My cat has been on Royal Canin Feline Urinary SO dry food for a couple of years. However recently Royal Canin changed the formula for that food and it is making cats puke. All reviews starting January 2020 have pet owners reporting this problem.
I came across "Purina Pro Plan Focus Urinary Tract Health Formula Adult Dry Cat Food" which does not require a prescription. I would like to know if it is comparable to Royal Canin Urinary SO and if it can be safely substituted?