- This post contains affiliate links. Read more here.
- Not a substitute for professional veterinary help.
Dogs can develop bald spots or thinning hair for a number of reasons, some more serious than others. While shedding is normal, serious conditions like food allergies and hypothyroidism can also lead to dog hair loss.
What Causes Dog Hair Loss?
Just like with human hair loss, there’s no one reason your dog may be losing their hair.
Here are some common reasons for hair loss in dogs.
Shedding
Most breeds of dog shed some amount of hair year-round, and some breeds, like labs, Akitas, and huskies, lose hair by the handful each spring. Seasonal shedding can be pretty dramatic for some dogs, so if you noticed your dog’s undercoat get thicker in the winter, you can anticipate that all of that fluff will be shed some months later.
Brushing can be a delicious treat for a shedding dog, as shedding is usually an itchy experience for many dogs. It can also help keep your home from looking like a dog hair blizzard blew through town.
Hormone Changes
Pregnant and nursing dogs sometimes experience hair loss due to hormone changes. This hair loss usually stops after the period of pregnancy and nursing is over and her hormones return to non-reproductive levels.
Another hormone-related cause of hair loss is hypothyroidism, which causes the body to produce too little of the hormone thyroxine. This can lead to a dull coat, bald patches, and seborrhea (dandruff). Hypothyroidism usually affects medium-to-large size dogs that are 4 years or older.
Allergies
Veterinarians have estimated that more than 70% of skin conditions in dogs, including hair loss, is due to allergies. Among allergens that commonly impact skin health are flea bites, food allergies, and environmental allergies like pollen and mold. Allergies are usually genetic and tracking down the cause can be a tricky process.
Allergy symptoms include itchy skin, hot spots, patchy hair loss, chronic ear itching, gastrointestinal problems, and chronic diarrhea or gas. If your dog is experiencing symptoms like these, talk to your vet about allergy testing.
Skin Infections
Just like people, dogs can get bacterial or fungal infections on their skin. Bacterial skin infections often begin with broken skin from a scratch or flea bites and can cause result irritation and hair loss.
Pyoderma is a term used for a bacterial skin infection, particularly when the skin is red and producing pus. Pyoderma can be treated with antibiotic ointment or oral medication, depending on the severity.
Candida, or yeast infections, can occur when the yeast that is always present on a dog’s skin becomes overgrown. A candida infection on the skin causes skin irritation, open sores, and can also lead to hair loss. Candida skin infections can be treated with antifungal creams or oral medication.
Ringworm, aka tinea, is a fungal infection (not actually a worm) that causes round patches of flaky skin and broken hairs. This infection is common in dogs, cats, and people (yes, we can share it with each other) and can be treated with antifungal creams or oral medication.
Fleas or Mites
The itchiness caused by fleas and mites can lead to hair loss for a few reasons. Dogs can simply scratch themselves raw, pulling out hair as they go, and leaving hairless patches on their skin.
Frequent scratching can lead to skin abrasion, which can cause bacterial and fungal infection, resulting in further hair loss.
Some dogs are also allergic to fleas or mites, and this can cause further skin inflammation and loss of hair. Both fleas and mange mites are highly contagious and can spread to other pets and even to people in your home, so if you suspect that your dog has fleas or mites, talk to your vet.
Both types of parasites can be treated with medications, and special shampoos can help soothe irritated skin.
Mange
A common reason for patchy fur loss in dogs, mange is caused by the Demodex mite. Most dogs have these tiny creatures living on their skin, but a compromised immune system due to stress or an autoimmune disorder can cause the mites to multiply unchecked, irritating skin and creating lesions.
Mange is treatable through medication, and while you may have heard motor oil can cure this condition, it is highly toxic to dogs and is not recommended as a treatment for mange in dogs.
Genetics
Sometimes, it’s natural for your dog to develop bald patches as they get older, often after they reach the 1-year mark.
Greyhounds, whippets, Chihuahuas, dachshunds, and Italian greyhounds are all susceptible to losing fur on their outer ear, chest, belly, thighs, or lower neck.
What to Do If Your Dog Has Hair Loss
If your dog has a bald spot or her coat is looking thinner than it used to, consider consulting your vet.
You may also want to take a look at the kind of dog food they’re eating, and if the symptoms are mild, exploring some hypoallergenic dog food options to see if that alleviates the issue.
It’s also a good idea to slowly eliminate the possible causes above. Checking for fleas in the home, ruling out mange and ensuring your dog has a calm environment may help stop the hair loss.
If you don’t see improvement, however, it’s a good idea to visit your vet to rule out some of the more serious conditions before things get worse.
WebMD recommends that you take your dog to the vet immediately if she has a bald spot in combination with:
- Itching
- Bad odor
- Irritated or infected skin
- Changes in behavior
- Any skin lesions in other pets or people in the household
Shampoos for Irritated Skin
If your dog is losing hair and has irritated, flaky skin, these shampoos might help.
Take a look at the active ingredients to determine if the shampoo targets the specific skin problem that your dog is experiencing.
Veterinary Formula Clinical Care Antiparasitic and Antiseborrheic Medicated Shampoo
Active ingredients: coal tar, salicylic acid, and micronized sulfur
Treats: seborrhea (dandruff and greasy coat) and soothes the discomfort of mange.
Find on ChewyCuraseb Antifungal & Antibacterial Chlorhexidine Shampoo for Dog & Cats 
Active ingredients: chlorhexidine and ketoconazole
Treats: yeast infections, ringworm, pyoderma (bacterial infection)
Find on AmazonArava Natural Medicated Dog Shampoo
Active ingredients: liquorice, mallow, chamomile, rosemary, yarrow, fennel, nettle, sage, burdock, aloe vera, jojoba, tea tree, calendula, origanum syriacum, oatmeal, flaxseed, benzoin, sea buckthorn, borage seed, pomegranate, evening primrose, argan, kelp, reishi, shiitake, maitake & dead sea minerals
Treats: fungal infections, skin irritation
Find on AmazonRichard’s Organics Anti-Bacterial Shampoo for Dogs
Active ingredients: tea tree and neem oil
Treats: fungal infections, bacterial infections
Pet MD Benzoyl Peroxide Medicated Shampoo for Dogs and Cats
Active ingredients: benzoyl peroxide
Treats: seborrhea (dandruff), mange, bacterial and fungal infections
