Objective—To determine the annual and overall proportion
of diagnoses of congenital portosystemic
shunts (CPSS) in dogs and identify breeds at
increased risk for CPSS.
Animals—2,400 dogs with CPSS from veterinary
teaching hospitals that reported to the Veterinary
Medical Database (VMDB) from January 1, 1980 to
February 28, 2002.
Procedure—The proportion of diagnoses of CPSS
was calculated for all dogs and each breed recorded
in the VMDB annually and for the 22.2-year period.
Odds ratios and adjusted confidence intervals were
calculated for breeds with at least 100 accessions by
comparing odds of each breed with a diagnosis of
CPSS with that of mixed-breed dogs.
Results—Congenital portosystemic shunts were
reported in 0.18% of all dogs and 0.05% of mixedbreed
dogs. The proportion of diagnoses of CPSS
increased from 5 in 10,000 dogs in 1980 to 5 in 1,000
dogs in 2001. Yorkshire Terriers had the greatest total
number of diagnoses of CPSS. Thirty-three breeds
were significantly more likely to have a diagnosis of
CPSS, compared with mixed-breed dogs. The greatest
proportions of diagnoses were found in Havanese
(3.2%), Yorkshire Terriers (2.9%), Maltese (1.6%),
Dandie Dinmont Terriers (1.6%), and Pugs (1.3%).
Conclusions and Clinical Relevance—Certain
breeds appear to be at increased risk for CPSS, compared
with mixed-breed dogs. The increased odds
ratios among specific breeds support the hypothesis
of a genetic predisposition for CPSS. Clients and veterinarians
should consider appropriate diagnostic
tests for dogs with clinical signs and those used for
breeding from breeds with increased risk of CPSS.
(J Am Vet Med Assoc 2003;223:1636–1639)