By the Pethocyn editorial team. Published October 28, 2026. Updated November 1, 2026. Sources are listed at the end of the article.

A cat’s footpads are skin too, and several diseases can make them swell, ulcerate, bleed or crust.

This guide covers the footpad problems that published studies and reviews describe in cats. For burns and cuts on a dog’s pads, see dog paw problems.

Plasma cell pododermatitis

Plasma cell pododermatitis is a disease in which the footpads fill with a type of immune cell called a plasma cell. Studies describe it as uncommon. [1][2]

What it looks like. In a study of 8 cats, the disease began as a swelling of the footpads, followed by ulceration. [3] Case reports describe:

  • Swelling, softness and ulceration of the footpads, with lameness. [2]
  • Enlarged footpads on the front and hind feet, with ulceration and chronic bleeding from the ulcers. One of the two cats was anemic. [4]
  • Soft, diffuse swelling across several paw pads. [1]
  • Swelling, softening, ulceration with crusts, and red to purple discoloration of several pads. [5]

The 8-cat study found no sex, breed or age predisposition, and no particular paw was more likely to be affected. [3]

What causes it. The cause is not known. A 1984 case report called it a disease of unknown cause, with a history that suggested a seasonal pattern in that cat. [2] A 1990 report said there is evidence that it might be immune-mediated, or perhaps an allergic disease, but that the cause had yet to be determined. [4] A 2026 case report supports the idea that it may be a hypersensitivity-associated reaction pattern rather than a strictly distinct disease. [1]

Other links reported:

  • Retrovirus infection. A 2020 report described one cat with plasma cell pododermatitis that was positive for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV); biopsies of the pads were positive for FeLV and negative for FIV. The authors highlighted retrovirus infection as a potential factor associated with the disease. [5]

Kidney disease. A 2026 review of the records of 25 cats that had both plasma cell pododermatitis and kidney disease of the filtering units (glomerular disease) reported: [6]

  • Affected cats were most commonly young (under 5 years) and castrated males.
  • Abnormal results included marked anemia, high blood globulins and protein in the urine.
  • A kidney biopsy showed immune complex glomerulonephritis in 14 of 17 cats (82%).
  • Median survival after the kidney disease began was short, about 1 month.
  • The authors concluded that cats presenting with plasma cell pododermatitis should be closely monitored for developing glomerular disease.

This study included only cats that had both conditions, so it does not tell how often cats with plasma cell pododermatitis develop kidney disease.

Treatment. In the 8-cat study, follow-up for over a year showed the lesions went into total remission after medical treatment in four cats and after complete surgical removal in two. [3] Your vet will choose the treatment; this guide does not name medicines or doses.

Cat litter granulomas in the paws

A 2026 study looked at 13 biopsies from the paws or paw pads of cats, submitted to 2 veterinary institutions between 2005 and 2023. [7]

  • The lesions often included chronic or intermittent paw pad swelling, ulceration and bleeding, or draining tracts, particularly in the front paws.
  • All the biopsies contained inflammation around material consistent with silica, which was similar to multiple brands of silica-based cat litter. Silica is a main ingredient of traditional clay-based litters.
  • Ten of the 13 biopsies also showed plasma cell pododermatitis. The authors suggest that existing paw pad disease may predispose some cats to litter getting implanted in the pad.
  • Recurrence was common after surgery. The authors advised that affected cats, and cats with paw pad disease, may benefit from a different litter substrate to prevent the lesion or its return.

Footpad changes from disease elsewhere in the body

Some diseases elsewhere in the body can show up on a cat’s pads:

  • Hair loss linked to internal cancer. A 2026 review of skin syndromes caused by cancer in cats describes a pattern of hair loss seen mostly with pancreatic and bile duct cancers. The hair loss starts on the belly, neck, inner legs and the area under the tail, and some cats also have scaly, crusted or cracked footpads. It tends to appear late in the cancer, and the outlook is poor. [8]
  • Superficial necrolytic dermatitis is a rarer skin syndrome in cats, reported with tumors of the pancreas or liver. The lesions appear painful, and in one reported cat a biopsy from a paw pad showed the typical changes. Blood tests may show raised liver values or high blood sugar, though some reported cats had few changes. [8]
  • Lung cancer that spreads to the toes. Feline lung-digit syndrome is a rare pattern in which a cancer that started in the lung spreads to one or more toes, sometimes on more than one leg. In a 2026 case report, the first sign was a lame front leg with a swollen toe that later ulcerated, and the cancer had also spread to many other organs. [9] See toe lesions in cats that start in the lungs.

Other conditions that can involve the pads

  • Mosquito bite hypersensitivity is an allergic reaction to mosquito bites. Itchy lesions gather mostly on the head, neck, ear flaps and bridge of the nose, and a 2017 review notes that the paw pads are sometimes involved too. The same review lists eosinophilic lesions, such as eosinophilic granulomas, among the common skin patterns of allergic cats. [10] See eosinophilic granuloma complex in cats.
  • Epidermolysis bullosa is a group of rare inherited diseases in which the skin layers do not hold together, so friction or minor trauma causes blisters. A 2023 report of two affected cats described a kitten first seen at 3 weeks old with crusts, hair loss and ulcers in the mouth. By about 9 weeks it had lost all its claws and had a swollen front paw with blisters in the nail bed. [11]

When to see your vet

  • Swollen or soft footpads. [1][2][3]
  • An ulcer on a footpad, or a pad that bleeds. [3][4]
  • Lameness together with pad swelling or ulcers. [2]
  • A draining tract in a paw. [7]
  • Scaly, crusted or cracked footpads, especially with hair loss on the belly or legs. [8]
  • A kitten with blisters on its paws, or claws that come off. [11]
  • A cat already diagnosed with plasma cell pododermatitis, so your vet can check for kidney disease, as the 2026 study authors advised. [6]

FAQ

Why are my cat’s paw pads swollen and soft?
Swelling and softness of several pads are the signs case reports describe for plasma cell pododermatitis. [1][2] In the case reports above, the diagnosis was made with a biopsy of the pads. [1][2][5] Your vet will need to examine the paws to tell it apart from other causes.

