Retrospective study of 942 small-sized dogs: Prevalence of left apical systolic heart murmur and left-sided heart failure, critical effects of breed and sex.

OBJECTIVES

The main goals of this study were (1) to carry out a retrospective study of the prevalence of left apical systolic heart murmurs, which are considered to clinically reflect the presence of MVD, in the 6 small canine breeds most popular in France, i.e., Yorkshire Terrier, Bichon Maltese, Dachshund, Poodle, Lhassa Apso and Shi Tzu and (2) to compare the results with those obtained in a recent report published by our group on MVD in 451 CKC.

BACKGROUND

Mitral valvular disease (MVD) has been extensively studied in Cavalier King Charles spaniels (CKC) but seldom studied and compared in other small-breed dogs. The first clinical sign of MVD is the early appearance of a left apical systolic heart murmur.

ANIMALS: Nine hundred and forty-two adult dogs were included in the present study (mean+/-SD, age=6.5+/-4.4 years, weight=6.2+/-2.6kg).

RESULTS

The average total prevalence of left apical systolic heart murmur was 14.4% compared with 40.6% in CKC. It was significantly more prevalent in males (18.5%) than in females (9.8%). Shi Tzu and Dachshunds were the most affected breeds investigated. Most (81%) of the dogs with left apical systolic murmur were classified in ISACHC heart failure class I.

CONCLUSION

This large retrospective study suggests that the prevalence of MVD is higher in CKC than in the 6 small breeds investigated. Moreover, most of the dogs do not develop congestive heart failure.