Demography, commonly diagnosed disorders and mortality of guinea pigs under primary veterinary care in the UK in 2019-A VetCompass study

[[[ Introduction: ]]] Guinea pigs are popular as domestic pets but there is limited information on the health of the wider pet population. This study aimed to report demography, commonly diagnosed disorders and mortality of guinea pigs under UK primary veterinary care. [[[ Methods: ]]] Diagnosis and mortality information on guinea pigs was extracted from anonymised UK primary-care clinical records in VetCompass. [[[ Results: ]]] From 51,622 guinea pigs under primary veterinary care during 2019, a specific breed was not recorded in 50,098 (97.05%). Of guinea pigs with information recorded, 23,206 (47.33%) were female and 25,828 (52.67%) were male. There were 1,020 (2.08%) neutered and 48,014 (97.92%) entire. Median adult bodyweight overall was 1.05kg (interquartile range [IQR] 0.90-1.19, range 0.40-2.66). From a random sample of 3,785/51,622 (7.33%) guinea pigs, the most prevalent disorders were overgrown nail(s) (n = 1,005, 26.55%, 95% confidence interval [CI] 25.15-27.99), dermatophytosis (228, 6.02%, 95% CI 5.29-6.83) and corneal ulceration (189, 4.99%, 95% CI 4.32-5.74). Among the 30 most common disorders, females showed predisposition for 3 disorders and males showed predisposition for 5 disorders. The disorder with the youngest age of affected animals was dermatophytosis (1.11 years) while weight loss had the oldest age of affected animals (4.64 years). From 757 recorded deaths, the median age at death overall was 4.03 years (IQR 2.56-5.44, range 0.17-10.00). Among deaths with a recorded cause, the most common causes of death were anorexia (n = 82, 13.87%, 95% CI 11.19-16.93), collapsed (58, 9.81%, 95% CI 7.54-12.50) and peri-anaesthetic death (20, 3.38%, 95% CI 2.08-5.18). [[[ Conclusions: ]]] These results can assist veterinarians and owners by providing demographic, disorder and mortality benchmarks that support improved clinical care and welfare outcomes in guinea pigs. Many common disorders in guinea pigs were husbandry related.