Canine heart worm disease is often life-threatening due to its various complications, including right side heart failure, caval syndrome and pulmonary eosinophilic granulomatosis. Several preventive medications and melarsomine have been developed and they are very effective to control heartworm infestation. However, in a case of severe infestation, melarsomine therapy often results in an unfavorable outcome because of the severe immune reaction caused by rapid killing of the adult worm. Surgical removal and an interventional method using flexible alligator forceps have been well described in the literature. Despite the usefulness of mechanical removal using flexible alligator forceps, the methodology still needs to be upgraded for increasing the applicability for treating dogs with severe infestation. We describe herein a newly developed percutaneous removal method for heartworms and this was successfully applied to 4 dogs with severe heartworm infestation. The follow-up studies also showed favorable outcomes with no complications.

Objective: To evaluate the efficacy and safety of biphasic (BP) defibrillation in toy breed dogs (<5 kg of body weight). Design: Prospective, clinical experimental study. Setting: Veterinary teaching hospital. Animals: Five dogs (pilot study) and 10 dogs (comparison study of biphasic versus monophasic defibrillation). Measurements and main results: The efficacy of defibrillation was compared by estimating E80 (80% probability of successful defibrillation) after biphasic (BP) and monophasic (MP) defibrillations. The E80 for BP defibrillation was 7.24±1.33 J (2.24±0.41 J/kg) and 10.24±1.34 J (3.18±0.12 J/kg) for MP defibrillation. BP waveform required 30% less shock energy for a successful defibrillation. In order to compare the safety of defibrillation, we evaluated changes in cardiac biomarkers, electrocardiogram, echocardiographical left ventricular index, and aortic pressure during and after BP and MP defibrillation. All dogs treated by either BP or MP defibrillation survived. Pulseless electrical activity occurred in 2 of 5 dogs during MP defibrillation. The levels of cardiac biomarkers were elevated and sustained for longer periods in the MP defibrillation group. Electrocardiographic changes (e.g., QT prolongation, the time to return to an isoelectric ST segment after shocks) were more severe and longer in the MP defibrillation group. In addition, overall left ventricular cardiac performance was severely depressed in the MP group compared with the BP group. Conclusion: Our findings suggest that BP defibrillation is more effective and safer than MP defibrillation. We determined the acceptable shock energy to be 2–4 J/kg for toy breed dogs.

BackgroundHeartworm disease in dogs is a life-threatening parasitic disease. Although adulticide treatment with melarsomine has been proven to be the most effective, complications associated with adulticide treatment are major concerns for clinicians.MethodsThis study evaluated the change in levels of D-dimer, interleukin-6, C-reactive protein and cardiac troponin I in 12 dogs with different severities of heartworm infection treated by the American Heartworm Society (AHS) recommended protocol during the treatment period. The serum levels of several markers were measured on the day of diagnosis (T-60), before the initiation of melarsomine therapy (T0), 1 day after the first injection (T1), 1 week after the first injection (T7), 1 month after the first injection (T30), 1 day after the second injection (T31), 1 day after the third injection (T32), 1 week after the third injection (T39), 1 month after the third injection (T62), 2 months after the third injection (T92), 3 months after the third injection (T122), and 6 months after the third injection (T182).ResultsThe serum levels of these markers were significantly different at the test time point after melarsomine treatment and also differed significantly according to the stage of heartworm disease in the dogs.ConclusionThis study found that monitoring of inflammatory and hemostatic markers in dogs with heartworm disease being treated with melarsomine might be beneficial in predicting the clinical outcomes and complications associated with melarsomine treatment.

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 ...

GATA4 is expressed early in the developing heart where it plays a key role in regulating the expression of genes encoding myocardial contractile proteins. Gene mutations in the human GATA4 have been implicated in various congenital heart defects (CHD), including atrial septal defect (ASD). Although ASD is the third most common CHD in humans, it is generally rare in dogs and cats. There is also no obvious predilection for ASD in dogs and cats, based on sex or breed. However, among dogs, the incidence rate of ASD is relatively high in Samoyeds and Doberman Pinschers, where its inheritance and genetic aetiology are not well understood. In this study, we identified and investigated the genetic aetiology of an ASD affected family in a pure breed dog population. Although the GATA4 gene was screened, we did not find any mutations that would result in the alteration of the coding sequence and hence, the predicted GATA4 structure and function. Although the aetiology of ASD is multifactorial, our findings indicate that GATA4 may not be responsible for the ASD in the dogs used in this study. However, this does not eliminate GATA4 as a candidate for ASD in other dog breeds.