It doesn't take much xylitol to kill a dog or a cat. thankfully cats don't have a taste for sweet things but it will kill them, it's poisonous. I won't allow it in my house and I'm always reading labels to make sure no xylitol is in things because it could fall on the floor and my dog could eat it. She is a medical service dog so thankfully she has been taught not to eat things off the ground. Xylitol in gum is very common and people spit their gum out all over the place.
https://vcahospitals.com/know-your-pet/xylitol-toxicity-in-dogs
... Ranting...Then she also slowly killed a goat. There was also three horses put down in one week. I don't know how that is acceptable that three horses have to get put down in one week. Horses got old. I don't know if she's took it into her own hands to kill the horses but most people who have old sick animals call a large animal vet to the property and humanely euthanize. They don't need to suffer in agony and get their brains blown out.
If a dog's behavior is intractable to where it is killing the neighbor's livestock then fix it so the dog is not roaming around off leash. A puppy needs to be trained. A dog needs training. A 14-month-old canine is still a puppy. Many dog breeds do not mature until they are 3 years old. She needed a trainer, to research training that breed, or rehome the dog. Goats are known to be ornery and mean, she should know these things before she gets farm animals.