Dogs | Species, breeds and lifespan | Evidence chain

FAQ

How long do dogs live, and are big dogs really shorter-lived?

Only the direction is certain: the larger the body, the shorter the average lifespan; the smaller the body, the heavier the burden on teeth and stifles. The Merck Veterinary Manual gives an overall average lifespan for dogs of 8 to 16 years depending on the breed, and the median age at death in the giant-breed population is 8.94 years. For the specific number of years in a given breed, consult the most recent lifespan research rather than applying a number from memory.

Are mixed-breed dogs healthier than purebreds?

Not necessarily. Mixed does not equal healthy — if both parents belong to the same high-risk group, for example a cross between two brachycephalic dogs, the risk is inherited just the same. Before buying or adopting, ask the breeder for the health and genetic test reports of the parents, including hip and elbow scores, cardiac, ophthalmic and breed-specific genes, and rely on the veterinarian's interpretation.

What should I watch for before my herding-breed dog is given any drug?

Dogs of the herding lineage (Collie, Shetland Sheepdog, Border Collie, Australian Shepherd, Bearded Collie and others) and their crosses may carry a deletion variant of the MDR1 (ABCB1) gene, so that some drugs at routine doses accumulate in the brain and produce neurotoxicity such as tremor, blindness, seizures and coma, which can be fatal. There is only one action: run MDR1 genetic testing before any drug is given, and tell the veterinarian the breed and the test result proactively.