Contact Dermatitis in Dogs

Contact dermatitis can be caused by any number of things.  It can either be a symptom of different conditions or can be considered an ailment on its own.  If your dog comes into contact with something that irritates his skin, he may develop symptoms immediately, or over a period of a couple days.  Treatment is typically in the form of symptomatic therapies to offer relief to your dog’s symptoms before they worsen.  For example, if he is scratching incessantly, he will be given an antihistamine or steroid to stop the scratching before he scratches so much it gets infected.  Most dogs recover very well from a diagnosis of contact dermatitis without any long term side effects.

Contact dermatitis is a skin condition your dog can develop from an overreaction of the immune system or from a substance that caused damage to the skin.  If you see your dog has developed skin irritation, is scratching a lot, and seems to be miserable from all the itching, take him to his veterinarian.

Symptoms may develop immediately upon contact or may take up to 48 hours to develop.  Symptoms may include: 

• Sore skin
• Inflamed pattches of skin
• Itchiness
• Color change
• Scaling
• Thickening of the skin
• Fluid discharge from the affected area
• Dry skin
• Self-mutilation 
• Secondary skin lesions from scratching
• Secondary bacterial infection

Types

Contact dermatitis in dogs is most commonly one of two types:  allergic contact dermatitis or irritant contact dermatitis. Allergic contact dermatitis occurs when the skin becomes sensitive to a specific substance that is actually harmless.  When exposed to the substance, the body’s immune system produces a response thinking it needs to protect itself.  The skin reacts, leading to the symptoms listed above, any time it comes into contact with the suspected substance.  For example, if your dog is allergic to a soap you use on him, every time you bathe him with it, he will break out with the symptoms of dermatitis.

Irritant contact dermatitis occurs when the skin comes into contact with a substance that damages the skin directly upon contact.  Damage to the skin can occur after multiple exposures to the substance, or after just one time.  For example, some plants release a substance that can irritate your dog’s skin and will cause contact dermatitis if your dog brushes up against it.

Depending on the type of contact dermatitis your dog is suffering, the cause can either be from an overreaction of the immune system or by the irritant actually damaging the skin.  Symptoms of each type are similar making it to be difficult to differentiate between one another.  Either way, it needs to be treated as soon as possible.

Diagnosing contact dermatitis in dogs tends to be more of a rule out type of process.  The veterinarian will see your dog’s symptoms and know it is some sort of dermatitis.  The hard part will be identifying the cause.  The veterinarian will collect a history from you to try and determine when it started.  She will ask questions such as if he has been around anything new, if he has been bathed recently, if he got into anything recently that could have been a hazardous exposure, and so on.  

The veterinarian may want to run a few diagnostics to rule out other possible causes of the symptoms your dog is experiencing.  A skin scraping may be collected to check for a bacterial infection or parasitic infestation.  The veterinarian will scrape off a thin layer of your dog’s cutaneous skin in a small area.   She will take the sample and look at it under the microscope to rule out any type of skin mite which could also cause the symptoms listed.

The veterinarian may also want to run blood work just to have a look at your dog’s internal organs and their function.  This is not mandatory and may not be suggested in every case, but it will offer helpful information of how the rest of your dog’s body is functioning.

Treatment of contact dermatitis will be as symptoms develop.  Medications will be prescribed to offer your dog relief from any itching he is suffering.  An antihistamine or steroid may be prescribed depending on his need.  

A cream or ointment may be prescribed for you to apply to the affected areas.  If a secondary infection develops, your dog will need antibiotics.  It is also possible she may prescribe a shampoo for you to bathe your dog with multiple times a week.  Many veterinary prescribed shampoos have antiseptic, antifungal, and antibacterial properties which will help your dog’s skin to heal. Other types of treatment will be administered by the veterinarian in accordance with your dog’s needs.

Most dogs recover without complications from contact dermatitis.  While it is irritating to your dog, it is not life threatening.  If a secondary infection develops, recovery will take longer and medications will be needed, but once the infection is cleared, he should recover without issue.

If you notice your dog scratching a lot and discover he has irritated skin, it might be a good idea to take him to the veterinarian. She will be able to ensure it does not worsen and offer him some much needed relief from the itching.