SDMD in Dachshunds
Sarcoglycan Deficient Muscular Dystrophy (*SDMD) is a type of Limb-girdle muscular dystrophy, an inherited disorder that leads to progressive muscle dysfunction. It tends to cause weakness in the muscles of the shoulders and hips, but can also affect vital organs such as the heart and esophagus. The disease is mainly seen in miniature smooth dachshunds and occasionally in miniature long hair dachshunds which might have been bred from miniature smooth dachshunds. Other dachshund varieties may carry the disease if crossed with miniature smooth hair dachshunds.
What are the symptoms of SDMD in Dachshunds?
Symptoms of SDMD in affected Dachshunds typically appear around 12 months of age, but can manifest as early as 6 months. Affected dogs may experience difficulty walking or running, muscle weakness, and an unwillingness to walk or step over objects. They may also have difficulty with eating, drinking, swallowing, and experience constant drooling and redish-colored urine. As the disease progresses, muscle wasting becomes more pronounced, and dogs may develop a hunched posture and struggle to rise from a lying position. Due to increased inflammation of the muscles, dogs may shiver from pain and appear to feel the cold.
*SDMD is also known or referred to as SGCD, SGCD, and Limb Girdle Muscular Dystrophy (LGMD).
How is SDMD diagnosed?
Diagnosing SDMD in Dachshunds typically involves a combination of clinical signs, physical examination, and genetic DNA testing. Unfortunately, there is currently no cure for this condition. The main focus is on managing the dog's clinical symptoms, such as providing ongoing pain medication. It's important to note that dachshunds affected by SDMD are highly susceptible to disc herniation (IVDD) due to muscle wastage and weakness. Other secondary conditions may include pneumonia due to difficulty in swallowing. In some cases, SDMD affected dachshunds have been misdiagnosed as having megaesophagus.
A DNA test is available from various institutions including the University of Minnesota, USA, Orivet Australia, Massey University, Paw Print Genetics, Wisdom Panel, Embark, and others. This test can identify the presence of a mutation that is autosomal recessive, meaning that both parents must be carriers in order to produce affected offspring. The test is able to identify dogs as clear, carrier, or affected. DNA testing for this mutation first became available in late 2019.
Responsible breeders and pet lovers
Taking on puppies from a breeder that is not carrying out the recommended testing can not only end in heartache but also encourages and rewards irresponsible breeding. It is never fair on the puppies and dogs that suffer, or the families that love them. Pet lovers that are making enquiries about dachshund puppies are strongly encouraged to ask for the parents DNA test results, ensuring at least one parent is DNA tested CLEAR. This means that the puppies aren't affected by the disease. CARRIERS will not show any signs of illness or disease but can still pass it on.
Ideally, both parents should undergo DNA testing for SDMD. If neither parent has been tested for SDMD, or if the puppy itself has not been DNA tested for SDMD, pet lovers are advised not to proceed.
If you need help interpreting DNA test results, talk to your vet or the Facebook group SDMD in Dachshunds - a great resource for support and information. It is crucial that pet owners do not breed from a dog that is an SDMD Carrier, or SDMD Affected. Because dogs can carry the gene without showing any evidence of the disease, haphazard breeding without testing is reckless and irresponsible.
It's heartening to note that in Australia and New Zealand, SDMD is being managed effectively thanks to the breeders' access to advanced DNA testing. Work to educate and raise awareness among breeders and pet lovers is also critical to ensure informed and responsible breeding practices.
For more information on SDMD in Dachshunds:
Facebook Group: Sarcoglycan Deficient Muscular Dystrophy (SDMD) in Dachshunds. A 'Guides' section is provided with pedigrees of affected dachshunds found in Australia and New Zealand, shared with permission.