Which antibiotic is associated with neurologic disease in dogs?

Metronidazole is known to be associated with neurologic disease in dogs due to its potential neurotoxic effects. When used in higher doses or for extended periods, this antibiotic can lead to adverse reactions such as seizures, ataxia, and tremors. These neurologic side effects can occur because metronidazole can cross the blood-brain barrier and has been implicated in causing toxicity in the central nervous system.

In contrast, the other antibiotics listed are generally not known to have such significant neurologic side effects in dogs. Ampicillin is a penicillin antibiotic that primarily affects bacterial cell wall synthesis and does not typically result in neurologic issues. Clindamycin, while it can cause gastrointestinal side effects, does not have a notable association with neurologic disease. Doxycycline, a member of the tetracycline class, is effective against various infections and is also not commonly linked to neurologic complications in dogs. The known risks and toxicities associated specifically with metronidazole make it the correct choice in this context.