Plasma cell pododermatitis is a rare immune-mediated condition in cats in which plasma cells infiltrate the paw pads, causing softening, swelling, and a distinctive cross-hatched surface texture. Most affected cats respond well to immunosuppressive therapy, and some cases resolve spontaneously.
Last reviewed: June 2026
What Is Plasma Cell Pododermatitis?
Feline plasma cell pododermatitis (PCP) is an immune-mediated inflammatory condition in which large numbers of plasma cells (activated antibody-producing immune cells) infiltrate the soft tissue of the paw pads. The precise trigger is unknown, but the condition responds to immunosuppressive treatment rather than antibiotics, confirming its immune-mediated nature. FIV infection has been identified as a risk factor in some cats, though many affected cats test negative.
As described in Côté's Clinical Veterinary Advisor, PCP most commonly affects the central (metacarpal or metatarsal) pads and may involve one or multiple paws.
Signs of Plasma Cell Pododermatitis
PCP causes visible changes to the paw pads that progress over weeks to months:
- Soft, mushy paw pads — the normally firm pad becomes noticeably soft and doughy when palpated
- Swelling and widening of the pad — the affected pad expands and may look disproportionately large
- Distinctive cross-hatched texture — a striated or "cobblestone" pattern develops on the surface of the swollen pad
- Purple or violet discoloration — distinct from the normal dark grey or black coloration
- Ulceration and bleeding — in advanced cases, the pad surface cracks and bleeds, causing pain and lameness
- Multiple paws affected — PCP commonly involves more than one paw simultaneously
Bettenay et al., 2007, Vet Dermatology confirmed that central metacarpal pads are most commonly affected, often bilaterally, with plasma cell infiltration confirmed by cytology or biopsy in all reviewed cases.
Diagnosis
PCP is diagnosed by clinical appearance combined with cytology or histopathology.
- Cytology — fine needle aspirate of the swollen pad typically shows a predominance of plasma cells and lymphocytes; this is usually sufficient for a working diagnosis
- Biopsy — confirms the diagnosis histologically; tissue shows diffuse plasmacytic infiltration of the dermis and subcutis
- FIV testing — recommended in all cases given the recognized association; the AAFP Feline Retrovirus Guidelines, 2020 note that FIV-positive cats may have altered immune regulation predisposing them to immune-mediated skin conditions
- Bacterial culture — indicated if the pad is ulcerated or signs of secondary infection are present
Treatment
Most cats respond well to treatment, and a subset achieve spontaneous remission.
- Doxycycline — first-line treatment in most cases; anti-inflammatory properties rather than antimicrobial action appear responsible for the response; a typical course runs 4–8 weeks
- Corticosteroids — methylprednisolone or prednisolone for cats not responding to doxycycline, as described in Plumb's Veterinary Drug Handbook
- Surgical excision — reserved for focal, non-healing, ulcerated lesions
- Wound management — gentle cleaning, protective bandaging, and pain management for ulcerated pads
Recurrence is recognized, particularly in cats with concurrent FIV infection.
When to See a Vet
Call your vet today if:
- One or more paw pads feel soft, swollen, or mushy compared to normal
- A paw pad has an unusual cross-hatched texture or purple discoloration
- Your cat is limping or favoring one or more paws without obvious injury
- A paw pad is cracked, bleeding, or looks ulcerated
Go to the ER immediately if:
- A paw pad is bleeding heavily and cannot be controlled with gentle pressure
- Your cat is in severe pain — vocalizing when the paw is touched, refusing to walk, or hiding
- Redness and swelling extend up the leg, or the cat has a fever alongside the paw changes
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Frequently Asked Questions
What does a cat's paw look like with plasma cell pododermatitis? The affected pad appears soft, swollen, and wider than normal. The surface develops a distinctive cross-hatched or striated texture that looks like a grid pattern pressed into the pad. The color may shift to purple or violet rather than the normal dark grey. In advanced cases the pad cracks open and bleeds. These changes are gradual and may affect multiple paws simultaneously.
Is plasma cell pododermatitis painful for cats? In early, non-ulcerated stages, many cats do not appear painful and walk normally. Pain and lameness develop when pads ulcerate, crack, or develop secondary infection. Prompt treatment before ulceration prevents most discomfort. Cats with bleeding or open ulcers need pain management as part of their treatment plan.
What causes plasma cell pododermatitis in cats? The exact cause is unknown. The condition is immune-mediated — the cat's immune system mistakenly attacks pad tissue. FIV infection has been associated with PCP in some studies, possibly by dysregulating immune responses, but many affected cats are FIV-negative. No specific environmental or dietary trigger has been confirmed.
How much does treatment cost? A vet exam and cytology typically run $100–200. FIV testing adds $50–80. A course of doxycycline costs $30–60. Corticosteroids add $30–80 for a standard course. Biopsy adds $200–350 if cytology is inconclusive. Surgical excision for severe focal lesions costs $500–1,200. Treating before ulceration occurs avoids the higher costs of wound care.
Can plasma cell pododermatitis come back? Yes — recurrence is recognized, particularly in cats with concurrent FIV. Some cats require periodic retreatment during flares. Cats without identified immune dysfunction often achieve sustained remission, and a subset resolve spontaneously without therapy.
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