English and Armenian share a very similar name for cats: the Armenian form is կատու (Western Armenian [W.A.] gadu [gadoo]; Eastern Armenian [E.A.], katu [katoo]). Interestingly, the former pronunciation is closer to Italian gatto and Spanish gato, while the latter mirrors English cat.
Where did the cat and its names come from? The word appears in most Indo-European languages, but also in Afro-Asiatic (Semitic and African), Turkic, and Caucasian languages. Linguists use the term “wanderword” to designate items and names that have gone together around the world and left their trace everywhere with an unclear origin.
As it happens with any other domestic animal, wildcats came first. Their origin seems to have been in Africa. Therefore, the ultimate source for English cat and other worldwide names of this feline should be in the same continent. English cat is derived from Latin cattus (“domestic cat”), indeed, but the Latin term appears to have entered the Roman Empire from North Africa, where we have words meaning “wildcat”: Late Egyptian čaute (the feminine form of čaus “jungle cat, African wildcat”), Nubian (spoken on the border of Egypt and Sudan) kadís, and Berber (spoken in Morocco) kaddîska.
However, the source of the Armenian word gadoo/katoo cannot be Latin cattus, despite the close resemblance. Why? Latin was in linguistic and political decadence by 500 A.D., after the fall of the Western Roman Empire, and, interestingly, the word կատու (gadoo) did not exist by then.
In the Golden Age of Armenian written literature (fifth century A.D.), cats were not called կատու, but կուզ (Classical/E.A. kuz, W.A. guz [gooz]).(*) This Armenian word, now out of use, came from an Iranian reconstructed form *kuz, which has survived in Kurdish kuze “cat.” That old Armenian gooz, in its turn, has survived in the name of a wild feline, the lynx: կզաքիս (gezakis).
Gadoo entered the Armenian language after the fifth century. Where did it come from? It has been suggested that the source should have been Syriac, a major literary language throughout the Middle East from the 4th to the 8th centuries, quite influential in the first centuries of Armenian literature. Armenian must have borrowed the name from qattu, the Syriac “cat,” and, afterwards, loaned it to Georgian (katuni) and other Caucasian languages.
If you were wondering about that, Armenian and English cats also share their colloquial name: puss has its counterpart in Armenian փիսիկ (pisig); compare also Romanian pisica. Probably all of them have come from the sound we make to attract these furry pets.
*) Knowledgeable people will notice that gooz is the same as the modern Armenian word for “hump,” but has nothing to do with it, except that Armenian կուզ (gooz) is a late medieval addition derived from Iranian kuz “hump.”