meningitis - by Dr G Saritha M.V.Sc,S.V.Vu

veterinary study material

1. ENCEPHALITIS

2. Encephalitis is an inflammatory condition of brain caused from invasion by an infectious agent and includes inflammation of nervous tissue or vessel wall . It is characterized by irritational signs followed by sings of loss of nervous function. 4/19/2024 2 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Encephalitis

3. Viruses like rabies, pseudo rabies, Japanese B encephalitis, bovine malignant catarrh, sporadic bovine encephalomyelitis, hog cholera, African swine fever, Equine infectious encephalomyelitis, 4/19/2024 3 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Aetiology

4. borna disease, scrapie, louping ill, visna, viral caprine leucoencephalomyelitis, western encephalitis of dog, infectious canine hepatitis, canine distemper, herpese canis encephalitis and parvoviral encephalitis. 4/19/2024 4 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

5. Bacterial agents like listeria, necrobacillus, haemophilus, enterotoxaemia, salmonella and erysipelas. 4/19/2024 5 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

6. Parasites like migratory larvae, multiceps multiceps and coccidiosis Fungal agents like cryptococcosis, coccidiomyces, histoplasma, blastomyces, aspergillus and mucor sp. 4/19/2024 6 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

7. Ricketsial agent - toxoplasma Toxic agents like lead, arsenic, salt poisoning, ipomia plant, etc. Trauma, vaccinations, allergy, old dog encephalitis and infections spreading from eyes, nasal sinus and external ears are also probable causes. 4/19/2024 7 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

8. Virus invasion causes death of neurons while bacteria and certain viruses (e.g. bovine malignant catarrh and sporadic bovine encephalomyelitis) affect principally vasculature . Virus may enter the nervous tissue by progressive peripheral nerve trunk (e.g. rabies, pseudo rabies and listeria monocytogenes). Entry of infectious agents can also occur via olfactory nerve. 4/19/2024 8 DEPT.OF VETY.MEDICINE, Pathogenesis

9. Encephalitis is invariably associated with systemic signs like fever and its attendant signs of anorexia and depression. Initially there is a period of excitement or mania which comprises viciousness and uncontrolled activities like blind charging, bellowing and pawing. Later , it is followed by mental depression including head pressing. 4/19/2024 9 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR CLINICAL SIGNS

10. The usual irritational signs include convulsions, Nystagmus, photophobia, champing of jaws, **salivation and muscular tremors of face and limbs. 4/19/2024 10 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

11. champing of jaws, salivation and muscular tremors of face and limbs.

12. The signs of loss of nervous functions may vary from paresis with knuckling at lower limb joints, spasticity of limbs with resultant ataxia to complete paralysis. 4/19/2024 12 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

13. Deviation of head, circling, abnormalities of posture, ataxia and in coordination occur more commonly as residual signs after recovery from acute stage. In Listeriosis , there is unilateral facial paralysis while in pseudo rabies and scrapie , par aesthesia and hyper aesthesia occur. Ataxia video 4/19/2024 13 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

14. ATAXIA 4/19/2024 14 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

15. There is no gross lesions of CNS but, lesions of other organs specific to the disease can be seen. Histological lesions vary with the type and mode of action of causative agent 4/19/2024 15 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR NECROPSY FINDINGS

16. Diagnosis depends to a great extent on the recognition of clinical signs of specific encephalitides . History and clinical pathology are important in poisoning cases. 4/19/2024 16 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR DIAGNOSIS

17. Encephalitis should be differentiated from acute cerebral oedema, focal space occupying lesions, poisonings, hypovitaminosis A, hypoglycaemia, Encephalomalacia and meniningitis. Encephalitis and meningitis are commonly associated with fever and toxaemia , while it is not so with other conditions. CSF analysis will reveal increased cell count in meningitis. 4/19/2024 17 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

18. Treatment to the specific agent should be given. If there is fever, antipyrogens like analgin (cattle & horse 10-30 gm and dog & cat 0.5 – 2.5 gm i/m or iv) or paracetamol (cattle & horse 1.5-3.0 gm i/m and dog & cat 0.75 – 1.5 gm orally bid) are to be administered. 4/19/2024 18 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR DIAGNOSIS

19. Hyperthermia due to tremors or seizures can be controlled by cold water application, ice packs or alcohol baths. In case of convulsions , anticonvulsants Dog: phenobarbitone 1.5 – 5 mg/kg i/v, 1-1.5 mg/kg i/m, 2.2 – 6.6 mg/kg orally; phenytoin 50 mg/kg/day in two divided doses orally; sodium valproate 60 mg/kg orally tid) are indicated while sedation ( diazepam 2-5 mg tid) is done during excitement stage. 4/19/2024 19 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

