41. INFECTIOUS CENTRAL NERVOUS DISEASES

Question 1

What diseases does infections cause in the brain:

Answer 1

meningitis, encephalitis, and meningoencephalitis

Question 2

infectious pathogens:

Answer 2

– Viral
– Bacterial
– Fungal
– Protozoal

Question 3

in cats:

Answer 3

• FIP, FeLV, toxoplasmosis etc

Question 4

in dogs:

Answer 4

• distemper, toxoplasmosis, neosporosis, cryptococcosis

Question 5

viral encephalitis route of infections:

Answer 5

• Inhalation
• Bite
• Ingestion of infected raw meat
• Vector

Question 6

Causes of viral encephalitis:

Answer 6

• Canine distemper (febris catarrhalis)
• Rabies (lyssa)
• Pseudorabies (Aujeszky disease)
• Tick encephalitis
• Feline Borna disease

Question 7

Canine distemper is caused by:

Answer 7

• Morbillivirus genus, paramyxovirus

- Remains virulent for several days in dried secretion, spread through urine and nasal secretions.

Question 8

signs of distemper

Answer 8

• General signs (apathy, fever)
• Gastrointestinal (diarrhoea),
• Respiratory (cough, mucopurulent discharge – nose, eyes)
• Neurologic signs
• Hyperkeratosis (hard pad – paws, nasal planum)
• Polysystemic signs: most often in young dogs with inadequate vaccination, less strong immune system

Question 9

The two types of distemper

Answer 9

Neuronal and glial cell death (polioencephalomyelopathy)

• Mostly young dogs
• Usually with history of seizures

Demyelination (leukoencephalomyelopathy)

• Mostly adult dogs
• Immune mediated
• Brain stem, cerebellar, vestibular signs
• Myoclonus!

Question 10

diagnosis of distemper

Answer 10

• PCR (urine)
• Conjunctival / bronchial smear
• inclusion bodies
• IF teszt

Question 11

Types of rabies

Answer 11

– Urbanic rabies: (from dog-to-dog) very rare in Europe

– Sylvatic rabies: dogs and cats are infected from rabid foxes

Question 12

Diagnosis of rabies

Answer 12

– Justification postmortem
– IF test: reaction of anti viral antibodies conjugated with fluorescent dye with tissue samples
– Real time RT-PCR
– Virus isolation on cell culture

Question 13

Pathogen of pseudorabies - aujeskys

Answer 13

• Alphaherpesvirus, porcine herpesvirus – 1, PHV-1

Question 14

Tick encephalitis pathogen:

Answer 14

flavivirus

Question 15

Tick encephalitis vector

Answer 15

• Ixodes ricinus (Europe)

Question 16

Symptoms of tick encephalitis

Answer 16

• fever, apathy or excitement, convulsions, ataxia, paraplegia, disorders of propriocepcion, aggressiveness, sensational disorders, tremor, nystagmus, mydriasis, anisocoria, strabismus, facial paralysis

Question 17

FELINE INFECTIOUS PERITONITIS (FIP) pathogen:

Answer 17

coronavirus

Question 18

FIP etiology

Answer 18

• Primarily intracranial and spinal cord structures are affected
• Typically associated with „dry”, pyogranulomatous FIP (noneffusive form of FIP)
• Immune complex vasculitis → inflammation of the ependyma, choroid plexus, meninges

Question 19

FIP signs:

Answer 19

1. Motoric disorders, cerebellar ataxia, tremor, hind leg paralysis
2. Menthal state: stupor/dementia or even aggressivness
3. Eyes: nystagmus, mydriasis, anisocoria, anterior uveitis, chorioretinitis

Question 20

Bacterial infection of CNS - route

Answer 20

– Direct invasion (after trauma of the skull or vertebral column)
– local source of infection (sinusitis, otitis, nasal passage)
– hematogenous (dog: endocarditis)
– Bacterial inflammation in the cns is rare

Question 21

Bacterial infection of CNS - pathogens

Answer 21

– staphylococcus, streptococcus, pateurella m. (mostlyincats), escherichia, klebsiella, actinomyces, nocardia, anaerobes: bacteroides, peptostreptococcus

Question 22

Bacterial infection - diagnosis

Answer 22

– history, clinical signs, (CT, MRI – abscess, oedema)
– CSF → citology: neutrophil pleiocytosis (toxic and degenerate neutrophils), intracellular bacteria
– CSF → biochemistry: protein, glucose ↑
– CSF → bacterial culture

Question 23

Treatment of bacteria in the cns

Answer 23

– AB (ampicillin, enrofloxacin, cefotaxime, metronidazol for anaerobes, 10-14 days after resolution of clinical signs)
– Glucocorticoids in antiinflammatory dose (max. 4 days)

Question 24

LISTERIA MONOCITOGENES

Answer 24

bacteria invades through (oral) mucosal lesions → reach the CNS via the nerves → cranial nerve damage → laryngeal paralysis

doxycyline for treatment

Question 25

toxoplasma gondii: host

Answer 25

- Cats are definitive hosts. | - In acute infection (young dog/cat)

Question 26

toxoplasma gondii: symptoms

Answer 26

- Severe in young cats, symptomless in older - Systemic signs (lethargy, anorexia, dyspnoe – pneumonia, diarrhea) - Classic sign: hyperextended pelvic limbs, chorioretinitis may be present - myositis - Nervous system: encephalitis, myelitis, peripheral neuropathies

Question 27

shed, Infection, Diagnosis,Therapy of toxoplasma :

Answer 27

shed - Oocysts are shed in acute illness for 2-3 weeks. Infection: - with cyst containing meat, spored oocyst, intrauterin Diagnosis - antigen: PCR, antibody (IgG, IgM): IF Therapy - clindamycin

Question 28

NEOSPORA CANINUM - host and infection

Answer 28

– Dogs are definitive hosts. – Dogs can be infected in utero or with infected meat – Neosporosis is frequently a complication of canine distemper – Not described in cats

Question 29

NEOSPORA CANINUM - symptoms

Answer 29

– nervous system: encephalitis, myelitis, peripheral neuropathies – chorioretinitis – pneumonia – myositis – in chronic cases, older dogs: aggression, depression, other behavioral changes

Question 30

NEOSPORA CANINUM - diagnosis and therapy

Answer 30

– antigen: PCR, antibody: IF – clindamycin, potentiated sulphonamids – A puppy with classic signs of pelvic limb hyperextension and rigidity secondary to Neospora caninum infection.

Question 31

Etiology of fungal infection of cns

Answer 31

Etiology: – Inhalation of fungal spores – local extension from nasal / frontal sinus – – haematogen spread

Question 32

pathogens of fungal infection of cns

Answer 32

Fungal organisms that may invade the CNS: Aspergillus, Blastomyces, Coccidioides (USA), Cryptococcus (USA), Histoplasma (USA)

Question 33

occurence of fungal infection of cns

Answer 33

``` – mainly as part of systemic mycosis – Slow progression – Fungal elements may be identifiable in urine samples – CSF: mixed cell pleocytosis – In cats concurrent FeLV / FIV common ```

Question 34

therapy of fungal infection of cns

Answer 34

- antifungal drugs that cross the blood –brain barrier: fluconazole, flucytosine long term (months- one year)