Cerebrospinal fluid eosinophilia in dogs.
BACKGROUND
Marked eosinophilic meningitis or meningoencephalomyelitis (EME) is rarely reported in dogs and the cause is usually undetermined. Long-term prognosis for dogs with cerebrospinal fluid (CSF) eosinophilia is variable.


METHODS
Twenty-three client-owned dogs.


METHODS
Retrospective case series. Dogs with eosinophilic CSF, defined as total nucleated cell count (TNCC) >3 cells/microL with >20% eosinophils, were identified by a computerized search of all dogs having cisternal and/or lumbar CSF analyzed as part of the diagnostic workup between 1992 and 2007.


RESULTS
TNCC in CSF ranged from 4 to 4,740 cells/microL (median 84 cells/microL, reference range <or=3 cells/microL), with 22 to 95% (median 78%) eosinophils in the differential count. An infectious agent was identified on necropsy in 4 of 23 (17%) dogs (Cryptococcus neoformans [n = 2], Neospora caninum [n = 1], and Baylisascaris procyonis [n = 1]). Each of these dogs had progressive neurologic deterioration. Sixteen dogs had idiopathic EME. Magnetic resonance imaging (MRI) findings were abnormal in 7 of 13 dogs with EME; 2 dogs had focal lesions and 5 dogs had multifocal lesions. Clinical signs in 12 of 16 (75%) dogs with idiopathic EME resolved with prednisone treatment. Three dogs with acute intervertebral disc herniations recovered after decompressive surgery alone.


CONCLUSIONS
Idiopathic EME is a common cause of eosinophilic pleocytosis in dogs. MRI findings are variable. Infectious causes of EME were less common and had a poor prognosis.
Windsor
R C
RC
Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616-8747, USA.
Sturges
B K
BK
Vernau
K M
KM
Vernau
W
W
D000818:Animals; D002452:Cell Count / Q000662:veterinary; D004283:Dog Diseases / Q000134:cerebrospinal fluid* / Q000473:pathology; D004285:Dogs; D004679:Encephalomyelitis / Q000134:cerebrospinal fluid / Q000473:pathology / Q000662:veterinary*; D004802:Eosinophilia / Q000134:cerebrospinal fluid / Q000473:pathology / Q000662:veterinary*; D005260:Female; D007964:Leukocytosis / Q000134:cerebrospinal fluid / Q000473:pathology / Q000662:veterinary*; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D008581:Meningitis / Q000134:cerebrospinal fluid / Q000473:pathology / Q000662:veterinary; D012189:Retrospective Studies