VOSVC_iStock_000078356715_LargeA diagnosis of cancer for your pet often comes with an assortment of words with which you may not be familiar. This can make an already scary process even scarier for many pet owners.

Of course the cancer experts here at Veterinary Oncology Services and Research Center are here to help you through the process, but making yourself familiar with the types of pet tumors that we deal with can help you begin to wrap your head around what is going on with your pet.

Remembering That “Cancer” Isn’t a Diagnosis

People often use the term cancer as a catch-all phrase that can encompass a very wide spectrum of disease processes. While many of us accept that a pet passed away due to “cancer”, we would never accept the same explanation in a human loved one. We would want to know what kind of cancer the person had, among other details.

The term “cancer” refers to the abnormal growth of cells in a tissue. Normally the body regulates how quickly cells grow and divide. In a cancerous process, though, this regulation is unable to be controlled.

The effects of this out-of-control growth depend largely on several factors. These include:

  • What type of tissue is affected
  • Where the affected tissue is in the body
  • How aggressively the cancerous tissue is growing
  • Whether the cancerous tissue affects other tissues/organs

In order for us to help your pet to the fullest, it is important that we correctly diagnose the type of cancer (what tissue the abnormality arises from). We often must also perform staging. This process often includes blood tests, radiographs, ultrasound, and/or lymph node sampling to determine how far the cancer has progressed. This information helps us to make the most effective treatment plan possible for your pet.

The Two Main Types of Pet Tumors

When we discuss types of pet tumors, we often place them into one of two broad categories:  benign and malignant.

Benign tumors are still abnormal populations of cells that are growing without normal regulation, but they generally are non-aggressive and are non-invasive. They can be potentially troublesome, however, if their location affects the function of nearby structures or organs. Some of the more common types of benign tumors diagnosed in pets include:

  • Lipomas (fatty tumors)
  • Histiocytomas
  • Cystic tumors
  • Sebaceous gland skin tumors

Malignant tumors are those that we generally refer to as “cancer”. They often grow quickly and invade the surrounding normal tissue. They are also very prone to metastasizing.  “Metastasis” is the term that refers to the spread of cancerous cells throughout the body via the bloodstream. This is how cancer cells may end up in distant lymph nodes or organs such as the lungs, nervous system, or bones.

Based which tissue or cell type the tumor is derived from, there are three major classifications of tumor types. Carcinomas develop from epithelial or glandular tissues. Sarcomas are from mesenchymal cells such as connective tissue, bone or muscle. Hemopoietic tumors originate from blood cells, lymph nodes, bone marrow or spleen. A lymphoma is derived from an organ such as lymph nodes or spleen. Leukemia is a bone marrow based malignancy. There are many types of malignant tumors; however, some of the more commonly diagnosed malignancies in pets include:

  • Lymphoma
  • Melanoma
  • Hemangiosarcoma
  • Squamous cell carcinoma
  • Osteosarcoma
  • Mast cell neoplasms

Understanding the origins and characteristics of an individual pet’s cancer is vital for us to mount the best attack against it. Sometimes the diagnostic process when a pet has cancer can seem long and drawn out, but the information we gain is essential to success.

When a pet develops cancer, it is never easy. With our help, though, we hope that you are able to better understand what the diagnosis is and what to expect.