Petco Text Logo
Petco Pet Logo

Why is my dog licking a bump on her rear after allergy meds?

Updated On September 23rd, 2025

Pet's info: Dog | Blue Heeler | Female | spayed | 43 lbs

I noticed this bump on my dog's hind end, of course after vet hours today. She has been licking the area a lot and scratching the last couple of weeks. I took her in to vet 1 1/2 wk ago. They gave her Cytopoint injection. Apoquel wasn't helping much. Any thoughts what this bump is?

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 Jenny, DVM

Veterinarian

Published on July 7th, 2017

It is hard to tell from the picture but it maybe the start of a pustule which can be a sign of a skin infection. It may also be a cyst or sebaceous adenoma or wart as they have a similar looking characteristic. Since she has been through Cytopoint and Apoquel with out much relief, she may benefit from a dermatologist to get intradermal allergy testing. Your vet can check that spot to be sure what it is and set up a referral for the skin if you wish to pursue that route

Vote icon

1Pet Parents found this answer helpful

Related Answers from Veterinarians

  • Image profile

    Answered By Angel Alvarado, LVT

    Licensed Veterinary Technician

    Published on July 7th, 2022

    Given that they developed so quickly, it is likely not a tumor. More likely is an allergic reaction, insect bite/sting or localized infection. You can either monitor them for change or have her seen by your veterinarian. If she is licking excessively, you can place an e-collar (cone) on her until she sees the doctor. any treatment will depend on the diagnosis after a physical exam.

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By Ricardo Fernandez, DVM

    Veterinarian, Veterinary Oncology Resident

    Published on August 2nd, 2019

    Thanks for using Petco Pet Education Center, formerly Petcoach! These could be benign or malignant growths. There is no way of knowing what it is just based on its appearance. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have her evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good day!

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By Megan, DVM, CVA

    Veterinarian

    Published on December 19th, 2017

    These look like possible masses or old lick granulomas. Lick granulomas are from chronic licking. If she is currently licking it, you can try Benadryl twice a day and a cone collar to prevent this. The bump may never go away but if you can break the habit of her licking, it could help prevent it from becoming bigger, ulcerated, and infected. See the link below for Benadryl dosing. If these spots are brand new and she isn’t licking them or if they are painful and she is obsessed with them, I would have your vet take a look at them. Your vet will be able to aspirate them and look for suspicious cells under the microscope. Your vet will also be able to see whether or not she needs any oral antibiotics or stronger allergy meds like steroids or apoquel. I hope this helps! https://www.petcoach.co/canigive/dog/benadryl/

