Ostopet is calcium. An excess of calcium floating in the blood can be harmful. Liv52 is given for a weak liver. I would say that before you add any supplements to its diet, get a blood test to check for any deficiencies. A single boiled egg given at night will do no harm even in summers. An egg has concentration of amino acids, important minerals including magnesium and zinc, vitamin A and B1 & B6 and vitamin D but no vitamin C as canines produce them. The white of a boiled egg is a good source of protein. However, the boiled egg should not be over-boiled, better to do it at home. An egg may be acidic in summers. Therefore, add curd or butter milk to the diet along with paneer. Also add full grain chapattis to the diet for fiber.