Cancers in cats are diseases caused by a tumour (a lump or growth) – a collection of abnormal cells within the body that grow and divide without control.

Tumours are classified as benign and malignant – benign tumours do not spread to other parts of the body. 

Malignant tumours are more serious than benign tumours and can invade surrounding tissues. 

The various types of cancer are referenced according to the abnormal cell they contain.  Carcinomas and sarcomas are solid tumours that arise from various different tissues.  Leukaemia originates from the bone marrow, causing abnormal cells in the bloodstream.

Cancer in cats can occur in any location or body system, and symptoms vary according to the type of cancer.  Cancer is the leading cause of death in cats over the age of 10, but it can occur in cats of any age.

Symptoms may be gradual and progress over weeks and months, or they may be more acute and rapid. With early diagnosis and treatment, many cats can beat the odds and live long healthy lives. 

Symptoms of cancer in cats

Any of these symptoms are not necessarily an indication of cancer, and a vet can make an accurate diagnosis.

Any new or ongoing changes should be investigated by a veterinary examination.

Early detection is key to treatment and increasing the chances of survival.

For this reason, it’s important to be aware of the signs and symptoms of cancer:

Diagnosing Cancer in Cats

Regular grooming sessions are ideal moments to check for any lumps or swelling. 

We can take the time to check for suspicious lumps on the back, legs, mouth, and under the neck.

If you have a female cat, watch for lumps on her belly, which could be a symptom of feline breast cancer.

Any lumps should be checked for the following:

Veterinary surgeons aim to provide an improved and good quality of life for cancer patients without producing any unacceptable side effects with treatment.

Veterinarians can make diagnoses based on tests such as blood, radiographs, ultrasounds, MRIs, and scans.

Tissue samples and cells can be collected by biopsy and aspirating a tumour with a needle for microscopic cell analysis.

The biopsy usually requires sedation and requires a much larger tissue sample for evaluation.

Aspiration can be used for subcutaneous masses or in internal organs, as long as the mass is easy to reach with a long needle.

Usually, these aspirations are performed with an abdominal ultrasound by a specialist veterinarian.

Reducing the Risk of Feline Cancer

Spaying and neutering

Spaying and neutering reduce the risk of developing cancer. Neutering male cats makes them less subject to testicular cancer, FeLV, and FIV.

Spaying female cats lower the risk of mammary, ovarian, and uterine cancer.

Female cats should be spayed before their first heat, as each cycle of heat creates a greater risk of mammary cancer.

Exposure to sun

The risk of skin cancer increases when a cat is exposed to direct sunlight for prolonged periods.

White cats, and those with white faces and ears, should be protected from the sun.

In warm climates, cats should be kept indoors while the sun is at its highest peak between 10:00 am to 4:00 pm.

Sunblock is also available for cats, as a useful preventative.

Exposure to second-hand smoke

Cats exposed to passive smoking have a greater chance of developing lymphoma, squamous cell carcinoma or mouth cancer.

When cats groom themselves, they ingest carcinogens that gather on their fur, which then come into contact with their mucus membranes.

Lifestyle

Providing a cat with a healthy lifestyle helps to prevent cancer.

We can choose natural or bio household cleaning products, provide fresh and organic foods, and clean and purified water.

Ideally, keep cats indoors as much as possible to avoid interaction with other cats and possible exposure to diseases.

Cats benefit physically and mentally from 10-minute sessions of interactive play.

The favourite games are fishing rod type toys, throw toys, and spot beams for cats to chase.

Viral infections

Viral infections in cats can also cause cancer, particularly feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV).

FeLV can infect the blood-producing cells of the bone marrow, and lead to the development of leukaemia or lymphoma.

A vet can test for the presence of both of these viruses.

Some of the most commonly encountered cancers affecting cats include the following:

Lymphoma and lymphosarcoma

Lymphoma is a type of blood cancer caused by the growth of abnormal lymphocytes – a type of white blood cell found in the tissues of the immune system.

It is one of the most common types of cancer in cats and can affect cats of all ages. 

The lymphatic system is part of the immune system and helps to fight infection. Lymphomas are cancerous tumours of the lymphatic system.

Affected areas can be the lymph nodes, spleen, thymus gland, and bone marrow.

Lymphosarcoma is a type of lymphoma that starts in the cells of the lymphatic system.

