Pentalogy of Fallot in a Crioulo Foal
DOI:
https://doi.org/10.22456/1679-9216.84706Abstract
Background: Cardiac anomalies account for 3.5% of congenital defects in horses. Tetralogy of Fallot (TOF) is characterized by ventricular septal defect, pulmonary stenosis, dextroposition the aorta and right ventricular hypertrophy secondary.Pentalogy of Fallot (POF) is a variation and is characterized by a defect in the right atrioventricular valve or persistence of the ductus arteriosus, in addition to the other defects observed in tetralogy. Affected animals usually have stunted growth,exercise intolerance, weakness, lethargy, cyanosis, dyspnea and syncope. The aim of this study was to describe a case of POF, as diagnosed in a Crioulo foal in southern Brazil.
Case: Clinical signs were observed at the ffth day of life and were characterized by cyanosis, intense tracheal stertor, tachycardia, marked heart murmur, HR 160 bpm, RR 80 breaths/min, T 39.8°C and syncope. These signs worsened with physical activity. Endoscopic evaluation of the upper airways revealed no anatomical conformation changes or tissue dys
function. A cardiac ultrasound showed a loss of continuity of the interventricular septum, right ventricular wall thickening, and a hyperechoic appearance of the area where the right atrioventricular valve (tricuspid) should be. The crises have become more severe and more frequent, the animal began to show signs of ischemia, such as loss of motor coordination and limited mobility. The foal died at 15 days old. At necropsy the liver was congested and had a nutmeg appearance, there was foam in the trachea, and the lungs were edematous. There was hydropericardium, and the heart was increased in size with a globoid shape. The heart had thickening of the walls of the right and left ventricle and pulmonary artery stenosis. There was also an oval orifce 2.5 cm in diameter in the interventricular septum connecting the ventricles (ventricular sep
tal defect), an overriding aorta and aplasia of the tricuspid valve. Histologically the liver had centrilobular to mediozonal necrosis, and there was pulmonary edema and congestion.
Discussion: The diagnosis of pentalogy of Fallot was based on the clinical signs, the ultrasound results and the macroscopic lesions observed at necropsy. Tetralogy of Fallot is one of the most common congenital cardiac malformations observed in horses, however, in a study of congenital malformations in this species, only 3.5% had cardiac malformations out of
the 608 foals examined. The prevalence of heart defects in horses compared with other domestic species is relatively low (0.1% - 0.5%). In this case, the malformation was probably sporadic because the foal was the only animal to be born with this malformation on the farm. In the Crioulo breed, congenital defect reports are scarce. In a retrospective study of equine diseases in southern Brazil over a period of 35 years, malformations were not observed in 708 horses of this breed, which
is the predominant breed in the region. In the present case, the fact that the mare had another three healthy foals with the same stallion reduces the possibility that this was a case of hereditary origin. It is likely that this case is of a sporadic nature with no chance of determining the cause. The differential diagnoses in animals with lethargy, cyanosis, and exercise
intolerance or syncope include complicated or multiple cardiac defects. There are no previous reports of TOF and POF in the Crioulo breed in Brazil.
Keywords: Pentalogia de Fallot, cardiac ultrasound, cardiac malformation, horse.
Downloads
References
Amorim S., Cuz C., Macedo F., Bastos P.T. & Gonçalves F.R. 2005. Tetralogia de Fallot: Factores de Prognóstico após Cirurgia de Correção. Revista Portuguesa de Cardiologia. 24(6): 845-855.
Bailliar F. & Anderson R.H. 2009. Tetralogy of Fallot. Orphanet Journal of Rare Diseases. 4(2): 1-10.
Bayly W.M., Reed S.M., Leathers C.W., Brown C.M., Traub J.L., Paradis M.R. & Palmer G.H. 1982. Multiple congenital heart anomalies in fve Arabian foals. Journal of the American Veterinary Medical Association. 181(7): 684-689.
Besser T.E. & Knowlen G.G. 1992. Ventricular septal defects in bovine twins. American Journal of Veterinary Research. 200: 1355- 1356.
Cargile J., Lombard C., Wilson J.H. & Buergelt C.D. 1991. Tetralogy of Fallot and segmental uterine aplasia in a three-year-old morgan flly. Cornell Veterinarian. 81(4): 411-418.
Hall T.L., Magdesian K.G. & Kittleson M.D. 2010. Congenital cardiac defects in neonatal foals: 18 cases (1992-2007). Journal of Veterinary Internal Medicine. 24: 206-212.
Larsson M.H.M.A., Pereira L., Jatene F.B., Freitas R.F., Barbusci L.O.D., Oliveira S.M. & Abduch M.C.D. 2000. Clinical diagnosis and alternative surgical treatment of tetralogy of Fallot in a dog. A case report. Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 52(5): 433-436.
Marcolongo-Pereira C., Estima-Silva P., Soares M.P., Sallis E.S.V., Grecco F.B., Fernandes C.G., Raff M.B. & Schild A.L. 2014. Doenças de equinos na região Sul do Rio Grande do Sul. Pesquisa Veterinária Brasileira. 34(3):205-210.
Pazzi P., Lim C.K. & Steyl J. 2014. Tetralogy of Fallot and atrial septal defect in a white Bengal Tiger cub (Pantheratigris tigris). Acta Veterinaria Scandinavica. 56: 12.
Rahal C., Collatos C., Solano M. & Bildfell R. 1997. Pentology of Fallot, renal infarction and renal abscess in a mare. Journal of Equine Veterinary Science. 17(11): 604-607.
Vitums A. & Bayly W.M. 1982. Pulmonary atresia with dextroposition of the aorta and ventricular septal defect in three Arabian foals. Veterinary Pathology. 19(2): 160-168.
Published
How to Cite
Issue
Section
License
This journal provides open access to all of its content on the principle that making research freely available to the public supports a greater global exchange of knowledge. Such access is associated with increased readership and increased citation of an author's work. For more information on this approach, see the Public Knowledge Project and Directory of Open Access Journals.
We define open access journals as journals that use a funding model that does not charge readers or their institutions for access. From the BOAI definition of "open access" we take the right of users to "read, download, copy, distribute, print, search, or link to the full texts of these articles" as mandatory for a journal to be included in the directory.
La Red y Portal Iberoamericano de Revistas Científicas de Veterinaria de Libre Acceso reúne a las principales publicaciones científicas editadas en España, Portugal, Latino América y otros países del ámbito latino