Delayed transforaminal brain herniation in a cat following bromethalin intoxication.

Area of Science:

• Veterinary Neurology
• Toxicology

Background:

• Bromethalin is a neurotoxic rodenticide commonly encountered in veterinary toxicology.
• Severe bromethalin intoxication can cause progressive neurological dysfunction in cats.

Observation:

• A 2-year-old cat with severe bromethalin toxicosis presented with nonambulatory tetraparesis and obtunded mentation.
• Despite aggressive treatment including osmotherapy, intralipids, and supportive care, the cat experienced initial neurological improvement and was discharged.
• Nine days post-discharge, the cat died suddenly, with postmortem examination revealing brain herniation secondary to white matter degeneration and increased intracranial pressure.

Findings:

• This case represents the first reported instance of delayed death in a cat following apparent successful treatment of severe bromethalin toxicosis.
• The delayed mortality was attributed to severe, progressive neurological damage (spongy degeneration) leading to increased intracranial pressure and brain herniation.

Implications:

• The findings suggest that initial neurological improvement in bromethalin toxicosis does not preclude the possibility of delayed, fatal neurological deterioration.
• Veterinarians should consider the potential for delayed complications and prolonged monitoring in cats treated for severe bromethalin intoxication.
• This case underscores the need for further research into the long-term effects and prognostic indicators of bromethalin toxicosis in cats.