Your dog is scratching or biting himself and rubbing against any surface he can reach to stop the itch. But what’s behind the skin irritation?

According to Nationwide Insurance (formerly Veterinary Pet Insurance), which provides pet health insurance for more than 550,000 pets, dog skin allergies and infections were the top reasons for claims in 2014, with more than 120,000 claims filed.

Only a vet can diagnose a dog, but if your pooch’s hide is making him dog-gone uncomfortable, here are six possible reasons.

Related: When to Take a Sick Pet to the Vet

Allergic dermatitis

“Dermatitis” simply means “inflammation of the skin.” Allergic dermatitis is caused by something the dog is allergic or sensitive to.

“One of the most common causes is a hypersensitivity to flea bites,” says Jennifer Schissler, DVM, an assistant professor at the Colorado State University Veterinary Teaching Hospital. She is accredited by the American College of Veterinary Dermatology. Allergic dermatitis also can be caused by an allergy to food, pollen or mold.

Symptoms: Redness, itching, skin lesions or changes in the skin. They can be found anywhere on the dog but usually appear on the face, feet, ears, armpit or groin. Flea irritation typically appears on the back or around the tail, Schissler says.

Diagnosis and treatment: Your veterinarian can diagnose allergies through tests and recommend what, if anything, should be removed from your dog’s diet or environment. If your dog has problems with fleas, the bedding and other upholstered items he comes in contact with, such as carpets or furniture, should be thoroughly cleaned and washed.

Prevention: There really isn’t prevention for allergies, says Schissler. The best way to protect your pet from fleas is to administer a flea and tick preventative, especially in warm weather months.

Related: Clean Carpets, Healthy Pets: How to Have Both

Skin infections and “hot spots”

Skin infections are often precipitated by allergies, says Schissler. They can lead to extremely itchy or red spots. “Hot spots occur when there is an overproduction of yeast due to a skin infection,” she explains. These types of infections are not contagious to humans or other animals.

Symptoms: Extreme scratching and redness in many of the same places allergic reactions occur

Diagnosis, treatment and prevention: Since hot spots are often precipitated by allergies, Schissler says to talk with your veterinarian about the best course of action.

Related: 13 Health Symptoms Dog Owners Should Never Ignore

Ringworm

Ringworm, aka dermatophytosis, is not a worm but a fungal infection of the skin that happens when dogs come in contact with infected dogs or infected soil, according to VCA Animal Hospitals. Humans can catch ringworm from dogs if they come in direct contact with either the fungus or contaminated items, such as bedding.

Symptoms: Schissler says this infection can present in many ways, including redness, little bumps, scabs and hair loss. What it doesn’t look like is the classic round lesion found on humans.

Diagnosis and treatment: Your veterinarian will treat with oral and topical anti-fungal medicine. The fungus can live in a household for several months, so thoroughly wash items the dog uses regularly, such as bedding, carpets and bowls, and separate any other dogs and cats in the household, Schissler says.

Prevention: Keep your pup away from dogs whose medical history you don’t know, advises Schissler. The only other way to prevent ringworm is to keep dogs out of the dirt. But that may be easier said than done. “You can’t prevent them from living normal lives, so it isn’t practical to keep them inside.”

Related: 5 Ways to Prevent Pet Medication Errors

Demodectic mange

You may not want to know this, but all dogs have mites. Demodectic mange occurs when there is an overgrowth of mites on your dog, which inflames the hair follicles, according to VCA Animal Hospitals. This type of mange, which happens most often in puppies due to their immature immune systems, is not contagious.

Symptoms: Redness and itching

Diagnosis and treatment: Your veterinarian can determine if your dog has demodectic mange through a skin scrape. Schissler says there are many treatments for mange. “The safety of the product depends on the breed, so it’s very important to discuss this with your veterinarian,” says Schissler. “Mange can be a very serious condition if left untreated.”

Prevention: If you’re buying a dog from a breeder, find out if demodectic mange is in the dog’s bloodline (a reputable breeder will be able to answer this question). If you are adopting a dog and don’t know its origins, there’s no way to tell if your dog might be susceptible.

Related: 2 Vaccines Your Dog Absolutely Needs, and 4 He Might

Sarcoptic mange

Sarcoptic mange is also a result of mites, but unlike demodectic mange, it is very contagious to other animals and humans.

Symptoms: Extreme scratching, especially on the ear flap, elbows, limbs and underbelly

Diagnosis and treatment: Your vet will perform a skin scrape. But since only 30 to 40 percent of tests in dogs with sarcoptic mange come back positive, she likely will recommend treatment if she strongly suspects this condition, Schissler says. Treatment includes dips, topical treatments and possibly oral medication. As with ringworm, everything in the dog’s environment must be cleaned, and other dogs should be kept away.

Prevention: Some flea and tick treatments may help prevent sarcoptic mange. And don’t let your dog come in contact with wildlife or other animals you don’t know.

Related: Are You Neglecting Your Dog’s Teeth?

Cheyletiella dermatitis

Schissler says this condition, which is also caused by mites, is most commonly found in the western Rocky Mountain region of the United States. It’s contagious to both cats and humans.

Symptoms: Red, itching scaling on the back

Diagnosis and treatment: Your vet can diagnose this with a skin scrape. It is treated much like mange.

Prevention: Make sure your dog doesn’t come in contact with animals you don’t know.

Related: How to Keep Your Dog Safe at the Dog Park


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Kerri Fivecoat-Campbell lives in a cabin in the woods with her husband of 30 years and their five recycled (rescued) dogs. Her book, “Living Large in Our Little House: Thriving in 480 Square Feet With Six Dogs, a Husband And One Remote…Plus More Stories of How You Can Too,” will be released by Readers Digest Books in 2016.