Warts on Cats: Paw, Skin, and Mouth Growths Explained
By Dr. Zubair Khalid, DVM, MS, PhD ·
A cat skin wart is a small, usually benign growth caused by a papillomavirus, the same family of viruses that causes warts in people and dogs. Most are harmless and may even fade on their own, but growths on the paws, ears, or in the mouth deserve a closer look because some skin lumps in cats turn out to be cancer. This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Most warts in cats are viral papillomas, benign growths that often regress without treatment [1][2].
- Papillomaviruses can also cause flat plaques that may progress to a type of skin cancer called Bowenoid in situ carcinoma, so not every "wart" stays harmless [1][3].
- A growth on a cat's paw is more likely to be a cyst, infection, or tumor than a true wart, and it should be examined.
- Any lump that grows quickly, bleeds, changes color, or causes pain needs veterinary sampling, often a fine needle aspirate or biopsy.
- There is no specific antiviral treatment for feline papillomavirus, so care focuses on removal, monitoring, and ruling out cancer [2].
What Feline Warts and Papillomas Really Are
A wart in the everyday sense is a rough, raised bump on the skin. In cats, the growths that look most like classic warts are called papillomas, and they are caused by papillomaviruses [1]. These viruses infect the surface layer of the skin and cause the cells there to multiply and thicken, which creates a visible lump.
Papillomaviruses are epitheliotropic, meaning they prefer skin and mucous membranes [1]. Cats most likely become infected through small breaks or abrasions in the skin [1][2]. The virus can also be found in completely normal cat skin, so simply detecting it does not prove it caused a particular lump [1][2].
Feline papillomaviruses are linked to several different skin lesions, not just warts. These include hyperkeratotic plaques (flat, thickened, scaly patches), cutaneous papillomas (the wart-like bumps), feline sarcoids (fibropapillomas), and Bowenoid in situ carcinomas, which are early, surface-level cancers [1][3]. Some of these lesions can progress to invasive squamous cell carcinoma, a true skin cancer [1]. That range is why a veterinarian cannot simply look at a bump and call it a wart.
True cutaneous papillomas are actually rare in cats. When researchers reported a viral papilloma on a cat's nose, they noted it was only the second such case described in the veterinary literature [4]. A later report of a similar nasal growth called it the third cutaneous papilloma reported in a cat [5]. So while warts are common in dogs, they are uncommon in cats, and other lump types are more likely.
Signs Owners Notice: Paw, Skin, Ear, and Mouth Growths
Warts in cats' paws
A lump on a paw is easy to spot because cats use their feet constantly. You might notice a small raised bump between the toes, on a toe pad, or along the edge of the paw. The cat may limp, lick the paw, or pull away when you touch it.
Here is the catch: true viral warts are rarely reported on cat paws. A paw lump is more often a cyst, an abscess, a foreign body reaction, a fungal infection, or a tumor. Because paw growths are frequently something other than a wart, they are a good reason to book a veterinary visit. If your cat also has redness, crusting, or swelling on the paws, our guide to a cat skin rash on paws covers other common causes.
Skin warts in cats
Skin warts in cats usually appear as small, raised, firm bumps. They may be smooth or rough, and they can be the same color as the surrounding skin or slightly darker. Some have a crusty or horn-like surface where keratin sticks out [6]. They are most often found on the head, face, and nose, based on the case reports available [4][5].
Many cats with papillomavirus skin lesions have no other signs at all. The bump is simply there, unchanged, for weeks or months.
Warts in cats' ears
Growths on the ear flap or inside the ear canal are less well described than nasal or body lesions. A bump on the ear can be a papilloma, but it can also be a cyst, an insect bite reaction, or a sun-related growth, especially on white or lightly pigmented ears. Any ear growth that causes head shaking, scratching, or discharge should be checked.
Warts in cats' mouths
Papillomavirus is now recognized as a cause of oral lesions in cats, not just skin lesions [3]. A case series of seven cats with oral in situ carcinoma found that six had viral cell changes visible under the microscope, and all had strong positive staining for a protein marker linked to papillomavirus [7]. Five of those lesions contained Felis catus papillomavirus type 3, and two contained type 1 [7].
The cats in that report had drooling and oral pain for more than six months before diagnosis, and the top surface of the tongue was most often affected [7]. Four cats had more than one oral lesion, and two had both oral and skin lesions [7]. Oral growths are easy to miss because cats hide mouth pain well. If your cat drools, drops food, chews on one side, or has bad breath, a mouth exam is warranted. Our article on feline oral disease explains other common mouth problems in cats.
Causes and Risk Factors
The main cause of wart-like growths in cats is papillomavirus infection [1][3]. Cats likely pick up the virus through small skin wounds or abrasions [1][2]. Most infections cause no signs at all, and the virus can be present in healthy skin [2].
