Table 126-2.
INFLAMMATORY BRAIN DISEASE CAUSED BY INFECTIOUS AGENTS IN THE DOG
| Disease/Agent | Typical Age of Onset | Onset/Progression | Typical Neurologic Signs | Typical CSF Characteristics | Serology/CSF Titers | Treatment* |
|---|---|---|---|---|---|---|
| CDV (paramyxovirus) | Young (<1 yr) | Rapid or intermediate | Cerebral, brain stem, cerebellum, or spinal cord (may be multifocal) | Normal to moderate lymphocytic; mild protein | Positive CSF CDV antibody or antibody coefficient; RT-PCR on CSF | No specific treatment; prednisone in chronic form; AEDs if seizures |
| Cryptococcosis (Cryptococcus neoformans) | Any age; often young (<1 yr) | Intermediate to slow | Brain stem (often multifocal brain stem signs) | Mixed (predominantly mononuclear or eosinophilic); high protein; may see organism rarely | CSF or serum antigen titer (CSF preferred) | Fluconazole |
| Coccidioidomycosis (Coccidioides immitis) | Adult | Intermediate to slow | Cerebrum or brainstem | Mixed; mild to moderate protein | Serum CF titer =1:8 | Fluconazole |
| RMSF (Rickettsia rickettsii) | Adult | Rapid | Diffuse or multifocal; often central vestibular component; neck pain | Mixed or suppurative; moderate protein | Rising IFA serum antibody titer (paired); PCR if negative titer in acute phase | Doxycycline, (chloramphenicol, enrofloxacin) |
| Ehrlichiosis (Ehrlichia canis) | Adult | Rapid or intermediate | As for RMSF | Mixed or non-suppurative; moderate protein | Positive IFA serum antibody titer at >1:20; PCR | Doxycycline |
| Neosporosis (Neospora caninum) | Young (<1 yr); rarely adults up to 7 years | Rapid | Caudal paresis, arthrogryposis, or tetraparesis (spinal cord); More generalized signs including brainstem and cerebral signs in adults | Non-suppurative; moderate protein | Positive IFA serum antibody (often =1:800) | Clindamycin; trimethoprim-sulfadiazine ± pyrimethamine |
| Rabies (rhabdovirus) | Adult | Rapid | Spinal cord, brainstem, and/or cerebral signs (may be multifocal) | Normal or mild mononuclear; normal or mild protein | NA (IFA testing of brain tissue most reliable) | None |
| Pseudorabies (herpesvirus) | Any age | Rapid | Hyperesthesia; spinal cord and brain stem signs (often multifocal) | Mild mononuclear; mild protein | None |
AEDs, antiepileptic drugs; CDV, canine distemper virus; CF, complement fixation antibody; CSF, cerebrospinal fluid; IFA, immunofluorescent antibody; NA; not available; PCR, polymerase chain reaction; RMSF, Rocky Mountain spotted fever; RT-PCR, reverse transcriptase polymerase chain reaction.
*
Preferred treatment(s) are listed first; other available drugs are listed in parentheses.