Detecting and recording cardiac murmurs in clinically healthy puppies in first opinion veterinary practice at the first health check

Congenital ventricular outflow tract obstructions in Boxer dogs: Results of a 17-year cardiovascular breed screening program in France (3126 dogs)

INTRODUCTION

Ventricular outflow tract obstructions including aortic (AS) and pulmonic stenosis (PS) are the most common canine congenital heart diseases, with Boxer dogs being predominantly affected. This has led to the French Boxer club adopting a mandatory national control program against AS and PS. The objective of this retrospective study was to analyze the results of 17 years of this cardiovascular breed screening program (2005-2021).

MATERIALS AND METHODS

The records of untreated and non-anesthetized adult Boxer dogs screened between 2005 and 2021 were retrospectively reviewed. All dogs underwent physical examination and standard transthoracic echocardiography with concomitant ECG tracing. All examinations were reviewed by one single board-certified specialist in cardiology.

RESULTS

Out of the 3126 dogs screened during the study period, 3001 dogs (female:male sex ratio = 2.2, median age [IQR] = 1.6 years [1.2-2.1]) were recruited for data analysis. A total of 218 operators were involved in the screening program. For most Boxer dogs (i.e., 93.8% for AS and 94.5% for PS), a single examination was required to obtain a definitive cardiac status, although most operators were non-specialist general practitioners. A left basilar systolic heart murmur was detected in all dogs with AS and PS, but also in 7.4% dogs free of heart diseases. A significantly higher proportion of the latter was detected when operators were board-certified specialists (P<0.001). Lastly, when comparing the start and the end of the breeding program, among dogs diagnosed with AS and PS (n = 364) in a French referral cardiology center, Boxer went from the 1st affected breed by AS to the 3rd, and from the 3rd affected breed by PS to the 6th.

CONCLUSION

This 17-year screening program has experienced a strong involvement of veterinarians, breeders, and owners throughout France. This may have contributed to reduce AS and PS prevalence in Boxer dogs at the studied referral cardiology center.

Temporal changes in the presence and intensity of innocent cardiac murmurs in clinically healthy Cairn terrier and Dachshund puppies between 4 and 8 weeks of age

BACKGROUND

Spontaneous week-to-week variation in the presence and intensity of innocent cardiac murmurs in individual puppies is unknown.

METHODS

Sixty privately owned, clinically healthy Cairn terrier and Dachshund puppies between 4 and 8 weeks of age were included. All dogs underwent weekly cardiac auscultation at the breeders' home by a veterinary cardiology specialist using an acoustic stethoscope. On each occasion, a phonocardiogram was recorded with an electronic stethoscope. Furthermore, all dogs were auscultated once at a first opinion veterinary practise and once at the authors' institution, where they also underwent an echocardiographic examination.

RESULTS

Two-hundred and eighty-one auscultations were conducted on 32 Cairn terriers and 28 Dachshunds, at the breeders' homes. Innocent murmurs were detected in 19 puppies. Two of these puppies had a detectable murmur on each auscultation. In five of the puppies, the murmur became undetectable during the observation period and in 12 puppies the murmur was intermittently audible. Auscultation at the authors' institution had an unpredictable effect on murmur presence and intensity. Phonocardiography revealed murmurs in 42 puppies. Interpretation of phonocardiograms by two independent observers showed nearly perfect agreement (κ = 0.859).

CONCLUSIONS

Remarkable and unpredictable spontaneous week-to-week variation was documented in the presence and intensity of innocent murmurs.