Pentalogy of Fallot in a Korean Sapsaree Dog

Abstract

ABSTRACT. A 5-month-old female Korean Sapsaree dog was presented with severe ascites, cyanosis, respiratory difficulty and exercise intolerance. Diagnostic imaging studies revealed a dextropositioned and over-riding aorta, pulmonary valvular stenosis, ventricular and atrial septal defects, and right ventricular hypertrophy. Based on these findings, the dog was diagnosed as a case of tetralogy of Fallot with atrial septal defect (pentalogy of Fallot). The dog was medically managed by use of diuretics and vasodilators and an occasional phlebotomy. KEY WORDS: congenital heart disease, Korean Sapsaree, pentalogy of Fallot.J. Vet. Med. Sci. 69(1): 73-76, 2007 Tetralogy of Fallot (TOF) is a rare complex congenital cardiac defect characterised by a ventricular septal defect (VSD) with an overriding aorta, pulmonic stenosis (PS) and right ventricular hypertrophy. In dogs, TOF is rare (0.25/ 1000 dogs examined) [9]. In cats, TOF has also been rarely reported [4]. However, the actual prevalence may be higher than has been reported previously, because severely affected animals commonly die at a young age before having been thoroughly examined [7].Pentalogy of Fallot (POF) is a more complex congenital cardiac malformation characterised by TOF with either an atrial septal defect (ASD) or patent foramen ovale [12]. It also occurs in association with right aortic arch abnormalities or coronary arterial abnormalities in humans [3]. Increased resistance to right ventricular outflow tract (RVOT), caused by PS, result in R-L shunting of venous blood (responsible for cyanosis). Moreover RVOT obstruction, caused by PS and accounting for RV pressure overload and subsequent RV (right ventricle) hypertrophy, will contribute to the R-L (right to left) shunting.Several genetic aetiologies including Jagged-1 [5], NKX2-5 (NK2 transcription factor) [6] and ZFPM2 (zinc finger protein multitype 2) [11] have been identified in human TOF. Autosomal recessive inheritance and a possible genetic aetiology have been observed with TOF in Keeshond dogs [10,15], as this breed had been intentionally inbred. Further pedigree and clinical studies of family members is warranted to clarify a genetic etiology.A 5-month-old intact female Sapsaree (9.5 kg, Korean native dog), was presented at the Veterinary Teaching Hospital, Kangwon National University with signs of severe dyspnea, ascites, exercise intolerance and cyanosis. On thoracic auscultation, a grade V/VI holosystolic murmur was heard at the left and right apical region of the heart with a precordial thrill.On the day of presentation, electrocardiographic studies showed a sinus tachycardia (120 beats per min) with right axis deviation (+120°) of an abnormal QRS-complex with S-waves in leads I, II, III, indicating right ventricular hypertrophy (Fig. 1). No significant abnormalities were observed in routine hematology and blood chemistry except polycythemia (58% of packed cell volume; normal range: 37-55%). Radiographic studies of the thoracic and abdominal cavities revealed a global shaped cardiac ...

Tetralogy of Fallot and atrial septal defect in a white Bengal Tiger cub (Panthera tigris tigris)

“…Failure to identify the ASD on echocardiography was most likely due to the small size of the ASD while the absence of obvious shunting between the two chambers on colour flow Doppler was likely due to the equalisation of pressures between atria. The pulmonary outflow pressure in this cub was mildly increased compared to the previously reported value in the Korean Sapsaree dog also diagnosed with TOF and ASD [13]. The ventricular right-to-left shunt velocity measured in the Tiger cub may have included the left ventricular outflow tract due to the concomitant overriding aorta and could have resulted in a measured shunt velocity that is not a true reflection.…”

“…The ventricular right-to-left shunt velocity measured in the Tiger cub may have included the left ventricular outflow tract due to the concomitant overriding aorta and could have resulted in a measured shunt velocity that is not a true reflection. Interestingly the right-to-left shunt velocity was of lower velocity than reported for the Korean Sapsaree dog [13], possibly related to the size of the VSD’s. The authors recommend if the classic findings of a TOF are diagnosed, it is advised to thoroughly exclude the possibility of a PDA or ASD to ensure the diagnosis of a POF is not missed.…”

“…Concurrent developmental abnormalities in addition to those causing TOF lead to ASD or PDA and resultant POF. TOF with ASD is a very rare condition and has been reported in only 2 animal species as sporadic individual case reports [13,17]. The white colour of Bengal Tigers is due to a recessive trait with selective inbreeding in captivity often encouraging the expression of recessive traits, and although TOF has not been associated with Bengal or white Tigers to date, abnormalities of the visual pathways have been associated with white Tigers [26].…”

“…Pentalogy of Fallot (POF) is a rare variant of the relatively more common TOF, comprising the aforementioned four classic features of TOF with an additional atrial septal defect (ASD) or patent ductus arteriosus (PDA). POF has previously been described in three dogs [12-14], two horses [15,16], a ram [17] and as a necropsy finding in a two-year-old Siberian Tiger [18], however, of these reports, only a Korean Sapsaree dog [13] and the Siberian Tiger [17] have been diagnosed exclusively with TOF and an ASD.…”

Surgical Interventions of Common Congenital Heart Defects in Dogs: A Comprehensive Review

“…Diagnostic imaging may show a dextropositioned and over-riding aorta, pulmonary valvular stenosis, ventricular and atrial septal defects, and right ventricular hypertrophy [45] . Conservative treatment includes diuretics, ß-blockers, and angiotensin-convertingenzyme inhibitor for relieving clinical symptoms.…”