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Pustules in cats

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

ORANGE for many/rapidly increasing pustules, pain, itching, oozing/pus, foul odor, or if the cat appears ill. RED for fever/apathy, necrotizing changes, or extensive skin detachment/blistering.

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Definition

Pustules in cats are small, raised skin changes filled with pus. They often occur as a result of infections, allergies, or skin irritations and can develop in various areas of a cat’s body.

Can Occur with the Following Diseases:

Basics and possible causes

Pustules form when hair follicles or sebaceous glands become inflamed. This inflammation can be caused by bacterial infections, fungal infections, or parasites. The most common bacterial cause is Staphylococcus intermedius, a bacterium that normally occurs on cats’ skin but can cause infections under certain conditions. Fungi such as Microsporum canis are also known pathogens that can cause pustules.

Parasites such as fleas or mites can also cause pustules by irritating the skin and triggering a hypersensitivity reaction. These reactions often lead to severe itching and increased scratching, which further damages the skin and promotes pustule formation.

Allergies are another common cause of pustules in cats. These can be triggered by food ingredients, inhalationInhalation is the act of breathing air or other substances into the lungs through the nose or mouth. In dogs and cats, inhalation of toxins, smoke, or allergens can lead to respiratory problems. allergens, or contact allergens. During allergic reactions, the cat’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. releases substances that promote inflammatory conditions and thus pustule formation.

Finally, environmental factors such as moisture or unsanitary conditions can also increase the risk of skin infections and thus pustules. Cats with a weakened immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body., whether due to illness or stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being., are also more susceptible to skin problems.

Typical accompanying symptoms

Itching: A common accompanying symptom of pustules is intense itching. The cat scratches more frequently, which can further irritate the skin and increase the risk of infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease..
Redness: The skin around the pustules is often reddened and inflamed, indicating the underlying inflammation.
Hair loss: Increased scratching and licking can lead to local hair loss, especially around the affected areas.
Crusts: After the pustules break open, crusts can form, providing further evidence of an existing skin infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease..
Odor: With bacterial infections, the affected skin may smell unpleasant, which is due to the formation of pus and dead tissue.
Behavioral changes: Due to the itching and discomfort, the cat may appear irritated or lethargic.

When to see a vet?

A visit to the veterinarian is strongly recommended if the pustules do not heal within a few days or worsen. Also, if the cat shows signs of severe discomfort, such as persistentPersistent means lasting or continuing for an extended period. In veterinary medicine, it can refer to chronic diseases or symptoms that do not subside. itching or pain, a veterinary examination is required.

Especially with young, old, or immunocompromised cats, a veterinarian should be consulted promptly, as the risk of severe infections is higher. If the pustules occur over a large area or if signs of a systemic disease such as fever or loss of appetite appear, prompt action is also required.

Another warning sign is when the pustules are accompanied by other symptoms such as bloody crusts, persistentPersistent means lasting or continuing for an extended period. In veterinary medicine, it can refer to chronic diseases or symptoms that do not subside. diarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems., or vomiting, as this could indicate an underlying serious illness.

Symptom recognition for the pet owner and veterinary diagnostic procedure

For the pet owner, the detection of pustules is usually visually possible. They appear as small, raised spots on the skin that are often filled with pus. The affected areas may feel warm and the cat may show discomfort when touched.

The veterinarian will first take a thorough medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. to gather information about the onset of symptoms, possible allergies, and the cat’s general health status. This is followed by a physical examination in which the skin changes are carefully inspected.

For further clarification, the veterinarian may take skin samples to examine them for bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease., fungi, or parasites. These samples can be obtained through skin scrapings, impression smears, or biopsies. Additionally, blood tests may be performed to assess the cat’s overall health and rule out possible systemic diseases.

What the pet owner can do and professional therapy options

The pet owner can take some measures to provide relief to the cat and support healing. First, care should be taken to ensure that the cat does not continue to scratch or lick the affected areas. A collar can be helpful here to protect the affected areas.

It is important to keep the affected skin areas clean and dry. Gentle cleaning with a mild, disinfecting agent can help control infections. Care should be taken to ensure that the agent is suitable for cats and does not contain irritating ingredients.

