Adrienne is a certified dog trainer and former veterinarian assistant who
partners with some of the best veterinarians worldwide.

Bumps or welts on your dog may be caused by a number of environmental

Bumps or welts on your dog may be caused by a number of environmental

Alexandru Rotariu

My Dog Has Bumps Under Its Fur All of a Sudden

Urticaria is the medical term used to denote the presence of hives, welts, or
wheels on a dog’s skin. The skin rash presents as uncomfortable raised, red,
itchy bumps. The welts can be localized on the dog’s head, legs, belly, or
back, or they can be widespread all over the dog’s body and may come and go.
Some dog owners describe the welts as dime-sized bumps on the dog’s skin.

While there are many causes of welts in dogs, they often tend to result from
an acute (arising suddenly) allergic reaction. A common culprit can be
vaccinations, which is why vets often recommend keeping an eye on the dog for
the first few hours after receiving shots. Other causes are allergic reactions
and exposure to certain types of plants, insect bites, household chemicals,
medications, foods, and even stress. In some cases, the presence of welts may
be indicative of other medical conditions. This article will focus on welts
triggered by allergic reactions.

Common Causes of Welts on Dogs

Grass Pollen


Insect Bites or Stings




Dust Mites


Food and Medication


Misc. Environmental Allergens

Mold Spores


Chemical Exposure



Why Does My Dog Get Welts on Their Body?

When it comes to allergic reactions, welts can form when there is direct
contact with an irritant. In this case, it’s called “contact dermatitis,” and
the allergic reaction is mostly localized to the area that came in contact
with the allergen. The welts or rash will, therefore, often show up on the
dog’s feet and the belly area if the dog happens to lie down on the trigger.
Inhaled allergens such as grass pollen, dust mites, or mold can also cause
welts, as well as insect bites.

Sometimes, the actual trigger may be difficult to pinpoint and the underlying
cause of the welts on the dog’s skin will remain a mystery. A veterinary
dermatologist may test for some common allergens, but the process can be
costly and challenging at times.

Above: Testing a dog for allergies as they do in human medicine with
transdermal injections.

Above: Testing a dog for allergies as they do in human medicine with
transdermal injections.

Caroldermoid CC-BY-SA-3.0

What Causes Welts?

When the dog’s immune system reacts to an allergen, mast cells in its
bloodstream release the compound histamine. Histamine triggers small blood
vessels under the dog’s skin to leak. The accumulated fluid, therefore, forms
large welts.

Welts Can Indicate a Risk for Complications

One concern about welts is that they can sometimes be accompanied by swelling
of the lips, nose, and eyes, which is medically termed angioedema. The eye
swelling may be so severe that a dog cannot open its eyes, and these cases may
require antihistamines and injectable steroids. Serious cases may also spread
to the throat (laryngeal edema), which can block the dog’s airway and lead to
anaphylactic shock. Other accompanying symptoms may include:

  • Vomiting
  • Abdominal pain
  • Diarrhea
  • Shock
  • Pale gums
  • Cold legs
  • Incoordination
  • Sudden collapse
  • Convulsions
  • Death

In an emergency situation, time is of the essence. According to the Merck
Veterinary Manual, dogs can die from anaphylaxis within minutes. These dogs
need immediate veterinary attention which typically requires a shot of life-
saving epinephrine. For those curious to know, yes, they do make epi-pens for

Respiratory distress can occur if the angioedema involves the nares, larynx,
or pharynx.

— Karen A. Moriello, DVM, DACVD

Veterinary Treatment for Welts in Dogs

In order to address welts in dogs, the underlying allergy needs to be
pinpointed. Benadryl is an antihistamine that blocks the release of histamine
and can help provide relief. According to veterinarian Dr. Christine M.:

Plain Benadryl (diphenhydramine) can be given at a dose of 1 mg per pound of
body weight every 12 hours until the dog’s symptoms are gone.

It’s always best to consult with a veterinarian before giving Benadryl to dogs
and to discontinue its use if the dog shows behavior changes such as
excitement or lethargy. Benadryl should not be given to dogs suffering from
glaucoma. Other prescription medications include Claritin (loratadine) and
Atarax (hydroxyzine), which are to be given under the guidance of a

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Prescription Steroids

For severe reactions, steroids are sometimes given as a shot or as an oral
medication (i.e., prednisone), but these drugs can have uncomfortable or
severe side effects at times and suppress the immune system. In some cases,
the dog may develop welts again once the steroid is out of its system.

Antibiotics for Secondary Infections

When dogs have rashes, the constant itching and scratching may cause lesions
and secondary bacterial or yeast infections; this may require a course of
antibiotics. A veterinarian will need to diagnose these secondary skin
conditions by analyzing a skin sample under a microscope. The infections are
often treated with antifungal or antibacterial shampoos such as chlorhexidine
shampoo for bacterial infections and Malaseb shampoo (an antifungal).

It is important to find out which environmental allergen is triggering your
dog's welts.

It is important to find out which environmental allergen is triggering your
dog’s welts.

