Common Dog Skin Allergies: Causes, Symptoms & Treatment

Reviewed by Dr. Fiona Lee

Skin allergies can have a significant impact on your dog's quality of life, often resulting in persistent scratching, loss of fur and a host of other serious health issues, including infections. Sadly, skin allergies are becoming more common. One study found that environmental allergies in dogs had increased 30.7% just from 2008 to 2017.¹

Identifying your dog's allergic trigger and treating it can require some trial and error with your veterinarian, as you test different possibilities and treatment options and check your dog's reaction. That's why if your dog is suffering from skin allergies, it's important to see a veterinarian sooner rather than later.

Symptoms of Dog Skin Allergies

Skin allergy symptoms are more complicated than just itchiness. Symptoms may vary depending on the type of allergy your pup has. Here are some examples:

• Itching (pruritus) and scratching²
• Redness and inflammation²
• Open wounds, hives or bumps²
• Excessive licking²
• Swollen paws,² face, ears, lips or eyelids³
• Hair loss or thinning²
• Ear infections³
• Shaking the head (often due to itchy ears)²
• Biting the skin²
• Secondary infections from scratching²
• Watery, itchy eyes³
• Dry or oily skin²
• Diarrhea, gas or other stomach issues⁴

The discomfort your dog feels can also lead to behavioral issues, such as:²

• Chewing
• Begging or stealing food
• Hyperactivity
• Seeking attention
• Becoming more reactive and irritable

Dog breeds that most commonly develop skin allergies are also some of the most popular. They include Doodles, Golden Retrievers, Boxers, Labrador Retrievers, Shih Tzus, Pugs, Dalmatians, Terriers, Irish Setters, German Shepherds, French Bulldogs and the Lhasa Apso.² But any dog, no matter the breed, has a chance of developing allergies.

Causes of Dog Skin Allergies

Skin allergies have a wide variety of potential causes. For example, if your dog's ear itches a lot, they could be allergic to yeast,⁵ inflamed from a food allergy or itchy from a different allergic reaction.² Here are nine causes your veterinarian might consider.

1. Environmental allergens

Environmental allergies may sometimes get worse during certain seasons. Some examples include (but aren't limited to):²

• Pollen
• Weeds
• Grasses
• Molds

2. Food allergies

Food sensitivities can cause itchy skin. Your dog may also have diarrhea, vomiting, hives, sneezing or red eyes. This allergy can start at any age and is often triggered by a specific protein. Beef is the most common culprit. Other triggers include dairy, chicken, wheat, lamb, or (to a lesser extent) soy, corn, egg, pork, fish or rice.⁶

It's important to note, however, that food allergies are much less common than you might think, and are often overdiagnosed. In one report, only 24% of dogs with skin problems were actually allergic to their food.⁷ Two other studies showed that in dogs with allergic skin disease, food allergy was the diagnosis in just 7% to 25% of those dogs.^{8, 9}

3. Contact dermatitis

Contact dermatitis refers to any allergy that starts when a substance makes physical contact with your dog's skin. Potential irritants include (but aren't limited to) cleaning agents, shampoos, soaps, herbicides, metal, plastic, textiles, cedar chips, carpet or litter deodorizers and topical medicine.¹⁰

4. Flea allergy dermatitis

Your dog can become allergic to the saliva in flea bites. In this case, you might see rashes, open wounds and a lot of itchiness, especially at the base of the tail.²

5. Atopic dermatitis

This is a chronic allergy, with symptoms that may resemble hay fever, along with very itchy skin.²

Many veterinarians currently believe that atopic dermatitis in dogs as well as humans involves defects in the skin barrier, alterations in the skin microbiome and antigens (such as environmental pollens or molds). When the allergen contacts the skin surface, the impaired skin barrier enables the antigen to penetrate the epidermis, initiating inappropriate inflammatory responses.^{11, 12, 13}

6. Yeast infections (Malassezia dermatitis)

Also called yeast dermatitis, this issue occurs when there's yeast overgrowth on your pup's skin, leading to inflammation. Pre-existing skin allergies can make your dog's skin more susceptible to yeast dermatitis. Symptoms are similar to allergies but may also include a musty odor or hyperpigmentation. Sometimes this can be a source of ear infections.⁵

7. Sarcoptic mange (scabies)

Sarcoptic mange (also called scabies) is a serious condition that occurs when mites live on the outer layer of your dog's skin. Your dog will have a serious allergic reaction to the mites and their feces, leading to extreme itching, red and crusty skin, fur loss and sometimes weight loss. Unlike allergies, mange is very contagious. A skin scraping or a blood test can help diagnose it so your dog can get the right treatment.¹⁴

