Re: I think my boyfriend is allergic to cats and some dogs.
Most animal allergies can be relieved for 24 hours with a dose of loratadine (generic). This is the drug that was origianlly marketed as "Claritin", but it is now sold over the counter, and quite cheaply. Just go to the drugstore to the allergies isle and pick up a pack labeled "loratadine". Jut make sure you get the plain loratadine, and not the stuff mixed with other drugs for treating bad colds.
Loratadine needs to be taken once ever 24 hours. If it doesn't work for you boyfriend, then he might want to consider removing the animals from his home.