Health Problems In Dogs Research Articles

Recent breeding history of dog breeds in Sweden: modest rates of inbreeding, extensive loss of genetic diversity and lack of correlation between inbreeding and health

One problem in modern dogs is a high occurrence of physical diseases, defects and disorders. Many breeds exhibit physical problems that affect individual dogs throughout life. A potential cause of these problems is inbreeding that is known to reduce the viability of individuals. We investigated the possible correlation between recent inbreeding and health problems in dogs and used studbook data from 26 breeds provided by the Swedish Kennel Club for this purpose. The pedigrees date back to the mid-20th century and comprise 5–10 generations and 1 000–50 000 individuals per pedigree over our study period of 1980–2010. We compared levels of inbreeding and loss of genetic variation measured in relation to the number of founding animals during this period in the investigated dog breeds that we classified as ‘healthy’ (11 breeds) or ‘unhealthy’ (15) based on statistics on the extent of veterinary care obtained from Sweden's four largest insurance companies for pets. We found extensive loss of genetic variation and moderate levels of recent inbreeding in all breeds examined, but no strong indication of a difference in these parameters between healthy versus unhealthy breeds over this period. Thus, recent breeding history with respect to rate of inbreeding does not appear to be a main cause of poor health in the investigated dog breeds in Sweden. We identified both strengths and weaknesses of the dog pedigree data important to consider in future work of monitoring and conserving genetic diversity of dog breeds.

Effects of weight loss on the cardiac parameters of obese dogs

Obesity is one of the most frequent nutritional problems in companion animals and can lead to severe health problems in dogs and cats, such as cardiovascular diseases. This research aimed to evaluate the structural and functional cardiac changes after weight loss in obese dogs. Eighteen obese healthy dogs were assigned into three different groups, according with their initial body weight: Group I (dogs up to 15 kg), Group II (dogs weighing between 15.1 and 30 kg), and Group III (dogs weighing over 30 kg). The animals were submitted to a caloric restriction weight-loss program until they lose 15% of the body weight. The M-mode echocardiogram, electrocardiogram, and blood pressure evaluations were performed before the diet has started and after the dogs have reached the target weight. Data showed a decrease in left ventricular free wall thickness during diastole and systole in Group III, decrease in the systolic blood pressure in Group III, and also in the mean blood pressure in Group II. It was possible to conclude that the weight loss program can reverse structural cardiac changes such as left ventricle eccentric hypertrophy in dogs weighing more than 30 kg, and decrease the arterial blood pressure in obese dogs.

Heritability of canine hip-dysplasia score and its components in Gordon Setters

Hip dysplasia (malformation of the hip joint) is an important health problem in dogs. The condition and the control scheme for Gordon Setters was organised by the British Veterinary Association (BVA) and the Kennel Club before 1976 and use hip scores. Our analyses of hip dysplasia in Gordon Setters used both hip scores and the scores for the nine components (which collectively defined the hip score). The scores for all nine components were available for 732 females and 420 males. These clinical data were merged with the Kennel Club pedigree database (animal’s identity, date of birth, and also similar data for its parents, including hip scores if the parent had been tested). Regression models showed strong positive relationships between offspring and parental hip scores as well as for some component scores. The heritability of hip dysplasia (assessed using both hip scores and the major components) was significant, particularly from dams. Our research emphasizes the need for both sires and dams — particularly dams, to have zero or small hip scores. Tested parents have been used increasingly in recent years, but greater reduction in offspring hip score will require stricter selection of potential breeding stock. The models reported here provide quantitative predictions of likely health benefits from selective breeding.