SERUM BIOCHEMICAL VALUES IN SLED DOGS BEFORE AND AFTER COMPETING IN LONG-DISTANCE RACES

Objective-To measure and compare blood values in sled dogs before and after long-distance racing. Design-Prospective study. Animals-17 adult sled dogs in the 1991 Iditarod Trail Sled Dog Race and 21 in a simula ted sled dog race. Procedure-Blood samples were obtained from 17 dogs 7 days before they began and after they finished (finisher group) or w ere eliminated from (nonfinisher group) the Iditarod Trail Sled Dog Ra ce. Blood samples were also obtained from 21 dogs before and after a s imulated sled dog race. Results-In finisher-group dogs, BUN and uric a cid (UA) concentrations were increased after racing; nonfinisher-group dogs had significantly lower postrace BUN and UA concentrations. Sign ificant increases in creatine kinase (CK) and aspartate transferase (A ST) activities were detected in all dogs after racing, and postrace va lues were higher in nonfinisher-group dogs, compared with finisher-gro up dogs. Mean alkaline phosphate activities were significantly increas ed after racing in nonfinisher-group dogs only. In dogs that ran the s imulated race, postrace values for serum albumin, total protein, calci um, and potassium concentrations, as well as Hct, hemoglobin concentra tion, and RBC count, were significantly lower than prerace values. Pos trace values for alkaline phosphate, alanine transaminase, AST, lactat e dehydrogenase, CK, BUN, and UA were significantly higher than prerac e values. Clinical Implications-High CK activities are indicative of s evere muscle degeneration and, in sled dogs, may represent a degree of muscle breakdown beyond which a dog cannot continue to work. Markedly high CK, and possibly AST, serum activities may be indicators of perf ormance failure in sled dogs competing in long-distance races.