8. Hot spots (acute moist dermatitis)

A hot spot is a painful, oozing sore on your dog's skin that seems to come out of nowhere. It can be triggered by trauma, like scratching, and gets itchier over time, causing more scratching that makes the issue worse. Sometimes allergies can cause the initial trigger, along with parasites, a dirty coat or even boredom.¹⁵

9. Staph sensitivity

Sometimes dogs' immune systems overreact to staph bacteria if it gets on their skin. This is more likely in dogs that already have a flea or inhalant allergy.⁴

Diagnosing Skin Allergies

The American Animal Hospital Association recommends that veterinarians do the following when diagnosing skin allergies in dogs:¹⁶

• Get a thorough history, including past medical records.
• Give a physical exam with a flea combing.
• Collect a skin scraping and perform a skin cytology (and culture if needed) and an ear cytology if the dog has ear symptoms.
• Treat secondary infections.
• Prescribe a flea and tick preventive.
• Try one medication and check the pet's response in two weeks. Try a different medication if there's no response.
• Conduct a four- to 12-week diet trial if there's no response or only a partial response to medications.

Sometimes a more thorough allergy test may be recommended, such as a serologic blood test or an intradermal skin test that injects a bit of allergen to test your dog's response.²

Treatment Options for Dog Skin Allergies

Remember: Discovering the treatment that works for your pup can be a trial-and-error process with your veterinarian, and treatment is generally lifelong. Your veterinarian may recommend any of the ideas below.

“Finding a treatment to ease the dog's suffering can be a long and expensive process," explained Dr. Jack Stephens, founder and president of Pets Best Insurance. "Dogs respond differently to the various options. It can take a while until a long-term solution is found."

1. Avoidance of allergens

Helping your dog avoid their allergic triggers is a great place to start. For example, if your dog is allergic to fleas, use a flea preventive.⁴ Some steps you can take to help control allergen exposure include keeping your windows closed, using a dehumidifier to counteract mold, washing and vacuuming pet mattresses and supplies and using a HEPA air purifier.²

2. Antihistamines

Antihistamines (like Benadryl or Zyrtec)⁶ can treat allergies, but they're not always effective. If they do work, this can be a more affordable option with fewer side effects.⁴ Your veterinarian will tell you what dosage to try.⁶

3. Corticosteroids

Corticosteroids can help with symptoms in the short term, but they come with potentially greater side effects. These include increased appetite, thirst and urination, as well as behavior changes and skin jaundice. More common skin side effects may include fur thinning, fur loss and skin thinning and stretching. Long-term use may put your dog at risk of diabetes or less resistance to secondary infections.⁴

4. Other medications

There are many other medications your veterinarian might try, such as:

• Apoquel (a daily pill) or Cytopoint (an injection), as both neutralize cytokines that cause allergies¹
• Cyclosporine, which reduces inflammation and itching by lowering certain immune mediators⁶
• Antibiotics, antifungals or ear medication, depending on the infection⁶

5. Topical treatments

Topical treatments may also help your pup's symptoms. Try medicated shampoos and baths that have antifungal or antimicrobial properties.⁴ An anti-inflammatory wipe might soothe some skin irritations.³ Your veterinarian can recommend the best cream, spray or shampoo for your dog's condition.⁶

6. Immunotherapy (allergy shots)

Another option is immunotherapy (aka allergy shots). These can help as many as 70% to 75% of dogs improve their symptoms by at least 50%. The downside is that shots can take four to six months to start working, or sometimes as long as a year.¹

7. Dietary management

If you believe food is your dog's trigger, your veterinarian may want to try a special diet to manage the symptoms. This might be a hydrolyzed protein diet, which uses a special protein broken down to not trigger the immune system. Another option is a novel protein that your dog has never eaten before.⁶

8. Bathing and grooming routines

Changing your dog's bathing or grooming routine might help, such as using a hypoallergenic and emollient shampoo. Or try rinsing the pads of your dog's feet and wiping their coat with distilled water after you've been outside.¹⁷

An oatmeal bath might also help soothe irritated, itchy skin because it helps keep your dog's skin hydrated. Talk to your veterinarian first.¹⁸

9. Supplements to support skin health

If your dog has a food allergy, your veterinarian might recommend supplements like fish oil or other types of omega-3s.³ Other supplements, like probiotics, extra fiber from pumpkin or shaved carrots, apple cider vinegar, raw yogurt or leafy greens, might help reduce inflammation and histamine production. Just check with your veterinarian first.¹⁷

See Your Veterinarian for Any Concerns

Your dog's skin allergies can be so uncomfortable that your pup might misbehave from the pain or even develop secondary infections. Finding the best treatment can take time, so it's important to see your veterinarian as soon as you notice changes in your dog's behavior or any concerning symptoms. With a little patience and a lot of love, you can discover your pup's triggers and help your furry best friend feel better again.

