Renal carcinoma in a horse.

This research examines a case of kidney cancer, specifically a papillary renal carcinoma, in a nine-year-old Thoroughbred mare which was diagnosed due to chronic weight loss and an abnormality detected via rectal examination. Post-mortem findings confirmed the diagnosis, with evidence of multiple metastases in the omentum and peritoneum.

Presentation and Clinical Examination

• The horse in question, a nine-year-old Thoroughbred mare, was brought to the veterinarians’ attention due to a noticeable decline in performance and continuous weight loss. These symptoms were of a chronic nature, implying that they had been on-going for a considerable period.
• Upon physical examination, the vet found an abnormal mass in the abdominal region during a rectal examination. Furthermore, an area of dullness, indicating a potential lack of healthy tissue or fluid, was identified when percussing (tapping to determine the condition and position of underlying body structures) the right flank or side of the mare.

Diagnostic Procedures

• In order to reach a diagnosis, biopsies (tissue samples for further examination hereafter) were taken from what was considered to be the liver region, as well as via the rectum.
• The pathological examination of these tissue samples revealed that the horse was suffering from a malignant, metastasising tumor. “Malignant” implies that the tumor was cancerous or life-threatening, while “metastasising” means that the cancer had the potential to spread to other body parts – in this case, it was revealed to be of urinary system origin.

Post-mortem Results

• Unfortunately, due to the advanced and aggressive nature of the cancer, euthanasia was deemed to be the most humane course of action for the horse.
• A post-mortem examination confirmed the presence of a specific type of kidney cancer: a papillary renal carcinoma. This type of cancer originates from the cells lining the small tubes in the kidney and is usually associated with a poor prognosis due to its aggressive behaviour.
• The post-mortem report further elucidated multiple metastases not only in the localized abdominal region but also in added areas – namely, the omentum and the peritoneum. These areas are membranes in the abdominal cavity – expansion of cancer to these areas indicates an advanced stage of the disease.