1. Malignant Catarrhal Fever Symptoms
Jeffrey Musser, DVM, PhD Professor Moritz van Vuuren
Suzanne Burnham, DVM
Texas A&M University University of Pretoria
College of Veterinary Medicine Department of
Veterinary Tropical Diseases
Malignant Catarrhal Fever

2. Malignant Catarrhal Fever
Host Range
The disease can occur in cattle, domesticated buffaloes, a wide range of captive antelopes and deer, and free-living deer.
Malignant Catarrhal Fever

3. Malignant Catarrhal Fever
Host Range
Under natural conditions only domestic cattle and deer develop clinical signs
MCF has never been reported in free-living wild animals in Africa
Malignant Catarrhal Fever

4. Malignant Catarrhal Fever
Host Range
In zoological collections a wide variety of ruminant species have been reported to develop clinical signs
Rabbits can be infected experimentally
Malignant Catarrhal Fever

5. Malignant Catarrhal Fever
Host Range
It was recently confirmed in pigs in Scandinavia
Malignant Catarrhal Fever

6. Reservoir ruminant species
Blue wildebeest
Black wildebeest
Domestic sheep
Goats
Malignant Catarrhal Fever

7. Malignant Catarrhal Fever
Blue Wildebeest
Malignant Catarrhal Fever

8. Malignant Catarrhal Fever
South Africa is the only natural habitat of the black wildebeest. The populations were nearly decimated by hunters but have recently increased in number. Prof. Moritz van Vuuren
Black Wildebeest
Malignant Catarrhal Fever

9. Transmission Neonatal and adolescent wildebeest shed virus
Malignant Catarrhal Fever

10. Transmission from reservoir animals to domestic cattle, deer
contact with calving wildebeest
contact with lambing sheep
Primarily the virus is cell associated. Cell-free virus is shed in nasal secretions by neonatal and adolescent sheep. Neonatal wildebeest may shed cell-free virus in lacrimal and nasal secretions and in feces up to 4 months of age.
Malignant Catarrhal Fever

11. Malignant Catarrhal Fever
Cattle are more susceptible to
Wildebeest derived MCF
than to the sheep or goat MCF
Bay Haven Farm Cleveland Bay Horses
Africa Dreams Safais: the Serengeti National Park
Malignant Catarrhal Fever

12. Congenital Transmission
Cow will die then later calf will die
Because the virus is usually intracellular there is no cow to cow transmission. Cattle are considered the dead end host.
Malignant Catarrhal Fever

13. Malignant Catarrhal Fever: Clinical Signs
In some cases MCF presents as chronic alopecia and weight loss as with deer infected with the Caprine herpesvirus.
However, MCF is typically fatal.
Malignant Catarrhal Fever

14. Malignant Catarrhal Fever
Clinical Signs
There are many factors that affect the duration of the disease in different species
The severity of the clinical symptoms will depend on those factors. Mortality is usually 100% but some animals face weeks of progressive disease
For this reasons, once the disease is identified, most elect to euthanized the affected animal.
Malignant Catarrhal Fever

15. Malignant Catarrhal Fever
Clinical Signs
High fever °F ( °C)
Depression
In deer - sudden death
Deer and bison that survive 2-3 days:
Hemorrhagic diarrhea
Bloody urine
Corneal opacity
Then death
Malignant Catarrhal Fever

16. Malignant Catarrhal Fever
Clinical Signs
The longer the animal survives the course of the disease the more severe the signs become.
For example, animals that die acutely may not develop lymphadenopathy or corneal opacity
Malignant Catarrhal Fever

17. As the disease progresses:
Catarrhal inflammation
Erosions and exudates in upper respiratory tract, ocular and oral mucosa
Swollen lymph nodes
Lameness
CNS signs (depression, tremors, stupor, hypo-responsive, aggression, convulsions
Malignant Catarrhal Fever

