You can fill it with any safe food for your dog (in healthy amounts). However, take into account that you will have to substract the calories from its daily intake.
If you use animal feed:
1- Mix the feed with peanut butter, cottage cheese, banana mash, natural greek iogurt, or any other healthy food that can be served as a paste to keep the feed in place.
2- Cover the small hole with peanut butter. Fill it with some feed and pour melted peanut butter. Add more feed and more melted butter until it is full. Freeze it solid.
3- Put the feed, a bit of water to make it stick to the walls and cover it with a spoon of peanut butter so it doesn’t leave the toy.
4- Wet the feed with water or chicken broth (better to dilute it if it contains high amounts of salt) and leave it swell inside the toy. Seal it with peanut butter or another product and freeze it solid. Take into account that it can wet the floor unce it unfreezes.
If you use wet food:
Canned dog food is one of the best options to fill your toy.
Just remember you will have to substract those extra calorties from its daily intake!
Put the wet food or paste into the toy and freeze it. Just that easy! (If you prefer it or the food is not that dense, you can seal it with peanut butter or another product).
Canned food can be expensive, that’s why we recommend to mix it with animal feed.
If you use liquids:
You can fill your RUCAN toy with liquid and freeze it to favor your dog’s hydration.
Cover the smaller hole with a piece of cold peanut butter. Place the toy in a cup with its biggest opening facing upwards. Fill it with the chosen liquid (water, saltless broth, coconut water, carrot or apple juice, etc…) and put the cup in the freezer until its frozen solid.
Give it to your pet at the exterior, given that the floor will end up wet.
TIP:
Invest in more that one toy. This way you won’t have to prepare the filling that often and you will always have some frozen for emergencies.