Cross-species transmission is possible. Viral DNA closely related to human and bovine papillomaviruses has been found in feline skin lesions, which suggests cats can sometimes be infected by viruses from other species [1][2]. One report described a cat with a nasal papilloma linked to human papillomavirus type 9 [4]. Another found a novel papillomavirus type in a cat's nasal growth [5]. These are individual case reports, so how often cross-species infection happens is not well established.
Other risk factors for skin tumors in cats in general include chemical exposure, solar radiation, hormones, and genetics [6]. Sun exposure matters most for cats with white or thin-haired ears, noses, and eyelids. Viruses are one of several known causes of skin tumors in cats, alongside environmental and genetic factors [6].
Age and immune status likely play a role. Some papillomavirus-related cancers in cats behave differently depending on the individual cat, and the exact triggers for progression from a benign wart to a precancerous or cancerous lesion are not fully understood [1][3].
How Veterinarians Diagnose These Growths
Diagnosis starts with a physical exam and a detailed history. Your veterinarian will ask when you first noticed the lump, whether it has changed, and whether your cat seems uncomfortable.
The next step is usually sampling the growth. Common options include:
- Fine needle aspirate: a thin needle collects cells for examination under a microscope.
- Biopsy: a piece of the growth is removed and sent to a lab for tissue analysis.
- Impression smear: a slide is pressed against the surface of an ulcerated growth.
Papillomavirus-related skin lesions can be confirmed by finding viral antigen in biopsy samples, seeing virus-like particles with electron microscopy, or detecting viral DNA with polymerase chain reaction testing [1]. A protein marker called p16 can also be used as a proxy for papillomavirus-related tumors [2]. In the oral case series, strong p16 staining supported a viral cause in every lesion tested [7].
Your veterinarian may also recommend blood work, imaging, or a referral to a veterinary dermatologist or oncologist if the growth looks aggressive or is in a hard-to-treat spot.
| Growth feature | What it may suggest | Typical next step |
|---|---|---|
| Small, rough, unchanging bump on the head or nose | Viral papilloma | Monitor, or remove if it bothers the cat [1] |
| Flat, scaly, thickened patch | Viral plaque or Bowenoid in situ carcinoma | Biopsy to check for precancerous change [1][3] |
| Lump on a paw pad or between toes | Cyst, infection, foreign body, or tumor | Exam plus sampling, since warts are rare here |
| Raised growth in the mouth or on the tongue | Oral papilloma or in situ carcinoma | Biopsy, because oral lesions can be serious [7] |
| Fast-growing, bleeding, or ulcerated lump | Possible cancer | Prompt biopsy and staging |
Treatment Options
There is no specific antiviral drug that clears papillomavirus in cats [2]. Treatment depends on what the growth turns out to be.
For a confirmed benign papilloma, many veterinarians recommend monitoring. Spontaneous regression is commonly expected, meaning the growth may shrink and disappear on its own [1][2]. If the growth is in a spot that catches on things, bleeds, or bothers your cat, surgical removal is a straightforward option. In one reported case, a nasal papilloma was removed and had not recurred six months later [5].
For viral plaques and Bowenoid in situ carcinoma, complete surgical excision should be considered when possible [1]. These lesions sit at the surface, so removing them early can prevent progression to invasive cancer. If a lesion has already become an invasive squamous cell carcinoma, treatment is more involved and may include wider surgery, radiation, or other cancer therapies chosen by a veterinary oncologist.
For oral lesions, the approach depends on the biopsy result. In the oral case series, outcomes varied widely: three cats were still alive at least six months after diagnosis, two died of unrelated causes at seven and fourteen months, and one was euthanized because of oral pain eighteen months after diagnosis [7]. That range shows why an individual exam and biopsy matter more than any general rule.
If your cat's growth turns out to be something other than a wart, treatment will target that condition. Itchy skin, for example, has many causes, which we cover in why is my cat so itchy. Overgrooming that leads to hair loss can also be mistaken for skin lumps or sores, and our article on psychogenic overgrooming in cats explains how stress and allergies can look similar.
Recovery, Outlook, and Long-Term Management
For simple papillomas, the outlook is good. Many regress without treatment, and those that are removed surgically often do not come back [5][1]. Your veterinarian will likely want to recheck the area in a few weeks to confirm it is healing and not regrowing.
For viral plaques and Bowenoid in situ carcinoma, the outlook depends on how early the lesion is caught and whether it is fully removed. These lesions can progress to invasive squamous cell carcinoma if left alone [1]. Regular skin checks at home help you catch new or changing spots early.
For oral lesions, long-term monitoring is important. Cats with oral in situ carcinoma may develop additional lesions over time, and some have both oral and skin involvement [7]. Your veterinarian may recommend periodic oral exams and rechecks.
Cats with a history of papillomavirus-related lesions may be more likely to develop new ones, so keep an eye on the ears, nose, eyelids, paws, and mouth. Photograph any lump with a ruler or coin next to it so you can track changes in size over time.
