Hair loss is a normal occurrence in all dogs. The bristles have indeed a limited lifespan. Once they have grown, they die, fall and grow back constantly. There are even so-called moulting periods during which the coat is renewed. These are the periods when the seasons change, that is to say in autumn and spring. In autumn, the summer coat gives way to the winter coat, while in the spring the reverse occurs. Hair loss in dogs is also common problem.
When to worry
Hair loss should get your attention if:
- It is accompanied by other symptoms such as itching, redness or even poor coat quality.
- It is so important that the dog presents areas where there is no more hair or almost. Alopecia is the medical term used to refer to hair loss leaving areas depilated.
In these situations, hair loss is abnormal. She should alert you and urge you to consult your veterinarian.
Reasons Your Dog Is Losing Hair
Different diseases can cause abnormal hair loss:
- Parasitic diseases: some skin parasites cause hair loss and are manifested, among other symptoms, by the presence of depilated areas. It can be fungal infections (ringworms) or microscopic mites (scabies, demodectic mange, cheyletiellosis for example), insects (fleas)
- Allergies: Allergic reactions can cause itching and hair loss. Allergies to flea bites or food allergies are common causes. It is sometimes difficult to identify the allergen (s) involved. In addition, some so-called atopic dogs are predisposed to exhibit allergic reactions to various substances (dust, pollen, etc.)
- Endocrine diseases: certain hormonal imbalances can manifest as alopecia, such as hypothyroidism, Cushing’s syndrome, or certain testicular tumors which secrete excess estrogen, for example
- Autoimmune diseases
- Certain skin cancers
- Certain racial or genodermatoses diseases (hereditary, with genetic support) such as alopecia of the diluted coats, follicular dysplasia,…
Apart from these causes which are related to pathologies, there are cases of increased hair loss, mainly due to poor quality food. This is neither a disease, nor strictly speaking an allergy, but inadequate or poor quality food intake which necessarily has repercussions on the quality of the coat.
Associated symptoms
Depending on the problem involved in hair loss, other symptoms may be associated.
Itching, also called pruritus, is a common symptom of skin problems. The pruritus is more in favor of an allergic problem or certain parasitic diseases such as scabies. Likewise, the presence of redness is also a frequent symptom in dermatology, often associated with itching.
Other symptoms may also be present on the dog’s skin: thickening, secondary bacterial infections, greasy, oozing or on the contrary very dry appearance.
In the case of general diseases, such as endocrine pathologies in particular, the dog may present general symptoms: increase in the amount of drink, fatigue, increase or decrease in appetite and weight.
Read More

Diagnostic
To be able to make a diagnosis, it is essential to take your dog to your veterinarian. Abnormal hair loss can indeed have such varied origins that it is best to seek the advice of an animal health professional. In addition, the appearance of the unstacked areas, their location and whether they are symmetrical or not will be important elements which he will only be able to realize during a consultation.
The veterinarian will begin with a general clinical and dermatological examination and a search for any associated symptoms.
Depending on these elements, he may propose additional examinations to confirm or not his hypotheses. These may be specific dermatological examinations: examination of hairs (trichogramma), scrapings and / or skin layers. An examination of the skin under a specific lamp (Wood’s lamp) may be offered to check for the presence of ringworm even if the results are not always certain when they are negative. Hair or pus samples to send to the laboratory are possible to look for fungi or bacteria, for example. In addition, skin tests can help identify the allergens involved. Finally, a biopsy can optionally propose to have a microscopic examination of the different layers of the skin.
In addition, blood tests may be necessary for a hormonal assessment in particular.
Treatment of hair loss in dogs
Treatment will of course depend on the diagnosis made. These may be local treatments (shampoos, disinfection, creams) or general treatments (antiparasitic treatments, antibiotics, anti-inflammatories, antihistamines, hormonal treatments). Environmental treatments aimed at eliminating possible allergens may recommend, including the prescription of a specific diet. Some diseases are incurable.
In any case, comply with the prescription and the advice of your veterinarian. This is all the more important as it can sometimes be long (often several weeks to months) and difficult to completely eradicate dermatological problems.
Prevention of hair loss
In some cases, preventive treatments will have to follow scrupulously to avoid relapses: shampoos and skin maintenance, anti-mite treatment in the environment, regular anti-flea treatment, specific diet.