Home » Pet Health » Genes and Cancer » What are Genes?


Genes are the basic biological components that determine the features passed on from parent to offspring. They are in all cells of human and animal bodies, where they are short sections of DNA that provide cells with the instructions to make molecules called proteins. Each strand of DNA carries multiple genes on it. The genes (and proteins) control all the machinery in your body, including cells that regulate the growth, division, and functions of cells. Genes also determine traits like eye color, hair color, skin color, height, etc. Generally, genes are like an instruction manual for our bodies.

Genes make you and your pets unique. All of us are different because of slight differences in our genes, leading to variations in our features from one generation to the next. Our uniqueness also comes from the number of genes we carry. Humans have around 25,000 genes, dogs have about 19,000, and cats have approximately 20,000.

When the body is functioning normally, damaged cells have the natural ability to self-destruct, but this isn’t always foolproof. Sometimes, specific changes to genes can impair the self-destruct mode of altered cells, allowing them to continue to grow and divide. Uncontrolled growth may lead to a cancerous tumor. Sometimes, these modified genes are passed on from parent to offspring.

Understanding genes are essential for cancer diagnoses and treatment. For example, gene therapy, a new form of treatment for various genetic diseases like cancer, is emerging with a promise to improve the conditions of cancer patients. Gene therapy targets cells with abnormally modified genes and restores normal function, thereby slowing down or stopping the disease. Because this type of treatment is new, scientists are continuously researching how to make gene therapy an effective cancer treatment.

Learning about your pet’s genetics helps you appreciate what makes your beloved pet who they are. It also allows you to understand what health risks they face and what treatments are available. You can also discuss with your vet what new gene-related therapies are available to treat your pet’s cancer.

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.

The team listing of those contributing to the information on this page is here:

Keep Your Pets Healthy Editorial Team

Last Updated: October 16, 2022

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The following sources were referenced to write the content on this page: 

Arendt, M, Nasir, L & Morgan IM, 2009, ‘Oncolytic gene therapy for canine cancers: teaching old dog viruses new tricks’, Vet Comp Oncol, vol. 7, no. 3, pp. 153-61.

Balmain, A, Gray, J & Ponder, B 2003, ‘The genetics and genomics of cancer’, Nat Genet, vol. 33, no. Suppl 3, pp. 238-244.

Pavlin, D, Cemazar, M, Sersa, G & Tozon, N 2012, ‘IL-12 based gene therapy in veterinary medicine’, J Transl Med, vol, 10, no. 234 (2012).

Ponder, BA 2001, ‘Cancer genetics’, Nature, vol. 411, no. 6835, pp. 336-341.

Portin, P & Wilkins, A 2017, ‘The evolving definition of the term “gene”‘, Genetics, vol. 205, no. 4, pp. 1353-1364.

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

For reprint requests, please see our Content Usage Policy.