Use of neurofilament light chain to identify structural brain diseases in dogs.

Background: Neurofilament light chain (NfL) is released into the peripheral circulation by damaged axons.

Objectives: To evaluate the diagnostic value of serum NfL concentration in dogs with intracranial diseases.

Animals: Study included 37 healthy dogs, 31 dogs with idiopathic epilepsy (IE), 45 dogs with meningoencephalitis of unknown etiology (MUE), 20 dogs with hydrocephalus, and 19 dogs with brain tumors.

Methods: Cohort study. Serum NfL concentrations were measured in all dogs using single-molecule array technology.

Results: Serum NfL concentration in dogs with each structural disease was significantly higher than in healthy dogs and dogs with IE (P = .01). The area under the receiver operating characteristic curve of NfL for differentiating between dogs with structural diseases and IE was 0.868. An optimal cutoff value of the NfL 27.10 pg/mL had a sensitivity of 86.67% and a specificity of 74.19% to differentiate the dogs with IE from those with structural brain diseases. There were significant correlations between NfL concentrations and lesion size: (1) MUE, P = .01, r = 0.429; (2) hydrocephalus, P = .01, r = 0.563.

Conclusions And Clinical Importance: Serum NfL could be a useful biomarker for distinguishing IE from structural diseases in dogs and predicting the lesion sizes of MUE and hydrocephalus.