Evaluation of a method to measure the ratio of pelvic limb to thoracic limb girth in dogs

Objective: To determine if a landmark-incorporated limb girth measurement in sound dogs, utilising the greater trochanter and the acromion process, would be both reliable and have a consistent ratio between pelvic limb (PL) and thoracic limb (TL) muscle measurements. Background: To establish a reliable and reproducible reference range for sound dogs. This reference range may help clinicians further evaluate dogs during lameness and musculoskeletal examinations. Evidentiary value: Prospective study of 115 sound dogs measured by a single observer. Methods: Examinations were performed by one observer, using a Gullick II tape measure for PL to TL ratio (PL:TL) measurements for 115 dogs. Bodyweight, breed, body condition score (BCS), and sex were recorded. Each limb was measured three times. The average PL:TL per dog was calculated. Further statistical analysis was used to calculate intra-observer variance and the correlation of limb girth to body weight, BCS, and sex, with significance set at P < 0.05. Results: The average PL:TL of the sample was 1.515 ± 0.049. Fifty-two dogs of the 115 cases (45%) had a PL:TL ratio of 1.500. PL:TL measurements were not related to dog weight, BCS, or sex. The intra-class correlation was reported to be 0.99. Conclusion: Our study suggests that a landmark-incorporated measurement in a weight-bearing position can be reproducible. Further investigation is required to determine if this measurement can be reproducible between multiple observers. Application: A landmark-incorporated limb girth measurement may guide clinicians in case progression and help pinpoint subclinical musculoskeletal disease in dogs.