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Fact Sheet:
Animal
Blood Types
Groups in Dogs
Currently, eight to twelve or more canine
blood groups are recognized, depending on which studies one
consults. In all cases, these various blood groups are organized
and categorized under the DEA system. The acronym DEA stands
for Dog Erythrocyte Antigen. Blood groupings, or blood types,
among dogs are specified by the letters DEA, followed by some
number(s) denoting which DEA system antigens are present on
the red blood cells of the dog in question.
Table 1. Eight
of the most common canine blood types and their approximate
incidence
in the United States.
Canine Blood Type Old Nomenclature Approx. Incidence
DEA 1.1 A1 40%
DEA 1.2 A2 20
DEA 3 B 5
DEA 4 C 98
DEA 5 D 25
DEA 6 F 98
DEA 7 Tr 45
DEA 8 He 40
For all canine blood group systems other
than DEA 1, the red blood cells from a dog can be either positive
or negative for that blood type. For example, a dog could
be DEA 3 positive or DEA 3 negative. The DEA 1 system is different.
It appears to have three separate subgroups: DEA 1.1 (also
known as A1) , DEA 1.2 (also known as A2) and DEA 1.3 (also
known as A3). A dog's red blood cells can be DEA 1.1 positive
or negative. Further, DEA 1.1 negative cells can be DEA 1.2
positive or negative.
Cross
matching and Transfusions in Dogs
In contrast to human beings and domestic
cats, dogs do not seem to have any naturally occurring antibodies
to other blood types. This has several important clinical
implications:
Blood cross matching, which is performed
to detect antibodies in the recipients blood to antigens in
the donor's blood, is less important in the dog, and may not
have to be done at all if the recipient dog has never received
a transfusion before (which frequently is the case).
An initial blood transfusion into a dog that has never before
received a transfusion is unlikely to cause a transfusion
reaction.
Antibodies to foreign blood groups may develop in a dog within
days of receiving a transfusion. So, if a dog has received
a transfusion before, it should be cross matched to insure
blood compatibility before receiving a second or subsequent
blood transfusion.
In the veterinary literature, most of
the emphasis on canine blood typing is placed on the blood
groups DEA 1.1 and DEA 1.2. Evidently, these are the two most
antigenic blood groups among dogs. Since DEA 1.1 is the single
most antigenic blood group, most veterinarians recommend that
DEA 1.1 positive dogs be avoided as general use blood donors.
Note, however, that DEA 1.1 positive dogs can donate to other
DEA 1.1 positive dogs with no problem. DEA1.1 negative and
DEA 1.2 negative dogs are often referred to as “universal
donors.”
Blood
Groups in Cats
Domestic cats have a two antigen
blood group system which yields three possible blood types
for a cat: A, B, or less commonly, AB. The majority of domestic
cats in the United States have type A blood - almost 99% of
domestic short hair cats in the USA have type A blood. These
percentages vary from country to country however, and probably
from region to region within a country as well.
Cat breeds other than the domestic
short hair have a much higher occurrence of Type B blood.
As the popularity of purebred cats increases, it seems likely
that the ratio of cats with Type B blood will also increase.
Cross
matching and Transfusions in Cats
There is no universal donor
blood type in felines. However, a cat receiving even a very
small amount of the wrong blood type can be seriously harmed
if that cat if it is already sensitized to that foreign blood
type. This can be of particular importance to British Short
hair, Cornish Rex, and Devon Rex cats, where the percentage
of Type B cats is much higher (about 50%). The Abyssinian,
Himalayan, Japanese Bobtail, Persian, Somali, and Sphinx breeds
also have a significant percentage of type B blood individuals.
If a type B queen (mother cat)
gives birth to type A kittens, severe reactions can occur
in the kittens. Type B cats have strong antibodies against
Type A blood. These antibodies are passed in the milk which
is very bad for any kittens that are type A. Since type A
is the dominant blood type, this means that most of the kittens
born will be type A when a type A father breeds with a type
B mother. Neonatal isoerythrolysis -destruction of the kitten’s
red blood cells by the antibodies in the mother’s milk- is
very likely to occur. In the breeds in which significant percentages
of type B blood occur, it is wise to know in advance what
the blood types of prospective parents are.
Blood Groups in Other
Animal Species
The blood group systems of companion
birds, reptiles, small mammals such as rabbits and ferrets
have not been extensively studied and their clinical significance
remains unknown.
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