Οχι, ειναι μελος της οικογενειας!
would it is only a dog also be correct?
Yes, and I see it as an accepted translation. Did you try it and have it rejected? Please let me know.
Yes it was rejected
Είναι μόνο ένας σκύλος. and Είναι απλώς ένας σκύλος.
What's the difference?
"μόνο" means "only" while απλώς is closer to "simply" but both are accepted as translations in this context.
Thanks for the quick answer :D