Angiosarcoma in Cats: Symptoms, Causes, and Treatments Explained by a Veterinarian

Angiosarcoma is a malignant tumor that develops in blood vessels. It primarily occurs in the skin and internal organs such as the liver and intestines. Although it is a rare tumor in cats, it can cause internal bleeding in the abdomen, and by the time it is discovered, it may have already metastasized.

This article will explain feline angiosarcoma in detail.

What is Feline Angiosarcoma?

Definition of Angiosarcoma

Angiosarcoma is a malignant tumor that originates in endothelial cells, which are the innermost cells of blood vessels, in contact with blood. It is a common tumor in dogs but is quite rare in cats. Angiosarcoma can occur wherever blood vessels are present, but it mainly manifests as cutaneous angiosarcoma, occurring in the skin and subcutaneous tissue, or visceral angiosarcoma, occurring in organs such as the liver, intestines, and spleen.

Frequency of Onset and Trends in Cat Breeds and Age

Feline angiosarcoma is rare, occurring in about 2 out of 100 cats. There is no particular breed with a higher incidence, but it tends to be observed in senior cats aged 8 years or older. However, it can also occur in younger cats.

Main Symptoms of Feline Angiosarcoma

Symptoms of Cutaneous Angiosarcoma

Cutaneous angiosarcoma, which develops in the skin and subcutaneous tissue, appears as a reddish-purple mass on the skin. The mass tends to grow larger.

Symptoms of Visceral Angiosarcoma

Visceral angiosarcoma occurs in the liver, intestines, abdominal lymph nodes, spleen, and other organs. Bleeding often occurs from angiosarcoma and may be discovered due to intra-abdominal hemorrhage. Anemia and a decrease in platelets due to bleeding are also observed. As the mass grows larger in the abdomen, symptoms such as lethargy, loss of appetite, vomiting, and difficulty breathing may appear.

Progression and Severity of Symptoms

Cutaneous angiosarcoma is considered to have a better prognosis than visceral angiosarcoma. If cutaneous angiosarcoma is noticed and surgically removed, long-term survival is possible. Visceral angiosarcoma tends to have widespread metastasis and lesions. In cases of visceral angiosarcoma, metastasis may have already begun at the time treatment starts, and even with treatment, life expectancy is often only about six months.

Causes of Feline Angiosarcoma

The exact cause of angiosarcoma is not clearly understood. In dogs, it is thought that genetics may play a role because certain breeds are predisposed, but this is not known for cats. In cats, there are reports of angiosarcoma caused by foreign bodies, so factors like ultraviolet light or trauma might be contributing causes.

Diagnosis and Treatment of Feline Angiosarcoma

Diagnostic Methods

Lumps on the skin are palpable, so owners may notice them quickly. However, visceral tumors grow internally and may only be noticed after symptoms appear.

Palpation checks not only for tumors but also for swollen lymph nodes. Anemia and clotting disorders may also occur, so the oral mucosa and skin for internal bleeding (purpura) are checked.

Imaging tests such as X-rays and ultrasound are crucial for angiosarcoma. Imaging helps identify the location of the tumor, presence of metastasis, and any internal bleeding (intra-abdominal hemorrhage).

If a tumor is found, a biopsy is necessary. However, angiosarcoma can be difficult to diagnose with a needle biopsy, requiring an excisional biopsy to remove and examine the tumor tissue for pathological diagnosis.

Treatment Methods

Surgery is the primary treatment for angiosarcoma. Cutaneous angiosarcoma can achieve long-term survival with excision, but in cases of visceral angiosarcoma, metastasis may be confirmed after surgery, necessitating concurrent chemotherapy.

If the cat's condition has deteriorated before surgery, it is essential to first improve its overall health.

Post-Treatment Follow-up

While cutaneous angiosarcoma can allow for long-term survival if completely excised, recurrence is possible if it has spread deep into the skin.

Visceral angiosarcoma is an aggressive malignant tumor that progresses rapidly; even after tumor removal and chemotherapy, cats often succumb within six months. Metastasis and recurrence are often seen within a few months. Whether cutaneous or visceral, regular follow-up examinations are always necessary even after treatment is completed.

Prevention and Early Detection Tips for Feline Angiosarcoma

Importance of Regular Health Checks and Massage

If it's cutaneous angiosarcoma, lumps on the skin may be noticed. Therefore, it's a good idea to brush and massage the cat's entire body as part of bonding.

Unfortunately, visceral tumors are difficult to detect early, and veterinary visits often occur only after symptoms appear. While an annual health check-up is recommended, angiosarcoma progresses rapidly, making early detection difficult even with annual exams. Since angiosarcoma is more likely to occur in senior cats, it is advisable to have health check-ups every six months.

Daily Precautions (UV Protection, Injury Prevention, etc.)

Since the cause of angiosarcoma is unknown, prevention is not possible. However, as UV radiation is considered a cause of skin cancer in humans, it is advisable to avoid excessive exposure to sunlight.

Prompt Response and Consultation with a Veterinarian When Anomalies Are Noticed

If angiosarcoma is not addressed promptly, metastasis may begin. Particularly in visceral cases, cats may go into shock due to bleeding or clotting disorders. At that stage, they will be listless and unable to move, and their mouth and tongue will appear pale, leading owners to notice something is wrong. In such a critical situation, it is crucial to find a veterinary hospital that can provide immediate care. Before reaching this critical stage, symptoms such as loss of appetite may occur. It is important to visit a vet even for slight changes.

Summary

Although feline angiosarcoma is a rare malignant tumor, it can be discovered due to intra-abdominal hemorrhage. Angiosarcoma progresses rapidly, making early detection difficult, especially for visceral forms. If you notice any abnormalities, consult a veterinarian immediately. Senior cats should have health check-ups every six months.