Aloe vera (Aloe barbadensis) is a succulent that stores water in its leaves and prefers to dry out fully between waterings. Water Aloe vera deeply but infrequently, allowing the top two inches of soil to become completely dry first. In spring and summer this usually means watering Aloe vera about every two to three weeks, while in winter the interval often stretches to once a month or less. Overwatering is the most common cause of failure with Aloe vera, so when in doubt, wait a few more days before watering. Always discard any water that collects in the saucer so that the roots of your Aloe vera never sit in moisture.
Aloe vera grows best in bright light and tolerates several hours of direct sun once acclimated. Place Aloe vera near a south- or west-facing window where it receives at least six hours of strong light each day. A plant kept in low light will stretch and grow pale, so move a leggy Aloe vera gradually toward a brighter spot to avoid leaf scorch. If you move Aloe vera outdoors for summer, increase sun exposure slowly over one to two weeks. Leaves that turn reddish-brown often indicate that the Aloe vera is receiving more intense sun than it has adjusted to.
The cited reference lists Aloe vera (Aloe barbadensis) as toxic to cats and dogs; ingestion can cause vomiting, diarrhea, lethargy, and loss of appetite. The saponins and anthraquinones in the leaf are the compounds the cited reference identifies as responsible for these effects in cats and dogs. Keep Aloe vera out of reach of pets, and if you suspect a cat or dog has chewed the plant, contact a veterinarian or a poison-control line rather than waiting for symptoms. The cited reference does not characterize any amount of Aloe vera as without risk to cats and dogs. Because this is a toxicity question, treat the cited reference as the only authority on what Aloe vera does to pets.
Aloe vera needs a fast-draining mix, so use a cactus or succulent potting blend amended with extra perlite or coarse sand. Plant Aloe vera in a container with drainage holes, since standing water at the roots quickly leads to rot. Repot Aloe vera every two to three years, or sooner when offsets crowd the pot or roots emerge from the drainage holes. Choose a pot only one size larger, because an oversized container holds excess moisture around the roots of the Aloe vera. After repotting, wait about a week before watering the Aloe vera so that any disturbed roots can heal.
Soft, mushy, or translucent leaves on an Aloe vera usually signal overwatering and the onset of root rot. Thin, curling leaves instead point to underwatering, so check whether the Aloe vera has gone too long without a drink. Brown, crispy leaf tips on Aloe vera can follow sudden exposure to intense direct sun before the plant has acclimated. A pale, stretched, and floppy Aloe vera is reaching for more light and should be moved gradually to a brighter location. If the base of the Aloe vera turns dark and soft, remove the plant, cut away rotted tissue, and repot it in fresh dry succulent mix.