What's causing my dog's extreme itchiness, skin wounds, and hair loss?

Hello. Toby has a type of dermatitis going on, but the underlying cause cannot be determined just from a photo. It could have a bacterial, autoimmune, fungal or even parasitic ( mange mites ) cause. Your veterinarian can use a couple of rather simple diagnostic aids ( skin scrapes, hair plucks, dermatophyte cultures ) to determine the cause of the hair loss & lesions, then the correct treatment can be started to resolve this. Good luck & thanks for using Petco Pet Education Center, formerly Petcoach.

It does look like Toby's skin is quite irritated! The small bumps could mean that there is bacteria in his skin (also known as pyoderma) and he should see a vet for examination and appropriate medications. However, there is usually an underlying cause for the itching and subsequent infection. The most common causes would be fleas, ticks, mites, or allergies. Allergies can be from a range of things, including flea saliva, food proteins like chicken or beef, or the environment like dust, pollen, mold, or grass. If Toby has a food allergy, he may benefit from a novel protein diet or a prescription dog food for allergies. These are good things to discuss with your vet. While you wait for his appointment, try to prevent Toby from further itching his inflamed skin to prevent further damage. You can cover him with a dog or human shirt or try to put socks on his feet. If he is licking then he may need to wear a cone/e-collar. You can try to use some hydrocortisone cream on the itchy spots, but don't let Toby lick it off!

Allergies can be frustrating to diagnose and treat, for the pet, the pet owner, and the veterinarian! It is the most common cause for itching in dogs. Medications like Apoquel can eliminate the itch due to allergies, though it won't work if there is a secondary bacterial or yeast infection. Food allergies won't be treated simply by a better diet, they need to be strictly on a prescription hypoallergenic diet without other dog or human treats, and even then it can take 3-6 weeks to see positive effects. Until then, anti-itch medications, steroids, or shampoos/topical mousses can be used to minimize the itch and treat any present infection. I would recommend continuing to work with your vet to find the best solution to Toes's itch issue.

It looks as if your dog has a skin infection, most commonly caused by an allergy, a skin mite (Demodex) or fleas. 

The allergy could be a due to a protein in your dog’s food or an environmental allergy like to dust, pollens, grasses, etc. 

The allergy causes your dog to itch and chew at the skin which breaks down the skin barrier. This then leads to infection. Skin infections are typically characterized by large areas of hair loss, redness, crusting, flaking, and pustules. A thorough skin examination by your veterinarian should be able to determine the cause of the itch so it can be treated appropriately. Your dog will most likely need antibiotics to help clear up the infection and possibly an allergy/anti-itch medication like Apoquel, Atopica, or Cytopoint to give some relief while the infection clears up. A medicated shampoo may be beneficial as well. I would also recommend he be on a good flea control routinely too. Once the infection has resolved a long term allergy medication (like Apoquel or Cytopoint) can be given on a regular basis to prevent any future problems. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.


It looks as if your dog has a skin infection, most commonly caused by an allergy, a skin mite (Demodex) or fleas. 

The allergy could be a due to a protein in your dog’s food or an environmental allergy like to dust, pollens, grasses, etc. 

The allergy causes your dog to itch and chew at the skin which breaks down the skin barrier. This then leads to infection. Skin infections are typically characterized by large areas of hair loss, redness, crusting, flaking, and pustules. A thorough skin examination by your veterinarian should be able to determine the cause of the itch so it can be treated appropriately. Your dog will most likely need antibiotics to help clear up the infection and possibly an allergy/anti-itch medication like Apoquel, Atopica, or Cytopoint to give some relief while the infection clears up. A medicated shampoo may be beneficial as well. I would also recommend he be on a good flea control routinely too. Once the infection has resolved a long term allergy medication (like Apoquel or Cytopoint) can be given on a regular basis to prevent any future problems. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

It looks as if your dog has a skin infection, most commonly caused by an allergy, a skin mite (Demodex) or fleas. 

The allergy could be a due to a protein in your dog’s food or an environmental allergy like to dust, pollens, grasses, etc. 

The allergy causes your dog to itch and chew at the skin which breaks down the skin barrier. This then leads to infection. Skin infections are typically characterized by large areas of hair loss, redness, crusting, flaking, and pustules. A thorough skin examination by your veterinarian should be able to determine the cause of the itch so it can be treated appropriately. A skin scraping and skin cytology should be performed to rule out mites and to determine the type of infection present (bacterial vs fungal). Your dog will most likely need antibiotics/antifungals longterm to help clear up the infection and possibly an allergy/anti-itch medication like Apoquel, Atopica, or Cytopoint to give some relief while the infection clears up. A medicated shampoo will be beneficial as well. I would also recommend he be on a good flea control routinely too. Once the infection has resolved a long term allergy medication (like Apoquel or Cytopoint) can be given on a regular basis to prevent any future problems. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.


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!