Why is My Dog Losing Hair? - Causes and Treatment

By Josie F. Turner, Journalist specialized in Animal Welfare. October 22, 2018
Why is My Dog Losing Hair? - Causes and Treatment

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Hair loss in dogs can happen for a variety of reasons, both as natural processes and as signs of an underlying problem. The former can be due to various factors such as age of the dog or the time of year. The latter has even more diverse causes and we need to pay close attention to concurrent symptoms. We also need to consider the way in which their fur falls out. If a dog is losing hair in patches or spots, then this implies canine alopecia. It is important to differentiate between this and normal shedding. Where on the dog's body is also important. Sometimes the hair loss is on their body, on their neck, on their legs or even on their tail.

AnimalWised answers why your dog is losing hair by investigating the possible causes. We'll also look into what to do if your dog's hair is falling out by looking at different treatment options. We want to start by stressing the importance of keeping your dog's coat healthy.

You may also be interested in: My Rabbit Is Losing Fur - Alopecia in Rabbits

The importance of a dog's coat

One of the main features when differentiating dog breeds is to look at their coat. Some have long hair draped around their eyes and mouth, some have sleek short fur all over. There are even some dogs which don't have any hair at all. Dogs which do have fur will have some combination of the following:

  • Overcoat: also known as the primary coat, this is the outer part which grows longer and has the ability to bristle and even reflect the dog's moods.
  • Undercoat: sometimes known as the secondary coat, this is a thicker coat which is used to regulate temperature. It most often grows in as the month's get colder to help preserve heat.
  • Modified hair: these are stronger and thick hairs which make up the whiskers and eyebrows. They are used as a tactile sense to gauge elements within their environment.

Some dogs only have an overcoat and lack an undercoat due to breeding. This may also have to do with the climate in which a dog breed is developed as those with a thick undercoat are better suited to colder climates. The quality of a dog's coat will depend on diet, health, genetics and the care we provide for them.

The color of a dog's coat is not important for anything other than aesthetics. The quality is the important factor. A dog's coat should be bright, shiny, smooth and strong. If your dog's coat is dry, brittle, losing shine and luster, it is likely they have a problem. This problem is likely getting worse if you start to see your dog losing their hair after it has dropped in quality.

A dog's coat also helps to protect the canine from developing disease. This is not simply in terms of keeping them warm in cold weather, but by acting as part of their communication system. They alert other animals to their mood and can protect them from injury. As we will see, you can help prevent the causes of hair loss in dogs by maintaining their coat as best you can.

Dog losing hair through shedding

As with many mammals, dogs will shed their undercoat as part of a shedding season. Molting will most often occur semi-annually, This is known as molting and it occurs to help the dog fare better in warmer weather. Once the warmer weather is over, they will regrow the undercoat and repeat the process again. However, it is not heat which instigates this hair shedding. Rather, it is the amount of light which is shed onto the dog. When the sun shines more on their skin, a greater amount of melatonin is released by their pineal gland, resulting in the beginning of the molt.

The process known as the teleogen phase is when the hair is at rest. This is when the dog can molt and the hair starts to fall out. When this happens, you will need to brush the dog more regularly than before. During the height of the molting season, this should be at least once a day and sometimes more if it is a particularly furry dog. The hair may not fall out evenly over the entire body, but this shouldn't be a problem in itself. If the hair loss is excessive and you start to see spots or patches of skin appear, then you will want to consult a veterinarian.

Why is My Dog Losing Hair? - Causes and Treatment - Dog losing hair through shedding

Hair loss in dogs

The telogen phase can be entered into for other reasons than natural shedding. This is the difference between normal shedding and canine alopecia. Canine alopecia is a general term for hair loss in dogs and has many different causes. None of them are usual parts of shedding or molting. While molting may not result in even hair loss over the body, it should not result in patches of hair being lost or in thinning so much that the skin underneath is visible. If this occurs, this is most likely to be due to one of the following causes:

