When to see a vet urgently
A painful or swollen claw area needs examination, with emergency help particularly needed if:
- Your cat cannot bear weight on the paw or pain is severe.
- A torn claw keeps bleeding despite gentle pressure.
- The paw swells rapidly, has heavy discharge or your cat becomes listless and stops eating.
- A claw has grown into the pad or there is a deep toe wound.
Contact a vet for transport advice. Find a vet near you.
Overview
A cat's claw is derived from skin and surrounded by soft tissue containing blood vessels and nerves. Infection or immune system disturbance causes inflammation, tenderness, claw deformity and difficulty walking.
Onychitis and paronychia may be acute after injury, scratches or splinters, or chronic with skin disease, fungal infection or immune disease.
The hard outer claw is keratin. Living tissue beneath contains vessels and nerves, so a deep tear can bleed and be very painful. The nail bed's close connection to the toe bone explains why spreading inflammation is taken seriously.
Nail fold inflammation describes location, rather than one particular cause. Similar redness and discharge can result from infection or immune-mediated inflammation. Appearance alone therefore cannot establish whether antibiotics are needed.
Causes
- Bacterial infections involving staphylococci, streptococci or Pasteurella.
- Fungal infections involving Malassezia yeasts.
- Viral diseases, less commonly as a complication.
- Autoimmune diseases, including pemphigus, lupus and immune-mediated dermatitis.
- Allergic reactions, including atopy and food allergy.
- Claw injuries from scratches, snagging or fractures.
- Chronic skin diseases.
Dermatophytes, the fungi causing ringworm, can also rarely damage a claw and surrounding tissue. They differ from yeasts, so not every fungal change should be called a yeast infection. Ringworm can spread to animals and people, but nail fold redness alone does not demonstrate it.
In pemphigus, the immune system attacks connections between skin cells, causing superficial blisters and crusts, including around the claws. Pus-like material may contain inflammatory cells without bacterial infection. Conversely, damaged skin can develop a concurrent infection. Mentioning viruses and lupus does not mean they commonly explain a single inflamed feline claw.
Risk factors
- cats that go outdoors, with more injuries and infections;
- older cats with reduced immunity;
- breeds predisposed to autoimmune disease;
- cats with allergies and chronic dermatitis.
Evidence on general breed predispositions to feline claw inflammation is limited. No clear breed predisposition to pemphigus has been shown, for example. Age alone does not prove reduced immunity. However, joint pain and less scratching in an older cat can impair normal claw wear. An overlong claw may curve into a pad and cause local injury.
Typical symptoms
- lameness and reluctance to use the paw;
- pain when a claw is touched;
- redness and swelling of surrounding skin;
- pus or clear discharge;
- thickened, deformed claws;
- brittle claws or claw loss;
- changes in several claws with systemic diseases.
At home, you may notice constant paw licking, less climbing or reluctance to have the leg touched. Do not force open a painful paw. Note whether one or several claws are affected and whether crusts also appear on the face, ears or pads. Pemphigus may affect several skin areas or sometimes mainly nail folds.
An injury may leave an obviously chipped or hanging claw fragment. Several claws changing together warrants examination of the whole skin but does not confirm autoimmune disease alone. Persistent swelling of one toe also needs investigation even if discharge decreases at times.
Complications and consequences
- chronic pain;
- claw loss or deformity;
- infection spreading to the toe bone, known as osteomyelitis;
- recurrence in autoimmune forms;
- reduced quality of life from pain and restricted movement.
Diagnosis at the vet
- clinical examination of paws and claws;
- discharge cytology and bacterial culture;
- skin scrapings and fungal culture;
- biopsy if autoimmune disease is suspected;
- a complete blood count in systemic disease;
- allergy investigations.
Samples are chosen according to findings
The vet establishes symptom onset, possible injuries and previous medicines. Show photographs if swelling or discharge changed before the visit. Whole-skin examination helps identify changes usually hidden by fur. Mention itching, appetite and other possible diseases too.
Cytology looks for inflammatory cells, bacteria, yeasts and abnormal skin cells. Culture can identify bacteria and antibiotic susceptibility. Sampling needs are assessed before new treatment starts. Do not wash away discharge or crusts just before the visit without instructions because they may provide useful sample material.
Fungal tests may use hairs, scales or crusts. A positive ringworm PCR does not always mean active disease: it may detect dead fungal genetic material or spores carried on the coat. Results are interpreted alongside symptoms and other investigations.
A biopsy helps distinguish immune disease and a tumour from other causes. Strong anti-inflammatory treatment can alter findings, so investigations are planned in advance. Do not stop medicines yourself for sampling, however. Blood tests assess general health and may be needed before immunosuppressive treatment.
