Thank you for your patience. There are a number of things that could be going on here this evening with your girl Dittie. Given her age, we need to consider everything from an acute gastroenteritis or toxicity, through to an internal organ or endocrine problem. It definitely sounds as though she is nauseous, hence the restleness and howling, but there could potentially be other symptoms here, so continue to keep a close eye on your girl if you can. For now, make sure there is plenty of water available for her and encourage her to drink. You can with hold her food for a few hours in case she does have a stomach upset here. If she seems particularly distressed and restless, then given her age, I would definitely encourage you to get her seen now if you can. It is always better to play it safe here and the howling and pacing is a strong signal that she is distressed and/or painful. A full physical exam and a couple of diagnostics will likely give your local ER vet an exact idea of what is going on here.
If you can't get her seen right now, please keep an eye on her mucus membranes, capillary refill time and respiratory rate tonight as follows (do be careful that your girl doesn't try to bite you):
Mucus membranes - flip her lip and look at the color of her gums. They should maintain a nice salmon pink color. Get her to the emergency Vet if they appear white or very pale pink, or if they are a dark deep red color.
Capillary Refill time - this measures blood perfusion and test this by putting your thumb on her gum to apply pressure. After you release your thumb you will see the gum blanch. Capillary refill time is the amount of time it takes (in seconds) for the gum to return to a healthy pink color from the blanched white color. If 2 seconds or less don't worry - if it is taking significantly more time, again - off to the emergency Vet.
Respiratory Rate - if she seems to be panting or breathing rapidly throughout the night, this is a sign of shock and or pain and a signal for a trip to the emergency Vet.
If you think this could indeed be related to nausea, then you may also want to try her with a little pepcid. The typical dose for this type of situation is 0.25mg per pound of body weight up to twice daily. You can read more about the use of Pepcid in dogs online here: http://www.petplace.com/article/drug-library/library/over-the-counter/famotidine-pepcid
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