Gross Necropsy Findings of Bovine Renal Lipofuscinosis in a Tanzanian Crossbred Yearling Male Calf: A Case Report

Bovine renal lipofuscinosis (BRL) is an incidental finding in cattle at slaughter. It is associated with brown to black kidney discoloration, which is condemned as unfit for human consumption. The aim of this chapter is to report a rare case of BRL that was encountered incidentally at necropsy. In June 2023 a yearling male calf was found dead in one of the dairy cattle farms in Mbeya City, Tanzania; after being sick for about a week. The owner requested a necropsy service to establish the cause of the death of the animal. After being permitted by the owner, a necropsy was carried out. It revealed significant gross pathological changes in a liver that was cooked-like and shrunken, with a flabby consistency and large pale necrotic foci. Furthermore, dark blue discoloration of both kidneys with normal gross morphology was evident. Based on the history and gross pathological findings, the animal was diagnosed to have died from acute hepatitis. The differential diagnosis for kidney discoloration included hemochromatosis, renal hemosiderosis, BRL, and melanotic renal cell carcinoma (MRCC). After ruling out hemochromatosis, renal hemosiderosis and MRCC in the list of possible causes of kidney discoloration based on the lack of gross pathological findings, particularly hepatic fibrosis, pallor, and a mass of tumor tissue in the kidneys that are characteristic of hemochromatosis, renal hemosiderosis and MRCC, respectively; the cause of kidney discoloration was diagnosed as BRL. In this necropsy, the history and gross pathology suggested that the animal’s death could be attributed to acute liver failure, which is one of the sequelae of acute hepatitis. Kidney discoloration was not considered an attributing factor to the animal’s death because, with the exception of discoloration, the kidneys did not have gross pathological changes. Moreover, to date, there has been no report of a clinical disease in cattle associated with BRL. However, BRL is an important disorder because it leads to condemnation of the affected kidneys as unfit for human consumption. Having a genetic etiology, this case of BRL could be associated with the importation of animals and semen from countries affected by BRL. This is the first report of BRL in Tanzania and the African continent at large. Based on gross pathological findings, it is concluded that the case of BRL reported here was an incidental finding at necropsy, and is not associated with the death of the animal.