Plants prepare their own food by a process called photosynthesis which involoves convertion of carbon dioxide and water into glucose, oxygen and water in the presence of sunlight. Chloroplasts are the sites of photosynthesis(sites of synthesis of food).
Plants are the producers and generally they never depend on other plants or animals for food.
But, animals are heterotrophs. They take food only from other organisms and never prepare food on their own.
Organisms which need to prepare food on their own only require chloroplasts(as choloroplasts are the sites of glucose synthesis)
Since, animals needn't prepare food on their own, they have got no cholorplasts.