Evaluation of the Swedish breeding program for cavalier King Charles spaniels

Abstract

A breeding program with the aim of reducing the prevalence of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCS) is currently ongoing in Sweden. In this investigation 353 CKCS were selected as a sample of the population and 150 were examined by auscultation for heart murmurs when they reached the age of six years in 2007 and 2009. The aim with this investigation was to study the prevalence of heart murmurs in six-year-old CKCS and to estimate if prevalence has decreased since the breeding program was introduced 2001. The effect of the breeding program was evaluated by comparing the prevalence of heart murmurs in the two groups. In 2007, the prevalence of heart murmurs was 52% (50% for females and 54% for males) and in 2009, the prevalence was 55% (44% for females and 67% for males). No significant difference was found in the prevalence of heart murmurs between 2007 and 2009 (P = 0.8). For all six-year-old CKCS, the prevalence of heart murmur was 53% (females 46% and males 61%), which is higher than previous Swedish investigations.

Occurrence of mitral valve insufficiency in clinically healthy Beagle dogs

“…Although cardiac auscultation alone can be used as a screening tool for diagnosing MVI, it might miss mild cases not producing mitral valve murmurs but demonstrated by CFD (Pedersen et al, 1999a;Lundin and Kvart, 2010;Trafny et al, 2012). We considered a regurgitant jet size of at least > 10% of the left atrial area for the diagnosis of a cardiologically significant MVI, in agreement with other authors (Pedersen et al, 1999a;Olsen et al, 2003;Drut et al, 2015).…”

“…Then, an electronic sensor-based stethoscope (Welch Allyn Meditron Master Elite Stethoscope System, The Stethoscope Welch Allyn Corp., Skaneateles Falls, NY, USA) was used by each investigator. Cardiac murmurs were described and their intensity was graded on the 0/6 scale according to previous descriptions (Sisson and Ettinger, 1999;Kvart and Hägg-ström, 2002;Lundin and Kvart, 2010;Vörös et al, 2011). After cardiac auscultation, a consultation on the absence/presence and grading of a murmur was made and the final classification on murmur characteristics was concluded based on the findings obtained with either stethoscope and on the agreement of at least two investigators where KV was always included.…”

Historical review, epidemiology and natural history of degenerative mitral valve disease

“…42 In contrast, a comparison of murmur frequencies in 6-year-old CKCS in Sweden in 2007 (53%) and 2009 (55%) did not show a reduction in the prevalence of murmurs after the start of a selective breeding program in 2001 to reduce the prevalence of mitral regurgitation. 43 Although the presence of a holosystolic murmur is a good indicator of the presence of the disease, it should be noted that dogs with mild disease may not have a murmur, even though they have echocardiographic evidence of MMVD and mitral regurgitation. c, 33,44 In particular, large breed dogs more commonly present echocardiographic diagnostic criteria for MMVD, like mitral valve thickening and MR, without a detectable murmur on physical exam.…”

Prevalence of and Risk Factors for Degenerative Mitral Valve Disease in Dogs Attending Primary‐care Veterinary Practices in England

“…The prevalence of DMVD has been found to increase with age6, 8, 15, 16 and can approach 100% in geriatric populations of high‐risk breeds 8, 15. Males are over‐represented in some epidemiological studies4, 5, 17 but statistically significant differences between the sexes are not consistently reported 3, 6. The current literature lacks multivariable analyses of risk factors for DMVD diagnosis in England that adjust for the effect of other confounding variables.…”

“…It was hypothesized that the breeds most commonly reported to be at increased risk of DMVD in the current literature, Cavalier King Charles Spaniels (CKCS),1, 3, 5, 15, 16, 22 Dachshunds,4, 5, 23, 24 and Poodles,5, 17 would have the highest odds of DMVD among purebred dogs in the VetCompass population. Moreover, small‐breed dogs (<20 kg) and male dogs would have higher odds of DMVD than large‐breed dogs and females respectively.…”