Dogs Dog Health & Wellness Dog Diseases & Disorders

Why Is My Dog Itching and Losing Hair?

Causes, Treatment, and Prevention

Dog Scratching

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When a dog is itching and losing hair, they likely have some kind of skin issue, such as parasites or an infection. To diagnose and treat your dog for an irritating skin condition, your veterinarian will become a medical detective, performing thorough examinations and laboratory tests to track down the source of your pup's displeasure. Here's what to do if your dog is itchy and losing hair, including what to expect at the vet.

What Causes Itching and Hair Loss in Dogs?

Hair loss (alopecia) and itching are symptoms of skin irritation in dogs. They can occur as a result of many possible dermatological afflictions ranging from simple external irritation to internal organ dysfunction. Possibilities include:

Symptoms Associated With Hair Loss and Scratching in Dogs

If your dog's skin is irritated, no matter the cause, you may notice the following signs:

  • Scratching or chewing skin
  • Licking paws
  • Patches of bare skin
  • Clumps of hair lying around the house
  • Red, inflamed, or bleeding skin
  • Skin odor
  • Dry skin

What to Do If Your Dog Is Itchy and Losing Hair

Contact your veterinarian if you notice itching, patches of hair loss, or other signs of illness in your dog. The vet will begin the search for the cause of your dog's hair loss by asking you some basic questions about the nature of your dog's signs, how long they have been going on, and if they've occurred in the past. Be sure to tell your vet if your dog is on any medications or supplements.

Physical Examination

The vet will perform a physical examination, looking for evidence of parasites, skin lesions (such as red spots, scabs, and sores), and overall health. The examination will include the eyes, ears, teeth, and other body parts as well. This is because skin disease can sometimes be a manifestation of disease in an internal organ system or other parts of the body.

Skin Tests

If your dog is suffering from skin disease and has been losing hair or scratching, there are several skin tests your veterinarian may recommend.

  • Skin scraping to look for evidence of the mites that cause mange
  • Skin cytology looking for evidence of yeast and bacterial infections in the skin
  • Fungal cultures that check for ringworm (not a worm) and other fungal infections
  • Skin biopsies if the vets suspects skin cancer or other serious skin disease

Blood Tests

In some cases, if your veterinarian suspects that a more systemic (whole-body) disease is causing your dog's skin disease, a blood screen may be recommended. A blood screen usually consists of a complete blood count (CBC) and a chemistry profile.

The complete blood count looks closely at the red and white blood cells in a blood sample. The blood chemistry profile allows the evaluation of kidney function, liver enzymes, protein levels, and electrolyte levels.

In dogs with skin disease, blood screening may also include tests that evaluate thyroid function, including total T4, free T4, and/or thyroid-stimulating hormone (TSH).

How to Treat Itching and Hair Loss in Dogs

Treatment for your dog's skin issues will depend on the cause and must be targeted to the specific organism or condition causing the skin inflammation. Your veterinarian will prescribe appropriate medications to relieve itching and treat infections, if present. However, additional steps may be necessary to discover and address any underlying conditions.

Flea Control

One of the first things your veterinarian will likely recommend is a reliable form of flea prevention if you're not already using flea control. This is because fleas can be difficult to find on dogs, even when fleas are the main trigger for the condition. Even if fleas are not the cause, it's crucial to control them because fleas are likely to worsen existing skin problems.

Food Trial

If your vet suspects food allergies, they may recommend doing a food trial. This involves feeding your dog a special diet for two months to bring your dog's immune system back to a non-reactive baseline.

This special diet is called a novel protein diet or a hydrolyzed (chemically digested) diet; it is devoid of all protein and carbohydrate ingredients that are the most common triggers of food allergy in dogs. Normal protein triggers are beef, milk products, chicken, and eggs, while common carbohydrate triggers are wheat, corn, and soy.

Once the dog's immune system has calmed down, these ingredients can be tried one by one to see if they induce skin reaction. If so, itching symptoms will appear within about three days. Most food-allergic dogs will show sensitivity to more than one kind of protein or carbohydrate.

Allergy Testing and Immunotherapy (Hyposensitization)

If other causes of hair loss and scratching have been ruled out and if your veterinarian is relatively certain that your dog is suffering from atopy (an immune system that is sensitive to something in your pet's environment), the vet may recommend allergy testing to determine which substances your dog is allergic to.

The treatment for an acquired allergy is immunotherapy, also called hyposensitization. This involves injecting a solution of the allergen (the substance causing the allergy) into your pet over some time in an attempt to train your pet's body to not respond abnormally to the allergen.

Prognosis for Dogs with Hair Loss and Scratching

The prognosis for a dog afflicted with hair loss and scratching depends on the cause of the symptoms. Most parasitic, bacterial, and fungal infections can be treated within a couple of months, and dogs resume their normal lives. Hypothyroidism can be managed with medication; liver disease may require more intensive treatment and carries the most guarded prognosis of the possible causes.

Dogs with allergic skin conditions may experience flare-ups despite your best efforts to manage their allergies. Be sure to see your veterinarian for recommended follow-ups and contact them if you notice any signs of skin problems.