Splenic lymphosarcoma in a horse.

This paper documents a case where a 10-year-old Tennessee Walker horse was discovered to have lymphosarcoma, a kind of cancer that affects the lymphocytes, in the spleen, liver, and lung, which led to its eventual death.

Case Background

• The study begins with the description of a case involving a 10-year-old Tennessee Walker horse who had a history of progressive weight loss, occasional bouts of colic and lethargy.
• Additional symptoms of the horse included a slight fever, tachycardia (an unusually high heart rate), tachypnea (rapid breathing), pallor (paleness), ascites (the accumulation of fluid in the abdominal cavity), and marked ventral edema (swelling of the lower abdominal region).

Clinical Findings

• The paper describes several clinical findings obtained from various tests performed on the horse. A blood analysis showed that the horse was suffering from anemia (a lack of red blood cells or hemoglobin), leukocytosis (an increase in the number of white cells in the blood typically occurring in infections), neutrophilia with a left shift (an increase in the number of a type of white blood cell called neutrophils), lymphopenia (decreased level of lymphocytes in the blood), and monocytosis (increase in the number of monocytes, one type of white blood cells).
• Further, the horse also showed hypoproteinemia, a condition characterized by abnormally low levels of protein in the blood, and slightly increased levels of SDH (Sorbitol Dehydrogenase), an enzyme found in the liver, the increase of which is typically a marker of liver disease.
• Abdominocentesis, the surgical puncture of the abdominal cavity, resulted in the extraction of red-orange fluid with a large number of red blood cells (RBC) and increased fibrinogen content, a protein that aids in clotting of the blood.

Diagnosis and Outcome

• The horse was also examined through rectal palpation which revealed a large mass in the left caudal abdominal quadrant. The presence of this mass, coupled with the numerous abnormalities reported in the blood analyses, suggested that the horse had a serious, systemic illness.
• The horse eventually died after resecting, or removing, the mass.
• The histopathological analysis, the microscopic examination of biological tissues to observe the appearance of diseased cells and tissues in very fine detail, of the excised mass resulted in the diagnosis of lymphosarcoma.
• Lymphosarcoma is a malignant tumor (cancer) that originates from lymphocytes, a type of white blood cell. In this case, it was concluded that the horse’s spleen, liver, and lung were the organs impacted by the cancer.