My dog's brown flea allergy spots aren't healing. When to see a vet?

Any type of irritation/inflammation can cause the skin to be darker in color when it heals. You can see that in the second picture. It is not abnormal for the darker color in the skin to last for a while, but it almost appears that the skin in the last picture is darker than the second (which might just be an artifical aspect of the picture). The skin appears to have healed well, so if the dark area is just taking a while to resolve, it likely isn't anything worry about. If it appears to be enlarging or getting darker however, I would have your vet examine Addison. I hope that helps! Thanks for using Petco Pet Education Center, formerly Petcoach!

These lesions may be in the healing process. Keep an eye on them for a few days, if they aren't getting better or seem to be spreading, have Curtis re-examined by the vet. He may need a biopsy to figure out what the active process is.

This is probably due to a severe allergy, although it could also be fleas or mites. First of all, in order to rule out skin parasites, you will need to treat Mia with a high quality flea treatment (e.g. Trifexis or Advantage), then get her to 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 discovering the cause of the allergy. Some medications can be given by the vet in order to repair the skin lesions (steroids and antibiotics). simultaneously you should start her on a prescription hypoallergenic diet for at least 2 months. Hopefully you will see some results after all this, if not you and your vet should consider putting her on a long term allergy treatment (Atopica or Apoquel).

It's a little odd that it is only on one side of the belly/leg. The rust color looks like saliva staining from your dog licking more frequently. The brown spots are likely clogged pores. I would work with your vet to treat itching (making sure he is on a good-quality flea preventative), food allergies, atopy, etc. You can also ask for a benzoyl peroxide dog shampoo to help flush the pores.

It could be local irritation and may or may not be related to the treatment. It does look "quiet" in the image provided though. Keep an eye on it, watching for redness, discharge or spread. You can clean it daily using a diluted Betadine or chlorhexidine (Hibiclens) solution. If there are any significant changes or if Miss Pebbles is scratching excessively, then she should be physically examined by your veterinarian.

Yes, it could be due to a flea allergy. The black you are seeing is post-inflammatory hyperpigmentation. I would not be overly worried about that. The lesion looks very quiet now. I would continue with the Seresto collar and if you notice this recurring or happening in another location I would have him seen by your vet for an exam.

Dogs with mange are typically extremely itchy and uncomfortable. This could be some local irritation or infection. Place an e-collar (cone) on Ben to prevent licking or chewing. You can clean the area daily using a diluted Betadine or chlorhexidine (Hibiclens) solution. Dry thoroughly afterwards. Treat him and the environment for fleas also if you haven't already done so. If the spot does not show signs of healing or worsens in the next few days, then have him physically examined by your veterinarian. Systemic and/or topical treatment may be indicated.