Plasma Cell Pododermatitis ("Pillow Foot") in Cats: Causes and Treatment
A cat's paw pads are normally firm. When one or more start looking soft, puffy, and slightly purple, like a small pillow instead of the usual tough leather, that's a specific and fairly well-recognized condition, not a random swelling. Vets call it plasma cell pododermatitis. Most owners just call it "pillow foot."
What's actually happening in the paw
The condition is named for what's found under a microscope: an infiltration of plasma cells, a type of mature immune cell that produces antibodies, into the tissue of the paw pad. According to Veterinary Partner (VIN), this immune activity causes the pad to swell and soften, sometimes described as feeling spongy rather than firm. One or multiple paws can be affected, and the swelling can look pink, purple, or show pale streaking across the surface.
What it looks like as it progresses
Early on, pillow foot might just look like a slightly puffier-than-normal pad, and some cats aren't bothered by it at all. PetMD notes that in more advanced cases, the swollen pad can ulcerate, becoming painful, prone to bleeding, and more likely to lead to limping or reluctance to walk on hard surfaces.
The FIV connection, and other triggers
One of the more consistent findings in cats with pillow foot is a link to feline immunodeficiency virus (FIV). Cats.com reports that roughly half of cats diagnosed with plasma cell pododermatitis test positive for FIV, though the condition also shows up in FIV-negative cats, sometimes linked to food allergies or other underlying immune triggers that aren't always identified. Exactly why plasma cells build up in the paw specifically, rather than elsewhere, isn't fully understood.
How it's diagnosed
The appearance is often suggestive enough for a vet to suspect pillow foot on sight, but a definitive diagnosis requires a biopsy of the affected pad, confirming the characteristic plasma cell infiltration under the microscope, according to Clinician's Brief. Testing for FIV is typically recommended alongside the biopsy, given how often the two occur together.
Treatment options
Some mild cases resolve on their own without any treatment at all. When treatment is needed, options include oral corticosteroids like prednisolone, the antibiotic doxycycline, or in more stubborn cases an immunosuppressive drug like cyclosporine, with improvement typically seen within one to two months. Cats with an ulcerated, actively bleeding pad may need pain management and, occasionally, surgery if a lesion doesn't respond to medical treatment.
Frequently asked questions
Is plasma cell pododermatitis contagious to other cats?
No, the pododermatitis itself isn't contagious, though if it's linked to FIV in a given cat, that virus can spread to other cats through deep bite wounds, which is a separate consideration in multi-cat households.
Does my cat need to be tested for FIV if they have pillow foot?
It's generally recommended, given how often the two are linked, even though not every cat with pillow foot turns out to be FIV-positive.
Can pillow foot come back after treatment?
Yes, recurrence is possible, and some cats need long-term or repeated treatment to keep symptoms controlled, particularly if an underlying trigger like FIV isn't something that can be resolved outright.
Sources
- Veterinary Partner (VIN), "Plasma Cell Pododermatitis (Pillow Foot) in Cats"
- PetMD, "Pillow Foot (Pododermatitis) in Cats"
- Clinician's Brief, "Feline Plasma Cell Pododermatitis: Key Signs & Treatment"
- Cats.com, "Pododermatitis in Cats: Causes, Symptoms, & Treatment"
This article is for general information and isn't a substitute for advice from your own veterinarian, who can properly diagnose and treat paw pad changes in your specific cat.
