The incident you describe is brought about after the giant farmer sells Gulliver to the queen of Brobdingnag for a thousand pieces of gold. Gulliver, for his part, is quite pleased to now be in the service of the Queen and the ladies; he requests that the farmer's nine year old daughter, Glumdalclitch, who had ever tended to his needs with affection and kindness, to continue as his nurse and instructor at court.
However, life at court proves almost as challenging as life with the farmer; Gulliver has to contend with many difficulties due to his size. Below, he describes one of the most distressing situations he has ever encountered in the royal garden.
When Glumdalclitch sets him down on the ground one day and wanders off with her governess, a white spaniel belonging to one of the chief gardeners picks Gulliver up, carries him in its mouth, and proudly brings him to its master. Usually, no dogs are allowed in the royal gardens; the little, white spaniel appears to have gotten in by accident.
The dog is so careful and gentle that Gulliver is not hurt. However, this innocent action by the dog puts the gardener into a great fright. After ascertaining that Gulliver has not been harmed, the gardener hurriedly returns him to his nurse, Glumdalclitch.
Meanwhile, Glumdalclitch is anxious when she finds Gulliver gone; she calls his name, but there is no answer. When the gardener returns with Gulliver, she scolds the gardener for letting his dog anywhere near Gulliver. However, the incident is never reported at court; Glumdalclitch is afraid of the queen's anger, and Gulliver isn't too anxious to be known as the little splacnuck who was carried about in the mouth of a spaniel.