Feline Mast Cell Tumor – Symptoms, Surgery, Treatment Methods, and Improvement TipsThe Power of the Immune System to Overcome Mast Cell Tumors

Mast cell tumors are a type of malignant tumor (cancer) that occurs in cats and can be classified into two types: cutaneous mast cell tumors and visceral mast cell tumors. Visceral mast cell tumors often metastasize, and it is generally said that the prognosis is poor. However, we believe that through immunotherapy, it is possible to improve the cat’s condition, maintain its quality of life (QOL), and restore its vigor and appetite.

In fact, there are numerous cases where the use of Cordy for immune support has allowed cats’ cancers to be controlled.

This page summarizes an overview of mast cell tumors, their causes, symptoms, treatments, and tips for improvement and cure. We also introduce many cases of improvement. We hope this will be a source of support and a light of hope for everyone.

What Are Mast Cell Tumors in Cats?

Other types of malignant tumors that can occur on the skin include squamous cell carcinoma, melanoma, cutaneous lymphoma, hemangiosarcoma, and fibrosarcoma.

What Are Mast Cells in Cats?

Histamine is involved in inflammation and immune responses and also affects the functioning of internal organs.

You may have a negative image of histamine as a substance that triggers allergic reactions in hay fever. However, the runny nose and tears that occur are defense mechanisms to eliminate foreign substances from the body.

The body is protected by the actions of mast cells.

It’s important to note that fat cells, which store fat, are involved in obesity, and there is no direct connection between fat cells and mast cell tumors.

Causes of Mast Cell Tumors in Cats

In Western countries, certain breeds like Siamese cats genetically exhibit skin-type mast cell tumors from a young age, suggesting that breed and genetic factors might also be involved.

Additionally, it is speculated that disseminated mast cell tumors or multiple cutaneous mast cell tumors could be related to Feline Immunodeficiency Virus (FIV).

Types of Mast Cell Tumors in Cats

Malignant mast cell tumors are life-threatening diseases for cats.

Surgical intervention is recommended as soon as possible if the tumor is operable.

Even if it appears that surgical removal was successful, recurrence and metastasis are not uncommon.

Whether a lump is a mast cell tumor or not can only be determined through veterinary examination.

Characteristics of Cutaneous Mast Cell Tumors

Cutaneous mast cell tumors typically present as small, hard lumps similar to warts on hairless areas of the body such as the head, ears, ear base, and feet, though they can also appear in scattered spots across a large area of the body.

There are often no initial symptoms such as pain or itching, which can lead to delayed detection.

While cutaneous mast cell tumors are often benign, early treatment is necessary for malignant cutaneous mast cell tumors.

We recommend seeking veterinary consultation as soon as you notice any abnormalities on your cat’s skin.

Moreover, there is suspected correlation between multiple (i.e., occurring in various locations on the body) cutaneous mast cell tumors and Feline Immunodeficiency Virus (FIV).

Characteristics of Visceral Mast Cell Tumors

In contrast, visceral mast cell tumors occur in the internal organs rather than on the body surface.

Because they occur in the internal organs, it is challenging to detect visceral mast cell tumors early, often leading to delayed discovery.

Additionally, about 90% of visceral mast cell tumors are malignant.

This makes treatment difficult when detection is delayed.

Due to the high malignancy of visceral mast cell tumors, it is recommended to visit a veterinary hospital for a check-up as soon as any of the above symptoms are noticed.

Symptoms of Feline Mast Cell Tumors

As mentioned above, the main symptoms of cutaneous mast cell tumors include the formation of hard lumps on the body surface or multiple bumps appearing in different areas.

Furthermore, mast cell tumors release large amounts of substances such as histamine.

While histamine is essential for life, its excessive release can cause various issues.

It can trigger allergic reactions and increase stomach acid, leading to gastric ulcers.

It can also affect the lungs and cause breathing difficulties.

These issues significantly reduce the quality of life (QOL) and can sometimes be life-threatening.

