Dogs are always pups

For some dogs never grow up and we have plenty of shredded evidence. I bought Bob a soft rug . It lasted two days, so I resorted to making dog duvets for him from old (washed) duvets. 

Now I don’t know what to try next, as you can see she (Ellie) shreds everything. And  Bob? He patiently waits to see if he will be left with anything to lie on.