This syndrome manifests itself by quite
specific characteristics. It is often quite easy to identify a
puppy/dog affected with this syndrome. Typically, MLS affected
beagles have short outer toes and they walk upright on their
front feet in what resembles a ballerina stance. Often all
four feet are affected. Affected beagles often have tighter
skin with limited “scruff”. Their bodies feel hard due to the
tight skin, tendons and muscles. They often appear very well
muscled. Their head shape is also notably different having a
flat skull, higher ear set, ear folds and slanted eyes. Tails
are often carried in a straight, stiff fashion and some
beagles have noticeable kinks in the tail as well. The
syndrome can be determined very early on at about 2 to 4 weeks
if you know what to look for.
is a picture of an entire litter at approximately 4 weeks
of age. There is little or no difference at a quick
glance. The MLS pups are the second one in the top row
and the first and third in the bottom row. Note--the MLS
pups have their tails stuck straight up in the air. You
can also see the stiff legs starting to really show in the
back legs, but front legs are still normal looking. You
can't see the high toes in the front, but they are easy to
see in the back legs.
The syndrome progressively gets worse until
about 1 year of age when the dog then stabilizes. It is also
important to note that there are varying degrees of
“affectedness” with many beagles and breeders should look at
any or all of the above indicators to assist in determining an
MLS diagnosis or a potential MLS carrier. Ear folds, high toes
or tight skin as a single trait does not automatically
indicate carrier or affected status. There have been dogs with
ear folds, high toes or tight skin that were not carriers.
Dogs with total normal appearance have been determined to be
carriers. The only way to determine normal or carrier status
is to TEST. Unless there are associated congenital or genetic
problems, these beagles will have a normal life span. A
genetic marker test has been developed and this
is available through the Veterinary Genetics Laboratory (VGL)
of the School of Veterinary Medicine at the University of
California, Davis. The DNA test is being offered at the very
reasonable cost of $50.
MLS is inherited as a recessive trait.
Current evidence suggests that dogs that have two copies of
the mutant gene are affected with MLS, though the severity of
clinical signs can be variable. Dogs inheriting only one copy
of the mutant gene can show subtle signs but do not appear to
have health-related defects. To the best available knowledge,
carriers cannot be identified based on their appearance. This
test determines whether dogs are normal (clear of the
mutation), carrier (have one mutant copy), and affected (have
two mutant copies).
N/N: Normal. The dog does not have
the MLS gene.
N/MLS: Carrier. The dog carries one copy of the MLS gene.
MLS/MLS: Affected. The dog has two copies of the MLS gene.
If a carrier dog (with a single mutant
copy of the gene) is used in a mating, an offspring from the
cross has a 50% chance of inheriting the mutation from this
parent. If two carriers are mated, 25% of the offspring in the
litter are expected to have MLS and another 50% of the puppies
are expected to be carriers. Mating two clear dogs will only
produce clear puppies, which need not be tested by DNA.
The links below will provide more
information, pictures and comments from owners of beagles
affected with MLS.
Chinese Beagle Syndrome Revisited-An Article in
the March 2005 Show Beagle Quarterly
Case Study-Printed in the SBQ March 2005
Pictures of Case Study Beagle
from Owners of beagles with CBS
Recently Published (2010) article
Most owners and breeders that have MLS beagles have noted an
abnormal ear cartilage. It may be felt as early as 3 weeks of
age. Some beagles just have a odd "ribbon" type feel in the
ear and others actual have extra folds from the cartilage.
Abnormal ear carriage can be seen almost at birth.
||Ears that stuck out at an odd angle at
birth was noted in two litters. The ear stands out and
does not fold down beside head as a normal puppy would. At
two to three weeks of age they fell into a more natural
position. In all cases, (with one exception) these puppies
were carriers or affected.
Slightly older dogs