Background: Although reported in other species, findings associated with renal lipidosis have not been previously described in horses and donkeys.
Objective: To describe the signalment, clinicopathologic indices, and postmortem findings of equids with histologic diagnosis of both hepatic lipidosis and renal lipidosis (HL+RL) and compare to matched cases with hepatic lipidosis only (HL). Animals: Twenty five equids with findings of renal and/or hepatic lipidosis at necropsy from a state diagnostic laboratory between 2008-2022.
Methods: Retrospective case-control study. Signalment, history, affected system, and selected biochemical data were extracted from medical records. Each case of HL+RL was assigned a matched control from group HL for comparison of selected clinical data.
Results: Renal lipidosis was diagnosed in 0.55% of equid necropsies. Donkeys with hepatic lipidosis were more likely to also have renal lipidosis (7/13, 54%) compared to horses and ponies (18/197, 9%; p< 0.005). No cases of renal lipidosis were identified without concurrent hepatic lipidosis. Renal lipidosis cases most commonly presented with gastrointestinal (61%, 16/25) or neurologic (46%, 12/25) disease. Group HL+RL had a higher median intake plasma lactate (+6.2 mmol/L, IQR 0.4-10.5; p=0.04) and higher GGT activity (+246 U/L, IQR 72-360; p=0.02) compared to group HL controls. No significant differences between groups were noted in creatinine or triglyceride concentration.
Conclusions: Renal lipidosis is an occasional postmortem finding in equids with hepatic lipidosis, but is markedly more common in donkeys. Cases with renal lipidosis were not more likely to be azotemic than those with only hepatic lipidosis. The clinical significance of renal lipidosis is unknown.
.jpg "Kali K. Slavik, DVM (she/her/hers) photo")