  • Genetics: as with humans, it is believed that genetic causes may be linked to alopecia in dogs. The breed might be an important factor as certain breeds such as Pomeranians have had studies linking alopecia to a certain gene[1].
  • Stress: another reason dogs might be losing hair is due to stress. This could be stress caused by an underlying disease, but it could also be due to mistreatment, inappropriate living conditions, not getting on with other dogs or many other stress inducing situations.
  • Trauma: if a dog has received trauma in the form of a blow or cut, then they quite often lick the area to reduce irritation. If this is the case, they may lick to the point bald patches of hair loss appear.
  • Hormonal imbalance: if your dog has a hormonal imbalance, then it can affect glands in the body such as the pineal gland or thyroid. If these glands act up, they can result in hair loss. Diseases such as Cushing's syndrome can result in hormonal issues leading to hair loss. Neutering your dog is one of he best ways to prevent hormonal imbalances.
  • Parasites: one of the most common reasons for a dog to lose their hair is due to the presence of parasites. External parasites can imbed in the skin and cause a lot of irritation and hair loss. Internal parasites can also stop the dog from digesting their food properly. This results in a lack of nutrients going to the skin and can mean the dog will lose hair.
  • Infection: different infections can result in the lowering of the dog's immune system and hair loss. There are many different types of infection of varying degrees of treatability. Taking your dog to the vet is the best way to ensure a dog is able to get the correct diagnosis.
  • Cancer: if your dog has cancer, then it is possible hair loss will result as a side effect. In some cancers, such as prostate cancer, the early stages are asymptomatic, so hair loss many only occur when it is advanced.


Why is My Dog Losing Hair? - Causes and Treatment - Hair loss in dogs

Treatment for hair loss in dogs

As with most canine health issues, prevention is better than treatment. This is why deworming and vaccination schedules are so important. Puppies should start vaccinations at around 8 weeks of age and get them until around 16 weeks of age. However, booster shots should be given every couple of years at the discretion of your vet. Deworming will occur more regularly. This acts to prevent parasites infecting the dog and causing infections or skin conditions linked to hair loss.

If the dog does receive trauma, then addressing the wound and using an Elizabethan collar is best to prevent the dog from licking the area. If the dog has hormone issues, then you will need to take them to the vet for a proper diagnosis and treatment options. As we state above, one of the best ways to prevent hormonal issues affecting your dog is to have them neutered. This will also help with behavioral issues and reduce unwanted pregnancy.

Sarcoptic mange (scabies) also needs to be treated as it can worsen. If you see the dog has irritated skin also, then this is most likely the case. If the problem is an infection, it will most likely be treated with antibiotics. Cancers which result in hair loss will need to be assessed on an individual basis and treatment such as radiotherapy or chemotherapy used accordingly. You may see articles offering natural home remedies for hair loss in dogs, but you need to discuss any possible treatment options with your vet first. Otherwise, you may not be treating the correct cause and the hair loss will only worsen.

Why is My Dog Losing Hair? - Causes and Treatment - Treatment for hair loss in dogs

Dog hair care

While many causes of hair loss in dogs can be treated, the best thing to do is always ensure you take good care of a dog's coat. Here are some ideas:

  • If you start to see any patches of hair loss on your dog, you need to take them to the vet. Not all causes are very obvious and a doctor's diagnosis is required for the proper alopecia treatment.
  • Food is key in ensuring your dog has a healthy looking coat and the diet needs to be adapted to the specific needs of the dog. If your dog's hair is weakened, you may be able to supplement with more omega-3 rich foods. You should consult with your vet before you make any major changes to your dog's diet.
  • Regular brushing is essential, even in shorter hair dogs. Choose the right brush and only use products which are safe for our dog's skin and coat.
  • Bathe when necessary, but do not overbathe. This is because it will lessen the natural oils on the dog's skin and take away some vital nutrients for the dog's fur.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Why is My Dog Losing Hair? - Causes and Treatment, we recommend you visit our Other health problems category.


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1 comment
K. Hondermann
My 4-yr. old shar pei recently gave birth to a litter of four perfect puppies. During the pregnancy she scratched herself more often and began to nibble her forelegs until there is barely any fur left. Now she has patches on her head without hair (from scratching) and her legs and trunk have noticeable patches without hair. Her left leg also seems to itch whenever she walks and it starts to jump (same as when you tickle a dog's belly). I would like to know if all this is simply due to the stress involved in her pregnancy, and a reduced immune system emanating from the pregnancy and birth. I hate seeing her like this.
Administrador AnimalWised

Before we say anything, you will need to take your dog to the vet. We cannot diagnose the problem, only they will be able to diagnose the problem properly. As we state in the article, there are many skin problems and pathologies which might be causing the hair loss. From the picture it looks like it could be dermatitis, but it could also be a parasitical infestation. If your dog has just given birth, the puppies are at their most vulnerable. If they get parasites, it can be particularly worrying. please take your dog to the vet for a diagnosis and treatment plan.
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