Canine dystocia in 50 UK first-opinion emergency-care veterinary practices: prevalence and risk factors
O’Neill, D. G. et al. (2017) Canine dystocia in 50 UK first-opinion emergency-care veterinary practices: prevalence and risk factors. Veterinary Record, 181 (4), pp. 88-93
The prevalence of dystocia is a major welfare concern in dogs of certain breeds. Previous studies have reported breed, body size and age as risk factors for dystocia but the results have been inconsistent.
Using data from 50 Vets Now first-opinion emergency care veterinary practices, this study investigated the prevalence of dystocia in the emergency care caseload of entire bitches and evaluated breed, bodyweight and age as risk factors.
The study population included 18,758 entire bitches. Analysis of the data identified 701 cases of dystocia – a prevalence of 3.7%. Breed data was available for 95.3% of the dystocia bitches: the breeds with the highest occurrence were the Chihuahua, Staffordshire Bull Terrier, Pug and Jack Russell Terrier. Bodyweight data was available for 33.8% of the dystocia cases, with a median bodyweight of 10.00kg, and age data for 94%, median age 3.0 years.
The study reported that purebred dogs had 3.4 times the odds of dystocia compared with crossbred dogs and that Kennel Club (KC) recognised breeds had 2.0 times the odds of dystocia compared to non KC recognised breeds. The Toy group had the highest odds of dystocia amongst the KC breed groups when compared to non KC recognised breeds.
Bitches at both ends of bodyweight showed increased probability of dystocia. Those in the under 10.0 kg group were 1.6 times, and those in the 40.0-49.9 kg group 3.5 times, the odds of dystocia compared with bitches in the 20.0-29.9 kg group.
Breeds with the highest odds of dystocia compared with crossbred bitches were French Bulldog, Boston Terrier, Pug and Chihuahua. Bitches aged between 3.0-5.9 years old had over three times the odds of dystocia compared with bitches under three years old.
The authors acknowledge that some variables, particularly bodyweight, had a high proportion of missing data which limited the possible interpretation of the results. The fact that the data came from an out-of-hours emergency setting may also mean that it differs significantly from caseloads seen in regular hours in primary care practice as, for some of the most affected breeds, owners opt for a planned caesarean during regular working hours to save costs.
The evidence from this study shows there is a strong risk of dystocia in brachycephalic breeds. There is also an increased probability of dystocia in bitches between three and six years old and at both extremes of bodyweight.
This evidence will be helpful to veterinary practitioners when advising new owners on breed choice and when discussing breeding with owners.
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