Loss of lean body mass, known as cachexia, is commonly associated with chronic diseases (eg, congestive heart failure, chronic kidney disease, and cancer) as well as acute illness or injury in cats.1 This process differs from sarcopenia, which is the loss of lean body mass associated with aging in the absence of disease.1 Cachexia in humans is a separate, negative predictor of survival and has been associated with impaired immune function, wound healing, and strength.1–4 One common definition of cachexia in humans is loss of 5% of body weight within the previous 1 year along with functional and inflammatory changes.5 However, because muscle loss may be hidden by gains in fat mass or fluid, and muscle loss begins very gradually, the criterion of weight loss of 5% makes it challenging to detect cachexia at its earliest stages.
In veterinary medicine, diagnostic criteria and research on cachexia and sarcopenia have focused on muscle, which is the primary tissue lost in those conditions.1,6–9 Clinically, muscle mass can be assessed with a subjective muscle condition scoring system that is available for dogs and cats.10 Quantitative assessment of muscle mass can also be performed by use of CT or dual-energy x-ray absorptiometry.6,11 These techniques, although useful, are limited by cost and the need for an animal to be anesthetized or heavily sedated. In addition, dual-energy x-ray absorptiometry relies on assumptions that may not be accurate for acute and chronic illnesses.12 Ideally, muscle mass could be quantitatively assessed noninvasively to detect early stages of cachexia and sarcopenia in cats. In another study6 conducted by our research group, epaxial muscle size in young and old dogs of a single breed was compared by use of ultrasonography and CT. To address differences in size of dogs, even within a single breed, muscle size was normalized on the basis of vertebral size.6 Another study13 was conducted by our research group to evaluate healthy dogs of various breeds and sizes by use of the ratio of epaxial muscle height (which was measured ultrasonographically) to length of T4 (which was measured radiographically) to calculate a VEMS. Results of that study13 indicate that the VEMS is reproducible and a valid measure for dogs of various sizes. However, it is not known whether this same value would be a valid measurement for a population of cats of various sizes. Therefore, the objective of the study reported here was to evaluate the ability of the VEMS to be used as a quantitative assessment of muscle mass in clinically normal cats independent of body size.
Presented in abstract form at the 10th International Conference on Cachexia, Sarcopenia, and Muscle Wasting, Rome, December 2017; and the American College of Veterinary Internal Medicine Forum, Seattle, June 2018.
Body condition score
Forelimb epaxial muscle score
Vertebral epaxial muscle score
Kodak CR800, Carestream Health Inc, Rochester, NY.
TruDR cSeries, Sound, Carlsbad, Calif.
Carestream Vue PACS, version 11.4, Carestream Health, Rochester, NY.
Philips Epic 7, Philips Medical Systems, Bothell, Wash.
Systat, version 13.0, Systat Software Inc, San Jose, Calif.
2. Lang T, Streeper T, Cawthon P, et al. Sarcopenia: etiology, clinical consequences, intervention, and assessment. Osteoporos Int 2010;21:543–559.
3. Fearon K, Strasser F, Anker SD, et al. Definition and classification of cancer cachexia: an international consensus. Lancet Oncol 2011;12:489–495.
6. Hutchinson D, Sutherland-Smith J, Watson AL, et al. Assessment of methods of evaluating sarcopenia in old dogs. Am J Vet Res 2012;73:1794–1800.
7. Geddes RF, Biourge V, Chang Y, et al. The effect of moderate dietary protein and phosphate restriction on calcium-phosphate homeostasis in healthy older cats. J Vet Intern Med 2016;30:1690–1702.
8. Peterson ME, Castellano CA, Rishniw M. Evaluation of body weight, body condition, and muscle condition in cats with hyperthyroidism. J Vet Intern Med 2016;30:1780–1789.
9. Story AL, Boston SE, Kilkenny JJ, et al. Evaluation of weight change during carboplatin therapy in dogs with appendicular osteosarcoma. J Vet Intern Med 2017;31:1159–1162.
10. World Small Animal Veterinary Association Global Nutrition Committee. Muscle condition score charts for dogs and cats. Available at: www.wsava.org/Guidelines/Global-Nutrition-Guidelines. Accessed May 17, 2018.
11. Michel KE, Anderson W, Cupp C, et al. Correlation of a feline muscle mass score with body composition determined by dual-energy x-ray absorptiometry. Br J Nutr 2011;106(suppl 1):S57-S59.
13. Freeman LM, Sutherland-Smith J, Prantil LR, et al. Quantitative assessment of muscle in dogs using a vertebral epaxial muscle score. Can J Vet Res 2017;81:255–260.