sf if you bleach it real good with straight bleach 2 or 3 times it may be aight. But wood, especially plywood can be hard to sterilize completely. A buddy of mine lost 2 litters in a row that he tried to raise in a plywood brooder up off the ground. Both litters got parvo and died even after it had been thoroughly bleached.. He asked me what I thought he should do about it so I went by his house one evening and set it on fire. Not one pup has got parvo over there since..