Dogs can experience hair loss, also known as alopecia, due to health issues, infection, parasites or fungal infections. Hair loss may be patchy, full body or concentrated to an area such as the stomach and legs. Many skin and hair problems have simple remedies, though some can signal serious underlying medical conditions. Veterinary advice is recommended to ensure accurate diagnosis and treatment.
Allergies and Parasites
Some dogs can be bitten by bugs and have no ill effects, while others have allergic reactions that result in hair loss. Flea dermatitis allergies can result in hair loss as can tick and insect bites, which are often concentrated on the area of the dog closest to the ground, primarily legs and stomach. Sensitive dogs also may have allergic reactions to plants, lawn or household chemicals they come in contact with, resulting in irritated skin and hair loss.
Mange and Nutritional Deficiencies
Mange is caused by the Demodex mite and can result in widespread patchy hair loss. Mange is often seen in young or old dogs experiencing infection, trauma and nutritional deficiencies. Dogs who have not been well cared for or received adequate health care may have underlying immune or endocrine system problems. Mange is treated using topical ointments and medicated shampoos, and by treating the underlying health problem.
Ringworm is a fungal infection that looks like raised circular welts with a red outer edge and pale, crusty or white center. Hair loss frequently occurs around these lesions and is often concentrated on the trunk, face, stomach and legs of dogs. Ringworm is highly contagious between human and animals and generally is treated with an anti-fungal medication.
Hot spots develop when a dog licks or chews at an irritated area of skin to the point he develops hair loss and open, red, wet sores. These occur more frequently on the stomach and legs, as these are the areas easiest for a dog to reach with his mouth. Many things can incite a dog to create hot spots, from bug bites to skin irritations. These usually are treated with topical anti-itch or antibiotic creams and by keeping the wounds dry and protected.
Other Causes of Hair Loss
Your dog could experience hair loss due to stress, a metabolic disorder, adrenal gland or thyroid problems. Hormonal fluctuations and skin yeast infections can be culprits as well. Some skin cancers and tumors also may present with hair loss. Your vet likely will diagnosis your pup's specific problem by conducting a physical exam, running blood and urine tests and possibly taking skin cultures for examination. Treatment will depend on the underlying medical problem.