Fatty liver pathology in female rabbits

Abstract

In this study we describe post-mortem findings related to fatty liver in rabbit does necropsied on commercial farms. We obtained the information from 11,194 visits to 1,320 rabbit doe farms in Portugal and Spain between 1996 and 2023. The median size of the visited farms in 2023 was 868 does (mean size 1,067 does, range 100‒6,000 does). Throughout the 28-year study, we necropsied 4,363 does on 504 farms. In a subset of 347 periparturient does necropsied on 107 farms, we saw lesions compatible with clinical pregnancy toxaemia/ketosis (CPTK). Our diagnoses were based on clinical observation of 3,531 dead and 832 euthanized females and fetuses on the visited farms. On-farm examinations were performed by a rabbit veterinary practitioner, with subsequent diagnostic confirmation by veterinary anatomic pathologists and veterinary microbiologists. We classified 260 cases as primary CPTK, with hepatic steatosis and other disorders including obesity and gastric trichobezoars. There were cases of secondary CPTK in the peripartum period, when hepatic steatosis was present, as well as intercurrent processes such as enteritis (57 does) or pneumonia (30 does). Apart from the 347 periparturient does, we report findings of fatty liver in other females with serious diseases including acute mastitis, enteritis, pneumonia, septicaemia (with confirmed aetiological diagnoses) and dystocia. In the liver, mixed diffuse steatosis (micro- and macrovesicular) was frequently seen, although centrilobular and diffuse purely microvesicular steatosis were also seen. Fetal livers had histological features similar to those in the dams, principally characterized by mixed diffuse steatosis. The thick limb of Henle's loop in the outer stripe of the renal medulla was the nephron segment most affected in renal lipidosis. Abdominal fat necrosis was associated with pancreatic necrosis. The results indicate that fatty liver is the main disorder in rabbit does with CPTK and other diseases.