Dog blood banks are much like people blood banks. Donors are screened, the blood is typed, and sometimes there’s a shortage.

The U.S. typically faces dog blood shortage several times a year, says veterinarian Jean Dodds, who runs the Hemopet canine blood bank in Garden Grove, California.

"It happens nearly every holiday season and in summertime when epidemics of parvovirus occur," she told NPR.

The highly contagious parvovirus attacks a dog's cells, and blood transfusions are often necessary. Most of the time, dogs require donated blood for the same reasons people do: car accidents, anemia or because they're undergoing surgery.

While there’s no centralized canine blood bank for dogs, there are several independent blood banks located throughout the country, and veterinary schools often do their own blood banking.

Dodds helped start some of the first canine blood banks. She worked with animals with diseases like hemophilia, and during the early 1980s she ran New York’s human blood program, which made her realize that veterinary medicine could benefit from something similar.

Before dog blood banks existed, vets would simply call someone who owned a large dog and ask them for a donation. While this still happens today, especially in rural areas, Dodds says blood banks are better because they separate blood into plasma and red blood cells.

Packed red blood cells are used for treating trauma, as well as some cancers and autoimmune diseases. Plasma contains antibodies, which makes it useful in treating infectious diseases like parvovirus.

The shelf-life of frozen red blood cells is two months and about one year for plasma.

Doggy donors

An Edmonton, Alberta, police dog relaxes after donating blood. An Edmonton, Alberta, police dog relaxes after donating blood. (Photo: NAIT/flickr)

Not all dogs are fit to donate blood, and they must undergo a screening process to determine whether they are. The first criterion is temperament — dogs aren’t sedated when blood is taken, so they must be calm and relaxed.

Canine blood donors must also be healthy, under the age of 8 and weigh more than 50 pounds.

When a dog arrives to donate blood, its paw is pricked to make sure its red blood cell count is adequate to donate. If levels are acceptable, a small area of the dog’s neck is shaved and cleaned and the dog lies on a table to have blood collected through its jugular.

Throughout the procedure, the dog is cuddled and petted and fed treats. The collection process for a pint of blood takes about 20 minutes.

"You can't communicate with a dog on a verbal level. But if we get them to the point that they're happy and they know what we want from them and they understand, then they're more likely to donate over and over again," Rebecca Pearce, a phlebotomist at the Blue Ridge Veterinary Blood Bank in Purcellville, Virginia, told NPR.

After processing, a pint of dog blood could help two to four canines.

Doggy donors are advised to avoid strenuous activity for 24 to 48 hours after donating. Only on rare occasions will they require fluids.

In return for their donation, dogs are often compensated with food or medicine. At the University of Florida Small Animal Hospital in Gainesville, donors receive a year's supply of preventive medicines for heartworm, ticks and fleas — to protect the blood supply — plus a 40-pound bag of food and treats.

Some controversy brews

greyhounds in kennels at Texas blood bank A former employee at a Texas dog blood bank says these poorly cared-for greyhounds were waiting to have their blood drawn. (Photo: PETA)

However, not all canine donation experiences may be so positive. A Texas-based company came under scrutiny in September 2017 when a former employee snapped a photo of ill-cared-for greyhounds locked in kennels with open sores, curling nails and rotted teeth. People for the Ethical Treatment of Animals (PETA) urged the sheriff to seize the retired racers that were kept as blood donors at the Pet Blood Bank northwest of Austin. An investigation is underway, reports The Washington Post.

There are no federal standards for animal blood banks, with only California regulating operations and requiring yearly inspections. Because there are no best practices, different clinics and companies have different procedures.

Some use the "closed colony" model, which means dogs that are kept solely for blood-donor purposes, like animals kept at a vet school or in a vet clinic. Because their care and environment is controlled, they are healthy. But critics say they don't live a normal life.

On the other hand, donors who travel to come in may have questionable histories if their owners missed a preventative health care step somewhere along the way. And, if they travel too far to donate, that can be a stressor.

That's why some people are fans of mobile blood banks that travel around to take donations from volunteers.

“We don’t have a problem with greyhound blood donors. We have a problem with captive greyhound blood donors,” David Wolf, director of the National Greyhound Adoption Program, told the Post. He mentioned the University of Pennsylvania’s veterinary hospital for foregoing its colony of canine blood donors in favor of a bloodmobile-based program. “Having blood donors is wonderful as long as they go home and sleep on their soft bed.”

What about cats?

Feline blood banks also exist, but, as any cat owner will tell you, cats can be a little more difficult to deal with.

Luckily, cat blood is less in demand than dog blood, according to Dr. Kirsten Cooke, a clinical assistant professor of small animal medicine at the University of Florida. The veterinary school also has an in-house cat blood bank with 10 cats enrolled in the donation program.

But blood from man’s best friend might be also be able to help cats, according to a report from New Zealand.

In August, a cat named Rory ingested rat poison and went limp, so her owner rushed her to the local veterinarian. There wasn’t enough time to test for the cat’s blood type, so the vet took a chance and used blood from a black Labrador retriever.

A wrong match would’ve proved fatal, but the interspecies transfusion was a success and today Rory is alive and well.

"Rory is back to normal and we don't have a cat that barks or fetches the paper,” Kim Edwards, the cat’s owner, told AFP.

Learn more about Rory's rescue in the video below.

Editor's note: This story has been updated since it was originally published in September 2013.