The Case of a "Bloody" MysteryIn an old issue of Corgi Quarterly (autumn 1993) there was an interesting article by Patsy Wallace-Jones, California.
One of her bitches was mated five times.
- The first breeding to Stud A produced nine live pups.
- The second breeding to Stud B produced no pups.
- The third breeding to Stud B produced three stillborns.
- The fourth breeding to Stud C produced two live and two stillborns.
- The fifth breeding to Stud D produced three live and two stillborns. A sonogram three days before whelping showed five live pups. The two pups that survived the whelping faded and died at eight days of age. Result - no survivors.
During the course of these pregnancies, many vets were consulted to determine the probable cause of puppy mortality. Was it dog food additives? Was it poisonous yard sprays? Was it contaminated water? Was it thyroid problems? Was it another autoimmune problem? Was it a low-grade bacterial infection that wasn't showing in the blood workup? With four different studs involved, it had to be the bitch - but why?
Through pure chance the unfortunate breeder made contact with Dr. Jean Dodds of Hemopet in California. Actually the intent was to thoroughly check the autoimmune system. After a discussion of the bitch's whelping history, Dr. Dodds said that the cause could be an incompatibility of blood groups, akin to the Rhesus system in humans.
There are 8 major blood groups in the dog, labeled as DEA (dog erythrocyte antigen) 1 to 8. Clinically the most antigenic blood type is DEA 1.1. It is important to note that while cats always have natural antigens against another blood group (a cat with blood type A has always antigens against blood type B and vice versa) this is not the case in dogs.
Dr Jean Doods' personal clinical experience, which was shared by her long time friend and late colleague, Dr. Robert Bull, indicated that incompatible matings between DEA 1 negative dams and DEA 1 positive sires led to hemolytic disease of the newborn pups after a second or subsequent blood type incompatible mating of the sensitized DEA 1 negative dam by mating with a DEA 1 positive sire. They wrote about these clinical cases in the 1970s.
And indeed, the bitch's blood tested DEA 1.1 negative, which confirmed Dr. Dodd's suspicions that the bitch's problems with dead and fading puppies in litters 2 through 5 were caused by blood group incompatibility. Three weeks after whelping, the bitch still displayed anti-red blood cell antibody activity presumably from the recent pregnancy from a positive male. The high titer probably indicates that she had been previously sensitized by earlier matings and that with each subsequent litter, this sensitization has resulted in hemolytic disease of the fetuses and newborns. Her health profile indicated no metabolic or other abnormality that would account for the puppy deaths.
There is, however, some controversy on this subject. According to an article from 2009 written by veterinary hematology colleagues of Dr Dodds naturally occurring hemolytic disease of newborn puppies only occurs when their dam has previously been sensitized by a DEA -1 incompatible blood transfusion rather than from sensitization by a prior DEA 1 blood group incompatible mating. Blais M-C, Rozanski EA, Hale AS, Shaw SP, Cotter SM. Lack of evidence of pregnancy-induced alloantibodies in dogs. J Vet Int Med 23:462-465, 2009.
As mentioned above, dogs, contrary to cats, have no naturally occuring antibody against other blood types and therefore first-time transfusion reactions do not occur. However, once sensitized by a previous transfusion from an incompatible donor subsequent incompatible transfusion can result in severe hemolytic reactions.
Experiments have also shown that neonatal isoerythrolysis in DEA 1.1 pups can be caused when a DEA 1.1 negative bitch is sensitized by transfusion with DEA 1.1 positive blood followed by a mating to a DEA 1.1 positive sire.
In case of an emergency it is therefore important to know that the donor is DEA 1.1-negative, as only the blood of a negative donor can be universally used without any complications.
With a simple test vets can determine whether a dog is DEA 1.1 positive or negative.
An ideal blood donor is a friendly, healthy, clinically normal animal that is not pregnant or has not produced a litter if an unspayed bitch. Donors should be vaccinated (although not within 10-14 days before donation) and free of infections and parasites, especially blood borne disease.