It was Friday morning. I was tired. I was recovering from a nasty cold, and had been up most of the night coughing. “I’ll take it easy this morning,” I thought to myself as I began my workday. But before I even got to my desk, my assistant grabbed me. “Ms. Somebody is on the phone and Somepuppy just ate Somemedication,” she rattled off at me. Ms. Who? What dog? What medication? “Tell her to call Animal Poison Control,” I said, trying to gather my wits about me and absorb the information. “And write down for me exactly what Somepuppy ate and when.”
I looked at the piece of paper she handed me. I checked who was available to handle urgent care on the Island that day. I looked at Somepuppy’s medical record. Then wits or no wits, I went into overdrive. Somepuppy was an absolutely lovely young dog with an absolutely wonderful owner, and she had just ingested an entire tube of fluorouracil ointment. Also known as 5-FU, this product is used topically in humans to treat precancerous skin lesions like actinic keratosis, or superficial tumors like basal cell carcinomas.
In people, 5-FU can be a potent teratogen, even when just applied to the skin. This means it can cause birth defects, so its use is contraindicated in pregnant or nursing women. Obviously, it is also not supposed to be eaten. But tell that to Thatcat, the kitty who loves to lick his owner’s cheeks. Tell that to Somepuppy, who thinks any tube of medication is a chew toy. Poor Ms. Somebody. Who would have thought in the two minutes she stepped out of the room that Somepuppy would steal the tube of fluorouracil and eat the whole thing?
Accidental ingestion of 5-FU by dogs and cats is an extreme emergency. More than half of animals who eat this stuff die within 24 hours, even with rapid veterinary care. Symptoms can begin as soon as 30 minutes after consumption, starting with vomiting and lethargy, then progressing to incoordination, tremors, seizures, respiratory distress, heart arrhythmias, and death. Even if Somepuppy survives the first day, complications such as gastrointestinal and/or bone marrow damage might still occur.
“Call Ms. Somebody back right now,” I barked, after quickly reviewing these details. Time was of the essence. I had my assistant tell the owner to feed Somepuppy a few slices of bread (to try to absorb the medication in her stomach until we could induce vomiting), to grab whatever was left of the tube or medication packaging (so we could calculate the exact dose ingested), and bring whatever she would need to head off-Island (because Somepuppy was going to need to be hospitalized as soon as possible).
Any time a pet ingests anything besides food, it is important that you get immediate advice from a qualified professional — ideally the pet poison hotline. If you’re lucky, the toxicologist will tell you it’s fine that Someotherpuppy ate an onion bagel. But if the item(s) ingested are problematic, the first thing you need to know is whether or not to induce vomiting. If whatever he ate is sharp or corrosive, this may be contraindicated. On the other hand, for many toxic things out there for which there are no specific antidotes, the most effective treatment is to get them out of the animal’s system as quickly as possible. Yes, there are ways you can induce vomiting at home in dogs, but your veterinarian has stronger methods that may empty the stomach more completely.
Somepuppy got to me with all possible haste. Her owner brought the medication packaging as instructed. I did the math. Somepuppy had eaten more than twice the lethal amount of 5-FU.
I administered a dose of apomorphine, after which she promptly vomited voluminous amounts of breakfast, bread, and, we hoped, most of the ointment. Once her stomach was empty, we gave an injection to stop the retching, followed by syringe-feeding her a whopping dose of activated charcoal. This would hopefully bind up any remaining toxin and keep her from absorbing it.
At this point, many owners would say, “She seems fine now. I can just wait and see if she develops any symptoms, right?” Wrong. Fluorouracil toxicity can rapidly progress to all kinds of bad things. Many dogs need to be maintained on ventilators and get anti-seizure drugs for days. Most die. Early aggressive supportive care increases the odds of survival. This is true for many toxins without specific antidotes. Chocolate, grapes, and raisins, some types of rat and mouse poison, lilies in cats.
Ms. Somebody was not an irresolute owner. “Whatever I need to do,” she said. “Just tell me.” I handed her an urgent letter to the Steamship Authority, and off they went to the ferry, then on to Cape Cod Veterinary Specialists. Somepuppy spent five days there in the intensive care unit, where she was treated with intravenous fluids, gastric protectants, antibiotics, and sedatives. She never developed seizures. She never needed a ventilator. She did develop evidence of bone-marrow suppression with a very low white-blood-cell count and platelet count, but that seems to be resolving.
Somepuppy is back home now. We will continue to monitor her blood, as well as watch for any delayed onset of gastrointestinal signs, but it looks like we are likely out of the woods. Her owner’s fast response and willingness to go the extra mile made all the difference.
Fluorouracil is a fairly common prescription for humans. I have an old tube of it from my dermatologist sitting on my dresser right now. It would never have occurred to me that my dog might want to eat it. For cats, it is even more deadly, with just a few licks being potentially lethal. So treat 5-FU with respect. Store the tube securely away from pets. Wash your hands carefully after using it. In the event that your pet does get exposed, be like Ms. Somebody: Recognize an emergency, and take urgent action.
