Great Pyrenees: body weight, osteosarcoma risk and monitoring
A Great Pyrenees weighing over 40 kg falls into a weight category that veterinary research directly links to a markedly higher risk of osteosarcoma, the most common bone cancer in dogs. Find all our health pointers in the dog care and grooming section.
What the landmark UK study shows
A study by O'Neill, Edmunds, Urquhart-Gilmore, Church, Rutherford, Smalley and Brodbelt, published in 2023 in Canine Medicine and Genetics using VetCompass data covering over 900,000 dogs, identified body weight as the single strongest risk factor for osteosarcoma (study on Google Scholar). Dogs over 40 kg carried roughly 45 times the odds of osteosarcoma compared with dogs under 10 kg, a gap that puts giant breeds like the Great Pyrenees squarely among those most affected, alongside the Saint Bernard and the Great Dane.
What this means in practice
- Closer attention from around age seven, the average age of diagnosis observed in giant breeds in the study, especially in the face of persistent lameness.
- A well-suited orthopaedic bed, which eases joint strain in an already heavy dog and limits repeated stress on the long bones.
- Strict weight management, since excess weight adds further mechanical strain to a skeleton already under pressure from the breed's build.
Spotting the signs and planning for the budget
Lameness that sets in, localised swelling, or pain on touch in a limb of an adult Great Pyrenees should prompt a swift check-up. A well-suited bed is part of the priorities: our dog bedding and habitat section covers the orthopaedic models best suited to large builds. Find the full breed profile on the Great Pyrenees page and browse all our guides on the dog hub.
Frequently asked questions
Is the Great Pyrenees at very high risk of osteosarcoma?
Its giant build puts it squarely in the strongest risk factor identified by the study, body weight, which justifies particular monitoring.
Does lameness automatically mean osteosarcoma?
No, but in a large-build dog, persistent lameness always deserves a swift veterinary opinion to rule this out.
Can diet lower this risk?
Keeping an optimal weight throughout life limits mechanical strain on the skeleton, even though the breed factor itself can't be changed.
This guide is part of Planète Pets’s Dogs universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.