& welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
How much does she weigh?
Was it milk chocolate or dark?
Now as I am sure you can appreciate, chocolate ingestion can be dangerous to our dogs. How much so depends on how much they have had as you noted, but also their size, and what kind of chocolate they have had. Now if this was 145g of dark chocolate in a dog as small as Peppa, then we do have to appreciate that this is a severe toxicity and adverse signs –both mild GI and severe ones --are a real risk here. Specifically, with doses this high we will often see GI signs (vomiting, diarrhea, appetite loss, drooling, etc) within 2-4 hours post ingestion as you have reported. Further to that, we do also have the risk of this toxicity causing her an irregular/fast heart rate, abnormal breathing, tremors and even seizures (which can appear up to 12-36 hours post chocolate intoxication).
Now if it has been a few hours ago, then we are getting passed a stage where inducing vomiting (How To) will be of benefit (since her GI signs suggest absorption is already occurring). Therefore, at this stage, we would need to consider administering activated charcoal (LINK) from the pharmacy to bind any remaining material in her stomach. charcoal, we tend to give 4 grams per pound is given every 8 hrs. This can be mixed with food to be fed or with water to syringe feed (do note that it stains, so keep it away from white carpets/clothes). This will just limit how much she absorbs and reduce the intoxication risk here.
Otherwise, since this dose is so high and with Peppa is already vomiting (which will make activated charcoal administration difficult), it would be ideal to consider getting her vet involved. They will be able to put her on IV fluids to flush the chocolate toxin (theobromine) out of her system before it can cause any lasting harm. Furthermore, they can give anti-vomiting treatment by injection to bypass her mouth and settle her stomach.
Finally, if you can get the activated charcoal into her and she settles, you can also take a few steps to try to reduce her GI signs. To start, you can give her an antacid to help. There are a number of antacids that are available over the counter and pet friendly. I would advise only treating with one, but the two I tend to use are Pepcid (More Info/Dose) or Zantac (More Info/Dose) These are usually given 20 minutes before food (to allow absorption) and of course you want to double check with your vet if she has a pre-existing condition or is on any medications you haven't noted before. Further to this, you can consider feeding small, frequent meals of a light diet (ie boiled chicken, white fish, scrambled egg, or meat baby food -- as long as its free from garlic or onion powder -- mixed with white rice) over the next few days to keep her stomach settled.
Overall, this is a high dose toxicity and with her vomiting already it tells us that she has started to absorb the chocolate toxin. Therefore, in this case, it would be best to be cautious at this stage. Therefore, do consider treating with activated charcoal to limit her risk here. But if she cannot stop vomiting or you can not administer this to her, then we need to think about getting her to the vet fluids and supportive care to reduce the harm this high dose could cause her.
In this situation, just in case you do wish to see an emergency vet, you can check HERE and @ http://www.vetlocator.com/.
I hope this information is helpful.
If you need any additional information, do not hesitate to ask!
All the best,