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Contact Allergies in Dogs: Causes, Signs, and Treatment


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Contact allergies are relatively uncommon in dogs, but they can cause itching, inflammation, and discomfort for your pet. Keep reading to learn the telltale signs of contact allergies and some home remedies to help you manage them.

What are contact allergies?

A contact allergy (also known as contact dermatitis) is a skin reaction that occurs when a particular substance directly touches a dog’s skin and causes the dog’s immune system to have an allergic response. The threshold for triggering an allergic response varies widely among individual dogs. Some dogs may only need a brief, one-time exposure to an irritant, while others require prolonged, repeated exposure. The concentration of that irritant also affects how severe a dog’s allergic response is. 

What are common allergens that trigger contact allergies in dogs?

Like humans, dogs can have allergies to certain plants, metals, chemicals, and textiles. 

  • Grasses and ground-covering succulents are the most common plant triggers. Plants like poison ivy and poison oak carry toxins that can also cause an allergic reaction if a dog brushes against them.  
  • Nickel is the most common metal allergy. It can be found in collar tags, buckles, metal bowls, and even jewelry. 
  • Some household chemicals, such as cleaning products, laundry detergents, pesticides, and fertilizers, can cause contact allergies.
  • Synthetic fabrics, rubber, and wool can all be triggers. If your dog is showing signs of allergies, check the material used in their bedding.

What are the signs of contact allergies in dogs?

Signs of contact allergies include skin irritation or inflammation at the site of contact within 72 hours of exposure. Dogs may chew or lick the site to try and relieve their itchiness, which can cause even more skin irritation. 

Common signs include:

  • Localized redness
  • Swelling
  • Hives
  • Hair loss
  • Crusty skin
  • Thickened and dark patches of skin

How does a veterinarian diagnose contact allergies?

Contact allergies are uncommon and differ from other types of allergies. They typically result in skin inflammation where the irritant was touching the dog’s skin. Unlike other types of allergies, contact allergies develop shortly after exposure to the allergen.

A complete history and physical exam are essential for an accurate diagnosis. Veterinarians sometimes use patch testing, which involves applying specific allergens to a dog’s skin and then monitoring to see if a reaction develops.

Can contact allergies be prevented?

The best way to prevent a reaction is to identify and then avoid the irritant. It’s a good idea to look through your home and systematically remove potential triggers.

Sometimes, the location and timing of the skin irritation can provide hints about what may be causing the allergy. For example, if your dog sleeps on their left side in a brand-new bed, and their left side is red and itchy shortly after, that suggests the new bed is responsible. 

What are possible home remedies to manage contact allergies?

If you notice an area of localized redness, there are certain treatments you can try at home, including:

  • Bathing using a hypoallergenic or oatmeal shampoo 
  • Chlorhexidine-based wipes
  • Apply a cool compress, using a cloth soaked in cool water (never apply an ice pack directly to the skin)
  • A thin layer of aloe vera gel
  • An antihistamine (remember to consult your veterinarian before administering any new medication)
  • Dietary supplements, including omega-3 fatty acids (such as fish oil)

Monitor the affected area closely at home for any signs of discharge, swelling, or odor. If any of these signs occur or the redness does not go away, please consult a veterinarian for advice.

How do veterinarians treat contact allergies?

Veterinarians take a multi-step approach to treating contact allergies:

  • First, attempt to identify and avoid the triggering allergen.
  • Topical treatments can include medicated shampoos, sprays, and ointments. These often have ingredients to control inflammation and treat bacterial and yeast infections.
  • Oral medications can be used in severe cases to control itching, reduce inflammation, and manage infections. 
  • A veterinarian may consider immunotherapy for severe or recurrent contact allergies. The goal of immunotherapy is to desensitize the dog’s immune system so they don’t have such a strong reaction to the allergen. 

With contact allergies, the goal is to avoid triggers and alleviate symptoms. Recognizing and managing allergen exposure will provide dogs with contact allergies the best quality of life.

Kari Cueva, DVM

Dr. Kari Cueva, DVM, is the Associate Director of Veterinary Genetics at Embark. She is a 2011 graduate of the University of California, Davis College of Veterinary Medicine. Her research background includes four years in canine genetics with Dr. Mark Neff, and genetics fellowships at Cornell University and the National Institutes of Health. She continues to practice emergency medicine at a local animal hospital.

Read more about Kari Cueva, DVM

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