Bacterial and Viral Dz of CNS Flashcards
Pachymeningitis
Inflamm. of the dura
Leptomeningitis
Inflamm. of the pia-arachnoid
Choroiditis
Inflamm. of the choroid
Encephalitis
Inflamm. of the paranchyma of the brain
Myelitis
Inflamm. of the SC
Encephalomyelitis
Inflamm. of the brain and SC
Polioencephalitis
Inflamm. of the gray matter
Leukoencephalitis
Inflamm. of the white matter
Routes of entry for bacterial Dz
Direct extension (penetrating wounds- skull fractures, paranasal sinuses, inner ear, improper dehorning)
Hematogenous
Histophilosis/ Thrombotic meningoencephalitis (TME)
Acute zoonotic infectious dz from H. somni
Recently weaned calves and feedlot calves ↑ risk
Affinity for heart and lungs
Gross characteristics of TME
Hemorrhagic infarcts
Fibrinopurulent meningitis
Generalized septicemia and thrombosis
Listeriosis
Circling dz from L. monocytogenes
From consuming spoiled silage or hay
Route of L. monocytogenes
Oral mucosa from wounds and invade and migrate along trigeminal n.
Manifestations of listeriosis
Encephalitis (brains stem in adult ruminants)
Septicemia with visceral abscesses/ necrosis (young rums)
Abortion and prenatal infection
Microscopic lesions for listeriosis
Collections of mononuclear cells +/- neutros close to BVs
Microabscesses
Where is listeriosis most severe?
Medulla and pons of the brainstem
Type D enterotoxemia
C. perfringes type D
Lambs, goats and calves
Epsilon toxin → endothelial damage → vasogenic edema
Manifestations of type D enterotoxemia
Focal symmetrical encephalomalacia in sheep
Acute neuro signs → then found dead
How does Type D enterotoxemia affect the kidneys?
Pulpy kidney dz and Overeating dz
Glycemia/ glycosuria
Watery diarrhea
Edema dz
E. coli Shiga toxin 2e (verotoxin)
Stx2e targets endothelial cells → vasc. necrosis → edema
What’s most affected by edema dz
Rapidly growing nursery pigs
Brain, stomach, mesocolon, larynx, SQ tissue for forehead and eyelids
CS of edema dz
Peracute death with no signs
Neuro signs and visible edema
Streptococcosis
Common cause of meningitis (zoonotic)
S. suis (common in URT) in post weaning piglets from stress, poor ventilation and overcrowding
Manifestations of Streptococcosis
Meningitis, septicemia, polyserositis, endocarditis
Cranial abscess syndrome
Secondary to antler trauma (deer)
Secondary to improper dehorning (cattle)
Trueperella pyogenes
Equine Encephalomyelitis
3 alphaviruses: Eastern, western and Venezuelan
Mosquitos biological vectors
Togaviridae family
Microscopic lesions of Equine Encephalomyelitis
Polioencephalomyelitis: perivasuclar cuffing- lymphos, neutros and macros
Neutros in early EEE and VEE
Neuronal degeneration
West Nile virus
Flavivirus from mosquito
Polioencephalomyelitis (lymphos) in birds, humans and horses
K9 Distemper
Morbilivirus (paramyxoviridae)
Demyelination of brain (cerebellum) and SC
Rabies
Racoon, skunks, foxes and bats
Trans: bite wounds/ saliva → mm
Microscopic lesions of rabies
Nonsuppurative encephalomyelitis with ganglioneuritis and parotid adentitis
Perivascular cuffing, focal gliosis and neuronal degeneration
Most prominent feature of rabies
Intracytoplasmic IBs (negri bodies) found:
Hippocampus (dogs and cats)
Purkinje cells (ruminants)
Brainstem and SC (horses)
Widespread brain (wild animals)
Pestiviruses
Classical swine fever (hog cholera)
Bovine viral diarrhea
Feline panleukopenia
Border dz (Hairy shaker)
Common features of pestiviruses
Cerebellar hyoplasia, microcephaly (small cerebrum), hydranencephaly, hydrocephaly and porencephaly
Herpesviruses
Malignant Catarrhal Fever
Bovine Meningoencephalomyelitis
Pseudorabies
Equine Herpesviral Myeloencephalopathy
Malignant Catarrhal Fever
Highly fatal in ruminants
Targets vasculature, lymphoid organs and epithelial cells
Ovine herpes 2 and alcephine herpes 1
Lesion of MCF
Nonsuppurative meningoencephalitis and vasculitis
Perivascular cuffing (lympho) in white matter
Bovine Meningoencephalomyelitis
BHV1 or 5 (more neurovirulent and necrotizing)
Multifocal nonsuppurative meningoencephalitis
Equine Herpesviral Myeloencephalopathy
EHV1 or sometimes 4, affinity for endothelial cells
Multifocal hemorrhage, edema, vasculitis, vasocentric malacia in gray and white matter of brainstem and SC
Pseudorabies
Suid HV1
Swine natural host and reservoir- inapparent dz or mild resp. dz usually
Suckling/ young: fatal encephalomyelitis (Mad itch)
Pregnant sows: abort, stillborn or mummified
Pseudorabies transmission
Nuzzling snout
Consumption/ biting meat → intense puritis, paralysis and death, encephalitis in humans
