Objective—To determine serum antibody titers against canine distemper virus (CDV), canine adenovirus type II (CAV-2), and canine parvovirus (CPV) in trained sled dogs prior to and after completion of a long-distance race.
Design—Prospective cohort study.
Animals—195 Alaskan sled dogs (from 18 kennels) that participated in the 2006 Iditarod Trail Race.
Procedures—All 1,323 dogs participating in the race had been vaccinated against the 3 viruses at 19 to 286 days prior to initial blood sample collection (obtained within the month preceding the race). Within 12 hours of race completion, blood samples were collected from 195 dogs (convenience sample) and matched with each dog's prerace sample. Serum antibody titers (90% confidence intervals [CIs]) were determined via serum neutralization assays.
Results—After racing, geometric mean titers against CDV and CPV were significantly higher (2,495 [90% CI, 321 to 16,384] and 6,323 [90% CI, 512 to 32,768], respectively) than prerace values (82 [90% CI, 11 to 362] and 166 [90% CI, 32 to 1,024], respectively). Sixty-one of 194 (31.4%) dogs had t 4-fold increases in anti-CPV antibody titers after racing. Prerace serum antibody titers against CDV, CPV, and CAV-2 varied significantly by sled team but were not associated with time since vaccination.
Conclusions and Clinical Relevance—Postrace increases in serum anti-CDV and anti-CPV antibody titer might reflect exposure of dogs to these agents immediately before or during racing. Dogs had no clinical signs of CDV-, CAV-2-, or CPV-associated disease; therefore, the clinical importance of these titer changes is uncertain.
Objective—To determine the effects of racing and
nontraining on plasma thyroxine (T4), free thyroxine
(fT4), thyroid-stimulating hormone (TSH), and thyroglobulin
autoantibody (TgAA) concentrations in sled
dogs and compare results with reference ranges
established for dogs of other breeds.
Animals—122 sled dogs.
Procedure—Plasma thyroid hormone concentrations
were measured before dogs began and after they finished
or were removed from the Iditarod Trail Sled
Dog Race in Alaska and approximately 3 months after
Results—Concentrations of T4 and fT4 before the race
were less than the reference range for nonsled dogs in
26% and 18% of sled dogs, respectively. Immediately
after racing, 92% of sled dogs had plasma T4 concentrations
less than the reference range. Three months after
the race, 25% of sled dogs had plasma T4 concentrations
less than the reference range. For T4, fT4, TSH, and
TgAA, significant differences were not detected in samples
collected before the race versus 3 months later.
Conclusions and Clinical Relevance—Plasma T4, fT4,
and TSH concentrations decreased in dogs that complete
a long distance sled dog race. Many clinically normal
sled dogs have plasma T4 and fT4 values that are
lower than the reference range for nonsled dogs. We
suggest that the reference ranges for sled dogs are 5.3
to 40.3 nmol/L and 3.0 to 24.0 pmol/L for plasma T4 and
fT4 concentrations, respectively, and 8.0 to 37.0 mU/L
for TSH. (J Am Vet Med Assoc 2004;224:226–231)