TABLE 2.
Information that may be useful in the diagnosis of infectious causes of CNS disease in cats
| Disease | Signalment and history | Common clinical signs | Useful diagnostic tests/findings | Frequency |
|---|---|---|---|---|
|
| ||||
| Feline infectious peritonitis (FIP) | Pedigree cats under 4 years of age that have often come from a large breeding colony Kittens from rescue centres Recent stress (eg, rehoming) | Systemic and ocular signs, multifocal (occasionally focal) CNS signs, altered mentation, ataxia, cranial nerve abnormalities, seizures | Non-regenerative anaemia, increased neutrophils, decreased lymphocytes; reduced serum albumin/globulin ratio; increased serum alpha-1 acid glycoprotein and serum bilirubin; increased serum and CSF FCoV titre; abdominal ultrasound examination; head MRI | Common |
| Other viral encephalitis (eg, Borna disease virus) or viral non-FIP encephalitides | Young to middle-aged cats | Behavioural and/or motor changes | Head MRI | Probably common |
| Protozoal meningoencephalitis (eg, toxoplasmosis) | Adult cats that hunt Occasionally in young cats as a congenital infection | Systemic and ocular signs, multifocal CNS signs, altered mentation, ataxia, cranial nerve abnormalities, seizures | Non-regenerative anaemia, increased neutrophils and lymphocytes; serum biochemistry (resulting from systemic disease); serum and CSF antibody titres; detection of organisms in aspirates or on histopathology; head MRI | Relatively common |
| Fungal meningoencephalitis (eg, cryptococcosis) | Adult cats with a history of upper respiratory tract disease | Nasal and ocular signs, multifocal or focal CNS disease, altered mentation, ataxia, cranial nerve abnormalities, seizures | Demonstration of organisms by India ink stain; serum latex agglutination antigen titre; head CT/MRI | Rare — but may be geographical location dependent |
| Bacterial meningoencephalitis | Any age, history of ear infections, or bacterial focus elsewhere in the body (eg, myocarditis) | Severe depression, pyrexia, neck pain, neurological deficits, ocular changes | Neutrophilia with a left shift; CSF and/or blood culture; head CT/MRI | Rare |
| FeLV-induced lymphoma | Young cats | Multifocal signs, cranial nerve deficits, seizures, altered mentation, spinal pain, paresis/paralysis | Blood FeLV antigen or PCR tests; lymphoma cells in CSF; head and spine MRI | Rare |