Hemangiosarcoma is one of the types of soft tissue neoplasms (cancer) most feared by dog handlers. And it is not surprising! It is extremely invasive and metastatic, affecting any vascularized organ. Its aggressiveness is due to the rapid dissemination of tumor cells by the hematogenous route, whose most common initial site is the spleen.
What is hemangiosarcoma in dogs?
Hemangiosarcoma is a mesenchymal neoplasm that originates in the vascular endothelium, and is considered a malignant, aggressive tumor that can affect several organs, developing regional or distant metastases. Due to its biological behavior, with a high rate of hematogenous or lymphatic spread, through tumor emboli, about 80% of the animals, at the time of diagnosis, already have metastases. The dog is the most frequently affected domestic animal, dying from the disease or being euthanized.
The primary site is usually the spleen, but the visceral form of the disease can affect other organs, such as the tongue, conjunctiva, liver, lungs, breasts, pericardium, right atrium, aorta, lungs, kidneys, muscles, bones, intestines, gallbladder, urinary tract, prostate, vagina, and peritoneum. This form of hemangiosarcoma is the most frequent and, although its etiology is unknown, it is known to be influenced by several factors, such as genetics, solar radiation and lack of control of angiogenesis (formation of new blood vessels).
Although less common, hemangiosarcoma can also manifest cutaneously, as a primary or metastatic site, and can affect the dermis and to the subcutaneous tissue, with a predilection for abdominal, preputial and pelvic limb skin. Short-haired or poorly pigmented dogs are more predisposed when excessively exposed to ultraviolet rays, triggering the primary variant of the disease. Cutaneous hemangiosarcoma in dogs is less aggressive than visceral hemangiosarcoma, with less metastatic potential.
Causes of hemangiosarcoma in dogs
The etiology of hemangiosarcomas is not yet fully understood, however, several causes have been considered, including genetic predisposition, the exposure to chemical substances, the ionizing radiation, the oncogenic virus, administration of vaccines or medications [1].
Some studies suggest that the prolonged exposure of dogs to cigarette smoke may contribute to the development of the disease, since nicotine it increases the proliferation of primitive endothelial cells in various models of angiogenesis. We talk about it in this article: "How does tobacco smoke affect animals?"
Hemangiosarcoma symptoms in dogs
The clinical signs in the dog with hemangiosarcoma are usually related to the site of origin of the primary tumor and whether there are metastases. In case of rupture of the neoplasm, the animal may present severe internal hemorrhage, perceived by the guardian by the appearance of abdominal distension and manifestations associated with acute hemorrhage (pale mucosa, tachycardia and tachypnea), in addition to other symptoms such as lethargy, depression, anorexia, weight loss, palpable abdominal mass, exercise intolerance, and shock. Acute death from hypovolemic shock (loss of large amounts of fluid and blood) can also occur.
Primary bone hemangiosarcomas in dogs are quite rare, with an incidence of less than 5%, and more frequentlyaffect long bones , such as the humerus, femur, ribs and vertebrae, and fractures can occur in these locations [2]
The development of cutaneous hemangiosarcoma in dogs is most common in the ventral abdominal region, back, head, neck and in the scapular, axillary, inguinal, and medial regions of the femur (inner thigh). Tumors with a nodular appearance or masses with a reddish color and a firm consistency appear. The following image shows a cutaneous hemangiosarcoma in a dog:
Diagnosis of Hemangiosarcoma in Dogs
The identification of the disease must be done by the veterinarian, who will carry out laboratory and imaging tests. The definitive diagnosis of hemangiosarcoma splo is established from the histopathological examination (biopsy or tumor excision).
Generally, the diagnosis of patients with hemangiosarcoma is delayed when the tumor has reached a reasonable size, because the clinical signs are nonspecific [1].
Treatment for Hemangiosarcoma in Dogs
The treatment of hemangiosarcoma is based on its staging, that is, on the stage of tumor development, on the involvement of the lymph nodes and on the appearance of metastases. The total removal of the primary tumor is the main goal of treatment, with the goal of allowing a higher cure rate. Initially, however, stabilization of the animal from shock, careful evaluation of blood tests, and correction of coagulation abnormalities are necessary. Surgery must be performed to remove all affected tissue, especially in cases of cutaneous hemangiosarcomas. Unfortunately, due to the rapid development of metastases, the surgical procedure generally does not interfere with the life expectancy of the affected animal and chemotherapy and immunotherapy must be used
Chemotherapy can prolong the life of dogs, being a palliative therapy, aimed at remission and/or comfort of the animal, improving its quality of life and reducing the symptoms of metastasis or tumors that no longer exist. can be intervened.
The acupuncture, associated with other treatment techniques such as those mentioned, has shown satisfactory results, improving the welfare of the animal, delaying the evolution of cancer and increasing life expectancy, in addition to favoring the rebalancing of the organism [2] In any case, it will be the veterinarian who handles the case who determines if is this type of treatment convenient or not.
Life expectancy of a dog with hemangiosacroma
The lifetime of a dog affected by hemangiosarcoma is highly variable and will depend on factors such as: characteristics of the dog, size of the tumor, if it is operable, if there are metastases and which organs were affected. The sooner it is diagnosed, the better the chances of treatment and the longer the survival for the dog.
Now that you know what hemangiosarcoma in dogs is, its symptoms and consequences, don't hesitate to go to the veterinary center if you notice any warning signs. Remember that rapid action is key in this pathology. Also, don't miss this article on Types of cancer in dogs to learn how to identify them.
