Anyone who’s been cheered up by their pup after a hard day knows the value of a canine companion. But a dog’s ability to do good isn’t limited to their own human family. Depending on their health, age, and size, your dog may be able to donate blood and save the lives of their fellow pets.

Just like humans, dogs can sustain traumatic injuries or undergo procedures that require blood transfusions. Dogs are also similar to people in that they have different blood types. A dog's blood type indicates the antigens its blood contains, and the seven types recognized by the dog erythrocyte antigen (DEA) system are type 1.1, 1.2, 1.3, 3, 4, 5, and 7. Blood type doesn’t matter for a dog’s first transfusion, but for subsequent transfusions, the donor’s blood type must be compatible with the patient’s.

There are canine blood banks across the country that supply animal hospitals with blood in emergency situations. Some centers rely on mobile blood drives or on-site kennels (usually housing dogs that would otherwise be euthanized) for blood donations. Pet owners can reach out to these blood banks directly or contact their local veterinarian, veterinary school, or emergency animal clinic to ask about having their dog’s blood donated.

Dogs must meet a list of criteria to be eligible to donate blood. Typically, canine donors should be 1 to 7 years old, weigh at least 50 pounds, and be calm and friendly enough to handle having their blood drawn. Health is a major consideration, and the donating dog shouldn’t be taking any medication other than the standard parasite preventatives. A veterinarian will need to test your dog's blood—both for blood type and potential blood-borne diseases—before they’re cleared to donate. The actual donation process lasts 15 and 30 minutes. Blood is taken from their neck’s jugular vein, and though they aren’t given anesthesia, dogs receive lots of pets and treats for being good boys and girls.

Most dogs don’t like going to the vet, but signing them up to donate blood has a big impact. Your pet’s donation could save the lives of up to four other dogs.