Energy expenditure in dogs with lymphoma fed two specialized diets

Cancer-caused cachexia has been reported to be caused in part by an increase in energy expenditure, and diets with nutrient profiles containing 30-50% nonprotein calories as fat instead of carbohydrate may exacerbate this state of inefficient energy utilization.

Indirect calorimetry was performed on 22 dogs with high-grade lymphoblastic lymphoma that were randomized into a blind study and fed isocaloric amounts of a high-fat diet (Diet A) or a high-carbohydrate diet (Diet B) before and after remission was attained with up to five doses of doxorubicin chemotherapy (30 mg/m2 intravenously). Indirect calorimetry was also performed on 30 normal dogs for comparison.

During the initial evaluation period, the resting energy expenditure (REE/kg0.75, P < 0.05) and respiratory quotient (RQ, P < 0.05) were significantly lower than in the controls. Six weeks after the start of the study, the REE/kg0.75 and oxygen consumption (VO2/kg0.75) were significantly (P < 0.05) lower in both groups of dogs with lymphoma compared with the controls. The RQ determined 6 weeks after the start of the study for the dogs fed Diet A was significantly (P < 0.05) lower compared with that in the controls evaluated at the same time. When the two groups of dogs with lymphoma were compared with each other, there was no significant difference in any of the outcomes. The REE/kg0.75 and VO2/kg0.75 values were significantly lower (P < 0.05) in the group fed Diet A after the third evaluation period compared with the second evaluation. The REE/kg0.75 and VO2/kg0.75 values were significantly lower (P < 0.05) in the group given Diet B at the fourth evaluation period compared with the fifth.

These data suggest that energy expenditure of dogs with lymphoma decreases transiently in response to chemotherapy and remission, but these values are less than those determined in normal dogs and not altered significantly by diet.