Congenital cardiac defects in neonatal foals: 18 cases (1992-2007).
BACKGROUND
Literature available regarding congenital cardiac defects in foals is limited to reports of individual cases or small case series.


OBJECTIVE
To describe the clinical, echocardiographic, and necropsy findings and breed predilection of congenital cardiac defects in neonatal foals.


METHODS
Eighteen foals < 15 days of age with 1 or more congenital cardiac defects.


METHODS
Medical records of foals diagnosed with congenital cardiac defects at the William R. Pritchard Veterinary Medical Teaching Hospital were reviewed. Data collected included history, signalment, clinical signs, laboratory data, diagnostic and necropsy results, and outcome.


RESULTS
Arabian foals represented 39% of cases with congenital cardiac defects and were significantly (P = .004) overrepresented (OR = 4.7 [CI: 1.8-12.4]) compared with the general hospital population. Ventricular septal defect (VSD) (14/18), tetralogy of Fallot (5/18), and tricuspid valve atresia (4/18) were the most common defects identified. A > or = 3/6 heart murmur (14/ 14) accompanied by tachycardia (14/17), tachypnea (17/17), and cyanosis of mucous membranes (7/16) were the most common clinical signs. Concurrent congenital defects were common (9/18). Two foals, both with VSD, survived for > or = 8 years after diagnosis and 1 was a successful performance horse.


CONCLUSIONS
Arabian horses appear to have a predisposition for cardiac defects. The presence of a loud murmur (> or = 3/6), cyanotic membranes, and tachycardia or tachypnea in a neonatal foal should warrant thorough evaluation of the heart for congenital defects. Foals with cardiac defects should be closely evaluated for concurrent congenital defects in other body systems.
Hall
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William R. Pritchard Veterinary Medical Teaching Hospital School of Veterinary Medicine, University of California Davis, One Shields Drive, 2108 Tupper Hall, Davis, CA 95616, USA.
Magdesian
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Kittleson
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D000818:Animals; D000831:Animals, Newborn; D005260:Female; D020022:Genetic Predisposition to Disease; D006330:Heart Defects, Congenital / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D006734:Horse Diseases / Q000151:congenital* / Q000235:genetics; D006736:Horses; D008297:Male; D009206:Myocardium / Q000473:pathology; D012189:Retrospective Studies