The mattress arrived with a yellow tint/stain to half of it and it appears something was spilt on it? There is no odor and it doesn’t appear to be used so I assume it is fine. The cover that goes on top of the mattress does not have a stain on it. 
Our dogs lay on it so I assume they like it but we mainly got it for asthetic reasons because our dogs will lay on just about anything! 

Overall, with the price I was disappointed that the mattress arrived in that condition.