(written from a Production point of view)
According to the script of "Shakaar", the USS Garuda was the ship on which Syvar served as science officer and which briefly docked at Deep Space 9. However, there were no references to the ship in the final episode.
The script called for the Garuda to be represented by stock footage of the "Prometheus-class" starship from "Second Sight". However this is likely an error, as there are no Prometheus-class ships in that episode, only a Nebula-class ship called the Prometheus.
The pronunciation for Garuda was "GUH-roo-duh". (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library)