Home » Pet Health » Genes and Cancer » Types of Mutations


Hearing the news of your pet’s cancer can never be easy. You might have a lot of questions and doubts in your mind. You may wonder what caused cancer in your pet and if you could have prevented it. Although sometimes there are no clear answers, you can find comfort in understanding cancer’s biology.
Cancer arises from changes to your pet’s genes. These alterations are called genetic mutations, and they can result from errors in DNA replication during cell division, exposure to mutation-causing agents, or a viral infection. Mutations occur in your pet’s cells, but most don’t lead to health problems because cells have a sophisticated repair mechanism to fix the errors. But sometimes, the repair mechanism becomes faulty, and the body can’t repair the mistakes, resulting in the rise of disease conditions such as cancer.

What types of genetic mutations exist?

There are two kinds of gene mutations: germline and somatic.

Germline mutations, also called hereditary mutations, occur in reproductive or “germ” cells–egg cells in females and sperm cells in males. The egg and sperm fuse together at conception and eventually start the division process to form the fetus. Germline mutations can pass from one generation of cells to the next, thus appearing in every cell in the offspring. Reports have shown that Rottweilers may be at higher risk of cancer associated with germline mutations, but this type of mutation is rare in other breeds. Others have demonstrated that German Shepherds may rarely develop kidney, skin, and uterus cancers because of germline mutations. In cats, recent investigations have determined germline mutations may be associated with breast cancer. However, germline mutations are generally rare in dogs and cats.

Somatic mutations occur in cell types other than reproductive cells, and somatic mutations do not pass from one generation to the next. Somatic mutations generally arise from environmental and lifestyle factors such as second-hand smoke, exposure to ultraviolet radiation, toxic chemicals, or simply DNA replication errors that don’t get repaired. Somatic mutations are the most common causes of cancer, and some examples include canine malignant melanoma and feline mammary carcinoma.

Learning what types of mutations lead to cancer allows you to understand better what caused your pet’s disease. Furthermore, this knowledge gives you the confidence you need to discuss treatment options with your vet and give your furry friend many happy days after diagnosis.

The Pet Cancer Foundation’s Website Editorial team is comprised of veterinarians, veterinary oncologists, and veterinary technicians, as well as scientific writers and editors who have attained their PhD’s in the life sciences, along with general editors and research assistants. All content found in this section goes through an extensive process with multiple review stages, to ensure this extended resource provides pet families with the most up-to-date information publicly available.

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Last Updated: January 30, 2023

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The Pet Cancer Foundation’s medical resource for pet owners is protected by copyright.

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