Prevention
There is no vaccine for feline papillomavirus, and no specific way to prevent infection [2]. Because the virus likely enters through skin breaks, keeping your cat's skin healthy and treating wounds promptly may help.
Limit sun exposure for cats with white or lightly pigmented ears, noses, and eyelids. Solar radiation is a known contributor to skin tumors in cats [6]. Keeping your cat indoors during peak sun hours and providing shade can reduce exposure.
Reduce skin trauma where you can. Fights with other cats, rough play, and scratching from fleas or allergies all create small wounds. Keeping up with flea control and treating itchy skin conditions lowers the chance of skin damage. If your cat scratches or grooms excessively, talk to your veterinarian about the underlying cause.
Finally, check your cat's skin and mouth at home once a month. Run your hands over the body, look inside the ears, and lift the lips to check the gums and tongue. Early detection is the single most useful thing you can do, because small lesions are easier to sample and treat than large ones.
Limitations and When to Contact a Veterinarian
No article can tell you whether a specific lump on your cat is harmless. Only a veterinarian who examines your cat and samples the growth can do that. Individual cases need a veterinarian's eyes and hands.
Contact your veterinarian the same day if you notice:
- A growth that appeared suddenly or grew quickly over days
- Bleeding, oozing, or an open sore that will not heal
- A lump on a paw that causes limping or refusal to walk
- A growth in the mouth, on the tongue, or on the gums
- Drooling, dropping food, or pawing at the mouth
- A lump that changed color, shape, or texture
Seek emergency care now if your cat has trouble breathing, cannot swallow, has heavy bleeding from a growth, or seems suddenly weak or collapsed.
Schedule a routine visit if you find a small, stable bump that does not seem to bother your cat. It may be nothing, but a baseline exam gives you and your veterinarian a record to compare against later.
Frequently Asked Questions
Are warts on cats contagious to people?
There is no clear evidence that feline papillomaviruses spread from cats to people. Viral DNA related to human papillomavirus has been found in cat skin lesions, which suggests cross-species transmission can occur in the other direction, but this is based on rare case reports and is not well established [4][1]. Normal hygiene, like washing your hands after handling a cat with skin lesions, is sensible.
Can a cat wart go away on its own?
Yes, spontaneous regression is commonly expected with papillomavirus-related skin lesions in cats [1][2]. Many benign papillomas shrink and disappear without any treatment. That said, a growth that is not biopsied could be something else, so have your veterinarian confirm what it is before you decide to wait.
How do I tell a wart from skin cancer on my cat?
You usually cannot tell just by looking. Papillomaviruses cause both benign warts and precancerous lesions like Bowenoid in situ carcinoma, and those can progress to invasive squamous cell carcinoma [1][3]. A biopsy is the only reliable way to know which one you are dealing with.
Should I remove a wart from my cat's paw?
Paw growths are rarely true warts, so removal is often recommended for diagnosis as much as treatment. If the lump causes limping, pain, or keeps getting irritated, your veterinarian will likely suggest removing it and sending it to a lab. The decision depends on the exam findings and your cat's overall health.
Do warts in a cat's mouth need treatment?
Oral growths in cats should always be sampled, because papillomavirus is linked to oral in situ carcinoma in this species [3][7]. Treatment depends on the biopsy result. Some oral lesions can be removed, while others need ongoing monitoring or more advanced care.
Related Articles
- Cat Skin Rash on Paws: Causes and Home Care
- Why Is My Cat So Itchy?
- Psychogenic Overgrooming in Cats: Stress-Induced Alopecia vs Flea Allergies
- Feline Oral Disease: Stomatitis, Periodontal Disease, and Tooth Resorption
- Warts On Dogs: Comprehensive Veterinary Reference Guide
- Cat Sneezing a Lot: Allergies, Infection, or Something Else?
- Cat Skin Growths: Lumps, Scaling, and When to Worry
- Cat Paw Horns: Why Cutaneous Horns Grow and What to Do
- Lumps and Cysts on a Cat's Mouth, Jaw, and Face
- Feline Papillomavirus
References
- Feline viral papillomatosis: ABCD guidelines on prevention and management. Journal of feline medicine and surgery, 2013.
- Feline Papillomatosis. Viruses, 2025.
- Papillomaviruses in dogs and cats. Veterinary journal (London, England : 1997), 2017.
- Feline cutaneous viral papilloma associated with human papillomavirus type 9. Veterinary pathology, 2007.
- Cutaneous papilloma associated with a novel papillomavirus sequence in a cat. Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 2022.
- Tumors of the Skin in Cats - Cat Owners. Merck Veterinary Manual.
- Feline oral in situ carcinoma associated with papillomavirus infection: A case series of 7 cats. Veterinary pathology, 2026.