Dog breeds and conformations predisposed to osteosarcoma in the UK: a VetCompass study

Osteosarcoma describes a serious bone tumour.

Affected dogs often show a bony or soft tissue swelling with severe pain.

Canine and human osteosarcoma show similar patient characteristics, clinical course and tumour biology that make studies on canine osteosarcoma highly valuable to inform on the human disease.

This study aimed to interrogate anonymised veterinary clinical data from the VetCompass Programme to explore whether demographic information on dogs such as breed, bodyweight and body shape could be useful to predict osteosarcoma.

VetCompass shares anonymised veterinary clinical records for welfare-focused research.

This study explored the records of 905,552 dogs under veterinary care in 2016 to identify all cases of osteosarcoma.

Advanced statistical methods were used to evaluate links between demographic factors and the risk of osteosarcoma.

From the overall study population of 905,552 dogs, there were 331 osteosarcoma cases identified to show a one-year period prevalence of 0.037%.

The breeds with the highest frequency of osteosarcoma were the Scottish Deerhound (3.28%), Leonberger (1.48), Great Dane (0.87%), Rottweiler (0.84%) and Greyhound (0.62%).

Eleven breeds showed increased risk of osteosarcoma compared with crossbred dogs.

Breeds with the highest risk included Scottish Deerhound (× 118.40 times risk), Leonberger (× 55.79), Great Dane (× 34.24) and Rottweiler (× 26.67).

Aging was progressively and strongly associated with increasing risk of osteosarcoma.

Dogs weighing heavier that the average for their breed had 1.65 times the risk than animals weighing below the breed average.

Insured dogs had 1.71 times the risk of being diagnosed with osteosarcoma compared with uninsured dogs which may indicate higher levels of healthcare given to insured dogs compared to uninsured dogs.

Chondrodystrophic (short-legged) breeds had 0.10 times the risk of osteosarcoma compared with non-chondrodystrophic breeds.

Compared with breeds with mesocephalic (average length) skull conformation, breeds with dolichocephalic (long) skull conformation (× 2.72) had increased odds of osteosarcoma while breeds with brachycephalic (short) skull conformation showed reduced risk (× 0.50).

This study cements the concept that breed, bodyweight and longer leg or longer skull length all predispose to osteosarcoma in dogs.

With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can define more useful study populations for better research.

Background Osteosarcoma is a malignant bone neoplasia that has high welfare consequences for affected dogs.

Awareness of breed and canine conformational risk factors for osteosarcoma can assist with earlier diagnosis and improved clinical management.

Study of osteosarcoma in dogs also offers translational value for humans.

Anonymised clinical data within VetCompass on dogs under primary veterinary care in the UK were searched for osteosarcoma cases.

Descriptive statistics reported overall and breed-specific prevalence.

Risk factor analysis used multivariable logistic regression modelling.

Results From 905,552 study dogs, 331 osteosarcoma cases were confirmed yielding a one-year period prevalence of 0.037% (95% CI: 0.033–0.041).

Breeds with the highest annual prevalence were the Scottish Deerhound (3.28%, 95% CI 0.90–8.18), Leonberger (1.48%, 95% CI 0.41- 3.75), Great Dane (0.87%, 95% CI 0.43- 1.55) and Rottweiler (0.84%, 95% CI 0.64–1.07).

The median age at diagnosis was 9.64 years (IQR: 7.97–11.41).

Following multivariable modelling, 11 breeds showed increased odds of osteosarcoma compared with crossbred dogs.

Breeds with the highest odds included Scottish Deerhound (OR 118.40, 95% CI 41.12–340.95), Leonberger (OR 55.79, 95% CI 19.68–158.15), Great Dane (OR 34.24, 95% CI 17.81–65.83) and Rottweiler (OR 26.67, 95% CI 18.57–38.29).

Compared with breeds with mesocephalic skull conformation, breeds with dolichocephalic skull conformation (OR 2.72, 95% CI 2.06–3.58) had increased odds while breeds with brachycephalic skull conformation showed reduced odds (OR 0.50, 95% CI 0.32–0.80).

Chondrodystrophic breeds had 0.10 times the odds (95% CI 0.06–0.15) compared with non-chondrodystrophic breeds.

Increasing adult bodyweight was associated with increasing odds of osteosarcoma.

Conclusions The current study cements the concept that breed, bodyweight and longer leg or longer skull length are all strong risk factors for osteosarcoma in dogs.

With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can robustly define more useful study populations for fundamental and translational bioscience.