Diaper rash creams/ointments such as Desitin/A&D ointment have a very low level of toxicity contrary to warning labels on the product. Here again, this product usually only causes oral/stomach upset.
If it does present some stomach upset, you should talk with your vet about using a dose of immodium to control diarrhea and vomiting.
Most of the ingredients in this product are harmless. It's a lot of oils, wax, fragrance and a little lanolin and petrolium jelly (petrolatum).
Let me know if you still have questions.