Delayed transforaminal brain herniation in a cat following bromethalin intoxication

To report a case of delayed death after initial successful treatment of severe bromethalin intoxication in a cat.

A 2-year-old neutered male domestic shorthair cat presented as a referral for bromethalin toxicosis and progressive neurological decline. At the time of referral, the cat was nonambulatory tetraparetic with minimal motor function in all 4 limbs and exhibited a dull mentation. Within the first 4 hours of hospitalization, the cat's neurological status continued to rapidly decline, and osmotherapy, corticosteroids, and intralipids were administered. The treatment regimen also included levetiracetam, thiamine, cholestyramine, vitamin E, and gingko biloba. Six days after bromethalin ingestion, the cat displayed marked neurological improvement with near normal mentation and mild tetraparesis and was discharged. The cat continued to do well at home with improving neurological status and function. Nine days after discharge, the cat was presented dead on arrival. Postmortem examination revealed transforaminal brain herniation secondary to spongy degeneration of the white matter and increased intracranial pressure as the cause of death.

To the authors' knowledge, this is the first report of a cat that suffered delayed death despite initial neurological improvement after being treated for severe bromethalin toxicosis.