Dog ate sponge, whole.

[felinedogs]

My Newfoundland dog stole a sponge out of the kitchen sink yesterday at noon and as far as I can see he ate it whole, did not chew it just swallowed it. The sponge was 4 1/2" long, 3" wide and 1/4 thick. He is eating and drinking normally, no vomiting, no diarrhea and is still carrying on like a fool.
Any suggestions would be very greatly appreciated. He has eaten a lot of odd things including paper towels, the cats toy mice, anything that isn't nailed down and has had no problems but a sponge is a concern.
Thank you.