What this means
A pimple is a small raised, usually red spot on the skin, and a pustule is a pimple with a dot of pus inside. They show best where the coat is thinner, such as the belly, groin, armpits, chin and lips. On a long-coated dog you may only notice them by feel or by spotting small crusts in the coat.
Pustules typically show a bacterial skin inflammation, but that is not the original cause. Infection often settles onto skin that was already damaged by itching, allergy, mites or other problems. That is why it matters to find what injured the skin in the first place.
Look at how the lesions are arranged. Pimples and crusts on the muzzle, around the eyes and on the front legs are sometimes linked to skin mites, especially in young dogs. Pustules with round bald areas or crusted patches look more like a surface infection. Also notice whether your dog scratches or licks.
Do not squeeze pimples or try to pick them out. That can spread the infection and damage the skin further. Write down where and when they appeared and show them to your vet.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Bacterial skin infection
Bacteria cause red pimples and pustules, often on the belly, groin and armpits. Infection often settles onto skin that is already irritated.
About the condition: Skin infections -
Skin mites
Some mites live in the hair follicles and cause pimples, crusts and bald patches, most often on the muzzle and legs. They turn up more in young dogs.
About the condition: Demodectic mange -
Allergy and itching
Allergy causes itching, and scratching damages the skin, letting bacteria in easily. Pimples and redness appear.
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Hair follicle inflammation
When hair follicles become inflamed, small pustules and crusts appear in the coat. It can be a primary problem or the result of another disease.
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Chin acne
In some dogs pimples appear on the chin and lips. A vet should assess whether it is infection or mites.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Where the pimples are: belly, groin, armpits, chin, muzzle, legs
- Whether they are full of pus or crusted
- Whether your dog scratches or licks those areas
- Whether hair falls out around the pimples
- Whether the skin is red, painful or hot
- Whether new pimples keep appearing and whether they are spreading
When to book a routine visit
Book a visit if pimples or pustules do not clear within a few days, spread or return, or if hair falls out, your dog scratches or the skin smells.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Demodectic mange Skin and coat Demodectic mange is a skin disease caused by microscopic Demodex mites that live in the hair follicles. A small number of them live on healthy dogs too, but when the immune system fails to keep them in check, the mites multiply rapidly and damage the skin and coat. It can stay small and local or spread over the whole body, which is a sign that the dog's body is struggling to cope.
- Skin infections Skin and coat Skin infections are caused by bacteria or yeast that start to multiply when the skin's defences are weakened, for example by an allergy, parasites, moisture trapped in skin folds or constant scratching. An infection can stay on the surface or reach the deeper layers of the skin, causing pain and intense itching. What caused the infection and what keeps it going is for a vet to work out.
Body systems: Skin and coat