Why Is My Dog So Itchy?

Every dog scratches from time to time. (You do too, right?) So when does scratching become a problem? According to Hobson Fulmer, DVM, owner of Apalachicola Bay Animal Hospital in Eastpoint, Fla., if your dog is constantly scratching an area, creating sores, losing hair, and keeping you (and him) up at night, it's a problem.

Itching Is a Symptom of a Dog Health Condition

When your dog scratches obsessively, it's a symptom of some underlying issue. There are lots of reasons a dog may have pruritus, aka itchy skin. The action of scratching might indicate there's something on the dog's skin (such as a parasite). Or the itch could be caused by something happening inside of your dog (such as an allergic reaction or fungus). Whatever the stimulus for the itch to begin with, it results in your dog scratching and feeling uncomfortable. A little sleuthing as to the cause of the itching can help you figure out how to get your dog the proper treatment.

Usually, itching can be traced to one of four major culprits: parasites, allergies, dry skin, or skin infections.

Your Dog May Itch Because of Parasites

There are several parasites that are eager to make a meal of your dog, making him feel itchy and uncomfortable.

Fleas

Just hearing this word sends fear into the hearts of most pet owners. That's because, once established, these tiny blackish-brown blood-sucking pests (adults measure about an eighth of an inch long) can quickly reproduce and make your dog's life miserable. (They also bite humans and can infest your home!) What's even more disturbing is that a flea can bite your dog up to 400 times a day. Each flea has a lifespan of 100 days. Flea bites hurt, plus their salivary glands give off a substance that's irritating to many dogs. That's why you'll often notice a pet with fleas violently scratching various parts of their body.

To add insult to injury, Fulmer says, "some dogs are also allergic to flea bites and will begin to develop bare spots (flea dermatitis)." You can also spot visible evidence of fleas, Fulmer says. "Flea dirt looks like dirt, and is the feces of fleas. It's digested blood," he says. The first step for getting rid of fleas on your dog is probably a visit with the veterinarian.

Ticks

These insidious little blood suckers hitch a ride on your dog when he's wandering around outdoors then settle in for a meal of blood. Gross, right? There are several types of ticks, and most are large enough to see; deer ticks are very small and look like flecks of dirt—until you see them crawling. Ticks attach to your dog's skin, then begin to suck your dogs' blood until they become engorged, after which they drop off your dog. "You might just find the attachment sites from ticks," Fulmer says. A tick leaves behind a red, itchy mark on your dog's skin. Ticks can also carry a number of diseases like Lyme disease, so it's important that they are removed and treated as soon as possible.

Mites

Mites are teeny tiny—measuring less than a millimeter long. Like ticks, they are not insects (as fleas are), but are related to spiders (arachnids) and have eight legs. Mites can cause itching conditions that result in dry skin and hair loss. Mites cause the disease called mange, which results in patchy areas of hair loss. There two common types of mange (caused by two different types of mites): sarcoptic and demodectic.

Sarcoptic mange (also known as scabies) causes intense itchiness which makes dogs scratch for relief, resulting in coat damage, skin inflammation, and scabs. Sarcoptic mange can also affect humans.

Demodectic mange (also known as red mange or demodex) causes hair loss, red areas with scaling and crusting, and lesions.

If your dog is concentrating on scratching his ears or shaking his head, he may have ear mites. All mite-caused conditions require a veterinarian's care.

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Your Dog May Itch Because of Allergies

If your dog doesn't have parasites, then allergies are the most common itching culprit. Allergies in pets are similar to those in humans. Fulmer says that dogs can be allergic to the same things that humans can be, "and instead of getting hay fever or asthma, allergies make dogs' skin breakout and itch." An itchy skin condition called atopic dermatitis can be caused by a reaction to food or medication. Allergens from the environment, such as pollen, dust, or mold, can also start an itch. Another itch-inducing problem, called contact dermatitis can be caused by coming in direct contact with something that causes an allergic reaction (think a flea bite or a rash from poison ivy).

Your Dog May Itch Because of Dry Skin

Drier air in winter may cause your dog's skin to become dry and itchy. Or, if your dog swims in your pool in summer, the pool chemicals may affect his skin as well as dull his coat. Some shampoos and soaps may also cause dryness—while some dog shampoos specifically for dry, itchy skin can help moisturize and alleviate discomfort.

RELATED: How to Prevent Cracked Dog Paws and Protect Your Pup's Skin from Dryness

Your Dog May Itch Because of Skin Infection

According to Fulmer, itching can also occur as a response to skin infections. "Bacterial, yeast, and fungal infections can all cause itchiness," he says. Bacterial infections can cause hot spots, (also known as pyotraumatic dermatitis) which make your dog scratch, lick, and bite an area of skin. Ringworm (dermatophytosis), which is a fungus not a parasite, shows up on dogs as round hairless patches with pink, scaly sores; while ringworm does not typically cause itchiness, your dog may still scratch at the area. Yeast infections in dogs are less common. All skin infections are best diagnosed by a veterinarian who will prescribe the appropriate medication for the type of infection.