Cancer is also a disease in dogs and cats that is more common in old age. Since our pets are getting older due to the development of medicine, the phenomenon is seen more and more frequently in veterinary practices. PetReader introduces you to the most common types of cancer and explains whether a cure is possible.
Cancer is characterized by the uncontrolled growth of body cells – and this can occur in any tissue: in the skin, bones, muscles, or internal organs. And even the white blood cells – cells that protect against pathogens – can develop cancer.
Benign tumors usually grow in one place in the body and can even go away on their own. Malignant tumors, on the other hand, form metastases – that is, they release cells into the blood and lymph vessels, which then attach to another point in the body and form further tumors.
In between, however, there are gradations: even benign tumors can metastasize at some point, and malignant tumors can be inactive for a long time. Unfortunately, cancer is unpredictable.
If malignant tumors are removed by surgery, it is relatively likely that they will come back. Nevertheless, many animals are also operated on for malignant tumors in order to improve their quality of life.
Why Does Cancer Make Your Animal Sick?
Tumor cells need a lot of energy to grow, preferably in the form of sugar and proteins. This leads to your animal becoming emaciated. For this reason, cancer patients should rather be fed a diet rich in fat, since the tumor cells cannot metabolize fat as well and do not “steal” from the animal patient.
With cancer, your animal is less productive due to the lack of energy. And his immune system is also less able to deal with infectious diseases.
In the lungs, liver, or spleen, tumors of a certain size hinder the actual task of these organs. This can lead to shortness of breath, liver failure, and many other complex clinical pictures. Blood vessel tumors can cause the animal to permanently lose small amounts or suddenly very large amounts of blood. Both create different problems.
Tumors in hormone-producing organs such as the thyroid, adrenal, kidney, or pancreas produce too many or too few of these hormones and lead to massive problems such as hypoglycemia or blood clotting disorders.
Canine Cancer: Skin Lumps are the Most Common
The most common tumors in dogs are tumors in the skin – and about 40 percent of them are malignant. The view of waiting and seeing whether the tumor continues to grow is completely out of date nowadays: With a syringe, your vet can “cut out” cells from the knot and look at them directly under the microscope. This does not cost much, is not laborious, and provides initial indications as to which cells the tumor originates from.
In some cases, a statement can even be made about the malignancy of the cells. Because not only skin cells can degenerate, mast cell tumors and the lymphoma explained below can also hide in the skin.
A cell examination is only nonsensical in the case of tumors in the mammary glands of bitches: This type of cancer is usually a mixture of benign and malignant tumors. This means that if you happen to catch benign cells with your needle, the lump “next door” can still be malignant. Therefore, breast tumors should always be completely removed.
Tumors of the Spleen and Liver
Large breeds of dogs in particular often have tumors in the spleen and liver when they get older – this is rather rare in cats. The tumors of the spleen often originate in the blood vessels (hemangiosarcoma) and form large or small blood-filled cavities. If these tears, the dog can bleed to death internally.
Therefore, splenic tumors should be checked very closely or removed by surgery. The entire spleen is usually removed.
This is not so easy with tumors in the liver – since it is not possible to survive without a liver. Individual liver lobes can be removed, but this procedure is significantly more risky than removing the spleen.
The most common tumors of the liver are metastases from other organs. In second place are the tumors of the blood vessels. The third most common are malignant tumors of the liver tissue and the bile ducts.
Lymphoma: What is It Actually?
In lymphoma, the bone marrow increasingly produces immature white blood cells (lymphocytes), which migrate into different tissues and lead to problems there. In dogs, mostly all internal organs are affected (multicentric), cats tend to suffer from the form in which only the gastrointestinal tract is affected. The animals show symptoms such as swollen lymph nodes, weakness, diarrhea, and emaciation.
Lymphoma is no longer a death sentence these days. This is because it can be treated with chemotherapy. Although this is expensive and time-consuming, animals have significantly fewer side effects than humans. In dogs, depending on the course of the disease, you can gain up to a year of life, in cats even more.
Lung Tumors are Mostly Metastases
Most of the tumors found in the lungs are metastases from other cancers in other parts of the body. A tumor that only grows in the lungs is rather rare.
If your vet finds cancer in your dog or cat, an X-ray of the lungs should be made for most types of tumors. Because if your animal already has metastases in the lungs, the prognosis is significantly worse. So you can make the decision about an operation with completely different background knowledge.
The Dreaded Brain Tumor
A brain tumor, which can only be detected by an MRI examination, unfortunately, has a very poor prognosis: Depending on the severity of the symptoms, the animals can live with it for a while – or have to be redeemed relatively quickly. Some clinics are slowly starting to surgically remove brain tumors. However, these interventions are still very rare in veterinary medicine and are therefore associated with a high risk.