What causes hair loss and red skin on my 3-month-old puppy's back?

I would have this checked by a vet. It sounds very much like ringworm. Although the name suggests otherwise, ringworm is not caused by a worm at all-but a fungus. This highly contagious infection can lead to patchy areas of hair loss on a pet, and can spread to other animals-and to humans, too. Classic symptoms of ringworm include lesions that typically appear on a pet’s head, ears, paws and forelimbs. These lesions can cause patchy, crusted circular “bald spots” that sometimes look red in the center. In mild cases of ringworm, there may be just a few broken hairs, while bad cases of ringworm can spread over most of a pet’s body. It’s also possible for a pet to carry the fungus and not show any symptoms whatsoever. Treatment of ringworm depends on the severity of the infection. A veterinarian may prescribe a medicated shampoo or ointment that contains miconazole or a dip such as lime sulfur to kill the fungus. In some cases, oral medications are necessary to cure ringworm. In severe cases, it may be necessary to use a topical and oral treatment, in addition to clipping away the fur. Once treatment begins, lesions should begin to heal in about one to three weeks. Please note, it is important to treat your pet for as long as recommended by your veterinarian. Even though the skin lesions may have cleared up, this doesn’t mean your pet is cured or can’t infect another animal or person. Certain diagnostic tests may need to be repeated in order to ensure cure. And unfortunately, there is no guarantee that reinfection won’t occur!

The area on Desi's back does not seem irritated, infected or swollen. I would continue to monitor it. Start by taking a ruler and measuring the affected area. In a week check back to see if it has gotten larger or smaller. It larger I would alter Desi in for an examination by her vet. There are several causes of hair loss, but he most common is traumatic biting by dogs when they have an itch in their skin. This could be caused by allergies or parasites. Best of luck with Desi and please ask as many questions as you need while this skin issues is being monitored. We are here to help!

There is a good chance that this is just a hot spot and allergies. Mange usually starts with hair loss on the feet or around the eyes, but not always. It could also be secondary to fleas. I would try some Benadryl twice a day (see link below) and also a cone collar to prevent him from chewing. If you can get in touch with the owner, I would talk to them about this and see if they want you to take him to the vet. The vet may be able to get him on a stronger allergy medicine, determine the cause and start antibiotics if needed. I hope this helps! https://www.petcoach.co/canigive/dog/benadryl/#!

Rosie should see a veterinarian for a skin scrape in order to determine if she has Demodex. This is a mange mite that is most common in young puppies and presents with hair loss, red skin and pustules like you see in the photo. There are several very successful treatment options for this. Thank you for using Petco Pet Education Center, formerly Petcoach.

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies. A secondary infection is likely and also needs to be addressed. There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests. Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!

Thanks for the pictures. By looking at them, there seems to be a different look to some of them. The one on the nose appears raised, and has me concerned that it is skin mass. It could just be the picture angle... Hairloss in dogs is usually related to mites, or allergies. I would recommend taking Parker into a veterinarian. They can see if the lesions are related to each other. They will also do some diagnostics such as a skin scrape to check for mites, skin cytology to check for secondary infections and possibly a fungal culture. If the nose lesion is actually a mass, they will most likely do a cytology (stick a needle in it, push cells on a slide, stain slide and look at them under a microscope). If it turns out to be allergies, please realize that allergies (just like humans) can't be cured, only controlled. It may take a few different treatments to get them under control. Hope Parker feels better soon! Thanks for reaching out to Petco Pet Education Center, formerly Petcoach!

Thank you for using Petco Pet Education Center, formerly Petcoach! I can see an area of hair loss, redness, thickening of the kin, and what appears to be a scratch. This can be caused by bacterial or fungal skin infections such as ringworm, skin mites, or autoimmune diseases. I recommend having your dog seen by a vet as ringworm can be transmitted to people. I hope this helps and that all is well!