Bulldog

The defining condition of the breed and the most severe example of it in common ownership. A drastically shortened skull compresses normal soft tissue into far less space - narrowed nostrils, an overlong soft palate, a narrowed windpipe - so breathing is hard work at rest and much harder after exertion. Corrective surgery on the nostrils and palate is common, effective and runs into the low thousands. Noisy breathing at rest, or gums going blue, is an emergency.

Dogs shed heat by panting, and a compromised airway does it badly, which makes heatstroke a leading cause of death in this breed rather than a background risk. Walk early and late, never leave them in a car for any length of time, and treat heavy panting at rest as a reason to cool them immediately.

The hip joint develops loosely, so the ball and socket grind instead of gliding. This breed screens worse for it than any other dog - the great majority of Bulldogs assessed are dysplastic to some degree. Many cope surprisingly well because they are light and inactive, but arthritis in middle age is common.

The facial wrinkles, the nose rope and the tail pocket all trap moisture, food and bacteria against the skin. It smells before it looks like anything, and it becomes a recurring infection unless every fold is wiped out and dried daily. This is the single most preventable cost in the breed.

The screw tail is malformed vertebrae, and the same developmental fault can appear further up the spine - usually harmless, occasionally pressing on the spinal cord and causing weakness or incontinence in a young dog. Reputable breeders x-ray for it.

The third eyelid gland prolapses and sits as a red lump in the corner of the eye, and entropion and ectropion both appear here too. All three are corrected surgically, and all three are common enough to budget for rather than hope against.