20. Corticosteroids betamethasone or dexamethasone : cattle & horse 10-30 mg, sheep & goat 2-5 mg, dogs & cats 0.25 – 0.5 mg i/m or i/v; prednisolone 1% soln : cattle & horse 0.5 mg/kg or 10-20 ml i/m, dog& cats 1-3 ml i/m help in recovery of the case. The symptomatic treatments should be followed until the disappearance of the clinical signs. 4/19/2024 20 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

21. Specific treatment to poisonings is necessary. In case of lead poisoning , calcium versenate (calcium di sodium EDTA) as 6% solution @ 1 ml/kg/day in divided doses of two to three times daily and thiamine hydrochloride @ 2mg/kg s/c may be given. 4/19/2024 21 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

22. In cases of arsenic poisoning , sodium thio sulfate 15-30 gm in 100-200 ml of water i/v followed by oral dosing of 30-60 gm at 6 th hourly intervals is indicated. BAL (2,3, dimercapto propanol) is efficient antidote for organic arsenical poisoning. 4/19/2024 22 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

23. Recumbent animals should be frequently turned to prevent decubital ulcers and passive congestion of lungs. There may be need for expression of bladder and use of suppositories to prevent constipation . 4/19/2024 23 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

24. MENINGITIS

25. Meningitis is inflammation of meninges and occurs due to bacterial or viral invasion of central nervous system . It is seen most commonly as a complication of a pre-existing disease and clinically manifested by fever, cutaneous hyperaesthesisa and rigidity of muscles 4/19/2024 25 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR MENINGITIS

26. Septicaemia in young animals caused by streptococcus, coliform and Salmonella infections, strangles in horses, Listeriosis, haemophilus, pasteurellosis, Leptospirosis, tuberculosis, pseudomonas aeruginosa mastitis of cattle and goats, Erysipelas. 4/19/2024 26 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR AETIOLOGY

27. Cryptococcus and Actinomyces sp. in horses and Mycoplasma mycoides in goats are the common bacterial agents associated with the disease. Infections take place through haemotogenous route . Most cases of viral encephalitides also cause meningitis. 4/19/2024 27 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

28. Direct extension of infectious agents may occur from fracture of skull, osteomyelitis, spinal cord disc protrusion, sinusitis, otitis, cauterization during dehorning and haemorrhage into sub- arachnoid space. Metastasis or embolic showers to CNS in case of left sided endocarditis are also probable causes of meningitis. 4/19/2024 28 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

29. The pyogenic bacteria cause inflammation around nerve trunk as they pass across subarachnoid space. The inflammatory swelling interferes with blood supply to brain and spinal cord. 4/19/2024 29 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR PATHOGENESIS

30. Inflammation of meninges also affects drainage of cerebrospinal fluid and associated signs of increased cerebrospinal fluid pressure develop. Thus, the clinical signs appear to be related to irritation of spinal nerve roots and neurons of cerebral cortex and to hydrocephalus . 4/19/2024 30 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

31. Acute meningitis develops suddenly and is accompanied by anorexia, fever and toxaemia in addition to nervous signs. Vomiting is common in early stages in pigs . 4/19/2024 31 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR CLINICAL FINDINGS

32. Nervous signs include generalized hyperaesthesisa, trismus, Opisthotonus, rigidity of neck and back leading to refusal to lower the head to eat and disturbed consciousness varying from excitement or mania (in early stages) to drowsiness and coma (in later stage). Blindness is common in cerebral meningitis . 4/19/2024 32 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

33. Young animals suffer from ophthalmitis with hypopyon. Pupillary light reflex is much slower than normal. Examination of fundus may reveal oedema of optic disc, congestion of retinal vessels and exudation. Respiration is usually slow and deep . However, Cheyne-Stokes or Biot’s respiration is often observed. 4/19/2024 33 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

34. Meningitis in farm animals is usually diffuse involving particularly brain stem and upper cervical cord. However, it may also be localized involving one or more cranial or spinal nerve. In such case, localized muscle tremor, hyperaesthesia and rigidity are noticed. The affected muscles are board like on palpation . Anaesthesia and paralysis may develop caudal to meningitis area. Clinical signs of the specific aetiology are also seen. 4/19/2024 34 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

35. Macroscopically, meninges are thickened with hyperaemia and haemorrhages. On microscopic examination, infiltration of tissue by neutrophils and lymphocytes is seen. Additional morbid changes specific to the cause may also be seen. 4/19/2024 35 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR NECROPSY FINDINGS

36. History and clinical signs are important in detecting the disease. There is neutrophilic leukocytosis of peripheral blood. Cerebrospinal fluid is turbid, and has tendency to clot. It contains high protein (20-270 mg/dl), increased cell count (>100 neutrophils/ m l) and normal (80% of blood level) or decreased (less than 50% of blood level) glucose levels. Bacteria may be seen on gram’s staining. 4/19/2024 36 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR DIAGNOSIS

37. Meningitis should be differentiated from encephalitis, acute cerebral oedema, spinal cord compression, cervical inter vertebral disc protrusion, hypoglycaemia and hypomagnesaemia. 4/19/2024 37 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

