TABLE 15-15.

Parasitic Diseases of the CNS

Disease	Cause	Incidence	Clinical Signs and Pathology	Course and Prognosis	Diagnostic Tests	Treatment
Dirofilariasis	Dirofilaria immitis, microfilaria or aberrant adult	Rare, areas with heartworm disease	CNS signs rare; microfilaria or migrating adult heartworms may cause infarction; seizures and other cerebral signs	Acute onset; prognosis guarded	Blood smear or serology to confirm heartworm disease, CSF (increased eosinophils suggestive), difficult to prove antemortem	None proven
Larva migrans	Toxocara canis and other species	Rare	Granulomas in brain or spinal cord from migrating larvae; signs related to location of lesion	Acute or chronic; prognosis depends on severity of signs	None, necropsy	None
Cuterebrosis	Cuterebra spp.	Rare	CNS signs depend on location of lesion	Acute to chronic; guarded prognosis	None, necropsy	None
Coenurosis	Coenurus spp.	Rare; most often reported in sheep	CNS signs depend on location of lesion	Acute to chronic; poor prognosis	None, sheep have softening of skull that can be palpated or seen on radiographs	Surgical removal in sheep