Can cat litter hurt my cat’s paws?
A 2026 study found silica consistent with cat litter in 13 biopsies from cats’ paws, and 10 of them also showed plasma cell pododermatitis. The authors suggest existing pad disease may let litter get implanted. [7]

Is plasma cell pododermatitis linked to kidney disease?
A 2026 study of 25 cats that had both conditions found the kidney disease was often immune-mediated and survival after it began was short. The authors advised closely monitoring cats with plasma cell pododermatitis for kidney disease. [6]

Can crusty paw pads be a sign of cancer?
Rarely, yes. A 2026 review describes cats with pancreatic or bile duct cancer whose hair loss came with scaly, crusted or cracked footpads, and lung cancer in cats can spread to the toes. [8][9] Your vet can look for the cause.

The bottom line

Plasma cell pododermatitis is an uncommon disease that starts as swelling of the footpads, followed by ulceration, and its cause is not known. [1][2][3] In a study of 25 cats that also had kidney disease, survival after the kidney disease began was short, and the authors advised closely monitoring cats with plasma cell pododermatitis for it. [6] Material consistent with silica cat litter has been found in diseased paw pads, and the study authors suggest existing pad disease may predispose cats to it. [7] Rarely, cancer elsewhere in the body can also show up as crusted or cracked pads or as a swollen toe. [8][9]

This article is for general information and is not a substitute for a veterinary exam. If you are worried about your cat’s paws, see your veterinarian.

Sources

  1. Müller N, Qiao Q, Loesenbeck G. Feline plasma cell pododermatitis with nasal involvement suggesting a hypersensitivity associated reaction pattern: a case report and review of the literature. Tierarztl Prax Ausg K Kleintiere Heimtiere. 2026;54(4):286-290. PMID 42624129. https://pubmed.ncbi.nlm.nih.gov/42624129/
  2. Drolet R, Bernard J. Plasma cell pododermatitis in a cat. Can Vet J. 1984;25(12):448-449. PMID 17422486. https://pubmed.ncbi.nlm.nih.gov/17422486/
  3. Dias Pereira P, Faustino AM. Feline plasma cell pododermatitis: a study of 8 cases. Vet Dermatol. 2003;14(6):333-337. PMID 14678445. https://pubmed.ncbi.nlm.nih.gov/14678445/
  4. Taylor JE, Schmeitzel LP. Plasma cell pododermatitis with chronic footpad hemorrhage in two cats. J Am Vet Med Assoc. 1990;197(3):375-377. PMID 2391277. https://pubmed.ncbi.nlm.nih.gov/2391277/
  5. Biezus G, et al. Plasma Cell Pododermatitis Associated With Feline Leukemia Virus (FeLV) and Concomitant Feline Immunodeficiency Virus (FIV) Infection in a Cat. Top Companion Anim Med. 2020;41:100475. PMID 32966900. https://pubmed.ncbi.nlm.nih.gov/32966900/
  6. Sarkan K, Hokamp JA, Cianciolo RE, Hart E, Shropshire S, Quimby JM. Feline plasma cell pododermatitis with concurrent glomerular disease: a case series of 25 cats. J Feline Med Surg. 2026;28(4):1098612X261437907. PMID 41876449. https://pubmed.ncbi.nlm.nih.gov/41876449/
  7. Agrawal A, et al. Cutaneous silica-associated (cat litter) granulomas in the paws of 13 domestic cats. Vet Pathol. 2026;63(1):97-106. PMID 40652357. https://pubmed.ncbi.nlm.nih.gov/40652357/
  8. Guillén A, Hendricks A, Verbrugghe A, Rocchigiani G, Espadalé E. Cutaneous paraneoplastic syndromes in cats: a comparative clinical review. J Feline Med Surg. 2026;28(1):1098612X251407872. doi:10.1177/1098612X251407872. Open access (CC BY-NC 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC12855766/
  9. Cabral I, Matos G, Fernandes Silva G, Carvalho F, Amorim I. Treatment of Feline Lung-Digit Syndrome with Toceranib Phosphate: Prolonged Survival and Novel Metastatic Findings. Animals (Basel). 2026;16(5):839. doi:10.3390/ani16050839. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC12985166/
  10. Diesel A. Cutaneous Hypersensitivity Dermatoses in the Feline Patient: A Review of Allergic Skin Disease in Cats. Vet Sci. 2017;4(2):25. doi:10.3390/vetsci4020025. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC5606602/
  11. Kiener S, Troyer H, Ruvolo D, et al. Independent COL17A1 Variants in Cats with Junctional Epidermolysis Bullosa. Genes (Basel). 2023;14(10):1835. doi:10.3390/genes14101835. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC10606533/