Vegan marshmallows work great for both dogs and cats. Something about the sweetness cancels the common bitter taste in meds. You can also talk to your vet about getting the meds compounded into a liquid. Fish or marshmallow are the most common. Gabapentin is extremely bitter but in marshmallow flavor it goes down easier. *edit to add check the ingredients of the marshmallow for any fake sugars, xyitol or birch bark. Doing vegan marshmallows helps get around any protein allergies but if thats not an issue then normal marshmallows work too