Hair Loss in Dogs and Cats: Identifying the Underlying Issues

Hair loss, also known as alopecia, is a common concern among pet owners. While some shedding is normal, excessive hair loss, bald patches, or skin irritation may indicate an underlying medical issue. At Homestead Animal Hospital in Mechanicville, NY, we help pet owners identify and treat the root causes of hair loss in dogs and cats.

We can provide skin scrapings, fungal cultures, and allergy testing to identify the cause.

  • Blood tests to check for hormonal imbalances.
  • Customized treatment plans, including medications, diet adjustments, and parasite control.

Common Causes of Hair Loss in Pets

Allergies

Pets can develop allergies to food, environmental factors (pollen, mold, dust mites), or flea bites. Allergic reactions often cause itching, redness, and hair loss due to excessive scratching or licking.

  • Flea Allergy Dermatitis (FAD): Just one flea bite can trigger severe itching in allergic pets. Learn more from Cornell Feline Health Center.
  • Food Allergies: Proteins such as chicken or beef can trigger reactions, leading to hair loss and digestive issues.
  • Environmental Allergies: Seasonal changes can worsen symptoms. Read about dog allergy symptoms and treatments.

Parasites (Fleas, Ticks, and Mites)

Infestations of fleas, ticks, or mites can cause significant hair loss, irritation, and infection. Demodectic and sarcoptic mange are caused by mites and often lead to bald patches and severe itching.

Fungal and Bacterial Infections

Ringworm, a fungal infection, causes circular bald patches, scaly skin, and redness. Bacterial skin infections, such as pyoderma, can also lead to hair loss, often due to underlying allergies or immune disorders.

Hormonal Imbalances

Hormonal disorders like Cushing’s disease (hyperadrenocorticism) and hypothyroidism can lead to thinning hair, dry skin, and weight changes.

Stress and Over-Grooming (Psychogenic Alopecia)

Stress, anxiety, or compulsive grooming behaviors can cause hair loss in both dogs and cats. Common stressors include environmental changes, lack of stimulation, or conflicts with other pets.

  • Cats may develop psychogenic alopecia, where excessive licking leads to bald patches.
  • Providing enrichment and reducing stressors can help manage this condition.

Poor Nutrition

A diet lacking essential fatty acids, vitamins, and protein can result in dull fur, brittle hair, and increased shedding.

  • Ensuring a balanced, high-quality diet supports skin and coat health.
  • Regular grooming can help distribute natural oils. Learn more from ASPCA’s guide to pet grooming.

Genetic and Breed-Related Alopecia

Certain breeds are prone to genetic hair loss conditions, including:

  • Color Dilution Alopecia (CDA): Common in blue or silver-colored dogs like Dobermans and Weimaraners.
  • Seasonal Flank Alopecia: Seen in Boxers, Bulldogs, and Schnauzers, causing temporary bald patches in winter.

Exposure to External Hormones or Medications

Pets can develop hormonal imbalances from exposure to human medications, such as:

  • Hormone Replacement Therapy (HRT) creams or gels
  • Testosterone or estrogen-based topical medications

If pets absorb these hormones through skin contact, they may develop hair loss, skin changes, or abnormal behaviors. Always wash hands thoroughly after applying medications and keep pets from licking treated areas.

Treatment Options for Pet Hair Loss

Allergy Management

Allergies are one of the most common causes of hair loss in pets. Identifying and managing allergens can significantly improve your pet’s skin and coat health. Treatment varies depending on the type of allergy:

  • Flea Allergy Dermatitis (FAD): Even a single flea bite can cause severe itching and hair loss in sensitive pets. Strict flea prevention with monthly flea control products is essential. A combination of topical, oral, and environmental flea treatments may be recommended.
  • Food Allergies: Some pets develop allergies to proteins like beef, chicken, or dairy. Hypoallergenic diets with novel proteins (such as duck or venison) or hydrolyzed proteins can help reduce allergic reactions. Food trials must be done for at least 8–12 weeks to accurately diagnose food allergies.
  • Environmental Allergies (Atopy): Pollen, mold, and dust mites can trigger itching and hair loss. Antihistamines, steroids, or allergy shots (immunotherapy) may help control symptoms. Regular bathing with medicated shampoos can also help remove allergens from the skin and reduce irritation.

