Contact dermatitis is a relatively rare skin disease that can occur when a dog or cat makes physical contact with a chemical or other irritating substance and has a negative reaction. There are two types of contact dermatitis -- allergic and irritant -- and while they are technically two different diseases, the symptoms, and treatments are so similar that they are often grouped together. Read on to learn what you need to know about both types of contact dermatitis in dogs and cats.
Causes of Contact Dermatitis in Dogs and Cats
There are two types of contact dermatitis: allergic and irritant. In both cases, the pet must make direct physical contact with an irritating substance in order to suffer a reaction.
Allergic dermatitis occurs when a pet becomes hypersensitive to substances in its environment. Most allergic reactions require a period of repeated physical contact and skin sensitization, so even if your pet has come into contact with certain chemicals or substances in the past without issue, an allergy could develop, and it may seem like it came out of nowhere. However, on average, skin sensitization can take anywhere from six months to two years to develop.
Common chemicals and substances that cause allergic contact dermatitis include topical antibiotics, flea collars/flea powders, certain metals (such as nickel), grasses and pollens, soaps/shampoos, carpet deodorizers, insecticides, dyes, and materials such as rubber, wool, leather, and plastic.
Irritant contact dermatitis, on the other hand, does not require a period of sensitization. A reaction will occur the first time that your pet makes contact with an extremely irritating substance, and any other animal that comes into contact with the substance may have a skin reaction as well.
Common chemicals and substances that cause irritant contact dermatitis include poison ivy sap, road salt (for melting ice), detergents, soaps, solvents, acids and alkalis, and petroleum byproducts (such as fertilizers, perfumes, and petroleum jelly).
Symptoms of Contact Dermatitis in Dogs and Cats
Contact dermatitis generally appears on areas of the body that are not well protected by hair, such as the feet, nose, lips, chin, stifles (“knees”), hocks (backs of “knees”), and underside of the body.
The primary symptom of both types of contact dermatitis is a skin rash characterized by itchy red bumps and inflammation. There may be weepy, blister-like lesions, hives, crusting, thickening, scaling, and hair loss. The pet will most likely scratch, bite, and lick the skin excessively, which may lead to a secondary bacterial infection.
In irritant contact dermatitis, you may also see ulcers.
Diagnosing Contact Dermatitis in Dogs and Cats
If you suspect that your pet is suffering from contact dermatitis, contact your veterinarian. Your pet’s medical history as well as current symptoms, will usually be enough to diagnose the skin disease.
The tricky part is isolating the irritating substance. This is usually accomplished through either exclusion trials or a patch test. In an exclusion trial, the pet is placed in a neutral environment, and potentially irritating substances are introduced one by one. In a patch test, the suspected allergen is rubbed or bandaged onto the pet’s skin. Then, the area of the skin is monitored for several days.
Treatment for Contact Dermatitis in Dogs and Cats
There is no cure for contact dermatitis. The best way to treat and prevent the disease is to prevent exposure to the irritating substance. This may mean removing a plant from your garden, changing detergents, or keeping certain chemicals locked away.
In the short term, your veterinarian may prescribe topical or oral corticosteroids or antihistamines to control itching and reduce inflammation. Certain shampoos and sprays can also relieve itching and other symptoms, such as Veterinary Clinical Care antifungal shampoo. And if the skin is infected, your veterinarian may prescribe oral or topical solutions such as Animax ointment specially formulated for dogs.
In the long term, you may want to consider switching to a hypoallergenic pet shampoo, a hypoallergenic detergent to wash pet bedding, glass or stainless steel food and water bowls, and toys that do not contain rubber.
Diets to Help Cat and Dog Dermatitis
Is your dog or cat’s skin itchy and irritated, and don’t know the cause? It could be that food allergies are the cause of these changes.
For cats and dogs, diet and nutrition can play a role in the cause and the treatment of food-allergy-related dermatitis--a chronic disease, also known as cutaneous adverse food reaction, that results in skin inflammation. Additionally, if your pet has not yet developed dermatitis, serving your loved one a nutritious, balanced diet can be an important part of prevention.
Signs of Food Allergy Dermatitis in Dogs and Cats
Dermatitis may affect dogs anywhere on their bodies, particularly on their faces, ears, and feet. Cats typically scratch their heads and necks. In addition to dermatitis, cats, and dogs may experience diarrhea and vomiting as a result of their food allergies; dogs may also experience difficulty breathing in rare cases. If you spot any of these issues, set up a veterinarian appointment right away.
Causes of Food Allergy Dermatitis
Food allergy dermatitis is often caused by a protein source--more commonly chicken and other poultry, beef, soy, dairy, or eggs, but also lamb and fish. Other culprits may include preservatives, fillers, colorings, and carbs, such as potato, wheat, corn, and rice. The exposure to the food substance is typically through consumption but may also be indirect via inhalation or skin contact. Malnutrition can also be a cause of dermatitis in pets.
The disease may strike at any age, though typically, symptoms are not found in pets under one year old, and symptoms will persist until the cause of the allergy is eliminated from the pet’s diet.
Note that because it can take a very long time, sometimes over a year or more, for a food item to cause problems, the issues your pet is experiencing may not be the result of a recent dietary change.
Steps to Treatment
Step 1: Elimination Diet
Because the symptoms of each type of dermatitis are similar, it can be difficult to identify and treat the underlying cause. To diagnose food allergy dermatitis, your vet will help you implement an 8- to 12-week elimination diet: substituting what your pet has been eating with a homemade or commercial diet that consists of one source of protein and one source of carbs--both of which your pet should not have ever consumed. You will also need to cut out treats.
