Metabolic Storage Disorders and Inborn Errors 

Naming Convention: Named based on the specific metabolic byproduct that accumulates.

Disease Progression:

• Animals typically appear normal at birth.

• Signs manifest within the first weeks or months of life.

• Progressive and usually fatal; no specific treatments currently exist.

Major Types in Small Animals (Dogs & Cats):

• Gangliosidoses (GM1 & GM2): Found in various breeds including Siamese cats, Beagles, and German Shorthaired Pointers.

• Sphingomyelinosis: Seen in German Shepherds, Poodles, and Siamese cats.

• Globoid cell leukodystrophy (Krabbe disease): Affects Cairn Terriers, Westies, Beagles, and Poodles.

• Mucopolysaccharidosis: Associated with lameness in dogs (e.g., Rottweilers, Labradors) and various types in Siamese cats.

• Metabolic/Blood Disorders: Includes pyruvate kinase deficiency and phosphofructokinase deficiency.

Major Types in Large Animals (Livestock):

• Mannosidosis (Alpha & Beta): Affects Angus and Saler cattle, as well as Nubian goats.

• Generalized Glycogenosis (GM1 & GM2): Identified in Holstein, Shorthorn, and Brahman cattle, as well as sheep and pigs.

• Neurologic Inherited Diseases: Shaker calf syndrome, maple syrup urine disease, and hereditary neuraxial edema.

• Structural/Tissue Errors: Goiter, osteogenesis imperfecta, and Ehlers-Danlos syndrome in cattle and sheep.

Horses: No reported lysosomal storage diseases; however, they exhibit inherited neurologic signs like inherited myoclonus and congenital encephalomyelopathy.

Primary Cause: Ingestion of specific plants containing enzyme inhibitors, most notably locoweed (Astragalus or Oxytropis spp).

Mechanism: Toxic components (e.g., locoine, swainsonine n-oxide) interfere with alpha-mannosidase activity.

Susceptibility: Horses are the most susceptible, though cattle, sheep, and goats are also affected.