Immunoglobulin is given in severe cases of dog bite which in cases like multiple deep bites, muscle evulsion.  It is not necessary for each n every time. But it is the vaccination ARV needed after bite. Its doses is on discrimination of treating doctor. Usual doses will be on day 0; day3; day7; day 28. But for a small Nick's or licking first 1 r 2 doses r enough. Based on severity of wound. And finally immunoglobulin is a antibody which we r supplying externally in severe cases as our own body may take some time to produce antibodies and these immunoglobulin fill those gaps