Why do pet dogs shed hair?

Causes of hair loss in pet dogs

1. Scabies: caused by scabies or demodex. Scabies mites mainly occur on the head (the bridge of the nose, eye sockets, auricles and their roots), and sometimes also occur on the chest, abdomen, armpits, inner thighs and tail, and even spread to the whole body. The surface of the skin is flushed, with rash-like nodules, thickened subcutaneous tissue, and the skin of the affected area is depilated due to frequent scratching, rubbing, and biting.

2. Lice disease: itching and skin irritation caused by lice parasitism, resulting in scratching, rubbing and biting. The hair on the affected part is rough and dull, easy to break and fall off. In particular, the parasitism of hair lice can cause a large amount of hair loss in dogs, and a large amount of shedding hair can be found in places where dogs often move.

3. Hookworm disease: Affected dogs are emaciated, with pale conjunctiva, rough and dull coat that is easy to break and fall off, and hair loss spots of different sizes often appear on the back, exposing the skin, and papules or scabs appear on the skin. Sick dogs have loss of appetite, vomiting, pica, diarrhea and constipation alternately, the stool is bloody or black, and has a rancid smell.

4. Alopecia trichophyton: It is mainly a fungal disease caused by Microsporum and Trichophyton in dogs. The course of the disease is long, and round or irregular bald spots appear on the skin, covered with off-white scales, which are more common on the head, neck and limbs, and can be connected into one piece in severe cases, affecting most of the body surface. Sometimes accompanied by dermatitis, papules or pustules.

5. Estrogen secretion disorder: It is more common in adult female dogs that have not been neutered. It is manifested as excessive estrogen secretion, itching all over the dog, hair loss (generally the hair loss is symmetrical), and skin pigmentation. Some sick dogs have swollen vulva and bloody secretions, showing symptoms of continuous estrus.

6. Canine acanthosis nigricans: The etiology is not clear yet, most of them think that it is related to the hormone secretion disorder in the dog body. It occurs frequently in old and weak dogs, and the skin symptoms are similar to estrogen secretion disorder. The symptoms are symmetrical hair loss, pigmentation, and skin thickening. It is the main symptom, and the skin has oily exudation at the same time, but there is no itching symptom.

7. Vitamin deficiency: Vitamin B deficiency can also cause hair loss, accompanied by symptoms such as weight loss, anorexia, general weakness, vision loss or loss.