Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

    rewards header
    Become a member today!
    Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
    Already a member? Sign in
    Petco Pay LogoBecome a credit card member today!

    Earn 2X Pals Rewards points at Petco
    when you use Petco Pay!

    APPLY NOW
    Learn More About Petco Pay Benefits

Why does my dog have a red, irritated rash under his armpits?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | neutered | 4 months and 11 days old | 97 lbs

My dog has a red rash under his armpits. One seemed just like an irritation but the other looked more red and looked almost bloody. He has a cone on right now and has not been licking it but that could just be because he knows he cant. I'm not sure if maybe this is irritation from something and/or irritation from being dirty since he hasn't been able to bathe. I'm sorry the pictures aren't the best.

This question includes photos that may contain sensitive content. Click to view.

View more to consider that the photos may include sensitive content.

2 Answers

Most Helpful Answer

Image profile

Answered By Ricardo Fernandez, DVM

Veterinarian, Veterinary Oncology Resident

Published on November 3rd, 2017

Thanks for using Petco Pet Education Center, formerly Petcoach! This could be due to allergies, especially if he is itchy. It really comes down to figuring out what is causing his allergies so that they can be treated or the specific allergen avoided. 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!

Vote icon

1Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on February 22nd, 2017

    You are correct that it could be allergies, but instead of food allergies, it could be due a contact or environmental allergy. It could also be due to a bacterial or fungal skin infection. I agree that seeing your vet is the best thing to do for Jack, and in the meantime, you can try giving him an Epsom salt bath or an oatmeal bath to see if that helps. I would have Jack seen by a vet in the next couple of days, tomorrow if possible. I hope this helps you!

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
Why is my mouse's eye swollen, cloudy, and has pus?
Is your mouse's eye swollen, cloudy, and pussy? Dr. Melanie, a certified vet, discusses severe eye issues like infection or abscess, urging an immediate visit.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
What fish dog food helps dry skin if my dog eats Science Diet?
Is your dog's dry skin a concern? A certified vet offers expert advice on finding the best fish-based dog food alternatives to Science Diet for essential oils.
Updated on February 04, 2026
Petco Pet Education Center
Health & Wellbeing
My pet is breathing hard, not eating, and lethargic. What's wrong?
Is your rat breathing heavily, won't eat, and has no energy? A Licensed Vet Tech explains potential causes like infection and age, urging a vet visit for diagnosis.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My pet has red spots all over. What's causing them and what to do?
See red spots on your pet? A certified Petco vet discusses common causes like allergies, infections, or mites, guiding you on diagnosis and treatment options.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My small pet is limping and can't bear weight. Should I see a vet?
Is your pet limping and can't bear weight? A certified vet explains why a suspected fracture needs immediate diagnosis and safe pain relief. Get expert guidance.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My degu has a white bump in its fur. Should I take my pet to the vet?
Worried about your pet degu's white pustule? A certified vet discusses this potential skin infection, explains why not to pop it, and guides your next steps.
Updated on December 04, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored