Sphynx

In 1966 a hairless kitten called Prune was born in Toronto, but today's breed comes mainly from hairless cats that turned up in Minnesota and Toronto in the 1970s. The hairlessness is caused by a recessive mutation of the KRT71 gene, the same gene that gives the Devon Rex its curl. It is an outgoing, very affectionate cat that sticks close to people: it looks for laps, gets into bed and greets visitors. It does not shed hair, but it is not a “no-maintenance” or allergy-free cat either: Fel d 1 is in saliva and skin, and many allergy sufferers react just the same. What it does do is leave grease wherever it lies down.

Its skin builds up oil and dirt that no coat absorbs: it needs a bath every one or two weeks with a mild cat shampoo, plus cleaning of the ears (lots of wax), skin folds and between the toes. It gets cold easily: keep the house at a comfortable temperature and provide blankets and enclosed beds. It burns in the sun, even through a window. It eats more than a coated cat to keep warm. It should never go outside unsupervised.

Hypertrophic cardiomyopathy (HCM), very common: regular echocardiograms of breeding cats (an associated genetic variant has been described, but scanning remains key). Hereditary myopathy or congenital myasthenic syndrome (COLQ), with a DNA test. Dermatitis, urticaria pigmentosa, sunburn, wax-related ear infections and dental problems.