Petco Text Logo
Petco Pet Logo

Why is my dog losing hair on his lower body and shedding a lot?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 1 year and 7 months old | 20 lbs

My dog has lost almost all of his hair on the bottom half of his body. There's no change in behavior or anything else that is a concern. Do you know what this could be? The hair he still has on top is shedding like crazy.

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

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

4 Answers

Most Helpful Answer

Image profile

Answered By David Darvishian

Veterinarian

Published on August 17th, 2017

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to hear about Sam. This is a bizarre hair loss pattern for sure. Not sure what is causing this and I would advise that you take Sam in for a vet evaluation. Many different things can cause hair loss including external parasites (fleas, ticks, mites, etc), bacterial skin infection, allergies, endocrine/hormone problems (thyroid, etc), contact irritants, etc. Your vet can evaluate Sam and then advise some diagnostic or treatment plan for Sam. Diagnostics may include some skin tests including a skin scrape, fungal culture, blood work, etc. to try to determine what is going on. Your vet may even advise a referral to a dermatologist in your area if they cannot determine what is going on. Once a diagnosis is made, a treatment plan can be recommended to treat this condition. I will just say that this pattern of hair loss is not typical so I am very interested to know what is going on.

Vote icon

1Pet Parents found this answer helpful

Related Answers from Veterinarians

  • Image profile

    Answered By Lauren Kennedy, DVM

    Veterinarian

    Published on

    I would be concerned about an allergy or a skin mite in Sam, especially if he is very itchy. This could also be a hormonal problem but is less likely based on his age. The good news is that his skin does not appear to be infected. I would recommend you take Sam to your vet to be checked out. You vet will check for skin infection, demodex (the skin mite) and ringworm. Your vet may prescribed some medication for Sam or may recommend a food change depending on what they find. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By Jennifer Summerfield, DVM CPDT-KA

    Veterinarian, Certified Dog Trainer

    Published on April 27th, 2018

    Hi there! There are quite a few things that can cause hair loss in dogs, so it's hard to say what might be wrong without being able to examine Mello and do some testing. Some common possibilities would include allergies, fleas, a bacterial or fungal skin infection, or skin mites (mange). Treatment will depend on what the underlying problem is, so it's important to get a diagnosis first. Because of this, I would recommend taking Mello to the vet for an exam when you are able to. He/she can do some simple skin tests to help diagnose the problem and get him started on appropriate medication to treat it depending on what is found.

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By Ricardo Fernandez, DVM

    Veterinarian, Veterinary Oncology Resident

    Published on August 15th, 2018

    Hi there! Thanks for using Petco Pet Education Center, formerly Petcoach! There is a variety of reasons that can explain alopecia or hair loss. The causes can easily be differentiated by the clinical signs associated with it and the physical exam findings as well as diagnostics. If Melo is only showing some hair loss without scratching or overgrooming then it could conditions such as alopecia areata that can affect dogs and usually resolves on its own. If there is evidence of scratching and you start noticing some redness or irritation associated with it, then other conditions such as allergies are possible. If you notice him overgrooming himself in that area then it could be something like psychogenic alopecia which is more of a behavioral issue. I think that since he is not having overt clinical signs and it is mostly hair loss, I think it is possibly transient and could resolve on its own. You can monitor this closely and if it does not resolve or it worsens then have him examined by your veterinarian. Good luck!

    Vote icon

    1Pet Parents found this answer helpful

See More Answers
image
Have A Vet Question?

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

Sponsored