses, although in human patients PP is reported to increase with age, as a result of vascular stiffness leading to increased SAP. 45 A much larger study population with individuals of various ages would be required to investigate any association between age and PP in horses.…”

Clinical Approach to Commonly Encountered Problems

“…229,230 In particular, in left-sided heart failure, blood is not effectively pumped from the left side of the heart, leading to increased blood in the pulmonary circulation and increased pulmonary vascular pressure. 229,230 In particular, in left-sided heart failure, blood is not effectively pumped from the left side of the heart, leading to increased blood in the pulmonary circulation and increased pulmonary vascular pressure.…”

“…257 Several other upper airway abnormalities have been documented, such as fourth branchial arch defect, subepiglottic cyst, aryepiglottic fold entrapment, and dorsal displacement of the soft palate. 229,230 Respiratory distress is a prominent sign of a rare form of pyrollizidine alkaloid toxicity associated with Crotolaria equorum. 302,303 Infrequently, laryngeal paralysis has been associated with hepatic dysfunction.…”