Clinical presentation, treatment, and outcome of 24 dogs with bacterial meningitis or meningoencephalitis without empyema (2010-2020).

Background: Bacterial meningitis (BM) and meningoencephalitis (BMEM) are associated with high case fatality rates and neurologic sequelae in people, but limited data exists on outcome in dogs.

Hypothesis/objectives: To report the clinicopathologic features, treatment and outcome of BM/BMEM in dogs, with a focus on clinical presentation, relapse and long-term neurological deficits.

Animals: Twenty-four client-owned dogs diagnosed with BM/BMEM without empyema.

Methods: Retrospective case series of dogs diagnosed with BM/BMEM from 5 veterinary referral hospitals between January 2010 and August 2020.

Results: Twenty-four dogs were included. Median duration of clinical signs was 2 days (range ≤24 hours to 30 days) and signs recorded included pyrexia (3) and cervical hyperesthesia (10). Neurological deficits were present in 18 dogs including altered mentation (12), ataxia (8), nonambulatory status (8), head tilt (8), and cranial nerve deficits (13). Intracellular bacteria were visualized on cerebrospinal fluid (CSF) analysis in 15/24 dogs, with positive CSF bacteriological culture in 8/21. Otitis media/interna (OMI) was diagnosed in 15/24 dogs, of which 6/15 dogs underwent total ear canal ablation and lateral bulla osteotomy. Twenty dogs survived to hospital discharge. Median duration of antibiotic administrations was 8 weeks (range, 2-16 weeks). Glucocorticoids were administered to 15 dogs. Median follow-up time was 92 days (range, 10-2233 days). Residual neurological deficits were reported in 9 dogs, with a single case of suspected relapse.

Conclusions And Clinical Importance: Clinical signs were variable in dogs with BM/BMEM, the nidus of bacterial infection was often OMI and the majority of dogs made a full recovery with treatment.