38. Treatment of meningitis is difficult due to which high mortality rate is observed. Antibiotics in large doses for several days intravenously or into cisterna magna or lumbosacral space are given. 4/19/2024 38 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Treatment

39. Chloramphenicol : Cattle and Horse – 2-4 mg/kg iv bid, 20-40 mg/kg bid im; Sheep and Goat – 10 mg/kg iv bid, 30-40 mg/kg im bid; Dog - 25-50 mg/kg iv, im, oral, bid 4/19/2024 39 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

40. Tirimethoprim – Sulfa : Large Animals - 30 mg/kg iv, im, oral, bid Dog - 15 mg/kg iv, im, oral bid 4/19/2024 40 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

41. Ampicillin : Cattle, Horse - 5-10 mg/kg/iv, im, tid Sheep and Goat - 5-10 mg/kg iv, im, tid Dogs - 10 mg/kg iv, im, tid ; 20 mg/kg tid orally 4/19/2024 41 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

42. Cefotaxime : Dog - 25-50 mg/kg/day iv in divided doses Cephaloridine : Dog - 15-30 mg/kg/day/i/m or iv in divided doses Enrofloxacin : Dog - 5mg / kg once daily Corticosteroids are used to combat deleterious effect of inflammation as outlined earlier. 4/19/2024 42 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

43. Muscle relaxants (glyceryl guaiacolate @ 90mg/kg as 10% solution in 5% dextrose) and anaesthesia, anticonvulsants, supportive therapy with intravenous fluids, antitoxin or toxin (immunization) and specific monoclonal antibodies are also used to manage the affected cases. 4/19/2024 43 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

44. 4/19/2024 44 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR D epression /stupor, profound weakness and recumbency

45. 4/19/2024 45 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis secondary to septicaemic Colibacillosis in a three-day-old calf that had failed to suck Colostrum.

46. 4/19/2024 46 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Bacterial meningitis. This neonatal calf was depressed

47. 4/19/2024 47 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Bacterial meningitis. calf, which is showing seizure activity, had a raised rectal temperature.

48. 4/19/2024 48 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR This calf with cerebral dysfunction (meningitis) is head pressing.

49. 4/19/2024 49 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Dorsiflexion of the neck in a calf with bacterial meningitis.

50. 4/19/2024 50 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: abnormal foreleg posture in heifer (Holstein, 4 weeks old)

51. 4/19/2024 51 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: calf leaning against wall, dilated pupils, frothing

52. 4/19/2024 52 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: recumbent dull calf with drooping ears and eyelids

53. 4/19/2024 53 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: extensor spasm and Opisthotonus in calf

54. 4/19/2024 54 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: Opisthotonus in calf

55. 4/19/2024 55 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis: congested meninges and brain at autopsy

56. 4/19/2024 56 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

57. 4/19/2024 57 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

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60. 4/19/2024 60 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

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62. 4/19/2024 62 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

63. 4/19/2024 63 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Pig, brain. Leptomeninges over the cerebral hemispheres are severely congested and contain foci of hemorrhage; the underlying gyri are flattened, and some sulci are cloudy due to the presence of purulent exudate (meningitis caused by Strep suis).

64. 4/19/2024 64 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Bacterial meningitis:  A neutrophil infiltrate in acute meningitis that involves the subarachnoid space

65. 4/19/2024 65 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR The  early  clinical  signs  of  meningitis  include lack of suck reflex, depression and weakness.

66. 4/19/2024 66 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Calves may show "head pressing" behaviour.

67. 4/19/2024 67 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Calves  are  blind  and  may  show  "star-gazing"   behaviour.

68. 4/19/2024 68 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Seizures  are  seen  in  meningitis  just  before death.

69. 4/19/2024 69 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Suppurative meningitis at the base of the brain of a calf (the milky white material in the center = pus or exudate)

70. 4/19/2024 70 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Typical clinical Streptococcal meningitis

71. 4/19/2024 71 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR High stocking rates post weaning are a major trigger of Streptococcal meningitis

72. 4/19/2024 72 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Suppurative meningitis  more common in large animals including pigs

73. 4/19/2024 73 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Streptococcus suis can cause suppurative meningitis in pigs

74. 4/19/2024 74 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningitis--inflammation of the meninges, Meningoencephalitis--inflammation of the meninges and brain- Magnetic Resonance Imaging (MRI)

75. 4/19/2024 75 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Meningomyelitis--inflammation of the meninges and spinal cord

76. 4/19/2024 76 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Acute Meningitis

77. 4/19/2024 77 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

78. 4/19/2024 78 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR Sulci may also fill with exudate. Note the milky purulent exudate in the sulci (arrows) in this brain.

79. 4/19/2024 79 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR

80. THANK YOU 4/19/2024 80 DEPT.OF VETY.MEDICINE,C.V.Sc.,PRODDATUR