Christmas was this past week. I have been at my new job for two weeks now, hence the delay in getting some blog posts out!
I worked Christmas Eve which spurred my thoughts on this topic: Chocolate Toxicity in Dogs.
Not too many people dislike chocolate! Many people bake over the holidays, and sometimes dogs decide to take a sample of those tasty treats.
We had a 2 year old pup come in on Christmas Eve. She had gotten into some Christmas baking, and had potentially eaten up to 225 grams of semi-sweet baker's chocolate some time between 1 and 1:30 pm. The owner had come home to vomit and the evidence was in plain view on the floor. However, her pup continued to vomit on and off for hours. She could not even keep water down. The owner believed that there was no more chocolate left in her belly, but was getting anxious as the vomiting would not stop.
Gastrointestinal signs, vomiting or diarrhea, are some of the signs a dog may experience when they consume chocolate. A dog with continuous vomiting will become dehydrated. The size of the dog will determine the severity of the dehydration, as if a dog cannot keep its body water at a normal level, their blood volume decreases, dropping their blood pressure. Patients with continuous vomiting will become hypovolemic, and if the dehydration is severe, their body can go into shock. The severity of the hypovolemia will be dependent on the size of the dog. Vomiting in a small breed dog will cause more issues than in a larger breed dog, as the smaller dogs tend to lose their percent body water faster than larger dogs.
When our patient presented, she was still regurgitating water. On physical examination, the pup was a little hyperactive and had an elevated heart rate at 160 beats per minute (her normal at a previous visit was 120). Fortunately, she was clinically stable with no arrhythmias or seizures.
How do you determine if your dog has consumed a toxic dose of chocolate? Well, if you're a veterinarian or veterinary student, then you can pull up the chocolate toxicity calculator on VIN (if you have access to VIN) Here you will see that if a 16 kg dog consumes 225 grams of semi-sweet baker's chocolate there is risk of seizures, collapse and possibly death. If your dog consumes dark chocolate or semi-sweet baker's chocolate, these are the more potent chocolate types. The toxic part being the methylxanthines, caffeine and theobromine. Most toxicities are dependent on the mg ingested per kg of body weight. So if the dog is a small dog that consumes a lot of dark chocolate, the toxicity will be higher and there will be more severe clinical signs. Since we could not be certain how much our patient had consumed or absorbed, the owner elected for in hospital monitoring.
It is fortunate that our patient had vomited most of the chocolate prior to it being absorbed through the gut, however, the toxin (methylxanthine) can be reabsorbed through the bladder wall when it is excreted through the kidneys into the urine. This can contribute to prolonged duration of toxicity. Placing the patient on IV fluid therapy can help flush the toxin out of her system faster.
Since we were able to support the patient over night, she was placed on IV fluids both to flush her system and to rehydrate her from the prolonged vomiting. She was given an injection of an anti-nausea medication as well as a low dose of diazepam for the agitation and hyperactivity. Since the dog had already vomited, and presented to our hospital 4 to 5 hours after ingestion, we were past the decontamination part of the treatment plan and on to supportive care. Supportive care is treating symptoms as they present. If the dog consumes chocolate and hasn't vomited on its own, then induction of vomiting could be part of the treatment plan, but that tends to be if you get the patient within 30 minutes of ingestion of the chocolate.
After setting our patient up on fluids, with the anti-nausea medication on board, we were then able to give activated charcoal that was mixed with some wet food. If you give a benzodiazepine medication (diazepam or midazolam), then your patient will likely feel hungry and eat the wet food-charcoal combination, saving your staff from having to force-feed charcoal - not so fun!
So, when do you bring your dog to the vet if they have consumed chocolate? Well, the sooner they are seen the better. This will again be dependent on the type of chocolate, the size of your pup and the amount of chocolate that they consume. The amount of methylxanthine differs with the type of chocolate that is consumed, with none in white chocolate, a small amount in milk chocolate, and a hefty amount in unsweetened baker's chocolate.
Here is a basic chocolate toxicity calculator for you to review.
What should you do if your dog consumes chocolate? Aside from calling your veterinarian, and seeking emergency care, you can also call the ASPCA poison control hotline.
For more information on Chocolate Toxicity in dogs, see the article on the Veterinary Partner.