Mitchell Orr

Natural Remedies for Nonsevere Dog Welts

  • Omega-3 Fatty Acids: Omega-3 Fatty Acids are also beneficial for the skin, but may take some time to kick in and provide relief. Veterinarian Dr. Kara recommends combining fatty acids and antihistamines as they are more effective in combination rather than when used individually.
  • Bathing Under Cool Water: Bathing may provide relief as it minimizes the time an allergen is in contact with the skin (pollen and grass accumulate on the skin). Oatmeal baths are soothing for dogs with allergies also.
  • A Hypoallergenic Diet: If the vet suspects that the welts derive from a food allergy, a special hypoallergenic diet may be recommended. This means no more table scraps or treats. Common prescription diets often contain novel proteins a dog has not been exposed to before. Hypoallergenic diets need to be followed for at least 2 to 3 months or more for the effects to be seen.


This article is not meant to be used as a substitute for veterinary advice.
If your dog has welts, please see your veterinarian.

This article is accurate and true to the best of the author’s knowledge. It
is not meant to substitute for diagnosis, prognosis, treatment, prescription,
or formal and individualized advice from a veterinary medical professional.
Animals exhibiting signs and symptoms of distress should be seen by a
veterinarian immediately.

Questions & Answers

Question: How long does it take for welts to fade away on a dog?

Answer: This depends by a variety of factors such as how severe the
reaction is, whether the trigger is still around (is the dog still exposed to
it? It’s hard to say if the trigger remains unknown) and whether medications
are given. Some dogs have them just for several minutes, others for hours and
some for several days.

Often, Benadryl is not enough to control hives in dogs, and stronger meds such
as prednisone are needed. Please see your vet for proper treatment. Sometimes
welts may progress and cause trouble breathing which may turn into a life-
threatening situation.

Question: We have tried so many things with our puppy. He is 4 months old
and has had hives for 7 weeks now. What else can we do for our puppy’s hives?

Answer: Have you seen a board-certified dermatologist? If you have had
repeated vet visits and got you nowhere, have tried medications, food trials
etc. it may be time to see a specialist who has made of skin problems the area
of specialty.

Question: What does a welt look like on a dog?

Answer: Welts in dogs typically appear as raised areas of the skin
varying in shape and size. They are often itchy.

© 2016 Adrienne Farricelli


ccrow on August 19, 2020:

“…presence of hives, welts, or wheels”

I think the word you’re looking for is ‘weals’.

Tina6969 on August 04, 2020:

My pits have allergies, (pitbuls),… I have been in business for animals for
33 years. The best thing is benadryl. 1mg. Per lb. Of your dog is the best,
but they need to hve breakfast 1st…. If that is not working within an hour,
and your animal is acting weird… Get them to E.R.!!!!

Don’t take the chance of death.

You know your baby.

Don’t listen to noone else.


And stay sfe peeps!

Harley C. on July 20, 2020:

Our dog started with welts and we’re thinking it’s her new “luxury” dog bed
from Costco. It’s been washed with non-perfume/dyes detergent but she still
has welts maybe from the fibers or filling? The bumps clear up after her bath
but return the following day. We’re experimenting now to see if it really is
the bed (it was an expensive bed) or maybe her food.

Lin on June 07, 2020:

My dog has had allergies for years, just recently I was told he needed a
L.I.D. went on that and the hives and itching gets worse. The food he was on
we did not have hives but we had issues with licking and chewing

Nathan Davis on November 28, 2019:

Vaccine damage.

Adrienne Farricelli (author) on June 02, 2019:

Linda H, this can be quite frustrating to deal with. There are so many
possible causes it can be overwhelming. Plastic food bowls, chemicals on the
floor, laundry detergent used to wash bedding, ingredients in foods are just a
few examples. Sometimes, vets (and human doctors too!) find it easier to give
meds to control the welts than try to pinpoint the exact cause.

Linda H on May 30, 2019:

I have 2 boxers, one is having raised bumps in the morning. The bumps go away
for the day but returns the next morning. I haven’t changed anything. Any

Firsttimemom on December 13, 2018:

Thank you soooo much this is what i wanted to read!

Art on October 23, 2018:

My dog has all the symptoms mentioned regarding allergies. Steroids is you’re
only hope. Not even a vet can figure it out. They prefer not to give steroids
however it’s they only alternative. Anything else is a waste of money and

Jackie Karp on September 12, 2018:

Will coconut oil help with a million. Bumps that are bleeding

Amanda norton on July 29, 2018:

Last night our indoor dog came in my room with really red eyes and swollen
bumps all over him?? He’s terrified of storms could it be his nerves??? He’s
never done this in the past??

Marisell on April 28, 2018:

My yorkie has bumps all over her body, the grass is high and she had a ant in
her coat when I bathe her last nite

Gina Auton on September 15, 2017:


Jenny on February 21, 2017:

Thank you. Helpful article!

Adrienne Farricelli (author) on June 05, 2016:

Thanks all! This is important information to be aware of as dogs can be prone
to allergic reactions and welts in dogs may not be readily identified as they
look different than welts in humans.

Devika Primić from Dubrovnik, Croatia on May 31, 2016:

I like the way you write about our friendly pets. Informative and always

Karen Hellier from Georgia on May 30, 2016:

Interesting article. I have never noticed welts on my dog’s body but she is 11
and has had hot spots and fatty tumors. Thanks for this information though.
Very thorough article.

stella vadakin from 3460NW 50 St Bell, Fl32619 on May 30, 2016:

Very interesting article and good advice. I have always used benadryl for my
dogs. I am lucky my smaller dogs do not seem to get much of anything.