Menbutone (Genabilin, Naftobil, Genabilic acid), or genabilic acid, is a derivative of oxybutyric acid which acts as a choleretic stimulating secretion, a trypsinogen and a pepsinogen.
Acute toxicity of menbutone in rabbits occurrs at accidental high doses, as the lethal dose is about 50 fold over the recommended therapeutic dose for other animals. Cardiac muscle, liver and kidneys are the main target organs for menbutone toxicity. Menbutone is not recommended for use in rabbits suffering from any cardiac and hepatic disorders, especially in overdosing situations. The calculated LD50 is 475 mg/kg BW in rabbits, indicating that menbutone has a relatively wide safety margin[1].
[1] S. O. El Okle, et al. World Rabbit Sci. 2014, 22: 215-222.