Musladin-Lueke Syndrome (MLS) in Beagles

Musladin-Lueke syndrome is a hereditary health condition that can affect dogs of the Beagle breed, which affects the normal development of connective tissue and organs such as the skin, muscles, bones and heart. The skin and connective tissue of affected dogs fails to form normally, which can have a range of different impacts on the way that the dog looks, moves and lives.

Beagles that have Musladin-Lueke syndrome will often be smaller than the breed norm, and may have an unusually flat head, sloped eyes, and skin that is tight and stiff. The signature gait that the condition causes too is quite distinctive, and may appear as if the dog in walking on the tips of their toes rather than on the flat pads of their feet.

Exactly how badly the condition affects any given dog can vary from case to case, with some dogs only exhibiting very mild symptoms and not looking significantly different from a normal, healthy beagle, while in others, the condition can be severe and have a significant impact on their health and wellness.

The condition cannot be cured or treated, and does not necessarily prove fatal for all or even most affected dogs; however, it can potentially have a significant impact on the dog’s quality of life, particularly if the condition leads to seizures too, which can happen in more severe cases.

Because Musladin-Lueke syndrome is a hereditary health condition across the Beagle breed, The Kennel Club runs a testing scheme to allow would-be beagle breeders to find out their own dog’s status prior to breeding, so that an informed decision can be made about whether or not the dog should be bred from.

In this article, we will look at Musladin-Lueke syndrome in more detail, including how the heredity of the condition works, and how dogs are tested for the condition. Read on to learn more.

More about Musladin-Lueke syndrome

The symptoms of Musladin-Lueke syndrome can vary from dog to dog, being very subtle in some but very pronounced in others. The most obvious indications of the condition are shorter than normal outer toes on the front feet, sometimes the hind feet too, highly-set ears with a crease in them due to abnormal cartilage growth, and slanting, narrower than normal eyes.

The skin too tends to be taut with little wiggle room, which is noticeable around the scruff of the neck. Puppies with the condition tend to be smaller than the breed norm, and due to their shortened outer toes, will sometimes have a tip-toeing gait.

Exactly how badly the condition affects any given beagle can vary considerably, with some dogs dying before they reach one year old due to the condition, whilst those that are only minorly affected often living for a normal lifespan with a good quality of life.

What sort of dogs does it affect?

Muslade-Lueke syndrome is a hereditary health condition that affects only dogs of the beagle breed, and which can be passed on from dog to dog by means of their breed line.

Cross breed and hybrid breed dogs that have some beagle ancestry may also inherit the condition too, although the hybrid vigour provided by outcrossing to other breeds greatly reduces the chances of non-pedigree dogs inheriting or passing on the condition.

How does the heredity of the condition work?

Musladin-Lueke syndrome is an autosomal recessive hereditary condition, and dogs are assigned one of three statuses for the condition: Clear, carrier or affected. Clear dogs are, as the term implies, not in any way touched by the condition, and so are unable to pass it on to their offspring. Carriers are unaffected by the condition themselves, but may pass it on. Affected dogs are of course those that are themselves affected by the condition.

In order for any given dog to inherit the condition, they need to inherit the right combination of gene mutations from their ancestry, and both sides of their parentage come into play. The heredity can be outlined in basic terms as follows:

• Two clear dogs will produce clear puppies.
• Two affected dogs will produce affected puppies.
• Two carriers will produce a mixed litter with odds for each pup of 50% carrier, 25% affected and 25% clear.
• A clear dog and a carrier will produce 50% carrier and 50% clear.
• A clear dog and an affected dog will produce a litter of carriers.
• An affected dog and a carrier will produce 50% carrier and 50% affected.

Testing for Musladin-Lueke syndrome

In order to test potential breeding dogs for the markers of the condition and return their status, all that is required is a DNA sample from the dog in question, which can be in the form of a blood sample, a buccal swab or a clipping from the dew claw.

This can then be sent to one of The Kennel Club’s approved laboratories, and the resulting status of the dog is returned to their owner.