Lafora disease in a Chihuahua dog: a case report

Abstract

The aging process is still not fully understood, although it has been studied for centuries. One of the processes in the brain during aging is the accumulation of extracellular and intracellular deposits of amyloid and lipofuscin. Deposits of various polyglucosan bodies (PGBs) are also found in brain tissue. The accumulation of the Lafora bodies (LB), a type of PGBs, can cause the Lafora disease (LD). Initial signs of the disease in humans are tonic-clonic seizures with blindness and myoclonus seizures. Normally, all haematological and biochemical indices are within the reference range in dogs with this disease. In this case, a 7-year-old Chihuahua dog with tonic-clonic seizures was presented. According to history, neurological examination, and blood test, toxic, metabolic, and infectious causes for the seizures were ruled out. The dog was started on phenobarbital 2.5 mg/kg twice daily per os. Two years later, the dog died due to complications caused by a duodenal foreign body. Postmortem examination revealed hyperaemic meninges and an enlarged, oedematous brain with flattened gyri and narrowed sulci. Histopathological examination revealed multifocal to diffuse, randomly distributed PGBs that were positive on periodic acid-Schiff (PAS) staining. The diagnosis of LD in dogs is of great importance because they are a good experimental model for neurological studies of neurodegenerative diseases in humans.