When the term PSSM2 (Polysaccharide Storage Myopathy 2) was introduced, it was used to group together all horses that displayed the same pattern under exertion as PSSM1 horses, but in which the mutation responsible for PSSM1 could not be detected.
As research progressed, it became clear that PSSM2 is not a single disease with one cause or genetic defect, but rather a group of various conditions, for which no causal mutations have yet been identified. Therefore, the genetic tests currently available are not reliable. The gold standard for diagnosing PSSM2 and distinguishing it from Myofibrillar Myopathy (MFM) remains a histopathological examination through a muscle biopsy.
The fact that PSSM2 very likely has different underlying causes is also evident from the observation that warmbloods often respond differently compared to non-warmbloods.
In warmbloods, it is surprisingly more often geldings than mares that are affected by PSSM2. In over two-thirds of warmbloods, irregularities in gait are always the first sign of PSSM2. Other signs include stiffness, a shortened stride, lack of forward drive, and mild hindlimb lameness without a clear cause. Additionally, the enzymes CK and AST often show no differences compared to healthy horses.
In warmbloods with PSSM2, tying-up episodes occur much less frequently compared to non-warmbloods, which are more commonly affected. Additionally, no increased glycogen concentration in the muscle can be detected compared to healthy horses. It is also notable that many warmbloods with PSSM2 have been diagnosed with gastric ulcers. So far, no specific warmblood bloodlines associated with PSSM2 have been identified.
In contrast to warmbloods, non-warmbloods diagnosed with PSSM2 via muscle biopsy are more frequently affected by tying-up, accompanied by elevated CK and AST values (especially Arabians and Quarter Horses). In Quarter Horses, PSSM2 is also often associated with muscle wasting and increased CK levels; in very young Quarter Horses, it can even present as an inability to stand or stiffness in the hindquarters.
PSSM2 has been identified in many breeds, including Icelandic Horses, Friesians, Morgan Horses, Arabians, Thoroughbreds, and various Warmblood breeds.
Horses that show abnormal desmin aggregates in histology have since been reclassified as having Myofibrillar Myopathy (MFM).
Similar to PSSM1 horses, PSSM2 horses also benefit from a low-carbohydrate diet, in which all easily digestible carbohydrates are removed from the feed, combined with regular daily exercise.
Richtiges Training und bedarfsgerechte Fütterung gehören untrennbar zusammen und oft ist das eine nicht ohne das andere möglich. In ihrer Praxis betreut sie Pferde, vom Rentner bis zum Sportpferd, aus allen Sparten der Reiterei mit verschiedensten Problematiken und unterstützt bei der anschließenden Gesunderhaltung der Pferde.
Sie selbst bildet sich jedes Jahr bei namhaften Trainern und Therapeuten weiter.
https://www.equus-solis.de/
🇬🇧 Elke Malenke has been a dual activation trainer since 2011, and in 2012 she added acupuncture massage for horses and dogs to her repertoire. To complement her therapeutic offerings, she completed the Equine Nutrition Advisor course with Dr. Christina Fritz in 2019.
Proper training and appropriate feeding are inseparably linked, and often one is not possible without the other. In her practice, she cares for horses of all kinds, from retirees to sport horses, across various equestrian disciplines, addressing a wide range of issues and supporting the subsequent maintenance of the horses' health. She continues her education every year with renowned trainers and therapists.
https://www.equus-solis.de/
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