Dogs also suffer from leukemia or cancer that affects the circulatory and lymphatic systems. This terrible disease affects four-legged pets and it is far from always possible for a pet to snatch a disease from its clutches. How is the disease manifested, and is there any way to cure the dog from it?
- Основные сведения 1. Basic information
- Распространенные типы лейкозов 2. Common types of leukemia
- Симптомы лейкозов у собак 3. Symptoms of leukemia in dogs
- Диагностирование лейкозов 4. Diagnosis of leukemia
- Лечение лейкозов у собак 5. Treatment of leukemia in dogs
- Прогнозирование при лейкозах 6. Prediction for leukemia
Leukemia is a cancer of a malignant nature, wearing a chronic form. The tumor affects the hematopoietic and lymphoid tissues. The disease arises due to the fact that cells lose their ability to differentiate and do not cope with their own specific duties. Such a violation is called anaplasia.
Leukemia in animals, including dogs, develops as a result of pathological changes in cells preceding lymphocytes. When undifferentiated blast cells penetrate the bone marrow, tissue structures of the spleen and liver, the process of inhibition of the hematopoietic system (hematopoiesis) occurs or the formation of cells of the immune system - lymphocytes (lymphocytopoiesis) is disrupted.
Risk factors for the occurrence of such diseases include the following:
- hereditary predisposition;
- some chemicals;
- radiation causing ionization;
- oncogenic viruses.
Common types of leukemia
There are several types of leukemia, but most often dogs are diagnosed with lymphocytic leukemia or malignant lymphoma - lymphosarcoma.
Lymphosarcoma is a tumor that develops from lymphoid cells, both young and mature. Most often, the liver, lymphatic system, and spleen suffer from this disease.
The statistics are striking - lymphosarcoma accounts for 80% of all tumor formations affecting the hematopoietic system. There are a number of criteria identified by immunological or histological studies that are important for therapy and prognoses for the future.
Lymphoid leukemia has a significant difference from lymphosarcoma. If in the latter case, tumors form on the periphery of the lymphatic system, here the lymphoid cells are synthesized directly in the bone marrow, from where they penetrate the blood. This phenomenon is called leukemia. Lymphoid leukemia is less common in lymphosarcoma.
There are two forms of lymphoblastic leukemia - chronic and acute, which depend on the type of cells and the clinical picture of the disease. In the acute form, pronounced penetration of immature lymphoblast into the bone marrow occurs, while healthy cells are displaced. Often, lymphoblasts are also found in peripheral circulation. Aleukemic leukemia is a condition where tumor cells do not penetrate the blood.
When the disease progresses, it is possible that the cancer cells re-infiltrate the lymph nodes, liver, spleen, and also the organs of the immune system.
In the chronic form of lymphocytic leukemia, tumors located in the bone marrow are composed of mature lymphocytes, and the level of leukocytes in the blood rises significantly.
Symptoms of leukemia in dogs
Symptoms of lymphosarcoma and lymphocytic leukemia are somewhat different. The clinical picture of lymphatic sarcoma is associated with the location of tumor formations. According to the type of localization, several types of lymphosarcoma in dogs are distinguished:
- multicentric - multiple tumors in the lymph nodes;
- mediastinal - thymus leukemia (thymus);
- gastrointestinal leukemia;
- extranodal - tumors are formed outside the lymph nodes.
Multicentric lymphosarcoma is the most common form of pathology, which is detected in 85% of cases of diagnosing the disease. The ailment is accompanied by an increase in lymph nodes on the periphery, which does not deliver pain.
The initial stage of the disease proceeds without symptoms, after which general symptoms are observed - refusal of food , lethargy, fever, weight loss, and often stool and vomiting develop. The late stage is accompanied by the development of anemia .
