Liquid Calcium and Vitamin D3 supplement for birds. Calcivet is also suitable for small animals. It is in a palatable syrup that can be diluted in drinking water or administered directly to the bird.When used as directed Calcivet will not only supply Calcium but will supplement the birds Vitamin D levels.. These elements are necessary for the production of egg shells and strong bones.Calcivet can be used in egg bound birds to aid in the expulsion of the egg and in cases of soft shelled eggs to deliver calcium to the shell glad. Calcivet should be administered to breeding birds for approximately one month prior to egg laying and through the chick rearing period. Calcivet can be used with Aviclens, Soluvet, Coccivet but not Psittavet.