LAUSR

Abstract Background Clinical signs and their progression in Beagles with Lafora disease are poorly described. Objectives To describe clinical signs in Beagles with Lafora disease. Animals Twenty‐eight Beagles with Lafora disease confirmed by genetic testing or histopathology. Methods Retrospective multicenter case series. Data regarding signalment, clinical signs, diagnostic tests and treatment were retrieved from hospital data files. A questionnaire was sent to owners asking about neurological deficits, changes in cognitive functions, behavioral changes, response to treatment and survival time. Results Onset of clinical signs was 8.3 years (mean; range, 6.3‐13.3). All dogs had myoclonic episodes as an initial clinical sign with tonic‐clonic seizures in n = 11/28 (39%) and n = 12/28 (43%) later developing tonic‐clonic seizures. Deficits of coordination (n = 21/25; 84%), impaired vision (n = 15/26; 58%), and impaired hearing (n = 13/26; 50%) developed later. Mental decline was observed as loss of house training (urination; n = 8/25; 32%), difficulties performing learned tasks (n = 9/25; 36%), and difficulties learning new tasks (n = 7/23; 30%). Common behavioral changes were: increased photosensitivity (n = 20/26; 77%), staring into space (n = 16/25; 64%), reduced stress resistance (n = 15/26; 58%), increased noise sensitivity (n = 14/26; 54%), and separation anxiety (n = 11/25; 44%). Twenty‐one dogs were alive (median age 11.9 years; range, 9.8‐18.6), and 7 dogs were dead (mean age 12.1 years; SD: 1.3; range, 10.5‐12.6) at time of writing. Conclusions and Clinical Importance Lafora disease in Beagles causes significant behavioral changes, and mental decline as well as neurological deficits in addition to myoclonic episodes and generalized tonic‐clonic seizures. Nevertheless, a relatively normal life span can be expected.