Every dog moults, and most of the hair I sweep off my table is completely normal. But now and then a coat starts thinning in a way that doesn't look like ordinary shedding at all: bald patches appearing evenly on both sides, skin that looks different, and a coat that just won't grow back. That pattern can point to a hormonal problem, and it's one of the things groomers are often first to notice. The short answer: hormonal hair loss usually shows as symmetrical thinning without much itching, it can be linked to conditions like Cushing's disease or an underactive thyroid, and it needs a vet to diagnose properly.
Normal shedding versus something more
First, the reassuring part. Most coat change is nothing to worry about. Dogs shed old and dead hair all year, with bigger moults in spring and autumn, and double-coated breeds drop a lot of undercoat seasonally. Normal shedding is fairly even, the coat underneath looks healthy, and new hair keeps coming through.
Hormonal hair loss looks different. The tell-tale signs are:
- Symmetrical thinning: hair loss that appears in roughly the same pattern on both sides of the body, often over the flanks, belly, chest or tail
- Bald patches without much itching: unlike allergies or parasites, hormonal loss often isn't especially itchy
- Hair that doesn't grow back after a clip or a shed
- Skin changes: darker, thickened or flaky skin in the thinning areas
If you're seeing that kind of even, non-itchy thinning, it's worth a proper look rather than assuming it's just a heavy moult.
Hormonal conditions that affect the coat
Several hormonal (endocrine) conditions can show up first in the coat, which is why a change in the fur is such a useful early clue.
- Hypothyroidism (underactive thyroid): when the thyroid doesn't make enough hormone, the coat can thin, become dull and lose hair symmetrically. Dogs may also gain weight, slow down or seem to feel the cold. You can read the medical background on hypothyroidism in dogs.
- Cushing's disease (overactive adrenal hormones): too much cortisol can cause thinning hair, a pot-bellied look, increased drinking and hunger, and skin changes. The general condition is Cushing's syndrome.
- Sex-hormone imbalances: less common, but imbalances linked to the reproductive hormones can also cause symmetrical coat loss.
The important theme: these are internal conditions. A dog can look perfectly happy and still have one brewing, so the coat change may be your first real hint.
Vet note: Groomers can spot the pattern, but we can't diagnose the cause. Symmetrical, non-itchy hair loss should always be checked by a vet, because the treatment depends entirely on which hormone is involved.
Why this needs a vet, not a guess
Here's where I'm firm. Hormonal hair loss cannot be diagnosed by looking, not by me and not by anyone without the right tests. Conditions like thyroid disease and Cushing's are confirmed with blood tests and sometimes further investigations, and each is managed very differently.
That matters because the underlying condition is usually more important than the coat itself. Left untreated, hormonal problems affect a dog's whole wellbeing, not just their fur. Once the condition is properly managed, the coat often improves over the following months, but that improvement follows the medical treatment, it doesn't come from grooming alone. For a reliable overview of dog health conditions to discuss with your own vet, the PDSA Pet Health Hub is a good, vet-written resource.
How grooming fits in
Grooming won't fix a hormonal problem, but it plays a genuine supporting role. Regular, gentle grooming keeps the skin clean and comfortable, helps you and me monitor how the coat is changing over time, and often catches that first patch of unusual thinning early.
If your dog is under a vet for a hormonal condition, do let me know. I'll keep the coat and skin comfortable, use a gentle approach, and flag anything that looks like it's changing. If you've noticed heavy shedding but the coat underneath looks healthy and even, that's much more likely to be ordinary moulting, and our deshedding treatment is designed exactly for lifting out that dead undercoat.
Frequently asked questions
What does hormonal hair loss in dogs look like?
Typically symmetrical thinning on both sides of the body, often over the flanks, belly or tail, without much itching, plus hair that doesn't grow back and sometimes darker or thickened skin.
How is hormonal hair loss different from normal shedding?
Normal shedding is even, seasonal and the coat keeps regrowing. Hormonal loss creates matching bald or thin patches, isn't usually itchy, and the hair fails to come back until the underlying condition is treated.
Which conditions cause hormonal hair loss in dogs?
Common causes include hypothyroidism (an underactive thyroid) and Cushing's disease (excess cortisol), along with less common sex-hormone imbalances. All need veterinary tests to confirm.
Can grooming fix hormonal hair loss?
No. Grooming keeps the skin and coat comfortable and helps monitor changes, but the hair loss only improves once a vet has diagnosed and treated the underlying hormonal condition.
This isn't veterinary advice
We're professional dog groomers, not vets, so please treat this as friendly general guidance. If you're worried about your dog, or before acting on anything here, speak to your local vet. In an emergency, contact your vet or nearest out-of-hours clinic.
Fluffs is a professional dog grooming salon in Wigginton, York, offering one-to-one grooming for dogs of every breed and coat type across Haxby, Strensall, Huntington, New Earswick and the surrounding villages. We keep a close eye on skin and coat at every visit, so unusual thinning gets noticed early and pointed your way. Book a gentle, unhurried groom.