Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to recognize poisoning in dogs [title] Look in your dog's mouth. [step] Your dog's gums and tongue should be pale to medium pink. If your dog naturally has black gums, look at its tongue.

Ending1: If the gums or tongue are blue, purple, white, brick colored or extremely bright red, seek veterinary medical attention immediately. This means that something is impeding the flow of blood throughout your dog's body. Ending2: If its mouth and tongue are white, wash your hands and see if any food leftover has come onto them. [title] Check to see whether your dog has a warm or cool environment. Ending3: When you see it, it's breathing heavily and displaying food-like lethargy. If the tongue is bright red in color, it may be poisoning your dog. Ending4: If its gums do not give two large enough turns, or if it fails to spit, it may have ingested a piece of leather. In this scenario, or for other reason, your dog may choke on liquid.

Answer format: ending1/ending2/ending3/ending4