Dog food (Kenilworth CV8)

I have a 12 Kg bag of Hills Metabolic Prescription diet dog food biscuits. I opened this 10 days ago and unfortunately I have no use for it now as I had to put my dog to sleep yesterday. The Dogs trust and food banks will not take unopened bags of food and it seems such as waste to bin it. I reckon there is more than 11Kg in the bag. I live in Kenilworth.