Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear that your girl got a hold of something she should not have and chewed on it, your Isagenix sleep spray.
This product has active ingredients including melatonin, l-theanine, lemon balm, tart cherry, chamomile, and valerian.
Unfortunately it also contains xylitol, as the second ingredient, and this artificial sweetener is highly toxic for dogs. She is a tiny dog, thus a little bit may be enough to affect her.
If we can get the xylitol out of their body before they have time to digest and absorb it, by inducing vomiting quickly, and they don't have time to start showing initial symptoms such as vomiting, weakness, incoordination, and severe lethargy, we are likely to be successful in avoiding the truly toxic effects of xylitol, seizures, coma, liver disease and/or failure.
Since it has already been 2 hours it is likely it is probably too late to induce vomiting. At this point you cannot change things much at home, and I would encourage you to get her to an emergency clinic now. Most dogs that are going to get sick show symptoms within the first 30 to 60 minutes post exposure, but some take a little longer.
Melatonin is a naturally found hormone in dogs and people that helps regulate the sleep/wake cycle and is involved in seasonal shedding in dogs.
This is a medication that we do use sometimes in dogs to help them relax and sleep, and in cases that have abnormal shedding patterns related to seasonal light changes or abnormal growth hormone fluctuations. The usual dose in dogs is 2mg to 12mg per dog every 12 to 24 hours.
Because both Melatonin and xylitol can cause lethargy it will be difficult to know which one is affecting her, and given that xylitol can be deadly it is important to have him under close observation and check his blood sugar levels.
Please let me know if you have any further questions.