Jens Häggström 1, Åsa Ohlsson 2 3, Torkel Falk 4, Gerhard Wess 5, Jana Friederich 5, Ulrika Olsson 3, Lennart Nilsfors 6, Jan-Gerd Kresken 7, Kjell Högström 3, Niek Beijerink 8, Mark Rishniw 9, Anna Tidholm 1 10, Ingrid Ljungvall 1
Background
Echocardiographic reference intervals normalized to body weight are crucial for identifying cardiac abnormalities in dogs. However, variations due to breed, sex, or age can affect these measurements, complicating interpretation. This study aimed to evaluate the impact of signalment variables (breed, sex, age) on echocardiographic dimensions normalized for body weight in a large cohort of healthy dogs.
Methods
The study retrospectively analyzed echocardiographic data from 2,689 healthy dogs across 125 breeds. Measurements included left atrial diameter, aortic root diameter, and left ventricular dimensions in systole and diastole. Data were normalized to body weight using allometric scaling. The effects of sex, age, breed, and body weight were analyzed through linear regression and mixed-effects models, with breed treated as a random factor.
Results
Body weight normalization reduced variance across most echocardiographic parameters. However, breed and sex remained significant sources of variation. Males exhibited larger body weight–normalized left atrial and ventricular dimensions than females. Age also influenced measurements, particularly left atrial diameter and wall thicknesses, which increased with age. Breed differences were notable, with sighthounds and brachycephalic breeds displaying distinct cardiac dimensions even after normalization.
Limitations
The retrospective design and reliance on existing echocardiographic databases introduce potential measurement variability and selection bias. Breed-specific reference intervals were not established, and clinical applicability may be limited for mixed breeds or less common purebreds.
Conclusions
Although body weight normalization improves consistency in echocardiographic interpretation, sex, age, and breed significantly influence cardiac dimensions. Awareness of these variables is essential for accurate assessment in clinical practice. Breed- and sex-specific reference intervals may enhance diagnostic precision in veterinary cardiology.
Density curves for body weight (BW)-normalized echocardiographic measurements by age group in 56 169 cats. The age group sizes were: < 2 years n = 33 860, 2–4 years n = 14 721, 4–8 years n = 6833, and > 8 years n = 755. Notice that comparably small differences in distributions existed between the age groups, but older cats had density curves shifted slightly towards higher BW normalized values of LV wall thickness in systole and diastole (IVSdinc, LVFWdinc, IVSsinc, LVFWsinc) as well as aortic and LA dimensions (Aoinc and LAinc), but LV cavity diameters (LVIDdinc and LVIDsinc) shifted towards lower values. Ao, aortic diameter; IVSd, interventricular septum diastole; IVSs, interventricular septum systole; LA, left atrial diameter; LVFWd, left ventricular free wall diastole; LVFWs, left ventricular free wall systole; LVIDd, left ventricular internal diameter diastole; LVIDs, left ventricular internal diameter systole.
How did we do?
Jens Häggström 1, Åsa Ohlsson 2 3, Torkel Falk 4, Gerhard Wess 5, Jana Friederich 5, Ulrika Olsson 3, Lennart Nilsfors 6, Jan-Gerd Kresken 7, Kjell Högström 3, Niek Beijerink 8, Mark Rishniw 9, Anna Tidholm 1 10, Ingrid Ljungvall 1Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.
