Does your cat have bald patches, a rash, or scabs on the skin?

Possible medical causes

• Flea-saliva allergy can cause itching and lesions; hair loss alone does not establish it.
• Food, environmental or parasite-associated allergies can cause itch and lesions; speed of onset does not identify the type.
• Ringworm (fungal infection): often shows as round patches of hair loss with broken hairs and gray scaling or crusts (it usually doesn't look like the "red ring" seen on people). This is zoonotic — it can spread to humans too — so be especially careful if you spot it
• Infection, other inflammation and lumps may look similar and need history, examination and indicated tests.

Initial at-home suggestions

• Use a flea comb to check for fleas or black flea dirt
• Record lesion site, size and photos; circular hair loss can suggest ringworm but is neither diagnostic nor exclusionary.
• If ringworm is suspected, temporarily avoid close physical contact and clean the environment to lower the risk of transmission between humans and pets
• Record onset, spread and accompanying changes; gradual lesions may still need care, so speed alone does not set urgency.

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