Visiting Vet: Don’t take chances with poisons

Visiting Vet: Don’t take chances with poisons

Sipping my morning tea, I was expecting a mellow Monday. January on the Vineyard, not many appointments scheduled. Then the phone rang. Pip, a 12-pound Cairn terrier mix, had found and consumed part of a block of rat poison.

“Bring Pip. Bring the block. Bring the poison container. Now!” I said.

When a dog eats a potentially toxic substance, it sometimes makes sense to do the math to determine if the amount ingested is truly dangerous before rushing to the vet, but in this case, with rat poison, and such a small dog, it was a case of better safe than sorry. When Pip arrived, we instilled a smidgen of apomorphine under her eyelid where it would be rapidly absorbed and tell her brain that she should vomit.

As she deposited multiple piles of bright green barf on strategically placed newspapers, I examined the rat poison container. Most rodenticides are anticoagulants, i.e., they work by interfering with blood clotting. The nice thing is that there is an easy antidote as long as you begin treatment immediately after ingestion, so I wasn’t initially too worried. Then I read the label.

“Drat,” I swore. “It’s not an anticoagulant. It’s bromethalin.” Bromethalin is a potent neurotoxin that works by disrupting nerve function, leading to central nervous system signs and death by respiratory paralysis…and there is no antidote. “Good thing you got here quickly,” I sighed.

The bait had been in a location that the owner thought the dog couldn’t reach, but somehow Pip had managed. Maybe some big rat had dragged it out. Who knows?

We carefully determined the maximum amount of bait Pip could have eaten. I did the math. LD 50 is shorthand for “Lethal Dose 50%,” the amount of a substance that when ingested will kill 50 percent of the animals. Pip’s exposure was probably about half the LD 50, enough to still be worrisome (though from the mess on my exam room floor, it looked like she had thrown up most of it.).

“We’ll give activated charcoal to help prevent further absorption of any poison left in her gut,” I said. “Take her home and watch her like a hawk. Call if you see anything like hyperexcitability, tremors, or seizures.” If Pip did develop clinical signs, all we would be able to do was give supportive care and hope she would survive.

I went on with my day with a constant nagging worry about Pip in the back of my mind, but as each hour passed, I relaxed a bit more. Then, late afternoon, just when I was feeling confident Pip would be fine, the phone rang. Another dog had just eaten a bottle of ibuprofen.

The dog’s name? Pip. I’m not making this up. This Pip, also a terrier mix, was a bit bigger, at 28 pounds. “Bring Pip. Bring the pill bottle,” I said.

The effect of ibuprofen toxicity in dogs is dose dependent. At lower doses it can cause severe gastrointestinal irritation, even ulceration. Moderate doses can lead to kidney failure, and high doses to central nervous system dysfunction. Fatalities are not uncommon. When Pip arrived we gave him apomorphine while I did the math. His owner thought the bottle had only been half full, maybe less, but couldn’t be sure. It sure was empty now. I read the label. 200 mg tabs. Fifty tabs when the bottle was full. For Pip’s size, 11 tabs would put him at risk for fatal kidney damage.

When Pip hurled, we could only find the remnant of two pills in the vomitus. Did that mean he had only eaten two? Or had he eaten 20 and the rest had just moved down into his intestines. Better safe than sorry. We instituted a treatment protocol of activated charcoal, gastric protectants, antacids, and intravenous fluids. It would be three days before we could be sure he was out of the woods. On Tuesday, we continued his intravenous fluids.

Pip One’s mom reported all was well. I went about my day, no longer worried about Pip One, but concerned about Pip Two. That afternoon another client called. Her dog was drooling and his lips were a bit swollen. Yesterday, on their walk, he had eaten something he found in the woods that was red and crumbly and looked kind of like plastic. She had taken it away from him and still had the remains.

Was his name Pip? I joked. No, it was Booley. “Bring Booley. Bring the red stuff,” I said.

When Booley arrived, I examined the remnant of red, waxy, material. It had a ridged surface pattern and bits of bird seed. All the rat poisons I was familiar with were green, but this sure looked and felt like a rodenticide. A little research determined it was, in fact, the anticoagulant brodifacoum. Since Booley had eaten it the day before, it was too late for vomiting or charcoal. He had already absorbed whatever toxin he had consumed.

Anticoagulant rodenticides are tricky as they take three to five days to cause symptoms. People think that because the dog looks fine at first, they will continue to be fine. Not. Once they start bleeding, the prognosis for survival plummets. I did the math. Worst-case scenario, Booley might have consumed one tenth of the lowest reported LD 50. That is right at the cut-off point where specialists advise treatment. Better safe than sorry. We started Booley on the antidote, vitamin K, advising his owners to keep him quiet and watch carefully for any signs of abnormal bleeding.

By Friday, Pip One was fine, his owner planning how to make the rat poison inaccessible in the future. Pip Two’s mother reported he had rolled on a dead fish and was pretty proud of himself. Booley seems okay, but because brodifacoum is a long-acting poison, he will need 30 days of Vitamin K.

I made myself another cup of tea, hoping for a quiet weekend. After all, it’s January on the Vineyard.