Lymphoma and lymphosarcoma are common among cats with feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV).

Siamese cats are also particularly susceptible.

Cats living in a smoker’s household are three times more likely to develop lymphoma.

Other contributory factors which increase the risk of a cat developing lymphoma include poor diet and genetics.

Symptoms of lymphoma in cats:

Relief of Symptoms of Cat Lymphoma

There are a number of ways to provide relief of symptoms for cats with lymphoma and lymphosarcoma. One approach is to use medication to help control the disease.

Chemotherapy drugs are used to kill cancer cells, and other medications can help to reduce inflammation and relieve pain. 

The goal of treatment is to relieve symptoms and extend the cat’s life as much as possible.

Common treatments for lymphoma and lymphosarcoma in cats include chemotherapy, radiation therapy, and surgery.

Chemotherapy is the most common treatment for these conditions, and it is typically administered intravenously.

Most cats on chemotherapy have no side effects or mild side effects. 

Radiation therapy may be used in conjunction with chemotherapy, or as a standalone treatment.

In some cases, surgery may be necessary to remove tumours or relieve pressure on the lungs or other organs.

Surgery is typically only used in cases where the tumour is localized and can be removed completely.

Cats with lymphoma or lymphosarcoma often require lifelong treatment, and the prognosis is generally considered to be guarded.

However, some cats do respond well to treatment and can enjoy a good quality of life for many months or even years.

Cat carers can help to improve their cat’s quality of life by providing a calm and stress-free environment.

This may include keeping them indoors, providing a comfortable bed or perch, and offering plenty of love and attention.

Some cats may also benefit from a special diet to help them feel better and maintain their strength.

Nutritional support is an important part of care for cats with lymphoma or lymphosarcoma.

A balanced diet can help to boost the immune system and keep the body strong.

Supplements such as omega-3 fatty acids may also be recommended.

Working with a veterinarian, cat carers can develop a care plan that is tailored to their cat’s individual needs and provides the best possible quality of life.

If you think your cat may have lymphoma, it is important to make an appointment with your veterinarian for a thorough examination.

Early diagnosis and treatment are essential for the best possible outcome.

Soft Tissue Sarcoma

Soft tissue sarcoma is an aggressive malignant tumour that develops in connective tissue anywhere on the body and feels like a firm lump or mass.

They arise out of the skin and subcutaneous connective tissues, including muscles, small blood vessels, fat and nerves.

Soft tissue sarcoma includes general tumours such as histiocytoma, nerve sheath tumours, liposarcoma, fibrosarcoma, and lymphangiosarcoma.

While soft tissue sarcomas can occur in cats of any age, they are most commonly seen in middle-aged to older cats, with males being slightly more susceptible.

The exact cause of soft tissue sarcoma is unknown, but there are several risk factors that have been associated with the disease.

One of the most significant risk factors is exposure to certain viruses, such as the feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV).

Other risk factors include immunosuppressive drugs, radiation exposure, and certain chemicals.

The prognosis for cats with soft tissue sarcoma is generally good if the cancer is caught early and treated aggressively.

If your cat has soft tissue sarcoma, you will need to closely monitor them and their symptoms.

With the proper treatment, many cats are able to live long and happy lives.

Soft Tissue Sarcoma Symptoms include:

Relief of Symptoms of Cat Soft Tissue Sarcoma

Long-term control of soft tissue sarcoma, or even a complete cure, is possible.

If your cat has been diagnosed with soft tissue sarcoma, there are a few things that can be done to help relieve symptoms.

Pain medication can be given to help alleviate any pain the cat may be experiencing.

Additionally, anti-nausea medication may be prescribed to help with any vomiting or nausea that is occurring.

If the tumour is causing difficulty breathing, oxygen therapy can be a recommendation.

In the early stages, subjecting tumours to radiation can be most effective.  This treatment is often combined with surgical removal. 

Surgery is a possibility which depends on the location and size of the tumour. 

Radiation can precede surgery to shrink large tumours, or after surgery to remove small tumours.

It is important to discuss all of the risks and benefits with your veterinarian before moving forward with any treatment plan.

Tumours can be aspirated for microscopic cell analysis.  Excisional or incisional biopsies depend on the size and location of the tumour.

