Unfortunately, dogs are not exempt from tumors. Adenocarcinomas are on the list of tumors that can appear in dogs, especially middle-aged dogs. Adenocarcinomas are malignant tumors of epithelial origin that can affect a wide variety of internal organs. The symptomatology associated with this type of neoplasm is usually non-specific, so its diagnosis requires ruling out many other diseases that present in a similar way.
If you are interested in learning more about adenocarcinoma in dogs, we recommend that you join us in the next article on our site, in the that we'll talk about your symptoms and treatment, among other things.
Types of adenocarcinoma in dogs
Adenocarcinoma is the malignant version of adenoma. It is a type of malignant epithelial tumor. Specifically, it is a carcinoma that originates in the glandular tissue that lines certain internal organs.
Being malignant tumors, adenocarcinomas:
- They are locally invasive, that is, they tend to invade surrounding tissues.
- They produce metastases, that is, they spread to other tissues. The rate of growth of these tumors is variable, but unfortunately metastases are very common. Initially, these tumors metastasize to the regional lymph nodes, and from there, they spread causing distant metastases in other organs.
In dogs, some of the types of adenocarcinomas that have been described are:
- Breast adenocarcinoma.
- Nasal adenocarcinoma.
- Laryngeal adenocarcinoma.
- Lung adenocarcinoma.
- Adenocarcinoma of ceruminous glands (external ear).
- Parathyroid adenocarcinoma.
- Sweat gland adenocarcinoma.
- Gastric adenocarcinoma.
- Intestinal adenocarcinoma.
- Renal adenocarcinoma.
- Anal sac adenocarcinoma.
- Perianal gland adenocarcinoma.
Adenocarcinomas commonly occur in dogs 7 to 12 years of age Depending on the particular type of adenocarcinoma, there appears to be some predisposition by race or sex. For example, anal sac adenocarcinoma is more common in German Shepherds, Cocker Spaniels, and Springer Spaniels, especially females and neutered males.
Symptoms of adenocarcinoma in dogs
As a general rule, tumors tend to produce non-specific symptoms that can also appear in many other diseases. As you can imagine, adenocarcinomas are no exception. In addition, since it can occur in a multitude of organs, the symptoms can be very diverse.
Below, we mention some of the clinical signs that can be associated with this type of tumor:
- General signs: such as anorexia, weight loss, listlessness, tiredness, pain, fever, anemia, polyuria (increased volume of urine) and polydipsia (increased water intake).
- Digestive signs: such as vomiting and diarrhea (often bloody), tenesmus (difficulty defecating) and hematochezia (blood in stool).
- Respiratory signs: such as tachypnea (increased respiratory rate), dyspnea (shortness of breath), exercise intolerance, sneezing, and bleeding through the nose (epistaxis).
Causes of adenocarcinoma in dogs
Like all neoplasms, adenocarcinomas are caused by a genetic alteration that gives rise to massive and disorganizedcell proliferation.
The specific cause that triggers this abnormal cell proliferation is unknown, although it has been proposed that exposure to certain contaminants (such as mercury) may favor the development of this type of tumor.
Diagnosis of adenocarcinoma in dogs
The following actions help guide the diagnosis of adenocarcinoma in dogs:
- Clinical signs and physical examination of the animal.
- Blood analysis: in some cases anemia, increased white blood cells (leukocytosis), decreased total protein (hypoproteinemia)), hypercalcaemia and increased alkaline phosphatase. However, in some cases, blood tests remain normal.
- Imaging tests: such as X-ray, ultrasound, MRI or endoscopy. These tests allow the detection of abnormalities in the primary affected organs and in organs with metastases.
However, these diagnostic tests only allow an approximation to the diagnosis. To reach the definitive diagnosis, it is necessary to perform a biopsy of the affected tissue to carry out a histopathological study Observing the biopsied tissue under a microscope will not only reveal the type of tumor and its degree of development, but will provide important information for the prognosis of the animal.
In addition, it is important to perform a cytology of the regional lymph nodes to rule out the existence of metastases in them.
Treatment of adenocarcinoma in dogs
The treatment of canine adenocarcinomas is surgical. As it is a malignant tumour, it is necessary to perform a radical excision of the tumour, leaving wide safety margins to prevent recurrences. In addition, it is necessary to remove the regional lymph nodes and analyze them to ensure the absence of regional metastases.
In some cases, surgery can be supplemented with postoperative chemotherapy treatment, with drugs such as carboplatin, cisplatin, piroxicam or melphalan. Thus, adenocarcinoma in dogs is curable, but this does not mean that it cannot metastasize.
The prognosis of these patients is reserved and depends, to a large extent, on the existence or not of metastasis at the time of the surgery. For all these reasons, at the slightest symptom it is very important to go to the veterinary center, since the sooner it is diagnosed, the better the prognosis.
