Dog bald patches: common causes and when to see a vet
Bald patches on a dog have a wide range of possible causes, from parasites and allergies to hormonal conditions and stress-related over-grooming. Some are minor and resolve on their own; others need specific veterinary treatment, and the pattern and location of the hair loss usually give a vet the first useful clues.
Usually not urgent
This is common and often manageable at home — but see a vet if it persists, gets worse, or comes with other changes.
What dog bald patches commonly look like
Hair loss can appear as one clearly defined circular patch, several smaller patches scattered across the body, symmetrical thinning on both sides at once, or more generalised thinning that is harder to pin to one spot. The pattern itself is a useful clue, since different causes tend to produce different shapes of hair loss.
The skin underneath can look completely normal, red and irritated, scaly, or thickened, and your dog may or may not be bothered by the area - some bald patches are itchy and clearly uncomfortable, while others cause no obvious discomfort at all. Noting when you first spotted it, whether it has grown, and whether your dog fusses at it are all useful details to bring to a vet appointment.
Common causes
Parasites, including fleas and mange mites, are among the most common causes, often producing itchy patches with some scabbing alongside the hair loss. Allergies - to fleas, food, or something in the environment - can also cause hair loss, usually alongside noticeable itching and sometimes redness. These causes can look very similar to each other in the early stages, which is exactly why guessing from appearance alone is unreliable.
Ringworm, despite the name, is a fungal infection rather than a worm, and classically causes circular patches of hair loss that may or may not be itchy. Hormonal conditions affecting the thyroid or adrenal glands tend to cause more symmetrical, gradual thinning without much itching, and stress or anxiety can drive some dogs to lick or chew at one area enough to remove the fur.
Red flags - when to see a vet
Get your dog checked if the hair loss is spreading, if the skin looks infected, red, scaly or thickened, if your dog seems generally unwell, has other symptoms like increased thirst or weight change, or if the patches are not improving with a proper flea treatment routine.
Ringworm is contagious to people and other pets, so any circular patch of hair loss, especially if more than one pet or person in the household develops something similar, is worth a prompt vet visit. This page is general information, not veterinary advice, and cannot replace an examination by the vet who knows your dog.
What you can do at home
A consistent, vet-recommended flea and worming routine removes one of the more common causes before it becomes a recurring problem, and is worth checking is still effective and up to date.
Try to reduce your dog's access to whatever they might be licking or chewing if stress or a specific spot seems to be the trigger, and avoid applying any product to the bald patch without your vet's guidance, since the wrong treatment can delay identifying the actual cause.
What can help
Reliable flea and worming prevention remains the single most useful everyday step for ruling out one of the most common causes of hair loss. A soft grooming brush also helps you check your dog's skin condition regularly.
For a dog with a diagnosed skin or coat issue, a supplement aimed at skin and coat support can be a helpful addition once your vet has identified the underlying cause - it works alongside veterinary treatment rather than replacing the need for a diagnosis.
What can help
Things we stock that owners commonly use alongside a vet’s advice — not a substitute for it.
Pet Head Hair Mist Peony & Cashmere
Pet Head Hair Mist Peony & Cashmere is listed in our dog clothing range for pets. The page brings together the available option labels and the product facts that can be checked, so unsupported claims are left out.
£8.99
Petkin Shampoo-Filled Pet Bath Sponges, 5 Pack
Shampoo-infused bath sponges for dogs and cats, 5 to a pack
£6.99
Pooch & Mutt Salmon Oil
Scottish salmon oil for dogs, dosed by weight from toy breeds to giants
£13.99
Petkin Big N Thick Pet Wipes
Petkin Big n' Thick pet wipes, 100 heavy-duty wipes for daily face, ear, eye and body cleaning
£7.99
Common questions
- What causes sudden bald patches on a dog?
- Parasites, allergic reactions, fungal infections like ringworm, and stress-related licking or chewing are all common causes of sudden hair loss. The pattern and location of the patch, along with whether the skin looks irritated, help a vet narrow down which is most likely.
- Is a bald patch on a dog always itchy?
- No, some causes of hair loss, particularly hormonal conditions, produce little or no itching, while others like flea allergy or mange are usually very itchy. The presence or absence of itching is one of several clues a vet uses to work out the cause.
- Can stress cause a dog to lose fur?
- Yes, some dogs respond to stress or anxiety by licking or chewing at one area repeatedly, which can remove enough fur to create a bald patch over time. Addressing the underlying stress, alongside a vet's advice, is usually needed to resolve it.
- Is ringworm the same as a worm infestation?
- No, despite the name, ringworm is a fungal skin infection rather than an internal parasite. It classically causes circular patches of hair loss and is contagious to other pets and to people, so it is worth having any circular bald patch checked.
- Will a dog's fur grow back after a bald patch?
- In many cases, yes, once the underlying cause is identified and treated, though the timeline depends entirely on what caused it. A vet is best placed to give you a realistic expectation once they know what they are dealing with.
- Can old age cause hair thinning in dogs?
- Coats can become thinner and less glossy with age, in the same way an older dog's mobility and energy change, but a distinct bald patch is different from general thinning and is still worth a vet check rather than assuming it is purely down to age.
Related
Sources
Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.
Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.