Blood tests include a complete blood count and a blood serum biochemical test.

If the tumour has progressed, chemotherapy will delay further growth, and is used in addition to other treatments for aggressive soft tissue sarcoma.

Metronomic chemotherapy uses low doses of drugs like doxorubicin or carboplatin in combination with non-steroidal anti-inflammatory drugs (NSAIDS) to prevent nutrients from reaching the tumour.

Finally, it is important to keep the cat comfortable and as stress-free as possible.

This can include providing a warm bed and soft blanket for the cat to sleep on. In addition to the above measures, it is important to consult with your veterinarian on a regular basis to ensure that the tumour is not progressing and to discuss any changes in symptoms that may be occurring.

Feline Mammary Carcinoma

Cat mammary carcinoma is a type of cancer that affects the mammary glands of cats.

This type of cancer is relatively common in cats and can be very aggressive.

There are several risk factors for cat mammary carcinoma, including age, gender, and spaying/neutering status.

Female cats that have not been spayed are at the highest risk for developing this type of cancer.

Cats that are older than 10 years of age are at an increased risk.

Male cats can also be affected, and Siamese cats are twice as susceptible.

Tumours begin in the mammary glands, later metastasizing to the lymph nodes, adrenal gland, lungs, liver pleura and kidneys.

Symptoms of cat mammary carcinoma can vary depending on the size and location of the tumour.

If you notice any of these symptoms, it is important to take your cat to the veterinarian for an examination.

Early diagnosis and treatment of cat mammary carcinoma are important for the best possible outcome.

Symptoms of Feline Mammary Carcinomas:

Relief of Symptoms of Feline Mammary Carcinoma

While feline mammary carcinoma is a serious and potentially life-threatening condition, there are treatments available that can help relieve your cat’s symptoms and improve their quality of life.

Treatment options for cat mammary carcinoma include surgery, radiation therapy, and chemotherapy.  Some cases of cat mammary carcinoma can be cured, but many others will require lifelong treatment.

The most effective method of surgery involves radical mastectomy to remove all glands on the affected side.  

Any remaining microscopic cancer cells already in the lymphatic system or blood vessels can be treated with chemotherapy or radiation therapy.

Chemotherapy is often very effective at shrinking tumours and relieving symptoms.  Any side effects are usually minimal, possibly extending to nausea and hair loss.

Radiation therapy can also be used to shrink the tumour and relieve symptoms. Possible side effects may be fatigue and skin irritation, but these are typically temporary and manageable.

A veterinary oncologist will ascertain the best option depending on the tumour and the cat.  Doxorubicin is a common chemotherapeutic remedy. The sooner chemotherapy is started, the better the prognosis.

There are a number of ways that you can help your cat to cope with mammary carcinoma, and these include providing a nutritious diet, keeping them calm and relaxed, and helping them to exercise regularly.

You should also keep an eye on their weight, as obesity can make mammary carcinoma symptoms worse.

Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is a type of cancer that arises from the squamous cells in the skin.

Squamous cells are the thin, flat cells that make up the outer layer of the skin.

SCC most often affects a hairless area of the body, typically inside the mouth, lips, nose, eyelids, ears, limbs, toes, nails, and areas that are under constant trauma and irritation.  

SCC is more common in cats that spend a lot of time outdoors.

White or light-coloured cats, and those with white ears and noses, should be protected from prolonged exposure to direct sunlight.

This is particularly important in the hottest part of the day in warm climates.

SCC is most commonly seen in middle-aged to older cats, and as a precaution, six-monthly oral examinations are recommended for cats over eight years.

The most frequent cause of squamous cell carcinoma in cats’ mouths is exposure to secondhand cigarette smoke (according to a study conducted by National Center for Biotechnology Information).

Any environmental carcinogens which adhere to the fur go on to be ingested when cats wash.

If you notice any changes in your cat’s skin, such as a growth or sore that does not heal, make an appointment with your veterinarian.

Early diagnosis and treatment of SCC are important for the best possible outcome.

Symptoms of Squamous Cell Carcinoma:

Relief of Symptoms of Squamous Cell Carcinoma

The vet uses a biopsy of the tumour to establish whether the cat has cancer and the type of cancer.  In the early stages, tumours can be treated surgically or by radiation.

Surgical removal of the tumour is the most common option, provided that all the cancer cells can be removed.