Pets Best Can Help You Keep Your Dog Healthy

Investing in pet insurance is a great way to help you protect your dog from diseases and allergies they may encounter. At Pets Best, our dog insurance plans can be customized for your pet's unique needs. In addition, Pets Best policyholders can speak to a veterinary expert anytime through a 24/7 Pet Helpline.

Sources/Citations

1. "More itchy pets? No problem," Katie Burns (2/2020), American Veterinary Medical Association, https://www.avma.org/javma-news/2020-02-15/more-itchy-pets-no-problem, accessed March 29, 2024.

2. "Skin allergies in dogs," (6/2022), Cabbagetown Pet Clinic, https://www.cabbagetownpetclinic.com/blog/june-2022/skin-allergies-in-dogs, accessed March 29, 2024.

3. "Types of dog allergies and how to treat them," (3/2024), American Kennel Club, https://www.akc.org/expert-advice/health/dog-allergies-symptoms-treatment/, accessed March 29, 2024.

4. "Effective treatment for dogs with allergic dermatitis," (11/2022), Berkeley Dog & Cat Hospital, https://www.berkeleydogandcat.com/site/blog/2022/11/15/allergic-dermatitis-dog-treatment, accessed March 29, 2024.

5. "Yeast dermatitis in dogs," Krista Williams et al., VCA Animal Hospitals, https://vcahospitals.com/know-your-pet/yeast-dermatitis-in-dogs, accessed March 29, 2024.

6. "Food allergies in dogs,"(4/2022), Veterinary Skin & Ear, https://veterinaryskinandear.com/food-allergies-in-dogs/, accessed March 29, 2024.

7. "Critically appraised topic on adverse food reactions of companion animals (3): prevalence of cutaneous adverse food reactions in dogs and cats," Thierry Olivry and Ralf S. Mueller (2/2017), BMC Veterinary Research, https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-017-0973-z, accessed April 9, 2024.

8. "Systematic review of evidence for the prevalence of food sensitivity in dogs," C.J. Chesney (4/2001), Veterinary Record, https://pubmed.ncbi.nlm.nih.gov/11338715, accessed April 9, 2024.

9. "A prospective study on canine atopic dermatitis and food-induced allergic dermatitis in Switzerland," F. Picco et al. (6/2008), Veterinary Dermatology, https://pubmed.ncbi.nlm.nih.gov/18477331/, accessed April 9, 2024.

10. "Contact dermatitis in dogs," (3/2024), Vetster, https://vetster.com/en/conditions/dog/contact-dermatitis-in-dogs, accessed March 29, 2024.

11. "Epidermal barrier in atopic dermatitis," Byung Eui Kim and Donald Y.M. Leung (1/2012), Allergy, Asthma & Immunology Research, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3242054/, accessed April 9, 2024.

12. "Current evidence of skin barrier dysfunction in human and canine atopic dermatitis," Rosanna Marsella et al. (3/2011), Veterinary Dermatology, https://onlinelibrary.wiley.com/doi/10.1111/j.1365-3164.2011.00967.x, accessed April 9, 2024.

13. "Canine and human atopic dermatitis: Two faces of the same host-microbe interaction," Domenico Santoro and Aline Rodrigues Hoffmann (6/2016), Journal of Investigative Dermatology, https://pubmed.ncbi.nlm.nih.gov/27212648/, accessed April 9, 2024.

14. "Sarcoptic mange (scabies)," Dr. Brian Collins (1/2024), Cornell University College of Veterinary Medicine, https://www.vet.cornell.edu/departments/riney-canine-health-center/canine-health-information/sarcoptic-mange-scabies, accessed March 29, 2024.

15. "Hot spot treatments and prevention on dogs," Elizabeth Racine (3/2024), American Kennel Club, https://www.akc.org/expert-advice/health/treating-and-preventing-hot-spots-on-dogs/, accessed March 29, 2024.

16. "Figure 1: Diagnosing allergic skin disease in the canine patient," (2023), American Animal Hospital Association, https://www.aaha.org/aaha-guidelines/2023-aaha-management-of-allergic-skin-diseases-in-dogs-and-cats-guidelines/figure-1-diagnosing-allergic-skin-disease-in-the-canine-patient, accessed March 29, 2024.

17. "Dr. Maro: Tips to help pets with allergies," Dr. Cynthia Maro (7/2023), The Times, https://www.timesonline.com/story/lifestyle/pets/2023/07/10/dr-maro-tips-to-help-pets-with-allergies/70388752007/, accessed March 29, 2024.

18. "Giving your dog an oatmeal bath: Helping dogs with itchy skin," (11/2020), Friendly Animal Clinic, https://www.greensboroncvet.com/site/friendly-animal-clinic-blog/2020/11/26/dog-oatmeal-bath, accessed March 29, 2024.