An immune-mediated mechanism is considered likely, but the exact trigger has not been demonstrated. Accumulation of immune cells in a pad does not alone reveal what started the response. Diagnosis therefore also involves distinguishing similar-looking inflammation and other pad lesions.
When to see a vet urgently
Seek help promptly if your cat has:
- heavy or persistent bleeding from a pad;
- severe pain or inability to walk and bear weight;
- ulcerated paws with fever, marked tiredness or loss of appetite;
- collapse or rapidly deteriorating general condition.
You can find a vet near you.
Overview
In plasma cell pododermatitis, plasma cells, a type of immune cell, accumulate in pad tissue. The pads enlarge and soften, and may turn purplish-blue, crack and bleed. Several paws are usually affected at once. The condition is particularly characteristic of cats and occurs very rarely in other species.
Plasma cells are immune cells that produce antibodies. They normally participate in immune responses, but in this disease large numbers accumulate in pad tissue. Blood proteins associated with antibodies may also increase. This supports immune activation but does not alone confirm the diagnosis of a paw lesion.
Changes often predominate in the large central pads of the front and hind paws. Smaller toe pads may also be affected, usually more mildly. Pododermatitis means inflammation around the paw; the word alone does not identify plasma cell disease. Lesions between the toes, around nail folds or on one individual toe, for example, may have a completely different cause.
Causes
The exact mechanism is not fully understood, but the main proposed factors are:
- Autoimmune processes, with the immune system attacking the body's own tissues.
- Chronic infections, including FeLV and FIV.
- Hereditary susceptibility.
- Immune imbalance associated with other chronic diseases.
Autoimmune disease means a defence reaction against the body's own structures, but the precise target in this disease is unknown. A definite claim of one autoimmune cause would therefore be too strong. A confirmed retroviral infection also does not show that it caused the pad lesion. The disease occurs in FeLV- and FIV-negative cats too.
Hereditary susceptibility and the contribution of other chronic diseases have not been confirmed as universally applicable explanations. Seasonal variation has been described in some cats, but this does not prove a particular allergen either. Treatment should therefore not be replaced by guessing at food allergy or treating an infection alone.
Risk factors
- FeLV- or FIV-positive cats.
- Cats with weakened immunity.
- Middle-aged and elderly cats.
- Chronic inflammatory diseases.
Information about predisposing factors is limited, and the condition is not confined to middle-aged or older cats. It has also been described in young cats. Positive FIV results are common in some case groups, but the association may reflect the cats studied rather than necessarily being causal. Equally, a negative result does not rule out plasma cell pododermatitis.
Typical symptoms
- Swollen, soft, enlarged pads.
- Colour changes with bluish or purplish-blue areas.
- Ulcers, cracks and bleeding.
- Tenderness when walking and lameness.
- Less movement and avoidance of jumping.
- Possible concurrent mucosal or skin lesions.
Early on, the pads may look abnormal without obvious lameness. Pale streaks and fine scaling may be visible, and the centre may feel softer than usual. Look at every pad because a change on another paw may be subtle. However, do not squeeze painful tissue to test its texture.
Ulceration can turn a mild finding into a painful problem: the cat starts avoiding walking or licking its paws. Also report mouth pain, drooling or nasal skin changes. A concurrent sign elsewhere may help guide investigations, but not every skin lesion on the same cat automatically has one cause.
Complications and consequences
- A chronic course with intermittent flare-ups.
- Secondary bacterial infections.
- Severe pain and reduced activity.
- Loss of pad tissue in severe cases.
Disease of the kidneys' filtering units has also been reported in some cats. This can allow protein to pass into urine. The association does not mean every cat with affected pads develops kidney damage: the published case series specifically selected cats with both conditions. Changes in drinking, urination, weight or general condition are nevertheless reasons to review the whole patient.
Diagnosis at the vet
- Clinical examination of the characteristic pad appearance.
- Cytology or biopsy showing plasma cell accumulation.
- FeLV and FIV testing.
- A complete blood count and blood biochemistry to investigate other diseases.
As well as the pads, examination checks between the toes, the claws, other skin and the mouth when appropriate. A firm lump on one pad, a foreign body or an abscess needs a different investigation from soft swelling on several paws. Alternatives considered include eosinophilic inflammation, fungal or bacterial lesions and tumours.
A fine-needle sample examines individual cells. Many plasma cells together with typical lesions may strongly support the diagnosis. A biopsy also shows tissue structure and helps when findings are atypical or other causes need exclusion. Separate samples may be used to look for infection before immunosuppressive treatment if necessary.
Blood tests can assess proteins, blood cells and organ function. Urinalysis may also be appropriate because renal protein loss cannot be seen from pad appearance alone. Any protein in the urine is investigated as a separate finding rather than automatically assumed to result from this skin disease.
