Generalized Tremors in Dogs: 198 Cases (2003-2023).

Abstract

BACKGROUND: Diseases associated with generalized tremors in dogs have not been extensively investigated in a large population of dogs. HYPOTHESIS/OBJECTIVES: Describe semiology, tremor phenotype, and diseases associated with generalized tremors in dogs, and identify clinical features that could be associated with the underlying disease. ANIMALS: A total of 198 dogs. METHODS: Retrospective, single-center study of dogs with generalized tremors and a final or presumptive diagnosis between January 2003 and December 2023. RESULTS: The most common diseases associated with generalized tremors in dogs were intoxication (91/198; 46%), idiopathic generalized tremor syndrome (IGTS; 49/198; 24.7%), hypocalcemia (13/198; 6.6%), meningoencephalitis of unknown origin (MUO; 9/198; 4.5%), hypoglycemia (6/198; 3%), hypercalcemia (5/198; 2.5%) and degenerative encephalopathies (5/198; 2.5%). Dogs with IGTS were females (p&#x2009;=&#x2009;0.002), younger (p&#x2009;=&#x2009;0.002) with an acute progressive lateralizing presentation (p&#x2009;<&#x2009;0.001 for all three), compared to dogs with intoxication that were males (p&#x2009;=&#x2009;0.002), young and middle-aged (p&#x2009;=&#x2009;0.002) with a hyperacute nonprogressive symmetric presentation (p&#x2009;<&#x2009;0.001 for all three). Behavioral changes (p&#x2009;=&#x2009;0.01), hypersalivation (p&#x2009;=&#x2009;0.04), abnormal mentation (p&#x2009;=&#x2009;0.01), bilateral mydriasis (p&#x2009;=&#x2009;0.02) or generalized hyperesthesia (p&#x2009;=&#x2009;0.002) were common in intoxication, whereas hyporexia and vestibulocerebellar signs (p&#x2009;<&#x2009;0.001 both) were common in IGTS. Dogs manifested only tremors in intoxication (45%) compared with IGTS (22%; p&#x2009;=&#x2009;0.01). Improvement within 48&#x2009;h from the onset of signs without corticosteroid treatment occurred exclusively in dogs with intoxication (p&#x2009;<&#x2009;0.001). CONCLUSIONS AND CLINICAL IMPORTANCE: Intoxication and IGTS were the most common diseases associated with generalized tremors in dogs. Historical and clinical features may aid the clinician in adjusting their differential diagnoses and formulating a diagnostic and treatment plan.