The sight of fur on your clothes and furniture is inevitable when you have a dog. Shedding is part of your dog’s normal cycle of hair growth. What isn’t normal is when dogs experience hair loss due to an underlying health condition or nutritional imbalance. When dogs scratch themselves, they can damage the hair shaft, creating bald spots. However, there can also be hair loss in dogs with no itching or scratching.
In the case of normal shedding, some dogs have a double coat, meaning they have a topcoat and an undercoat. The topcoat gives your dog their distinctive coloring and texture along with protecting their skin from moisture and debris. Their undercoat, which lies under the topcoat, tends to shed year-round, particularly in the spring and fall.
Conversely, hair loss or alopecia occurs when dogs develop bald spots or thinning hair as a result of allergies, skin infections, endocrine diseases, hormonal factors, genetic factors, or environmental conditions. If your dog is losing too much hair at once, it’s important to consult with your veterinarian. Read on to learn about hair loss in dogs, including symptoms, causes, and treatments.
What Is Alopecia in Dogs?
“Alopecia is a common condition that refers to thinning of hair or bald areas,” says Dr. Jerry Klein, DVM, Chief Veterinarian for the American Kennel Club. This condition isn’t the same as shedding, which is a normal part of a dog’s hair growth cycle and can be managed by grooming your dog regularly. The amount of shedding depends on the breed and type of coat, with double-coated breeds more likely to shed year-round.
“Excessive shedding may be a cause for concern if there is an injury to the skin, or if it’s a result of a poor or imbalanced diet, stress, parasites, hormonal issues, or skin disease,” he adds. The appearance of alopecia can vary depending on the underlying cause. Some conditions lead to pruritis (scratching), whereas other conditions lead to hair loss with minimal scratching. For example, dogs with allergies may be prone to scratching their ears or bellies or chewing on their paws, resulting in cuts and abrasions.
Alopecia can occur in any dog breed and anywhere on the body, and it may involve partial or complete hair loss. Moreover, alopecia can affect the appearance of the skin including the following signs:
- Redness
- Thickness
- Inflammation
- Dark pigmentation
- Pustules or mucous discharge
- Bleeding
- Foul odor
- Dry or scaly skin where fur is missing
If ticks or fleas are causing alopecia, you’ll be able to see these organisms on your dog’s skin. In contrast, microorganisms aren’t visible to the human eye and need to be identified using a microscope. These include bacteria, fungi, and mites.
What Causes Alopecia?
Alopecia can occur for multiple reasons, Dr. Klein says. Here are some common causes of hair loss in dogs:
- Bacterial infection
- Fungal infections, like ringworm
- Allergies with scratching or chewing
- Parasites, like fleas and ticks
- Mange caused by mites
- Genetic susceptibility, such as hairless breeds
- Nutritional causes, like vitamin deficiency
- Endocrine or hormonal disorders, such as Cushing’s disease and hypothyroidism
- Chemotherapy to treat cancer
- Hormonal changes
- Pressure sores
- Trauma
- General aging
In the case of fleas, these parasites feed off the blood of animals. A flea bite can make the area red, itchy, and swollen, prompting your dog to scratch. In addition, dogs may develop “flea bite dermatitis, which is an allergic reaction to the saliva of a flea,” Dr. Klein explains. The saliva can cause excessive scratching, hair breakage and loss, and a possible secondary skin infection if bacteria enters the wound.
Another potential cause of hair loss is genetics, he says. Some breeds are genetically hairless, such as the Chinese Crested, American Hairless Terrier, Peruvian Inca Orchid, and Xoloitzcuintli. Other breeds can develop demodectic mange as a result of poor breeding practices. Many long-haired, intact female dogs also lose significant hair following a heat cycle.
Moreover, some breeds are prone to developing endocrine disorders, such as Cushing’s disease or hypothyroidism, both of which can cause hair thinning or hair loss, he adds. These breeds include the Bulldog, Doberman, Greyhound, and Dachshund. Cushing’s disease occurs when the body produces too much of the hormone cortisol, which can weaken a dog’s immune system. Hypothyroidism occurs when the body produces insufficient thyroid hormone, which tends to slow down a dog’s metabolism.
How Do Veterinarians Diagnose Hair Loss?
To diagnose hair loss, a veterinarian will begin by taking a thorough history of a dog’s health from their owner. They’ll assess the signs and symptoms of alopecia. For example, they’ll want to know if your dog has been scratching the affected area. Next, they’ll examine the dog to see if the hair loss is all over, confined to a certain area, or has a symmetrical pattern, and whether the hair loss is normal or abnormal for that individual dog.
After carefully examining a dog, the vet may perform diagnostic tests, such as skin scrapes and skin biopsies, to aid in the diagnosis. Skin scraping involves using a scalpel to collect a skin sample for examination under a microscope.
How Do You Treat Hair Loss?
“Treatments for hair loss depend on the etiology or cause of the hair loss,” Dr. Klein says. For example, a veterinarian can prescribe medication to treat itchiness and inflammation. They could also give your dog an antibiotic or antifungal medication if they have a concurrent secondary infection due to scratching. With parasites, the vet’s goal is to eliminate the organism or microorganism from the dog’s fur and eradicate parasites from the environment through cleaning and disinfecting.
For endocrine disorders, the vet can administer medications to help correct hormonal imbalances that affect organ function. For example, they could give a dog hormone replacement therapy to treat a low thyroid level. Another example is Cushing’s disease, which is caused by a tumor on the pituitary or adrenal gland. This condition is most commonly treated using medication since surgery on the tumor is risky.
When alopecia has a genetic cause, it doesn’t always require treatment. This is especially true if the condition is not affecting the dog’s quality of life, Dr. Klein adds. Shedding of your dog’s undercoat, especially seasonal shedding, isn’t a cause for concern. Shedding of your dog’s undercoat, especially seasonal shedding, isn’t usually a cause for medical intervention.
If your dog’s fur is thinning or developing bald spots or if your dog seems itchy or uncomfortable, speak to your vet to determine what’s causing hair loss and options for providing symptom relief. Your vet will also discuss your dog’s nutritional needs to ensure that they’re receiving a complete and balanced diet for their age and activity level.
This article is intended solely as general guidance, and does not constitute health or other professional advice. Individual situations and applicable laws vary by jurisdiction, and you are encouraged to obtain appropriate advice from qualified professionals in the applicable jurisdictions. We make no representations or warranties concerning any course of action taken by any person following or otherwise using the information offered or provided in this article, including any such information associated with and provided in connection with third-party products, and we will not be liable for any direct, indirect, consequential, special, exemplary or other damages that may result, including but not limited to economic loss, injury, illness or death.