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.
Do not squeeze, squish, or otherwise disturb the muscle sample, as that can damage cells.
A 1/2-1" 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. We also accept formalin fixed or unstained paraffin embedded formalin fixed slides for evaluation. Schedule muscle biopsies from Monday to Wednesday to avoid delayed freezing of samples over weekends. If circumstances are such that a biopsy cannot be submitted that day (e.g. death of animal on a weekend), divide the sample into two pieces and place half in formalin and half in a -20 C freezer and ship together on Monday on ice packs. However, this will considerably decrease the quality of the sample 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.