This is the 716th most frequent Swedish word.
föddes
"Föddes" means "was born."
The word 'föddes' here is in the past tense and is a passive form of the verb 'föda', indicating the event of being born occurring to the subject.
Jag föddes i Stockholm.
I was born in Stockholm.
In this question, 'föddes' is used in an interrogative sentence, again showing its function as the passive past tense form of the verb 'föda'.
När var du föddes?
When were you born?
In this context, 'föddes' represents the past event of the dog being born, emphasizing the time of the event.