Alopecia or hair loss commonly occurs in dogs, in such condition animals will experience partial or complete hair loss. In some cases alopecia will affect the dog's lymphatic system, immune systems, endocrine system and skin. This condition can affect cats and dogs regardless of their gender, breed or age and will be either acute or gradual.

What Causes Dog Hair Loss?

There are a wide range of reasons that a dog's hair may fall out, including:

1. Skin Infections and Parasites

Parasites such as mites, lice and fleas can lead to hair loss due to the itching. The itching leads to the dog biting or scratching vigorously and this in turn causes the hair to break off or be chewed. Once the skin is chewed and moist, it is prone to infections, including bacteria, ringworm and yeast. Each of these causes much more itching, leading to increased hair loss. You can typically assume that the parasite is responsible for different area of hair loss: fleas focus on back above the hips; lice will be the back legs and back; mites attack mouth, ears, eyes and elbows.

2. Allergies

Pets show allergic reactions via their ears and skin as opposed to their nose and eyes (like humans do). This means that allergic dogs will have itchy skin, causing them to chew or scratch out their hair. Allergies may include food, allergens in the air or some other materials they come in contact with. Common food allergies for dogs are yeast, milk, meats, fish and grains. Common inhaled ones include perfumes, cigarette smoke and pollen.

3. Lack of Proper Nutrition

In order to stay rooted to the skin, hair needs many nutrients, including Omega 6 and Omega 3 fatty acids, antioxidants, minerals, and vitamins. If the hair doesn't receive these nutrients, it will loosen and become dull, eventually falling out. Typically hair loss that is due to poor nutrition will occur all over the dog, although it may be more noticeable on the hips and back due to shorter growth cycles. Certain breeds are prone to specific deficiencies, such as Siberian Huskies, and other Northern breeds are prone to zinc deficiency.

4. Organ Function Which Is Abnormal

The body's organs such as the intestines, liver and kidneys regulate nutrients within the blood and as such, any issue with those organs (via drugs or disease) may lead to hair loss. Dull, thinning hair all over the body may indicate cancer, inflammatory bowel disease, or that a pet has received chemotherapy. Dull, bedraggled coats may indicate kidney failure and usually include a urine smell on the skin. Liver failure will lead to jaundice as well as weak and flaky, but long nails.

5. Abnormal Blood Flow

Throughout most of the hair cycle, it receives its nourishment via blood. This means that poor circulation will lead to dog hair loss. This means that dogs with chronic anemia, low blood pressure, or weak hearts might have dull coats and cool skin. In this case, the thinning coat will be due to the hair falling out from its follicle as opposed to the dog's actions.

6. Deficient or Excessive Hormone Levels

There are multiple hormones which influence hair growth, including cortisol, thyroxine, growth hormone, melatonin, estrogen and testosterone. If any of these hormones have irregular levels, the dog may have hair that is too thick or too thin. If, for example, cortisol levels are high, the hair will thin from the back through the tail of a dog, resulting in a rat tail with tufts at the end. If the opposite is true and cortisol is too low, it may also lead to hair loss.

7. Medications

Certain injected, topical and oral medications may also lead to hair loss in dog. Steroids when used in the long term, for example, may lead to the hair follicles shrinking so the hair falls out. The hair won't regrow until the follicles return to normal with the reduction of steroid levels. Certain topical flea medications may also lead to hair loss as well as some injected vaccines.

8. Behavior (Anxiety and Excessive Grooming)

Sometimes hair loss will be due to behavior. Dogs who suffer from separation anxiety may lick off hair from their legs, a behavior known as acral lick dermatitis. In some cases, the dog will lick to the point of breaking down the skin, leading to an infection that is challenging to cure. This typically affects the area of the front legs immediately above the wrist and the area of the back legs by the ankle.

What to Do If Dog Hair Loss Occurs

Treatments vary depending on the cause of hair loss in dogs.

1. Alopecia Due to Parasites

There are many topical medications for this type of alopecia. Shampoos, tick, flea control as well as other similar products tend to be effective for the hair to return to normal length, they may take a few weeks or months to come into effect though.

2. Alopecia Due to Hormonal Imbalance or Endocrine Disorders

This type of alopecia is treated by giving the dog treatment for the underlying condition. In some cases hair loss due to stress or specific hormone imbalances can be remedied by neutering or spaying the dog.

3. Alopecia Due to Allergies

When the alopecia is due to immune-mediated reasons such as allergy, the easiest treatment is to identify the allergen and remove it. Sometimes, however, this proves to be very challenging, and in that case options include corticosteroid therapy, oral/topical antihistamines or anti-inflammatories, and medicated shampoos.

4. Additional Treatments

Supplements of oral melatonin, vitamin D, and essential fatty acids are safe for dogs and prove to be effective in certain cases, both at helping hair regrow and improving the overall condition of the dog's coat.

How to Prevent Dog Hair Loss

1. Provide a Diet of High Quality

Perhaps the best method of preventing hair loss in dogs is to ensure your dog is eating a quality diet. Although quality food costs more, it is made from premium protein sources, such as those dogs evolved to digest, which let your dog absorb more of the vitamins and minerals.

2. Opt for Human-Grade Food

Some dogs that are only fed with dry kibble will have dry skin due to lack of moisture, and dry skin will lose hair more easily. To remedy this, give your dog more foods that are human-grade, whole and unprocessed to improve his coat and skin. Some options to feed your dog several times a week include raw meats (minus the bones), eggs and steamed, unseasoned finely grated vegetables.

3. Give Omega-3 Oils

When you increase the number of omega-3s your dog gets and combines this with other changes, you can notice an improvement in his coat texture. This is due to calming down inflamed skin as well as decreasing shedding, both of which reduce hair loss.

4. Keep Fleas Under Control

As mentioned earlier, fleas are one of the parasites that can lead to hair loss in dogs. This is typically due to the dog scratching constantly until the hair falls out or the skin becomes damaged or infected, leading to hair loss. Keeping the fleas under control can avoid such situations, therefore prevent dog hair loss.

5. Regularly Brush

Groom your pooch regularly using a de-shedding tool as these will eliminate the amount of loose fur without pulling out fur that is still attached. Be sure to use these tools right before spring and in the fall when the dog's coat changes.

6. Give Regular Baths

Regularly bathing your dog helps the loose hair fall out during the bath instead of around your home. Be sure not to over-bathe your pooch, as this can lead to dry skin and shedding.