FeLV and FIV tests assess infection status; they do not alone confirm plasma cell pododermatitis. The practice assesses whether a screening result needs confirmation and how recent exposure may affect interpretation. Explain earlier test results and whether your cat may have met cats of unknown status.
Treatment
Treatment is chosen according to pain, ulceration, extent of lesions and other health factors. A mild, painless change may sometimes need mainly vet-planned monitoring, whereas ulcerated disease causing lameness requires active treatment. The same medicine is not prescribed for every cat simply from pad colour.
Medication aims to regulate the abnormal immune response. Some antibiotics used for this also have immunomodulatory effects. Benefit from them therefore does not prove that the condition is an ordinary bacterial infection. Responsible antibiotic use and the risk of increasing bacterial resistance are considered when selecting medication.
Any secondary bacterial infection is treated separately as needed. Surgery may be considered if medication does not help or there is a severe ulcerated tissue lesion. The extent of surgery and subsequent wound care are planned individually. Supportive care also includes pain relief; do not give human painkillers to a cat yourself.
Response is monitored through walking, activity and pain as well as pad size and surface. Some medicines act gradually, so a review date and reasons to make contact are agreed at the start. Do not stop or change prescribed medication yourself even if an ulcer looks closed. Rapidly worsening pain or deteriorating condition needs assessment before the planned check-up.
Home care and monitoring
Make food, water and the litter tray easily accessible if walking is painful. Watch whether your cat actually reaches them or remains in one place. Record lameness, licking, bleeding and general condition. Photographs of the same pad can help compare changes without repeatedly handling the tissue.
Agree on wound protection and any need for a collar with the practice. If a pad is bandaged, keep the dressing dry and watch for wetness, smell or slipping. Swollen or cold toes require contact with the practice. Do not make a tight home bandage or alter a prescribed dressing by adding tape over it.
Feed a nutritionally balanced diet suitable for your cat. Random vitamins or other supplements are not a proven way to correct this disease's immune response. Tell your vet about products being used so the whole situation can be assessed. A cat eating poorly or losing weight needs reassessment.
Prognosis
Many cats respond well to treatment, but the course varies. Lesions settle spontaneously in some, while others relapse or need prolonged treatment. Recurrence alone does not establish a new infection. Kidney or other systemic diseases also affect prognosis and follow-up needs.
Prevention
- Have your cat tested regularly for FeLV and FIV.
- Support immunity through varied nutrition and good care.
- Reduce stress and infection risks.
- Arrange regular veterinary checks for at-risk cats.
No reliably effective preventive measure is known. Repeat FeLV/FIV testing is agreed according to exposure risk and previous results; regular testing alone does not prevent pad disease. Good nutrition and care support general health, but should not be promised to prevent the immune reaction. New pad changes need investigation even in a well-cared-for indoor cat.
Important for cat owners
Plasma cell pododermatitis is an immune-related disease characteristic of cats. Remember that swollen or altered pads, cracks or lameness are reasons to take your cat to a vet as soon as possible. When identified early, the disease responds well to treatment, but is often chronic and needs monitoring and supportive care.
This article provides general information and does not replace veterinary care. If you notice signs of illness in your cat, contact a vet.
Frequently asked questions
Does a swollen pad always mean this disease?
No. A foreign body, infection or other inflammation, for example, can cause similar changes. Diagnosis depends on examination and, when necessary, cytology or biopsy, rather than a photograph alone.
Does plasma cell pododermatitis mean my cat definitely has FIV?
No. The condition also occurs in retrovirus-negative cats. FIV is tested separately, and the meaning and confirmation of a positive screening result are assessed by a vet.
Can it clear permanently?
It can, but this cannot be promised. Some cats have further episodes or need long-term treatment. Monitoring assesses pain, walking and possible other disease as well as pad size.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Feline immune-mediated skin disorders: Part 2, Journal of Feline Medicine and Surgery, accessed 2026-11-05.
- Feline plasma cell pododermatitis, Canadian Veterinary Journal, accessed 2026-11-05.
- Feline pododermatitis, Royal Canin Academy / Veterinary Focus, accessed 2026-11-05.
- Feline plasma cell pododermatitis with concurrent glomerular disease: a case series of 25 cats, JFMS Open Reports, accessed 2026-11-05.
- Feline Plasma Cell Pododermatitis, Clinician’s Brief, accessed 2026-11-05.
- Feline Immunodeficiency Virus (FIV), Cornell Feline Health Centre, accessed 2026-11-05.
- Frequently Asked Questions & Myths, WSAVA Global Nutrition Committee, accessed 2026-11-05.
- Bandage and Splint Care for Cats, VCA Animal Hospitals, accessed 2026-11-05.
- Get the Facts about Pain Relievers for Pets, U.S. Food and Drug Administration, accessed 2026-11-05.
- Initial Triage and Resuscitation of Small Animal Emergency Patients, Merck Veterinary Manual, accessed 2026-11-05.