They observed that the NfL concentration was significantly higher in dogs with meningoencephalitis (serum, 125 pg/mL; CSF, 14,700 pg/mL) than in healthy dogs (serum, 11.8 pg/mL, p < 0.0001; CSF, 1410 pg/mL, p = 0.0002). Here, NEFL is linked to meningoencephalitis.