My dog has a dime-sized spot with red inside on her neck. What is it?

That lesion is very irritated on Nana's poor little neck! Lesions like this can be related to trauma, a skin infection, the beginning of a hot spot or an infected cyst under the skin. I can't tell from the photo, but if it looks like bruising, then there is also a concern for a bleeding disorder and she needs to get to the vet right away. Assuming there is no bruising, I recommend to have the lesion examined by the veterinarian since it is so red. There are a few things you can do at home that may help until you get her into the vet. You can try adding in an omega 3 fatty acid supplement for dogs, this can help improve the skin health. You can wash the lesion with soap once a day and rinse well (don't wash her whole body, just the spot). Protect the areas from licking or scratching. A cool (not cold) compress twice a day may also make it feel better. Best of luck and please feel free to post any additional questions.

Bo's lesion looks most suspicious for a bacterial skin infection, but could also be due to ringworm, mange, or bruising. Since it does not seem to be bothering him, you can monitor the lesion for the time being to see if it changes colors, grows, becomes itchy, or spreads elsewhere. You can also try bathing him with an antimicrobial shampoo (here is one example: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=27982 ). However, if the lesion worsens or seems to be causing discomfort, it is worth taking a trip to the vet for evaluation. I hope that all goes well!

This lesion could indicate a local bacteria infection, possibly ringworm, an insect bite, or just an area of rotation of unknown cause. You could continue to monitor if you feel comfortable and if it does not go away within a few days I would reconsider seeing your veterinarian to ensure it's nothing contagious like ringworm. However if it starts to grow, bleed, become raised, or seems painful it should be seen sooner. In the meantime you could consider cleaning it with a very mild soap and warm water and keeping it clean and dry during the day. As there is a possibility it could be ringworm wash your hands thoroughly after handling the site.

Unfortunately, without physically examining the area and potentially performing some diagnostics, I can't say for sure what sort of lesion that is. At first glance, it looks like something that could have been self-induced due to a primary issue causing itchiness. You should probably schedule a veterinary appointment and in the meantime get a cone to prevent your pup come itching the area further. If you do not believe your pup is itchy, then I would be more concerned about some sort of animal bite or bacterial infection. Hope this makes sense.

It looks he has a dermatitis which could be secondary to a bacterial or fungal infection. You could clean the area with a wound wash and see if it resolves. If not and/or he has multiple lesions, he should be examined by a vet for treatment.

It’s uncommon for older dogs to get ringworm, and when they do it’s generally on the face. This area may have started to itch and she got it red and irritated from licking. I would clean the area with a medicated shampoo that kills both bacteria and yeast. Then apply a thin film of antibacterial ointment on it. In addition use a cone if she’s licking the area. If you wash your hands well after touching her you shouldn’t get anything. If it’s not healing or there are other areas then please take her in for an exam and skin tests to determine if it’s ringworm or infection. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for your dog.

Ring worm is a possibility and is contagious to both people and other animals. There is no way to be certain from the photos. Your vet can check it with a woods lamp to see if it reacts or do a culture to confirm it. It may be a reaction from a tick or allergy that is also causing those spots You can try to keep the spot clean and apply a topical antifubgal until you get the seen to be safe