Allergy is not confirmed with one blood or skin test. Food allergy investigation relies on a carefully conducted elimination diet and planned challenge. Other foods, treats and flavoured products can interfere. A diet trial does not replace examining a painful toe.
Investigating a persistent toe change
If swelling persists or bone damage is suspected, X-rays and tissue sampling may be needed. In cats, a lung tumour can sometimes spread to a toe without respiratory symptoms. This is not the assumed cause of every claw injury, but tissue findings suggesting a tumour may lead to chest imaging too.
Treatment
Treatment depends on the cause:
- topical and oral antibiotics for bacterial infection;
- antifungal medicines for fungal infection;
- immunosuppressive medicines, such as glucocorticoids or ciclosporin, for autoimmune disease;
- an allergy diet and antihistamines for allergies;
- antiseptic paw treatment;
- regular claw trimming and care.
Severe cases may require removal of the affected claw.
The list describes options for different causes. Not every cat needs every treatment or automatically both topical and oral antibiotics. Selection depends on findings, samples and inflammation depth. Concurrent infection is also considered when treating immune disease.
A loose fragment of damaged claw may need removal to allow healing. Pain relief and sometimes sedation or local anaesthesia are needed. Do not pull off a torn claw or cut a claw embedded in a pad yourself. Ordinary healthy claw care differs from a procedure on a diseased claw.
Home care and monitoring
While awaiting care, gentle pressure with a clean dressing may help bleeding if your cat safely allows it. Pain can make even a calm cat bite, so stop if they defend themselves. Bandage and cleaning instructions apply to the particular injury; do not add creams or other skin products yourself.
A collar may prevent further licking damage but does not treat the cause. Monitor lameness, discharge, swelling and appetite. Report worsening or new affected claws. Do not give human painkillers because they may cause serious poisoning.
Prognosis
The outlook depends on the cause. A local claw injury and chronic immune disease require different follow-up. Pemphigus can often be managed, but reducing or stopping treatment may trigger recurrence. Adverse effects are monitored with agreed tests; mention increased drinking or other new symptoms, for example.
Prevention
- Care for claws regularly.
- Prevent injuries, particularly in cats that go outdoors.
- Have skin and allergic diseases treated promptly.
- Maintain normal weight, as obesity burdens the paws.
- Keep the home and bedding clean.
Particularly check claw length in older, less active cats. Provide suitable scratching places and address joint pain with veterinary help. Not every sharp claw needs trimming. If necessary, ask for a demonstration and shorten only the safe tip without damaging the vascular part. Stop if your cat is painful or resists.
Important for cat owners
Onychitis and paronychia are painful conditions that may result from infection or indicate a more serious disease. Remember that lameness, claw tenderness and surrounding discharge warrant prompt veterinary attention. Timely diagnosis identifies the cause and guides appropriate treatment.
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 an inflamed nail fold always need antibiotics?
No. Injuries, infections and immune diseases cause similar changes. Cytology and culture where needed help select treatment.
Can ringworm cause nail fold inflammation?
Rarely, yes. Appropriate tests establish ringworm; claw appearance alone cannot identify it reliably. Possible infection in other household animals is considered too.
Can I trim a torn claw at home?
Do not forcibly handle a painful, bleeding or deeply torn claw. The vet assesses which part needs removal and the required pain relief.
Why does the vet examine the other paws too?
The distribution helps find the cause. Crusted nail folds on several claws may fit pemphigus, for example, but diagnosis also requires other findings and samples.
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
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- Vet Q&A: How do I trim my cat’s claws?, PDSA, accessed 2026-11-03.
- Pemphigus foliaceus in cats, The Canadian Veterinary Journal, accessed 2026-11-03.
- Feline toe biopsy reveals a bigger problem, Texas A&M Veterinary Medical Diagnostic Laboratory, accessed 2026-11-03.
- Guideline for Dermatophytosis (Ringworm) in Cats, ABCD, accessed 2026-11-03.
- Diagnosis of Skin Diseases in Small Animals, Merck Veterinary Manual, accessed 2026-11-03.
- Cutaneous Food Allergy in Animals, Merck Veterinary Manual, accessed 2026-11-03.
- Get the Facts about Pain Relievers for Pets, U.S. Food and Drug Administration, accessed 2026-11-03.
- Skin problems in cats, PDSA, accessed 2026-11-03.
- Feline immune-mediated skin disorders: Part 1, Journal of Feline Medicine and Surgery, accessed 2026-11-03.