ABSTRACT
BACKGROUND: A high perinatal mortality rate in the Stabyhoun breed prompted one of the Dutch breeding organizations to start an investigation. Preductal segmental tubular aortic hypoplasia is an extremely rarely documented congenital vascular anomaly in dogs, and it is suspected to be the result of constriction of ectopic ductal tissue in the aortic wall at birth. METHODS: Over a period of 18 months, Stabyhoun puppies that were stillborn, died or were euthanized before 3 weeks of age were submitted to post-mortem examination at the reporting institution. Pathologic findings were documented. RESULTS: Eight Stabyhoun puppies were submitted during the study period. In five of them, a severe preductal segmental tubular aortic hypoplasia was found. Two of the five puppies were stillborn, and three died spontaneously or were euthanized. CONCLUSIONS: Preductal tubular aortic hypoplasia was found in an unusually high frequency in the examined Stabyhoun puppies. Because the condition is believed to cause clinical signs only after birth, this anomaly cannot explain the death of the stillborn puppies. However, it might be responsible for cardiogenic pulmonary edema in the postnatal period. Routine dissection of the great vessels in perinatally deceased puppies would help to establish the prevalence of congenital anomalies of the aorta.
ABSTRACT
Though permanent pacemaker implantation is the only effective therapy for certain bradyarrhythmias in dogs, it is not without risks. Bacterial infection of the device is one of the most common complications. Human guidelines recommend besides systemic antibiotics, surgical explantation of the pacing lead and pulse generator in case of device-infection. This report describes a 13.5-year-old dog that received a transvenous endocardial permanent pacemaker because of syncopal episodes resulting from paroxysmal third-degree atrio-ventricular block. Five days after an uneventful surgery, a painful swelling appeared around the subcutaneous part of the lead where this was inserted into the jugular vein. A 4-week course of amoxicillin and clavulanic acid combined with enrofloxacin failed to clear the infection on long-term. Ultrasound-guided puncture of the abscess was performed to gain a sample for bacterial culture and antibiogram. Oral clindamycin of 4 weeks' duration successfully resolved the infection with Staphylococcus aureus without having to explant the device. Repeated ultrasonographic examinations and fine-needle aspiration biopsies were used to evaluate for persistent local inflammation, guiding the length of the antibiotic therapy. Though the described approach has traditionally been ill-advised because of the risk of introducing bacteria and damaging the pacemaker lead, it was successful in our case.
ABSTRACT
BACKGROUND: Patent ductus arteriosus (PDA) is one of the most common congenital heart defects in dogs and is considered to be a complex, polygenic threshold trait for which a female sex predisposition has been described. Histological studies in dogs suggest that smooth muscle hypoplasia and asymmetry of the ductus tissue is the major cause of PDA. The Stabyhoun population is small and a predisposition for PDA has been suggested. The aims of this study were to describe the incidence, presentation from a clinical and histopathological perspective, and the population genetics of PDA in the Dutch Stabyhoun population. RESULTS: Forty-six cases were identified between 2000 and 2013. Between 2009 and 2012 the birth incidence of PDA in the Stabyhoun breed was 1.05 %. We estimated this to be 7-13 times higher than expected in the general dog population. Twelve of the 46 cases were part of a litter in which more than one sibling was affected. There was no sex predilection in our case cohort. Dogs diagnosed in adulthood showed severe cardiomegaly. The mean inbreeding coefficient of the reference population of Stabyhoun dogs was 31.4 % and the actual and effective numbers of founders were 14 and 6.5, respectively. The heritability of PDA was 0.51 (±0.09) for the reference population and 0.41 (±0.10) for the phenotyped population. Histopathology of sections of the PDA from two dogs showed findings similar to those described in other breeds although the smooth muscle of the ductus adjacent to the pulmonary artery appeared more hypoplastic than that in the ductus adjacent to the aorta. CONCLUSIONS: The Stabyhoun breed shows a strong predisposition for PDA. Apart from the absence of a higher incidence in females, no other significant features distinguish PDA in Stabyhouns from the condition in other dog breeds. Heritability and the mean inbreeding coefficient are both very high making the Dutch Stabyhoun breed particularly suited to the study of inherited risk factors for PDA.
