cross over trial

Good day

I would like some imput on what whould be the most appropriate test to do in this case:

I have a cross over trial in which two products administered to an animal is deemed accepted (retains the product in mouth) or refused (animal drops the product out of mouth). Half of the animals were dosed with product 1 the first week, and the other half with product 2. The next week the groups were crossed over. I wish to determine whether or not there is a significant difference in acceptability between the two products.

Because both products are tested on the same animals, the data are paired and thus a chi squared test is inappropriate. Furthermore, the expected frequencies of some cells are less than 5. I read up that Garts test might be a possibility but I do not know how to run this test in my stats program (SPSS). What about Fisher's exact test? Any suggestions?