TS Eliot and the Russian author of the poem on the reverse of the card have similar ideas on the addressing of a cat.
TS Eliot says:
With cats, some say one rule is true
Don't speak 'til you are spoken to
Myself I do not hold with that
I say you should ad-dress a cat
But always bear in mind that he
You bow, and taking off your hat
Ad-dress him in this form: "O' cat!"
The Russian poet, Boris Zachoder, says something very similar:
The most important thing
Don't even try
To be on first name terms with a CAT (tutoyer in French, duzen in German)
Because even the smallest
CAT is a CAT
As lovely as the card is, I find the text interesting because it's so difficult to translate into English. There are verbs in both French and German to describe using the familiar "you" but of course no such verbs exist in English. I guess there is an equivalent in Spanish but I'm sorry to say I don't know how many other languages have both forma and informal "you".