Soft Tissue Sarcoma in Dogs: Stages and Prognosis

Whenever we hear the word sarcoma, we should know we're dealing with a malignant tumor. Naturally, our dog receiving this diagnosis will cause us great concern. But it's possible to treat it.

Unfortunately, the prognosis for this type of cancer will depend a lot on the stage at which it's detected. Hence the importance of regular vet check-ups to catch these types of diseases early.

What Are Soft Tissue Sarcomas?

Sarcoma is a malignant tumor that can have different origins. For example, fatty or connective tissue, blood vessels, nerve sheaths, or muscle cells. It occurs both on the body's surface, meaning we'll detect it on the skin, or inside organs. In the first case, we'll be able to see it directly.

But when they grow inside the body, they'll be hard to diagnose. This means they're usually detected once they're already large enough to cause clinical signs in the dog. Generally, they grow fairly slowly, and only once they've been affecting the dog for a while do they develop metastasis, meaning they spread to different organs.

These are usually the lungs and liver. As for their appearance, there are considerable differences. Some are perfectly well-defined, as if forming a capsule. Others, on the other hand, have no detectable edges and infiltrate all the surrounding tissue. Unfortunately, they're not rare in dogs.

Types of Canine Soft Tissue Sarcomas

There are different types of these sarcomas dogs can develop, forming the group known as soft tissue sarcomas. They're classified based on where they occur. They're fairly common, especially the cutaneous ones. Below, we'll highlight some of the most common in this species:

• Hemangiopericytoma: grows from the cells arranged around small arteries.
• Fibrosarcoma: appears in fibrous connective tissue.
• Neurofibroma or schwannoma: found in peripheral nerve sheaths.
• Liposarcoma: usually found on the limbs or in the armpits.
• Other sarcomas, such as hemangiosarcoma or oral fibrosarcoma, aren't considered part of this tumor group, since they generally show different characteristics or behave much more aggressively.

Which Dogs Get Soft Tissue Sarcomas?

A sarcoma can appear in any dog, but it's more often diagnosed in certain breeds. In addition, since it's cancer, it's more common in older dogs, or at least middle-aged ones. It's known there's a genetic predisposition in dogs as popular as the following:

• The German Shepherd.
• The Boxer.
• The Saint Bernard.
• The Basset Hound.
• The Great Dane.
• The Golden Retriever.

How Is a Soft Tissue Sarcoma Detected in Dogs?

If we detect any abnormality on our dog's skin, we need to see the vet. There are lots of possible causes, and all require this professional's assessment, who will take a sample to analyze in the lab. This way, we can find out what type of cells are present. This is how a diagnosis is reached.

On the other hand, when the sarcoma is growing inside the dog's body, it could go unnoticed for a long time. That's why it's recommended that every dog, from roughly seven years of age onward, get a complete vet check-up at least once a year.

This can help detect this and other conditions early. Either way, if we notice any sign of illness in our dog, such as weight loss or vomiting, we need to see the vet. Sarcoma is diagnosed through X-rays, ultrasounds, CT scans, and biopsies.

Treatment for Canine Soft Tissue Sarcomas

Treatment for these sarcomas will depend on the type and extent of the affected tissue. So, generally, surgery can be used to remove them completely, along with radiotherapy or chemotherapy. Often, several of these therapies need to be combined to treat the sarcoma as successfully as possible.

Life Expectancy in Dogs With Soft Tissue Sarcomas

There are multiple factors to consider when establishing the prognosis once a soft tissue sarcoma is identified in a dog. Among other elements, the most important to consider is the stage the tumor is at when treatment begins. These sarcomas are classified into stages based on how mild or severe they are.

The milder ones usually show a low rate of both metastasis and recurrence. The latter refers to the possibility of them coming back. The more severe ones, luckily less common, can, on the contrary, have a greater capacity for recurrence and metastasis.

The tumor's size and location also need to be considered, which can determine whether surgical removal is possible. Either way, studies on this topic still show contradictory data. In addition, there are quite a few individual differences between these types of tumors.

Bibliography

Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.