Examinations for Feline Mast Cell Tumors

Cytology

## Cytological Test

Cytological tests do not use anesthesia or use only local anesthesia to collect cells, so the burden on the cat’s body is minimal. However, since the puncture site is small, it is not uncommon to fail to collect cancer cells.

Therefore, a definitive diagnosis might not be possible.

### Biopsy and Histopathology

Biopsy and histopathology involve the partial removal of tissue to be examined in detail under a microscope. These tests are highly reliable as they examine a wide range of tissues, such as those removed during surgery.

### Blood Tests and Tumor Marker Tests

When a cat has cancer, abnormalities may appear in the blood components. Additionally, blood tests are often conducted to check if the cat can withstand chemotherapy and to assess the overall state of health.

### Imaging Tests

These tests use equipment like X-rays, ultrasound (echo), and CT scans to create images. Imaging tests are effective for cancers in the internal organs and can also determine the presence of metastasis.

However, imaging tests alone cannot definitively diagnose cancer, and tiny cancers may not be detected through such tests.

## Treatment of Feline Mast Cell Tumors

The prognosis for mast cell tumors largely depends on whether they can be completely removed surgically.

If the cancer cells are left behind after surgery, there is a high likelihood of recurrence, making it a highly malignant cancer.

It is difficult to determine whether a mast cell tumor is benign or malignant just by its appearance, so surgical excision and histopathological examination are performed.

### Surgery – Treatment of Feline Mast Cell Tumors

This is because leaving behind mast cell tumor cells makes recurrence more likely.

In cases of recurrence, curing the cancer is generally considered extremely difficult.

Surgery may be performed even when it is known that not all cancer cells can be removed.

Mast cell tumors release large amounts of histamine, leading to various health issues.

Reducing the tumor size through surgery can alleviate some symptoms. Incidentally, surgery performed for the purpose of symptom relief is referred to as a palliative surgery.

The cost of surgery, including pre-operative and post-operative tests, hospitalization fees, and medication through IV drips, is expected to be over 100,000 yen.

### Chemotherapy – Treatment of Feline Mast Cell Tumors

Because anti-cancer drugs act throughout the body via the bloodstream, chemotherapy is considered when the tumor has spread too much to be completely removed by surgery.

However, the effectiveness of chemotherapy for feline mast cell tumors has not been proven, and the costs are also significant.

For older cats or those with decreased strength, it might be better to avoid chemotherapy. In fact, many veterinarians do not actively recommend chemotherapy in such cases.
To undergo chemotherapy, in addition to the cost of antineoplastic drugs, expenses for medications to suppress side effects and testing fees are also necessary, so the monthly cost is approximately 30,000 to 40,000 yen – not inexpensive by any means.

If you decide to proceed with chemotherapy treatment, by using Cordy for immune support and Japan-made SPF pig-derived placenta extract for liver and kidney care, it is expected to improve the Quality of Life (QOL).

Radiation – Treatment for Feline Mast Cell Tumors

Radiation therapy can be performed in well-equipped facilities such as university hospitals.

Moreover, anesthesia is required, and due to the issue of radiation exposure, repeated treatments are not feasible.

There are only a few facilities equipped for radiation therapy, and the treatment costs are high.

A single treatment session costs approximately 30,000 to 80,000 yen, and it is typically performed 3-5 times a week for about 4 weeks (a total of 12-60 sessions), thus the total cost becomes very high, ranging from 400,000 yen to over a million yen.

Furthermore, if there is metastasis, the effectiveness is limited, so it is recommended to thoroughly discuss with the veterinarian about the costs and the expected effects before proceeding with treatment.

Other Treatment Methods – Treatment for Feline Mast Cell Tumors

When mast cell tumors are not completely removed by surgery or cannot be excised, steroids (prednisolone) are used, but the effects are not highly expected.
When considering splenectomy for a mast cell tumor in the spleen, postoperative steroid administration is contraindicated.

Additionally, due to the severe inflammation associated with mast cell tumors, we recommend using krill oil to help reduce the inflammation.

What happens if a cat’s mast cell tumor is left untreated?

