While carcinoma is the term that is used to denote cancer, specifically malignant tumor which can affect any part of the body, adenocarcinoma indicates malignancy in the glands. ‘Adeno’ indicates glandular tissues. The cancer cells affected are the epithelial cells that line a glandular tissue. Thus, adenocarcinoma is a malignant growth of the glandular tissue cells. Adenocarcinomas of the lungs are the most common lung tumors in the dogs that make up around 75%-80% of all primary lung tumors. This malignant and metastatic neoplasm can grow and spread rapidly to distant parts of the body including the organs, lymph nodes, bones, brain and eyes.
Like other neoplasms, older dogs, over ten years of age, are most affected. Although the tumor can occur in any dog, boxers have been reported to have higher incidence of this tumor than other breeds.
In adenocarcinoma of the lungs, most symptoms are related to respiratory system but due to metastatic nature of the cancer, symptoms may vary according to the location of the metastasis. Common symptoms seen in dogs with adenocarcinoma of lungs include
Dyspnea (difficult breathing)
Tachypnea (rapid breathing)
Low energy level and lethargy
Gradual weight loss
Hemoptysis (coughing up blood)
Lameness, in cases with metastasis to bones
Fever in some patients
Ascites (an accumulation of fluid in the peritoneal cavity of the abdomen)