Doxycycline is very bitter (same for Baytril), and some rats are very sensitive to bitter tastes, so you will want to add some sweetener even if you use something savoury to disguise the med taste.
Some ratties can be a real challenge in this regard. Somewhere there is a whole thread devoted to the topic. Forum members have devised ingenious ways of getting meds into ratties!
SQ has had success with taking the meds (mixed with something tasty) and wrapping it in a tiny piece of bread, then making a little ball. Most rats love bread.
My Caramel was skittish about any new food or meds at first. I finally found that she would take Doxycycline if I mixed it with some Lyle's Golden syrup (if you can't find it at a supermarket, Scoop n Save on Prospect Street is a good place to find it) and Strawberry Nesquick. The first couple of times I threw in a couple of peas to entice her, another time I put tiny pieces of cooked spaghettini. She is now OK with taking her meds. Another favourite med-disguiser for my rats is some mashed up banana with a bit of olive oil and something sweet & some baby cereal. I make up a few days' worth to keep in the frig for a quick addition to the meds.
Another hint: if you are compounding your own meds from crushed tablets, it helps to use something sweet for the liquid. I have been using Rice Dream, sometimes with a bit of Strawberry Nesquick added. I measure a suitable amount of this sweet liquid to add to the crushed medication.
Good luck!
