What should I consider before allowing my pet to be a blood donor?

I can't speak for the USA but in the UK a key factor is the pet's weight, another is its age.

No pet is accepted as a donor if it weighs less than a critical value. For example a dog must be over 25kg, irrespective of breed.

For more details, many of which will be useful in the US, look at this.

For cats and dogs in Norway to donate blood the criteria are:

Cats

• Age 1-6 years old (must have started donating blood before the age of 4 years old).

• At least 5 kg body mass, but not overweight.

• Healthy and not using any medication (deworming and medication against parasites is OK).

• Preferably indoor cats only.

• Not have antibodies against FIP/FIV.

• Not pregnant or planning to have kittens.

• Vaccines need to be up to date, needs to be dewormed regularly.

Additional information: your cat will get a free yearly check-up, including bloodwork for the period it donates blood. The cat gives 40-50ml blood each time, is under anesthesia during this and will be kept at the clinic until awake.

Dogs

• Age 1-6 years old, healthy and fully vaccinated.

• Needs to be calm and well balanced.

• At least 27 kg body mass.

• Blood values (hematocrit) above 40%.

• Blood preferably type negative.

• Must not have been out of the country, not have had puppies.

• The dog must not have undergone a blood transfusion.

Additional information: the dog gives 450ml each time and it takes 5-10 minutes, with check-up it takes 30 minutes in total.

Sources for this information:

• in Norwegian: https://www.anicura.no/tjenester/blodgiving-hund/ they have clinics in ten countries;

• in English: https://www.anicuragroup.com/

For cats and dogs in Germany:

Animals can give blood in any animal clinic and at most vets, the conditions are:

General:

• up to date with vaccinations
• no worms
• checked for ticks
• no animals that take certain medication
• no animals from southern countries
• no animals that have been pregnant
• no animals that have received a blood donation

Dog:

• Age between 1 and 7

• weigh more than 25kg

• patient character, has to lie still for ca. 10 mins
• will donate 250-400ml

Cats:

• Age between 1 and 9

• weigh more than 4kg

• patient character, most cats receive a calming injection though if the owner agrees

• will donate 10ml per kg of weight

I think when choosing an emergency clinic, go for proximity first. If there are several close by it might depend on the time of the emergency. If they have blood at the given time or if a blood donor can come in. If you want to prepare choose a clinic and talk to them beforehand and also check out the blood type of your pet.

Sources:

Anicura Klinik - Blood donations

University Berlin - Blood donations