Submission for Neuromuscular Testing

General Information

It is a Veterinary Diagnostic Laboratory Policy to submit samples and report results to your veterinarian. Direct involvement of your veterinarian allows for optimal management of this genetic disease as well as other concurrent medical conditions your horse may have that will affect its management.

Genetic Testing Protocols

Genetic testing can be performed on either whole blood OR on mane or tail hair samples.

If submitting whole blood: Draw 3 - 7 ml into a purple top EDTA tube clearly labeled with the horse's and owner's ID.

If submitting hair: Pull twenty mane or tail hairs with roots intact. Inspect the hair to ensure that a clear bulb is present on the roots of the sample. The required DNA for the test cannot be obtained from cut hair. Place the hairs in a completely sealed envelope or plastic bag and label the bag with horse's and owner's ID.

Muscle Biopsy Protocols

It is important to select the most appropriate muscle for biopsy in order to get an accurate diagnosis. In general, we recommend open surgical biopsies.

• Exertional myopathies and Polysaccharide Storage Myopathy (PSSM); biopsy Semimembranosus or Semitendinosus muscle.
• Equine Motor Neuron Disease; biopsy Sacrocaudalis muscle.
• Immune-Mediated Myositis and horses with atrophy of topline muscles; biopsy a fresh Semimembranosus combined with 3-4 formalin fixed 14 gauge TruCut samples of epaxial or glutal muscles.
• For evaluation of focal muscle atrophy, an open biopsy of the specific muscle group is most appropriate.

For detailed muscle biopsy procedures please click here.

Packing Muscle Samples

Do not squeeze, squish, or otherwise disturb the muscle sample, as that can damage cells.

A ½ - 1" cube of fresh muscle should be wrapped in saline moistened gauze, placed in a hard, watertight container for protection, and shipped overnight on ice packs in an insulated container to the address below. The gauze should be moist and wrung out. Please do not ship samples floating in saline.

Fresh samples are best, since frozen muscle samples for histochemical analysis require special processing prior to freezing. If circumstances are such that a biopsy cannot be submitted that day (e.g. death of animal on a weekend), samples can be placed in a freezer and submitted on Monday on ice packs. This is not ideal and should be avoided if at all possible.

Formalin fixed - If samples larger than TruCuts are submitted, they should sit in the air for five minutes before they are placed in formalin to prevent contraction bands from forming.

Shipping

Enclose a completed submission form for each animal. Label the tube or envelope with owner and animal name. Blood samples must be shipped within 48 hrs. of collection. Place blood samples on frozen gel packs, place samples in an insulated container and ship overnight to the address below. Hair samples can be shipped by regular mail.

Address:

Veterinary Diagnostic Laboratory
University of Minnesota
1333 Gortner Ave
St. Paul, MN 55108
Phone: (612) 625-8787