I have a tenant that is the only one in the apartment complex with pets.

I only require it if they have a pet to help cover any potential liability that may cause.

Would he be willing to get rid of cat, if not pay pet deposit. 

If you want proof, just look at the Slinkey, the Hoola-Hoop, and my favorite...the Pet Rock.

I did the monthly pet fee/rent.

If you're in your 20s and have not started collecting kids, pets, and commitments, work your a$$ off, delay gratification, and set yourself up for the future.

@Blake Valdez For me personally I like single-family homes for rentals as the rental pool is a bit larger and you can make more allowing pets which is another topic to debate if it's worth it.

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

We also have a "no pet" policy were a couple tenants brought in pets that caused issues. 

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.