In consultation with the veterinarian, special shampoos or ointments containing anti-inflammatory or antibacterial agents can also be used. However, these should only be used after consultation with the veterinarian to avoid possible allergies or irritations.

Dietary supplements such as omega-3 fatty acids can also have a supportiveSupportive refers to supportive treatments that aim to alleviate symptoms and improve quality of life without directly treating the underlying cause of the disease. effect, as they have anti-inflammatory properties and promote skin health. A varied, balanced diet can strengthen the cat’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. and promote healing.

Outlook on current research

Current research on pustules in cats focuses on the immunological and dermatological aspects of this symptom. Scientists are investigating how cats’ immune systems respond to various stimuli that can lead to pustule formation. The role of mast cells, a type of immune cellsImmune cells are specialized cells of the immune system that help to identify and fight pathogens and foreign substances. These include leukocytes such as lymphocytes (T cells and B cells), macrophages, and dendritic cells. that play a key role in allergic reactions, is being examined more closely. Researchers are trying to determine which specific triggers cause an overreaction of the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. in cats and whether certain genetic factors play a role.

Another area of research is the investigation of bacterial and viralViral refers to viruses and their effects on the organism. Viral infections in dogs and cats can range from harmless colds to severe, life-threatening diseases. infections that can cause pustules in cats. This examines how various microorganisms penetrate the skin barrier and cause inflammatory conditions. Recent studies suggest that the skin microbiome, the totality of microorganisms that colonize the skin, plays an important role in protecting against infections. Researchers are working to develop probiotics and other therapeutic approaches to support the natural balance of the skin flora.

Additionally, there is research on developing new treatment methods for pustules in cats. These include both topicalTopical refers to the direct application of medications or treatments to the skin or mucous membranes for a local effect, without being absorbed into the body. and systemic therapies. The development of medications that specifically target inflammatory processes in the skin is the focus. It is also being examined how modern technologies such as genome editing and targeted drug delivery can contribute to improving healing processes.

Finally, some studies are dedicated to the preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. of pustules through nutritional strategies. The role of nutrients, particularly essential fatty acids and antioxidants, is being investigated to promote skin health and reduce susceptibility to skin problems. This research could lead to long-term dietary recommendations that minimize the risk of pustules in cats.

Frequently asked questions

1. What are pustules in cats?

Pustules are small, pus-filled blisters on a cat's skin. They can occur due to infections, allergies, or other skin irritations.

2. What do pustules look like?

Pustules appear as small, raised, fluid-filled bumps on the skin. They may look red and inflamed and are often surrounded by an area of irritated skin.

3. Are pustules painful in cats?

Pustules can be uncomfortable or painful for cats, especially if they are infected or inflamed. Cats may try to relieve them by scratching or licking, which can worsen the situation.

4. How are pustules diagnosed in cats?

A veterinarian diagnoses pustules through a thorough examination of the skin and may perform additional tests such as skin swabs or biopsies to determine the cause.

5. Can pustules disappear on their own?

Some pustules may heal on their own, especially if they are caused by minor irritation. Nevertheless, it is important to identify and treat the cause if necessary to avoid complications.

6. What treatment options are available for pustules?

Treatment depends on the cause of the pustules and may include topical creams, antibiotics, or dietary changes. It is important to carry out treatment under the guidance of a veterinarian.

7. Can I treat pustules on my cat myself?

It is not recommended to treat pustules in cats without veterinary advice, as improper treatments can worsen the situation. A veterinarian can recommend the best course of action.

8. Are pustules in cats contagious?

Pustules themselves are not contagious, but the underlying cause, such as an infection, could be. A veterinarian can determine if there is a risk of contagion.

9. How can I prevent my cat from getting pustules?

Good hygiene, regular grooming, and a balanced diet can help prevent skin problems. It may also be helpful to protect the cat from known allergens.

10. When should I see a veterinarian?

If your cat develops pustules that do not heal within a few days, or if it shows other symptoms such as fever or lethargy, you should consult a veterinarian for an accurate diagnosis and treatment.