Radiation therapy and chemotherapy are often used in conjunction with surgery.

The vast majority of cats suffer no side effects or only mild side effects from chemotherapy

Small or superficial tumours may be successfully and affordably treated by cryotherapy and plesiotherapy.

Cryotherapy destroys the tumour tissue by treating it with liquid nitrogen, avoiding the need for incisions.   

Plesiotherapy is a topical application of a radiation source to the targeted lesion.

Mast Cell Tumours

Mast cell tumours (MCTs) are one of the most common types of cancer in cats, with older cats and Siamese cats, particularly at risk.

The precise cause of MCTs is unknown.

MCTs can occur on the skin (cutaneous) or within an internal organ (visceral).

Mast cells are white blood cells which are part of the immune system.

When they multiply abnormally on the skin they form hard, flattened tumours or small lumps.

The top of the head, ears, neck and limbs are most commonly affected.

The vet may recommend an Elizabethan or cone collar to prevent the cat from irritating the inflamed area.

Cutaneous (skin) MCTs are usually benign.  This is the most common type of mast cell tumour, and it’s the second most common skin tumour in cats.

The majority of cats affected can be successfully treated and tumours are unlikely to return. 

Visceral MCT is less common than cutaneous MCT and causes signs of illness associated with their presence in the spleen, liver or intestine.

MCTs in internal organs are often aggressive and malignant. 

Symptoms of cutaneous MCT

Symptoms of intestinal MCT

Symptoms of MCT in the spleen

If your cat is displaying any of these symptoms, it is vital to take them to the vet for an examination.

While not all of these symptoms may be indicative of a mask cell tumour, it is always best to err on the side of caution.

Once at the vet, various tests can be performed to confirm or rule out the presence of a tumour.

Relief of Symptoms of Mast Cell Tumors

Cats with cutaneous MCTs are typically diagnosed by subjecting the tumour to fine-needle aspiration to gather and analyse the cells.

Diagnosis of visceral MCT may involve a combination of blood tests, X-rays, ultrasound, CT scan and surgical biopsy. 

If a mask cell tumour is diagnosed, there are a few different treatment options available.

The course of treatment will depend on the size, location, and type of tumour.

Treatment options for cutaneous MCTs include surgery, radiation therapy, and chemotherapy.

Surgery is the most common treatment option and aims to remove the entire tumour.

Surgical excision can be straightforward or complex, depending on the location, accessibility and size of the tumour.

In some cases, surrounding tissue may also be removed to ensure the elimination of all of the cancerous cells.

For visceral mast cell tumours, chemotherapy is a common choice, possibly by a veterinary oncologist, and including lomustine.

Where necessary, surgery may be possible to remove the spleen (splenectomy).

For intestinal MCT, surgical removal may not be an option.

Radiation therapy can be used to follow up on surgery

Follow up care involves physical examination, chest X-rays, radiographs and/or ultrasound.

A long term prognosis will depend on the type of mast cell tumour, the location, and the overall underlying health of the patient.

Prompt veterinary care is important if a cat develops signs that indicate that it may have a mast cell tumour, either in the skin or internally.

Bone Cancer (Osteosarcoma)

Osteosarcoma is a rare and slow-progressing type of bone cancer that can affect cats, and is the most common type of bone cancer, accounting for 95% of cases. It affects the cells that create and break down the bones. 

The cause of this cancer is unknown, although larger and giant breed cats are most at risk.

Osteosarcoma is very painful and can affect any bone in the body.

The rear legs are most frequently affected, as well as the skull, pelvis, ribs, or vertebrae.

Symptoms of Osteosarcoma of a limb (appendicular osteosarcoma)

Symptoms of Osteosarcoma of the jaw (axial osteosarcoma)

Relief of symptoms of Osteosarcoma

If you suspect that your cat has osteosarcoma, it is important to seek veterinary care immediately.

A physical and orthopaedic examination may be necessary to rule out other causes of lameness.

The main diagnostic tests for osteosarcoma are radiographs.  Any problem areas identified on the X-ray will be biopsied.

The vet will also search for indications of spread to other locations in the body.

This involves blood tests, urinalysis, X-rays of the lungs, and possibly an abdominal ultrasound. 