Step 2: Choosing Uncommon Food Sources
Finding a food your pet has never tried is a good way to halt symptoms. Some less-frequently used protein sources, like bison or deer, may be recommended by your veterinarian. If your feline forages and hunts (i.e., rabbits or rodents), finding food sources that your cat has never been exposed to may pose a bit more of a challenge as your pet’s previous food encounters will have been more varied.
Step 3: Finding the Cause and Moving Forward
If your pet’s symptoms improve, then your veterinarian may recommend that the old diet be reinstated. This is so you can definitively diagnose the cause of dermatitis. For example, if your pet’s food was changed in May and your dog improved by July, it may be hard to tell if it was food or blooming apple blossoms that led to the problem. For this reason, reinstating the old food will let you pinpoint the cause of dermatitis.
On the other hand, if things are going well with the new diet, many pet parents decide not to try this. They would rather simply find out next spring whether it was the apple blossoms or the food that caused the allergies and continue to use the food that’s working in the meantime. If the allergies don’t return, your pet will be on a usable diet, and you won’t have to switch diets again.
If you reinstate the old food and your pet has food allergy dermatitis, signs of irritation will likely return within hours or days. From there, your vet will help you determine what to feed your cat or dog to avoid further skin issues.
Other Treatments for Dermatitis
Weekly baths, allergy medications, or a prescription or hypoallergenic diet may also be recommended as a part of your pet’s treatment plan.
Other Causes of Dermatitis
Be aware that dermatitis can also be the result of non-food-related allergens, including:
- Fleas, flies, ticks, mites, lice, maggots
- Puppy acne
- Tumors or masses
- Exposure to extreme weather conditions
- Other diseases
- Hypersensitivity to environmental irritants
Talk to your vet to be sure you both understand what’s causing dermatitis, so you can move forward with the best treatment plan.
Frequently Asked Questions
What does contact dermatitis look like on dogs?
Contact dermatitis in dogs can have various manifestations, depending on the severity and cause of the reaction. Typically, it can cause red, inflamed patches on the skin that may be itchy or sore. Some dogs may also develop small bumps or blisters on their skin, which could be filled with fluid or pus. The affected skin may become scaly or develop a crust. If the condition is severe, the dog may experience hair loss in the affected area. Additionally, the dog may scratch or bite at the area, trying to relieve the itching or discomfort. Common areas where contact dermatitis appears in dogs include the face, paws, ears, and belly.
How do you treat contact dermatitis in cats?
The treatment for contact dermatitis in cats will depend on the severity of the reaction and the underlying cause. The first step in treating contact dermatitis is to identify and remove the allergen or irritant that is causing the reaction. This may involve changing the cat's diet, removing household chemicals or plants, or avoiding certain fabrics. Your veterinarian may prescribe topical medications, such as creams, ointments, or sprays, to reduce itching and inflammation and promote healing of the affected skin. In some cases, your veterinarian may prescribe oral medications, such as antihistamines or steroids, to reduce inflammation and relieve itching. Bathing your cat with a soothing shampoo may help to remove any remaining allergens or irritants and promote the healing of the skin. To prevent further irritation of the skin, your veterinarian may recommend the use of an e-collar or a protective shirt to prevent your cat from scratching or licking the affected area.
Can you catch contact dermatitis from a dog?
It is possible to develop contact dermatitis after coming into contact with a dog that has the condition, but it is rare. Contact dermatitis is a localized skin reaction that occurs when an individual's skin comes into contact with an allergen or irritant, and the reaction is specific to the individual. So, while a person may develop contact dermatitis after coming into contact with a dog that has the condition, it does not mean that everyone who comes into contact with the dog will develop the reaction. However, it is essential to take precautions when handling a dog with contact dermatitis. Avoid touching the affected area of the dog's skin, and wash your hands thoroughly after handling the dog. If you develop symptoms of contact dermatitis, such as redness, itching, or swelling, seek medical attention promptly.
What are the clinical signs of allergic dermatitis in dogs and cats?
Allergic dermatitis is a common skin condition in dogs and cats, and the clinical signs can vary depending on the severity and type of allergy. The most common sign of allergic dermatitis is intense itching or scratching. The affected animal may scratch, lick, or bite the skin, causing redness, irritation, and sometimes even bleeding. Allergic dermatitis often causes redness and inflammation of the skin. The affected area may appear swollen, warm to the touch, and painful. In more severe cases, allergic dermatitis can cause the formation of skin lesions, such as papules, pustules, or scabs. The lesions may be moist, crusty, or scaly and may be accompanied by hair loss. Allergic dermatitis can also lead to ear infections in both dogs and cats. The ears may appear red and inflamed and produce a foul-smelling discharge. In some cases, dogs and cats may rub their faces on furniture or carpet to relieve itching around the face and head.
What triggers dog dermatitis?
Environmental allergens, such as pollen, dust mites, and mold, can trigger allergic reactions in dogs that lead to dermatitis. Some dogs may develop dermatitis in response to certain foods, such as chicken, beef, or grains. Infestations of fleas, ticks, or mites can cause dermatitis in dogs. Dogs may develop dermatitis when their skin comes into contact with irritants, such as chemicals, detergents, or plants. Some breeds of dogs, such as Bulldogs, Retrievers, and West Highland White Terriers, are more prone to developing dermatitis than others. Lack of proper grooming can lead to the development of dermatitis in dogs, particularly in areas where moisture and bacteria can accumulate, such as the ears, paws, and skin folds. It is essential to identify the underlying cause of your dog's dermatitis to provide appropriate treatment and prevent the recurrence of the condition.
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