Why Does My Dog Have Itchy Skin, Bumps, Scabs?

Dec 12, 2008Updated 8 months ago

When a dog starts itching (and often yelping as they scratch and itch), most dog owners will take a closer look at the dog's skin. Often, what the owner finds is a dog with red, itchy bumps on his skin, and even scabbing, flaking and peeling.

When a dog suffers from itchy skin, itchy red bumps on the skin, scabbing and skin rashes, there are two common causes: allergies and parasites.

Allergies as a Cause of Itchy Skin, Red Bumps and Scabs on a Dog's Skin

Contact dermatitis is a fairly common cause of skin rashes in dogs. Often these skin rashes can include red, raised bumps, scabs, intense itching and scratching, and even some minor swelling due to irritation from the dog's frequent scratching.

Contact dermatitis is a skin rash that occurs when an irritant or allergen comes in direct contact with the dog's skin. Some of the most common causes of contact dermatitis in dogs include:

  • Shampoos and Conditioners
  • Laundry Detergent and Fabric Softener
  • Household Chemicals and Cleaners
  • Carpet Freshener and Air Freshener
  • Fabrics and Carpeting
  • Dog Perfumes and Colognes
  • Plants
Contact dermatitis, like other allergies, can be difficult to pinpoint because allergies can literally arise overnight. So a dog who may have tolerated a exposure to a particular shampoo or other irritant in the past may suddenly develop a serious case of contact dermatitis.

In most cases, a dog who is suffering from an allergic reaction will improve when given an antihistamine like Benadryl (though it should be noted that Benadryl is not extremely effective in dogs, so a dose of Benadryl may not lead to noticeable improvement in cases of serious skin irritation in dogs; prescription antihistamines are typically more successful in controlling itching, skin bumps, and other symptoms.)

In the case of allergies in dogs and other pets, it can be difficult to pinpoint the cause of the allergy. The allergy diagnosis process in dogs usually involves trial and error. Keeping a dog log can be helpful when allergies are suspected in a dog; the log can be used to record all chemicals that are used in the home, places the dog visits, etc. to determine a correlation between the presence or severity of the contact dermatitis and a potential allergen.

Food allergies can also cause serious skin rashes, itching, scabbing, and other symptoms similar to contact dermatitis. But unfortunately, food allergies are difficult to diagnose and therefore, canine food allergies are typically explored only once all other possible diagnoses are ruled out.

Parasites as a Cause of Itchy Skin, Red Bumps and Scabs on a Dog's Skin

Parasites can cause serious skin irritation in dogs, including severe itchy skin, red raised bumps on the dog's skin, scabbing, hair loss, and flaking.

Parasites, unlike skin allergies and food allergies in dogs, are fairly easy to diagnose. A veterinarian can diagnose skin parasites in dogs by performing a skin scraping. The skin scraping procedure involves scraping the very outer layer of skin cells from the surface of the dog's skin. The sample is then examined under a microscope and if parasites are present, the veterinarian will usually see signs of the parasites in the skin scraping sample. Treatment typically consists of Ivermectin, an anti-parasitic medication.

Dog owners should remember that not all skin parasites are visible like fleas. Some skin mites that affect dogs live in the hair follicle and they're so tiny that they're only visible under a microscope. These mites are also not affected by anti-flea shampoos and sprays; Ivermectin is the only remedy.

Another fairly common cause for a dog with itchy skin or red bumps and rashes in dogs is shampoo residue. If the dog has recently had a bath, there's a chance that the shampoo wasn't rinsed out of the fur completely, leaving a very itchy residue. Rinsing the dog with warm water will help to remove the shampoo residue. If the dog has scratched to the point where scabs, scrapes and sores are present, a medicated soothing shampoo will be helpful to disinfect the scabs and sores that have formed, promoting healing.

Related Reading

Dog owners may also be interested to read about the problem of Itchy Dry Skin in Dogs, Dry Skin in Dogs and How to Treat Skin Allergies in Dogs, along with the Symptoms of Skin Parasites in Dogs.