Every dog sheds. Some seasonally, some year-round. But certain shedding patterns are your dog's coat telling you something is wrong internally.
When to take it seriously.
Normal shedding is diffuse and consistent with the season or breed. When it's accompanied by itchy skin, hot spots, or recurring infections, food allergies in pets is often an overlooked contributor — one that shows up in the coat before owners connect it to diet.
The most common medical cause: hypothyroidism.
A 2025 PMC study found hypothyroidism in 14% of clinically affected dogs, with Golden Retrievers and middle-aged dogs overrepresented. Approximately 85% of hypothyroid dogs present with skin or coat abnormalities — it's the most common presenting complaint in the clinic. Thyroid hormone reduction pushes hair follicles into the resting (telogen) phase prematurely, stopping growth before the hair is replaced. The result is shedding without regrowth.
Other signs of hypothyroidism: unexplained weight gain without increased appetite, lethargy, exercise intolerance, cold sensitivity, and frequent ear or skin infections.
Other causes of abnormal shedding:
Cushing's disease - Produces thin skin, a pot belly, and hair loss — and it often develops alongside metabolic conditions tied to diet and weight. The connection between kibble and pet obesity and hormonal disruption is worth understanding if you're ruling out endocrine causes.
Food or environmental allergies — typically causes itchy skin alongside shedding
Nutritional deficiencies — omega-3 deficiency in particular produces a dull, brittle coat
Chronic stress — elevated cortisol suppresses healthy coat growth
The nutrition connection.
Dogs fed diets low in animal-sourced omega-3 fatty acids frequently present with coat issues that improve with diet change. Organ meats and bones covers the nutritional role of whole-food animal protein in coat and skin health specifically.
Diagnosis and treatment.
A simple blood test measuring T4 and TSH levels confirms or rules out hypothyroidism. If confirmed, daily oral thyroid hormone replacement resolves most coat and skin symptoms within 4 to 6 months.
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