We very often top with raw eggs. In winter we soak the biscuits in boiling water and give them to them slightly warm which they have always loved. Left overs from dinner are always a hit.

Sardines or salmon even mackerel i get the small tins from the tuna isle my dogs get them twice a week and love it !

Yep, sardines are great, preferably in spring water. But one in olive oil can be good too. Also greek yoghurt is good

I like to add sardines weekly (in springwater), an egg, probiotic yoghurt, blueberries, strawberries and watermelon (summer) to add something different to their diets. Even home brand tinned oysters