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Training & Behavior
My pit bull is prone to allergies. Usually has itchy ears, paws and genital area. I’ve been using a comfy cone to prevent excess licking, chewing and scratching on these areas. The other day, I noticed a “growth” on her vulva with irritation around
This may be an abscess, a cyst or a tumor. You should have it examined by your veterinarian, as it is not possible to distinguish these by just looking at a photo. An abscess can usually be treated with antibiotics and/or be lanced, and a cyst can be evacuated. To identify a tumor, your vet may want to do a fine needle aspirate (he takes some material from the bump with a needle and then looks at it under the microscope) to determine whether the mass is concerning.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
About 2 days ago, I noticed my dog, Mojo, had been licking a lot and found places where his fur had fallen out with a red bump in the middle. They only appear in this one spot. There is no sign of it anywhere else on him or his sibling. Could it be s
Thanks for using Boop by Petco! This is possibly due to allergies. It really comes down to figuring out what is causing his allergies so that they can be treated or the specific allergen avoided. 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 envir
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog keeps getting spots(like bumps), last time I took to vet was given an injection and cefabactin. All cleared up but after another month they seem to come back again. Giving him a wash with a medicated shampoo as well. He suffers from environmen
This is probably due to an allergy, although it could also be infection or mites. First of all, in order to rule out skin parasites, you will need to treat with a high quality flea treatment, then ask the vet to perform a skin scrape - this might reveal an infection or a mite infestation. If all of those came back negative, the next step is to treat the allergy symptomatically and try to discover the cause of the allergy. Three main type of allergies are usually affecting pets: food allergies, flea and parasite related ones and environmental type (allergens coming from trees, pollens, dust etc etc). Some medications can be given by the vet in order to repair any possible skin lesions (like steroids and antibiotics). Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog has constantly been licking and biting his belly. He seems to have some type of pimples or small bumps on it as well. Doesn't seem painful if I touch it lightly. He started with licking and chewing his paws but now its just the stomach. But he
Hi there. What you are describing is suspicious of allergies. While I always recommend that my clients get a skin scrape first to make sure there are no mites, etc, if this is negative we begin the journey to diagnosing the possible allergens. Many dogs have flea allergies. If your pet is up to date on a good flea preventative, this is not as likely. Commonly, dogs can develop food allergies over time as well. The worst part of checking for this is that a true food trial (a new specialized diet) has to be the ONLY thing you feed and can take a few months to see real resorts. Allergy medications are available now through your veterinarian's office. Depending on what they see on physical exam, your pet might be. Candidate for Apoquel or chtopoint injections to control itching. I hope this information helps!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog got this random red bump under his hair... I don't know what it is .. any suggestions before I take him to the vet ? I shaved the hair down around it too see if maybe it had a white head but I don't see any puncture marks nothing... he will li
From your pictures, a possible cause might be a lick granuloma. These start for some reason (sometimes a bug bite, a small scratch, or a small skin mass) and the dog licks at them and makes it worse. They lick at it and push surface bacteria deeper which makes it itch, so they lick. It becomes almost a habit like a human biting their fingernails. So- I would recommend a visit to the veterinarian. They can check to make sure that is what it is , make sure that the inciting cause is gone, and do some diagnostics to determine a treatment plan. Has there been any changes to Neo's environment? Sometimes stress can start a lick granuloma or prolong it. Your veterinarian will most likely start antibiotics and anti-inflammatories. They might also recommend increasing his activity in case boredom is a cause. If there is a small skin mass present- they will recommend diagnostics on that. Good luck! Sometimes these take time, so have patience. Thanks for reaching out to Boop by Petco
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My aunt left on a cruise yesterday. I am watching her female 8 month old dog (she is large) a few weeks ago I noticed little bumps on her inside ear area, asked about it but she said it was garden thorns? I also noticed some little marks on her under
Hello. This looks pretty typical for an allergic dermatitis that has lead to a skin infection. Ideally, this should be addressed by your veterinarian. They can discuss possible causes (food allergy, contact allergy, flea allergy, etc) and prescribe medications which may include antibiotics for the raised lesions and allergy therapies.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Can anyone please help me and tell me what this could be? It's been here for a long time and it doesn't go away, parents believe that it's nothing to worry about. It's itching her horribly & she has few of them on her abdominal area but this one is
This looks like a little skin wart which are usually nothing to worry about. It doesn't look red or infected at the moment. It could be that she has an underlying skin allergy that is causing the itching. If you are worried you should take her to the vet for an examination. Alternatively you could try giving her a daily antihistamine to see if that settles the itch.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog has blister like bumps all over when caught they bleed no puss or anything he has allergies all white
It sounds as if your dog has a skin infection, most commonly caused by an allergy or fleas. The allergy could be a due to a protein innyour 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 redness, crusting, flaking, and pustules. 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. I hope this helps. Thanks for using Boop by Petco. Best of luck!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Anasha is an older dog she was coughing and all of a sudden stopped and this happened...bumps all over her body took her to the vet they said a food allergy but it has gotten worse after benadryl for a week her eyes are red and back legs very weak
Poor thing. That looks very uncomfortable. This does look consistent with an allergic reaction to something, although it could anything she's reacting to. Skin issues like this can also be caused less commonly by a primary problem with the skin or even some types of cancer. I would recommend going back for another visit as soon as possible to try to get to the bottom of this. A simple reaction wouldn't stick around so long. Next steps may include general blood work, sampling the bumps (either with a needle or a minor surgery), or even a trial of different medication. If you're vet isn't sure what to do next, I'd strongly recommend asking for a referral to a dermatologist.
Updated on September 24th, 2025
Petco Pet Education Center
Training & Behavior
Hi, recently my dog has gotten these lumps and rashes on her stomach, privates and thigh/armpit area (front and back legs). We Think maybe allergies but tried researching and having found anything. It keeps her up a lot licking, scratching and biting
This looks like a secondary infection due to allergy or pyoderma which is a bacterial skin infection. Either way it requires being seen by a vet to establish exactly what is going on, then treat appropriately. If allergy we need to distinguish if it is good or environmental. Primarily the skin infection needs treated though, likely with antibiotics and medicated shampoo.
Updated on September 24th, 2025
image
Have A Vet Question?

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

Book Now

Sponsored