Why is my cat losing fur on its neck and chest with a skin issue?

Hi, and thanks for your question. This could be due to an allergy, although it could also be infection or mites. First of all, in order to rule out skin parasites, you will need to treat with a high quality flea treatment, then ask the vet to perform a skin scrape - this might reveal an infection or a mite infestation. If all of those came back negative, the next step is to treat the allergy symptomatically and try to discover the cause of the allergy. Three main type of allergies are usually affecting pets: food allergies, flea and parasite related ones and environmental type (allergens coming from trees, pollens, dust etc etc). Some medications can be given by the vet in order to repair any possible skin lesions (like steroids and antibiotics). The following products can be found online and can be tried as a first line approach: Douxo PS Calm shampoo, Essential 6 spot on by dermoscent, Krillex Krill oil chews.
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