How to prevent feline upper respiratory illness<br>Get your cat vaccinated. Vaccination against cat flu is considered an essential vaccine. The flu vaccine needs to be given regularly and it comes in a variety of types (modified live, modified live intranasal, killed vaccine) which determines how often the vaccine needs to be given.
The word "feline" contains the letter "g". 
It is definitely incorrect because the word "feline" when carefully examined from left to right clearly does not have the letter "g". The system got it wrong because it doesn't understand spelling words from the context. 