Why is my cat's fur missing in a patch and not growing back?

That is definitely an interesting pattern of hair loss. I suspect this has to do with some sort of trauma. A scrape if he was trying to get “through” something, a chemical or thermal burn down the back, even a reaction to a topical medication such as a flea and tick application. From the picture the skin appears pretty normal, but pictures can be deceiving. If the fur does not appear to be growing back soon, or if it looks to be spreading then I would encourage you to have him evaluated by your veterinarian as soon as possible. Best of luck and thank you for using Pet Coach.

Hair loss is that area could be a few things. If you are using a topical flea medication and applying it there, that could be the cause. Cats can also get skin mites, allergies or ringworm (which humans can get), or an injury. Could the dried blood be from her scratching with her hind paw? From the photos, I don't appreciate any hair loss around the ears. Minor wounds can often heal on their own. Monitor the lesion closely, if it doesn't begin healing within a week or if it starts looking worse, have her examined by the veterinarian. Also make sure she is not scratching at the area. Best of luck.

I have seen this as a reaction to certain spot-on flea/tick treatments, vaccines and microchipping. If any of these were recently done, then I would be most suspicious of them being the cause. The skin appears a red, which indicates that something is irritating it and it appears oily, but I'm assuming that's from the antibiotic ointment. For now, it's best to just keep the area clean with a medicated cat shampoo. You can get this at the pet store. I would clean it once daily and not put the antibiotic cream on it. Use cool water when washing and rinsing to give some relief. You can stop the daily cleanings when the skin appears healthy again and the hair is obviously growing back. If the hair loss continues and the skin appears worse, then it's best to have a vet look at it, because it may need special treatment. I hope that helps and Phoebe gets better soon.

If this hair loss is in the area where the vaccine was given (sorry, I can't tell from the pictures exactly where it is) it could be a reaction to the vaccination. I'd recommend placing a call to the vet and describing the location of the hair loss; this may be an aberrant response to the vaccine that needs to be reported to the manufacturer.

We can sometimes see color changes in haircoat in animals as they age, or as a result of inflammation or trauma to the skin. If there are no lesions (redness, crusts or scabs, raised bumps, etc.) and your kitty is not bothering at the area by licking/scratching at it, I would just continue to observe the site. I would check it weekly for changes. If he begins to lose hair, starts licking/scratching, the skin looks red or irritated or other spots appear, then a vet exam is recommended.

Looks like Bolinha is having a mild skin reaction perhaps to the vaccine, if it was injected in this area. This isn't considered normal but it is a reaction and it is best to notify your vet that this occurred. A pre-medicaiton can be given before this vaccine is given in the future to help avoid this from happening again. Unfortunately the hair may not grow back, but as long as he is not having any other symptoms (lethargy, not eating, vomiting) then he should be ok. An antihistamine injection through the vet can help stop the skin reaction fr continuing. Best of luck with Bolinha and I hope everything goes well.

No, Missing hair is not a common side effect of vaccinations, and certainly not within hours of the vaccines. I would worry more about things like ring worm or mites. I would encourage you to have a follow up appointment with your veterinarian. They may consider a skin scrape or a fungal culture for ring worm. In the meantime I would recommend using good hygiene as ring worm is contagious to people as well. Best of luck and thank you for using Pet Coach.