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Kalli’s had a situation that I want to make you aware of in hopes that you can spread the word, so no other dog has to go through what she’s been through … with more to come.

The bottom line is that if any of your animals — or people — are prescribed an antibiotic called Metronidazole, check out all this information before administering it.

Kalli was on Metronidazole in an effort to kill bad stuff in her gut, let the good stuff flourish, and end recurring/intermittent diarrhea.

Turns out there’s something called Metronidazole neurotoxicity. It can hit sensitive dogs at ~below~ the label-suggested levels and veterinary neurologists are now recommending significantly lower dosages. (Links below.)

Cats also get this neurotoxicity. Don’t know for sure about people, although they are prescribed this antibiotic. I focused my research on dogs.

This is not related to the collie gene mutation MDR1, any breed can get it. However, collies, as a bunch of us know, do tend to be medicine sensitive overall, so there is that.

Vestibular Symptoms

The symptoms mimic a very bad case of vestibular disease. A less serious episode Kalli had in June was put down to vestibular disease (also called old dog syndrome) — however she had a shorter course of Metronidazole around the same time (after multiple but months-apart previous short courses of it), so I suspect it’s all been a reaction to this antibiotic.

Vestibular has to do with the balance part of the ear. If it goes wonky, the dog gets major vertigo. The dog’s balancing system is basically telling it the world is whirling, sliding, climbing, dropping … with a cascade of results. This can be caused by ear infections, serious conditions, or be idiopathic (cause not known). The later crops up frequently in older dogs, hence some folks calling it “old dog syndrome.” Metronidazole neurotoxicity affects the same area, though they don’t know quite how.

Symptoms include loss of balance (including falling, rolling, inability to walk or get up), rapid eye movements, vomiting, diarrhea, head tilt, excessive drooling, panting, disorientation. As you can imagine, all this can make the dog anxious.

Kalli had all except diarrhea. She was unable to stand or adjust her lying down position without help for 48 hours.

This can actually go on much longer (2-3 weeks). I’d found all this while researching while waiting for vet calls.

Toxicity From Antibiotic

Then I kept researching and found that veterinary neurologists were successfully treating dogs for Metronidazole neurotoxicity with Valium and cutting the symptomatic period down dramatically (sometimes to hours.) So I pushed the vet and got Kalli started on Valium at 4 pm yesterday … About 4 hours later, she started tracking me visually, which she had not been doing. Less than 24 hours later, she started standing without my holding her and at her own instigation. So, even though we’re giving her lower dosage of Valium because of her sensitivity, she is responding.

We’re not at the finish line by a long shot — poor dog falls down when she tries to shake her head and she still can’t walk more than a step or two. And there’s no knowing if this will be a full recovery, though the prognosis for most dogs is good.

What to remember: Check all antibiotic prescriptions. If doc recommends Metronidazole (and lots of vets are using it a lot and at label-recommended levels), come back to this or research yourself for updated acceptable levels (or opt for a different antibiotic, after researching that one.) If dog displays symptoms, check into Valium treatment (cats and people might be different in their reactions!).

The vet did not know about the neurotoxicity. Did not know about neurologist-recommended reduced dosage. Did not know about the Valium treatment. Kalli would still be immobile if not for my researching habit…and being adamant. Beware!

Feel free to share this.

Research Links

Metronidazole Toxicosis From NeuroPetVet

Metronidazole and Metronidazole neurotoxicity

More on neurotoxicity

Interactive chart showing proper dosage per pound. [Note that most sources have kilograms, so this saves a couple steps of calculating. Thanks to my sister Cathy for finding it.]

Diazepam (Valium) as treatment for Metronidazole neurotoxicity

Dosage of Valium