Because osteosarcomas tumours are so aggressive, amputating the affected limb followed by chemotherapy to treat metastasis is the most common treatment.

Many cats can still enjoy a good quality of life after amputation.

If metastasis has occurred, chemotherapy may be recommended. 

Palliative treatment, which aims to make your cat more comfortable but doesn’t provide a cure, can include conventional radiation therapy and drugs to reduce pain.

The vet will provide a pain management programme.

The prognosis for osteosarcoma depends on the severity and spread of the disease and on the treatment you choose.

As with any cancer, the earlier it is diagnosed and treated, the better the chances that treatment will be successful.

Basal Cell Tumors

Basal cell tumours are the most common type of skin cancer found in cats.

They are frequently found in cats over the age of 10, with long-haired breeds of cats being most susceptible.

The exact cause of basal cell tumours is unknown, although contributory factors can be sun exposure, viruses, chemicals, genetics and hormonal factors.

Basal Cell Tumors form as small, firm lumps anywhere on the body.

They are commonly found on the head or neck and are often pigmented.

These tumours are usually slow-growing and benign.

However, if left untreated, they can spread to other parts of the body and become more aggressive.

If a basal cell tumour is malignant, ulceration and infection of the tumour are possible. 

Symptoms of Basal Cell Tumors

Relief of Symptoms of Basal Cell Tumours

The vet will conduct a physical examination followed by tissue biopsy, needle aspiration, or surgical excision. 

This establishes whether the tumour is malignant or not, and the stage, grade, and type of cancer cells.

Benign tumours may not necessitate treatment, and regular monitoring is often more advisable. 

Treatment options for basal cell tumours include surgery, radiation therapy, and chemotherapy.

Surgery is the most common treatment for basal cell tumours.

The tumour is surgically removed, along with a small margin of healthy tissue around it.

This helps to ensure that all of the cancerous cells are removed.

Radiation and chemotherapy may be used as adjunctive treatment following surgery.

Chemotherapy is typically reserved for more aggressive tumours that have spread to other parts of the body.

The most common chemotherapy drug used to treat basal cell tumours is cisplatin.

Antibiotics can be recommended for between two and four weeks to treat or prevent infection.

Cryosurgery with liquid nitrogen can be used on small tumours to freeze them.

This treatment is less invasive than actual surgery and can be just as effective

The prognosis for basal cell tumours depends on the type, however, even more, aggressive carcinomas tend to develop relatively slow when compared with other cancers.

Most cats make a full recovery after benign or malignant basal cell tumour removal.

Share Cancer in Cats Symptoms

Fibrocarcinoma

Fibrocarcinomas are malignant and tend to grow quickly, causing serious health problems.

They are a type of cancer that most often affects connective tissue, although they can also develop in other tissues.

They are most commonly found on the hip, back and shoulders. 

Fibrocarcinomas are hard lumps which develop beneath the cat’s skin, particularly at the site of an injection or vaccination.

Always check the injection site of vaccines in case a tumour starts growing.

If tumours appear, keep an eye on their size and mention the presence of any tumour to a veterinarian. 

Fibrocarcinoma can also be caused by a microchip or a foreign body lodged in a wound.

In rare cases, cats with Feline Leukemia Virus (FeLV) can develop a fast-growing virus called Feline sarcoma virus (FeSV).

Early detection is crucial for successful treatment, so it is important to be aware of the signs and symptoms of this type of cancer.

Symptoms of Fibrocarcinoma

Symptoms of Oral Fibrocarcinoma

Relief of Symptoms of Fibrocarcinoma

Your vet will diagnose a fibrosarcoma using a combination of tests, including physical examination, chest Xrays, biopsy and blood tests.

It is necessary to determine the extent of cancer in order to determine which treatment option is best for your cat.

Treatment generally involves combinations of surgery, radiation therapy and chemotherapy.

Without complete removal of the fibrosarcoma with surgery and radiation therapy, it is very likely to recur. 

Limb amputation may be necessary where the tumour has been particularly invasive.

Like all cancer treatments, the earlier a tumour is detected and treated, the longer your cat is likely to survive.

The prognosis for a cat with fibrosarcoma depends on the advancement of the growth, but swift treatment will extend your cat’s life.

In general, about fifty per cent of cats have a chance of survival.

FAQs Cancer in Cats Symptoms