Meningitis - Pedigogy

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Meningitis:

Inflammation of pia and arachnoid membrane (meninges) is known as meningitis.
Inflammation involving dura is known as pachymeningitis.
Involvement of meninges of brain is known as cerebral meningitis and involvement of meninges of spinal cord is known as spinal meningitis.
Meningitis is usually associated with a bacterial infection and is manifested clinically by fever, cutaneous hyperesthesia, and rigidity of muscles.
Meningoencephalitis is common in neonatal farm animals

Etiology:

Cattle:

Viral disease including bovine malignant catarrh, sporadic bovine encephalomyelitis, IBR
Bacterial disease: Streptococcal infection, Listeria monocytogenes, Necrobacillus infection, Staphylococcal infection, coliform, Pasteurellosis, Leptospirosis, Corneybacterial infection, Tuberculosis
Facial paralysis syndrome of calves

Sheep:

Horse:

Pig:

Dog: Rabies, Canine Distemper, otitis media

Cat: Nasal Cryptococcosis, middle ear infection

Clinical Findings:

Acute meningitis develops suddenly and accompanied by fever and toxaemia
Vomiting is common in early stages in pigs
Trismus (tightening of jaw muscle), opisthotonus, rigidity of neck and back
Motor irritation causing tonic spasm of muscles of neck causing retraction of head, muscle tremor and paddling movements
Cutaneous hyperesthesia manifested by severe pain when touching slightly on skin
Excitement or mania in early stage followed by drowsiness and coma in later stage
Blindness is common in cerebral meningitis.
Ophthalmitis and hypopyon may occur in young animal.
Pupillary light reflex is slower than normal
In uncomplicated cases of meningitis, Cheyne-stokes breathing (breathing pattern characterized by period of apnea followed by gradual increase in depth and rate of respiration) or Biot’s breathing (irregular breathing pattern characterized by group of quick, shallow inspiration followed by period of apnea)
Terminally there is quadriplegia and clonic convulsion
Localized muscle tremor especially of elbow and flank region
Muscle in affected area are board-like and firm on palpation.
Circling and falling to one side, propulsive walking, recumbency, nystagmus
In terminal stage, continuous irritation, hyperaesthesia and diminished function of nerves leads to paresis or paralysis.

Diagnosis:

Neurological examination of animal to assess functions of brain
Analysis of CSF: turbid appearance, increased protein concentration, high cell count and contains bacteria
Blood test reveals marked leukocytosis indicating severe systemic illness secondary to septicemia.
Necropsy Findings:
- Hemorrhages in meninges
- Thickening and opacity of the meninges, specially over base of brain
- CSF is often turbid and contains fibrin.

Differential Diagnosis:

Cerebral edema: No temperature, less irritation, no hyperaesthesia
Spinal cord compression: No temperature, paralysis- flaccid in nature, spastic paralysis in meningitis

Treatment:

Most promising antibiotics in farm animals in case of bacterial meningitis is trimethoprim-sulfonamide combinations, the third-generation cephalosporins, and fluoroquinolones
Sulphonamide and penicillin may be used. Sulphadiazine may be used as a drug of choice as it attains maximum concentration in CSF. It should be used for 5-7 days
Chloramphenicol @4-10 mg/kg, b.wt. may be used.
Crystalline penicillin may be given through intrathecal route as well as through IM route at 6 hours’ interval
Chloral hydrate or Phenobarbitone may be used to reduce spasm
Corticosteroids may be administered to reduce inflammation. Dexamethasone or Betamethasone may be given
50-500 ml of 50% glucose through IV route, magnesium sulphate 10-20% solution @20-100 cc through rectal route or mannitol @100-300 ml through IV to reduce intracranial tension.
Fluid should be offered ad libitum
Plenty of alkali should be provided particularly when sulpha drug are used.
Nutrition should be maintained and proper nursing and care should be extended.