There are many stiffener products on the market, besides buckram. You can even use liquid stiffener in the spray or paint on types. To find the product that will work best for you, ask at your local...
For a short trip, like to a vets office - try a carboard box with a few small holes for air or even a suitcase with the zipper open just enough to allow air. Also, it may seem cruel, but a fabric bag...
It depends on what you are using it for. If you are using it for cooking, as in frying something, you could substitute any vegetable oil, you could substitute lard, if you really wanted to be...