Animal Aid is campaigning against charities such as Oxfam and Send A Cow, which offer livestock as gifts for people in developing countries.
Andrew Tyler, the charity's director, said the gift schemes were a "cynical marketing ploy to convince people that there is a quick fix to third world poverty".
The World Land Trust has also approached Oxfam to express its concerns.
"Grazing livestock is one of the main causes of third world poverty," said John Burton, chief executive of the trust. "They eat everything in sight, causing catastrophic desertification."
An Oxfam spokesman denied that the animals cause desertification and said that they were a "living bank account" for poor families.
Martin Geake, chief executive of Send a Cow, said: "Our approach includes support to ensure that livestock is not a burden."