ATRIAL-FIBRILLATION ASSOCIATED WITH CENTRAL NERVOUS SYMPTOMS AND COLIC IN A HORSE - A CASE OF EQUINE CARDIOMYOPATHY

A 18-year-old Dutch Warmblood mare was referred for colic. Upon arriva l, lethargy, blindness, head pressing, ataxia, and circling were the m ain clinical signs. On rectal examination a hard mass and oedema aroun d the cranial mesenteric artery were palpated. Plasma liver enzyme act ivities and the ammonia level were elevated. Atrial fibrillation with a pulse frequency of 36-52 beats per minute was noticed. On both sides a holosystolic murmer with the maximum intensity on the right side co uld be auscultated. Postmortem examination revealed eccentric hypertro phy of the right atrium and a pale spotted myocardium, most prominentl y of the right ventricle, with secondary venous congestion of the azyg os and mesenteric veins. The liver changes were indicative of chronic congestion. Despite the normal pulse rate, it appeared that congestive heart failure due to cardiomyopathy, was responsible for the presenti ng symptoms of this patient.