It is permissible to offer one sheep or camel as Ud-hiyah on behalf of the deceased. Whoever says that a camel can only be offered on behalf of a group of people is wrong. On the other hand, the sheep is sufficient as an Ud-hiyah for one person who may include his household in the reward.
The camel is sufficient for one to seven people who share its price. One seventh of it is regarded an independent sacrifice for each of the seven people. The same applies to cows.May Allah grant us success. May peace and blessings of Allah be upon our Prophet Muhammad, his family and Companions!