Why does my 4-week-old puppy have hair loss patches and sores on legs?

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!

From the photos here it looks like these are patches of hair loss. We can have hair loss at points of pressure if a dog likes to lay on hard surfaces, but we also worry about things like ringworm (a fungal infection), skin mites, and bacterial infection causing patches of hair loss. I would recommend bringing your dog in to the vet to examine the area. They may recommend a fungal culture if ringworm is suspected or a cytology of the skin to check for bacteria or a skin scrape to check for mites.

This is very suspicious of an infection called ringworm, it is a common fungal infection in puppies. you will need to take him to the vet in order to get it confirmed and treated with an antifungal medication.

I am sorry to hear of your concern for Chelsea! I would recommend having Chelsea examined by your regular veterinarian. Without seeing her in person it is difficult to determine the nature of the hairless patches. However, in a young dog hairless patches on the legs and body would make me concerned about a parasite like demodex. Your veterinarian can do a thorough physical exam and will likely recommend some diagnostics such as a skin scrape, to help them determine the nature of these lesions. Your vet May prescribe medications such as a topical or oral parasite treatment, medicated shampoo and antibiotics.

Thanks for using Petco Pet Education Center, formerly Petcoach! This is likely either due to mites or allergies. I highly recommend that you have him evaluated by a veterinarian for further assessment and treatment. They would be able to diagnose this so that therapy can be started. Best of luck!

Hello! Thanks for using Petco Pet Education Center, formerly Petcoach! First off, you're doing a great job by keeping fleas off the mother dog and combing the pups regularly. Looking at the spots of hair loss on the head, my top suspicions would be ringworm, demodectic mange, or a bacterial skin infection. I would recommend you take her into a vet to find out what the problem is. Ringworm is a skin fungus that can be transmitted to people, but it is treated fairly easily if it is caught early. The vet will likely recommend a DTM culture to test for fungal infections, and a skin scraping and impression smear to find the root of the problem. I hope that helps!

Puppies are at risk for mites like demodex, ring worm, bacterial infections. I would recommend an exam with your vet and a skin scrape to look for mites. Some mites are contagious to people like sarcoptic mange. Some mites are not. Hope that helps