The carrier you choose for your cat/rabbit/rat makes a big difference in how pleasant your trip to the veterinarian will be. We still see cats brought in to us in cardboard boxes, pillowcases, and those old semi-homemade plywood and hardware cloth jobs that weigh a ton. Some people load several cats into a large dog crate and then struggle to get it out of the car, into the clinic, down the hall, and into the exam room, where it takes up the entire floor. Cats brought in cardboard boxes have been known to escape onto the street and run away.
Here's how you can avoid this sort of misery:
The PetMate Two Door Deluxe cat carrier is versatile, and in my experience the very best carrier on the market for cats. The top door allows us to lift kitty out easily, or even administer some treatments right in the box. The front door allows the cat to walk right in or out if it is so inclined. It comes in two or three sizes and is the perfect solution for transporting your cat.
(For the record, I have no financial interest in making this recommendation. I do own one, and need to get another! They can be found at Petco and PetSmart, and probably other larger pet stores)
Rabbits may be safely transported in the same type of carrier.
Rats and other pocket pets should not be brought to the office in their housing structure. Please place them in a secure box with air holes, or one of the specially designed pocket pet totes made of clear plastic available at any pet store.
Oh, and last but not least, remember to put a folded terrycloth towel in the bottom of the cat's carrier to absorb and urine in case of accident, and put a paper towel or two in the bottom of the rat's tote.