Lymphosarcoma of the gastrointestinal tract develops in 5-7% of all cases. A solid form of the tumor is isolated when large tumor nodes form in the stomach, intestines, adjacent lymph nodes. This condition leads to the development of intestinal obstruction - the pet develops constant vomiting, he refuses food and loses weight greatly. The second form is diffuse, accompanied by constant loose stools and hypoproteinemia, when the body loses protein.
The acute form of lymphoblastic leukemia is accompanied by the following symptoms:
- the development of anemia;
- a decrease in the level of leukocytes and platelets;
- increased susceptibility to infectious pathogens;
- possible bleeding;
- insufficiency of functions of some organs caused by infiltration may be observed.
Similar symptoms indicate an imminent death for the dog. The chronic form of lymphoblastic leukemia is more common and is characterized by slow development. In the first stages, it is asymptomatic and in most cases is detected with a significant increase in the content of leukocyte cells in peripheral blood. With the development of the disease, common signs appear - anemia, increased thirst, frequent urination, and the lymph nodes and spleen increase in size.
To detect leukemia, a detailed blood test is prescribed. Most often, with lymphosarcoma, strong changes in the analysis are not visible. White blood cell count may be elevated, decreased, or within normal limits. Cancer cells are rarely found in the blood. If a large number of blasts penetrated the bone marrow, serious malfunctions in the hematopoietic system, causing anemia, a decrease in the level of leukocytes and platelets, are manifested. In this case, lymphoblasts are detected in the analysis.
Biochemical analysis indicates changes that depend on complications and disorders in the activity of internal organs. Symptoms in a dog with lymphosarcoma are not specific, so differential diagnosis is required - x-ray, ultrasound, cell cytology, tissue biopsy.
In acute lymphoblastic leukemia, a detailed blood test reveals the presence of lymphocytosis with immature blasts, in chronic - with mature ones. The clinical picture in the latter case is less altered than in acute leukemia. If the dog has leukemia leukemia, then the analysis will not reveal blast cells. In this case, bone marrow tissue puncture will be required.
Leukocytosis, lymphocytosis can be accompanied not only by leukemia, but also severe forms of infectious diseases, blood poisoning, trauma, the formation of pus and other diseases. Therefore, a differential examination is required, excluding the remaining options.
Dog Leukemia Treatment
Lymphatic sarcoma in dogs responds quite well to chemotherapy. On average, 15% of pets are completely cured of this disease. The goal of therapy is to achieve complete remission of tumor formations (such an outcome is possible in 80% of patients) or involution to improve the quality of life of the animal. If the disease recurs, then there are chances to introduce the disease into a new stage of remission.
Today, many anti-cancer drugs are produced, most often for the treatment of dogs, cyclophosphamide, Doscorubicin, Vincristine are used. Often used Prednisolone, Decarbazine, Methotrexate, etc. The combination in chemotherapy of Prednisolone and Vinksristin sometimes leads to remission, albeit short or partial.
Surgical methods are used only in extreme cases, when tumor neoplasms disrupt the gastrointestinal tract, or form localized in the skin.
The chronic form of leukemia is better treatable than acute. If the ailment is asymptomatic and was detected by accident, then regular examinations and tests are enough.
Therapy is prescribed when the level of leukocytes exceeds the norm or obvious signs of the disease appear. Chlorambucil, Vincristine, Prednisolone can be prescribed. The dog is prescribed regular blood donations once a week. Later, the analysis is taken less often or only with the onset of symptoms of leukemia.
If the pet has lymphosarcoma, but he does not receive proper treatment, then the animal dies within two to three months. With timely chemotherapy, the chance of remission is high, the lull of the disease can last a year and much longer. Poor prognosis for lymphosarcoma of the gastrointestinal tract and other organs.
Disappointing forecasts are also in the acute form of lymphocytic leukemia. The chronic form of the disease also can not be completely cured, however, with proper therapy, there is a chance to achieve a stable remission lasting from 1 to 2.5 years.
Leukemia is a serious, almost incurable disease. But the pet needs care and treatment, because 12 months of remission by canine standards is more than five years of life without illness.