medication -- n. a substance used in treating disease or relieving pain
lungs – n. organs that people and animals use to breathe air
resistant – adj. not affected or harmed by something
lethargic – adj. feeling a lack of energy or a lack of interest in doing things
veterinarian – n. a person who is trained to give medical care and treatment to animals
tremendously – adv. very large or great
optimistic – adj. expecting good things to happen
chronic – adj. continuing or occurring again and again for a long time
expectancy – n. a feeling that something is going to happen
species – n. a group of animals or plants that are similar and can produce young animals or plants
sanctuary – n. a place where animals can be protected in a natural setting