Prevalence of tracheal collapse syndrome, congenital portosystemic shunts, or both in Yorkshire Terriers at one veterinary hospital

Abstract Objectives The prevalence of tracheal collapse syndrome (CTCS) and congenital portosystemic shunts (CPSS) in Yorkshire Terriers is poorly characterized. It is conceivable that CPSS could affect the likelihood of CTCS development if the observed prevalence rate of both conditions is lower than the expected prevalence rate based on multiplication of the individual prevalence rates of each condition. Animals Yorkshire Terriers diagnosed with CTCS, CPSS, or both at the Animal Medical Center (AMC). Methods In this cross-sectional, single-institution study, medical records of Yorkshire Terriers were reviewed for patient date of birth, sex, weight, date of last visit, and reported diagnoses of CTCS, CPSS, or both. Medical records were reviewed to confirm the diagnosis of CTCS or CPSS. Observed and expected age-specific prevalence rates were compared within defined age groups. Results A total of 11 061 Yorkshire Terriers were identified, with 7263 having data for age at last visit available. The observed prevalence of CPSS was 0.8% (93 dogs), severe CTCS was 6.7% (739 dogs), and both conditions were 0.05% (6 dogs). The median age at diagnosis was 2.7 years (interquartile range IQR, 1.0-5.7) for CPSS and 10.0 years (IQR, 8.0-13.0) for CTCS. The observed age-specific prevalence rate of both conditions (joint) in each age group was similar to the expected joint prevalence rates in each age group. Conclusions Further investigation is needed to confirm whether there is a link between CPSS and the development of CTCS in Yorkshire Terriers. Investigation into genetic and physiologic interactions is warranted.