The concept of
hybrid vigor assumes that a crossbred animal (and
this term is most often used in discussing dogs)
will be healthier than a purebred. In
reality, this is often false.
In order to be a
hybrid, an animal must be the product of two
different species: donkey and a horse, offspring
is a mule; lion (m) and a tiger (f), offspring is
a liger; tiger (m) and lion (f), offspring is a
tigon; wolf and domestic dog, offspring is called
a wolf hybrid. Remember high school Biology,
animal classification: Kingdom, Phylum, Class,
Order, Family, Genus, and Species?
Each animal in
the crosses mentioned share the same Family (Equus,
Felis, Canis) but are different species.
The offspring are hybrids. Domestic dogs are
the same species familiaris. When you cross
breed domestic dogs (Canis familiaris ),
you are within the same species; therefore, not
creating a hybrid.
Hybrids are not
problem free. In Ligers, no fertile male has
ever been found and necropsies have proven
sterility in them. Other issues in ligers
and tigons: ligers may be prone to gigantism and
tigons may be prone to dwarfism. Both
hybridizations have shown an increase in cancer
rates and decrease in lifespan. (Tiger Territory,
M. Annabell, 2001). In wolf/dog hybrids,
there are often behavioral issues. The
domestic dog differs greatly in behavior from a
wolf. Dogs were bred to be cooperative with
humans while wolves fear humans and try to avoid
us.
Even domestic Wolves are far different
from dog in terms of behavior. Dogs often
accept leadership happily while adult wolves will
fight for leadership within the pack. The
wolf/dog hybrid can be a time bomb temperamentally
when they hit full maturity. Wolves also
differ from dogs in other ways including: skull
structure, nutritional needs, estrus cycles, etc.
(Canine Hybrid Issues Surrounding the Wolf Dog ,
M. Sloan, J. Moore Porter, 2001)
Returning to the domestic dog: Canis familiaris.
A breed is not a separate species, it is just a
set of genes specifically bred to exhibit certain
traits like the coat an Old English Sheepdog has
or the build of a Rottweiler. With C. Familiaris,
we just took traits in dogs of the same species
and developed them to various breeds.
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