Parasite Control

Parasites such as fleas, ticks, mites, and ringworm can cause severe itching, skin infections, and patchy hair loss. Preventative and treatment strategies include:

  • Routine flea and tick preventatives: Monthly flea and tick control products reduce the risk of infestations that lead to allergic reactions and secondary infections.
  • Mite and ringworm treatments: Mange caused by Demodex or Sarcoptes mites requires medicated dips, oral treatments, or injections. Ringworm, a contagious fungal infection, often requires antifungal shampoos and oral antifungal medications.

Medications for Skin Infections

Bacterial and fungal skin infections often develop secondary to allergies, parasites, or underlying health conditions. Treating these infections promptly prevents further complications:

  • Antibiotics or antifungals: Bacterial skin infections (pyoderma) require oral or topical antibiotics, while fungal infections like ringworm are treated with antifungal medications.
  • Medicated shampoos and topical treatments: Regular bathing with antimicrobial or antifungal shampoos helps control infections and soothe irritated skin. Some pets may also need topical ointments to reduce inflammation.

Hormonal or Endocrine Treatments

Hormonal imbalances can lead to thinning hair, excessive shedding, and brittle fur. Depending on the underlying condition, treatment may include:

  • Thyroid supplements for hypothyroidism: Low thyroid hormone levels cause hair thinning, weight gain, and lethargy. Daily thyroid hormone replacement therapy can restore coat health and energy levels.
  • Medications for Cushing’s disease: Pets with Cushing’s disease produce excess cortisol, leading to hair loss, skin infections, and excessive thirst. Medications such as trilostane help regulate hormone levels and manage symptoms.

Stress Reduction & Behavioral Support

Anxious pets may over-groom or excessively lick themselves, leading to hair loss. Stress-related conditions such as psychogenic alopecia in cats require a multi-faceted approach:

  • Enrichment activities: Providing mental stimulation through puzzle feeders, interactive toys, and regular playtime can help redirect excessive grooming behavior.
  • Pheromone diffusers (such as Feliway or Adaptil): These products release calming pheromones that help reduce anxiety and stress-related behaviors.
  • Behavioral therapy: For pets with severe anxiety, a veterinarian may recommend anti-anxiety medications or a consultation with a veterinary behaviorist.

Preventing Hair Loss in Dogs and Cats

Routine Grooming & Skin Care

Proper grooming is essential to remove loose fur, distribute natural oils, and detect early skin issues. Regular grooming can help prevent matting, irritation, and excessive shedding:

  • Brushing: Regular brushing removes dead hair, dirt, and dander. The frequency depends on breed and coat type—long-haired breeds require more frequent grooming.
  • Bathing: Using vet-approved shampoos helps maintain skin hydration and prevents infections. Over-bathing can strip natural oils, so consult your vet about the right bathing schedule for your pet.

Learn more about why regular grooming is essential for maintaining skin and coat health.

Balanced Diet & Supplements

A nutritionally complete diet is critical for maintaining healthy skin and fur. Deficiencies in essential fatty acids, vitamins, and proteins can lead to dull, brittle hair and increased shedding.

  • High-quality diet: Feed a balanced diet rich in protein, Omega-3 fatty acids, and essential vitamins to support coat health.
  • Omega-3 supplements: Fish oil supplements help reduce inflammation, improve coat shine, and strengthen hair follicles.

Veterinary Check-Ups

Routine veterinary care is key to catching underlying health issues before they lead to significant hair loss.

  • Annual wellness exams: Early detection of allergies, infections, and hormonal imbalances allows for prompt treatment.
  • Routine bloodwork: Helps screen for metabolic diseases, hormonal conditions, and immune disorders that can contribute to hair loss.

When to Seek Veterinary Care

If your pet’s hair loss is accompanied by:

  • Red, inflamed skin
  • Excessive scratching or licking
  • Bald patches or scabbing
  • Weight loss or behavioral changes

…they need a professional veterinary evaluation. Left untreated, skin infections and hormonal imbalances can worsen, leading to chronic conditions, secondary infections, and discomfort.

At Homestead Animal Hospital, we are committed to comprehensive pet care. If you’re concerned about your pet’s coat health, schedule an appointment today.