As summarized above, the cost of surgery, chemotherapy, and radiation treatment can be high, causing some pet owners to hesitate in taking their cats to a veterinary hospital.

Skin-type mast cell tumors can often look like simple growths, leading owners to leave them untreated without visiting a vet.

However, mast cell tumors are malignant, meaning they are cancerous, and if left untreated, they will progress and eventually metastasize.

Regularly touch your cat and if you notice anything unusual, take them to a veterinary hospital as soon as possible.

How to prevent mast cell tumors in cats

However, if a mast cell tumor is detected early, there may be a chance to remove it surgically.

Although it’s not a preventive measure, it is recommended to regularly check the skin and have routine health check-ups.

If you notice any unusual symptoms, observe for a few days, and if the condition doesn’t improve, take your cat to a veterinary hospital for an examination.

When visiting the vet, make sure to communicate when the symptoms started and how they have persisted.

There’s no need for excessive worry, but having your cat examined at an animal hospital can prevent unnecessary anxiety.

Mast cell tumors occur more frequently with aging, which suggests a correlation between decreased immunity and increased incidence of mast cell tumors. Routine immune care is advisable for prevention.

Improving the prognosis of cats with mast cell tumors

Enhancing immunity with Cordy may help improve the prognosis and prevent recurrence of mast cell tumors.

Moreover, if the tumor has spread locally or metastasized to distant areas, surgery alone may not be sufficient.

Even in such advanced cases, Cordy may be helpful. It might be too soon to give up even if Western medicine treatments seem insufficient.

There have been instances where cats given a terminal diagnosis for mast cell tumors have maintained a good appetite and energy levels for a prolonged period.

For preventative purposes, the highly safe Cordy can be used with confidence, as it doesn’t have side effects typical of pharmaceutical drugs. Preventing cancer, including mast cell tumors, is the best approach.

Our laboratory is researching whether administration of Cordy can modulate immunity and if its effects on cancer are promising.

Harness the power of immunity for cats with mast cell tumors

When a cat is diagnosed with a mast cell tumor, aggressive treatments may not be feasible due to the cat’s age or physical condition.
Even in such cases, Cordy can be incorporated as it does not burden the body, and it often helps ensure a peaceful daily life.

During periods of immune suppression due to surgery or chemotherapy, Cordy can be used to support immunity without placing additional stress on the body.

Our laboratory is continuing to study whether administering Cordy during periods of immunosuppression can accelerate the recovery of immune function.

It’s uncertain how much improvement to expect or how responsive it will be, but there is a sufficient possibility that at the very least, it can help restore appetite and energy.

When using medications like chemotherapy drugs, steroids, or antibiotics, there is also concern about liver function deterioration. In such cases, combining it with Domestic SPF Pig-Derived Placenta Extract Powder may help minimize liver damage.

There are numerous cases where administering Domestic SPF Pig-Derived Placenta Extract Powder has improved liver function within about a month, even for those whose liver values have already deteriorated.

Furthermore, since mast cell tumors often involve inflammation, it is considered effective to also administer Antarctic Krill Extracted EPA/DHA and Krill Oil, which can be expected to have anti-inflammatory effects.

Our laboratory continues to research the potential benefits of Cordy for immune modulation, Domestic SPF Pig-Derived Placenta Extract Powder for liver protection, and Krill Oil for its anti-inflammatory properties. If you have any questions, please contact us.

監修獣医師：林美彩　　所属クリニック：chicoどうぶつ診療所

代替療法と西洋医学、両方の動物病院での勤務経験と多数のコルディの臨床経験をもつ。　モノリス在籍時には、一般的な動物医療（西洋医学）だけでは対応が困難な症例に対して多くの相談を受け、免疫の大切さを痛烈に実感する。
ペットたちの健康維持・改善のためには薬に頼った対処療法だけではなく、「普段の生活環境や食事を見直し、自宅でさまざまなケアを取り入れることで免疫力を維持し、病気にならない体づくりを目指していくことが大切である」という考えを提唱し普及活動に従事している。

所属：

• 獣医保健ソーシャルワーク協会

著書：

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