Tekst oryginalny - Łacina - lupus non est lupum

This is not correct Latin. If it is Latin it should be "Lupus non est lupus", or else lupum could be a word in another language.

Esta frase es un ejemplo más del genitivo plural que se suele usar en poesía en función de la métrica. Así, con "lupus no est lupum" se quiere decir que el lobo no pertenece a otros lobos, que es dueño de sí mismo.

Después de lo que me dijo, espero que apple no se tome a mal esta pequeña corrección.

Il genitivo plurale di lupus è luporum, caro il mio sapientone.

Es un genitivo poético, "lupûm" (con la "u" bien larga), que surge de asimilar la segunda declinación a la cuarta, es una licencia poética, sólo eso.

Beh, allora mi dovresti anche dire di che poeta si tratta, perché a me non risulta.

No necesariamente pertenece a una poesía, es tan sólo una licencia poética, puede ser una frase anónima (un dicho, un probervio, un refrán...)

Comoda la licenza poetica......

cara apple, por favor, si no estás convencida, fijate aquí.

Please, apple, translate this proverb into Italian - io non sono bravo. Bacio!

Sorry, Pirulito, but I'm not persuaded at all. Your link didn't solve my doubts. First of all, you said that it was made similar to 4th declination, but 4th declination should have two u (-uum, and the Latins didn't use the circumflex accent, as far as I know.)
Second: why on earth such a poetic licence should be used, if it is not from a poem or from a reckoned proverb (not the fake latin proverbs that sometimes appear on cucumis)?
I searched on google and didn't find this text in any serious site about Latin proverbs and mottos.
Anyway, I'm not the Latin expert: Xini will decide what to do.

Simply, the translator may explain the situation in the notes (in Italian).
How the original text should be,
The correct declination,
The poetic license conjecture
and so on.

Por supuesto que el circunflejo no existe en latín, se suele usar para indicar una contracción (ûm = uum)

The girl who proposed the text seems not to speak Italian, although she lives in Italy. Her main language is Hindi and she can read only Latin and Hindi, if her profile tells the truth.
Strange, isn'it???
Xini, since Latin is your native language, you should translate the text and write an explication note in Latin.
heheheheheh
Xini, adesso è al posto giusto, non ti vorrai mica tirare indietro?

So what do we do with it ? Remove ? Meaningonly ?

I've put a note and changed to meaning only.

And about the meaning: pirulito said it should mean: a wolf is not of the other wolves (i.e. a wolf is his own master). On the contrary, I think that wolves are maybe the most gregarious mammals in the world (and that's the reason of the special relation between man and dog, that the man is felt by his dog as his "leader of the herd". )