18. Malignant Catarrhal Fever
Clinical Signs
On average the time to death for European cattle is longer than for deer, bison and water buffalo; usually 7-17 days after the appearance of clinical signs
In cattle the swollen lymph nodes and severe eye lesions are more frequent
Malignant Catarrhal Fever

19. Malignant Catarrhal Fever
Clinical Signs
Hemorrhagic enteritis and cystitis are more frequently seen in bison and deer than in cattle
Skin lesions are common in animals that do not succumb quickly
Most eventually die, about 5% recover clinically
Malignant Catarrhal Fever

20. Malignant Catarrhal Fever
Clinical signs
Depressed and VERY SICK
Stertorous respiration
Enlarged lymph nodes
Malignant Catarrhal Fever

21. Malignant Catarrhal Fever
Clinical Signs
Present with extended head, stertorous breathing, and lesions in the oral mucosa. Also notice the encrustation around the muzzle. MvV
Animals suffer, are painful and cannot breathe well
Malignant Catarrhal Fever

22. Malignant Catarrhal Fever
Clinical Signs
Secondary bacterial bronchopneumonia may be eventual cause of death if not euthanized first. Animals suffer, are painful and cannot breathe well. Euthanasia is usually recommended.
Mvv
Secondary bacterial bronchopneumonia may be eventual cause of death if not euthanized first
Malignant Catarrhal Fever

23. Malignant Catarrhal Fever
Clinical Signs
Cattle stand with neck stretched out and eyes closed due to painful ophthalmia. This cow also has a nasal discharge. MvV
Painful swollen eyes
Malignant Catarrhal Fever

24. Malignant Catarrhal Fever
Clinical Signs
Ocular and
nasal discharge cb
Malignant Catarrhal Fever

25. Malignant Catarrhal Fever
Clinical Signs cb
“snotsiekte”
Malignant Catarrhal Fever

26. Mucopurulent discharge, crusting occludes the nostril;
Mucopurulent discharge, crusting occludes the nostril; animal begins open mouth breathing. MvV
Mucopurulent discharge, crusting occludes the nostril;
animal begins open mouth breathing.
Malignant Catarrhal Fever

27. Malignant Catarrhal Fever
Erosions develop MvV
Malignant Catarrhal Fever

28. Malignant Catarrhal Fever
Epithelial erosions, severe encrustation of the nostril. MvV
Malignant Catarrhal Fever

29. Characteristic of MCF Early corneal opacity begins at the limbuscb
Progresses to total opacity
Malignant Catarrhal Fever

30. Malignant Catarrhal Fever
Clinical Signs
Severe panophthalmitis, hypopion, corneal erosions are more frequent in cattle
mvv
Malignant Catarrhal Fever

31. Malignant Catarrhal Fever
Severe Ocular lesions
mvv
Painful Conjunctivitis
Malignant Catarrhal Fever

32. Severe Ocular lesions Progresses to corneal opacity
mvv
Progresses to corneal opacity
beginning at Limbus
Malignant Catarrhal Fever

33. Malignant Catarrhal Fever
Severe Ocular lesions
Eye lesions are almost pathognomonic. Almost always present in cattle, corneal opacities are bilateral and begin at lateral limbus and progress to center. Hypopion, ulceration, complete opacity and blindness ensue. MvV
Characteristic eye lesions
Malignant Catarrhal Fever

34. Malignant Catarrhal Fever
Severe Ocular lesions
mvv
Characteristic eye lesions
Malignant Catarrhal Fever

35. Malignant Catarrhal Fever
Severe Ocular lesions
mvv
Malignant Catarrhal Fever

36. Oral Lesions Erosions on gums, dental pad and near teeth
No lesions on the dorsal surface of the tongue. MvV
Malignant Catarrhal Fever

37. Oral Lesions
Erosions near the teeth
mvv
Malignant Catarrhal Fever

38. Oral Lesions Necrosis of papillae similar to rinderpest mvv
Malignant Catarrhal Fever

39. Oral Lesions Erosions here are similar to bluetongue in Africa mvv
Malignant Catarrhal Fever

40. Malignant Catarrhal Fever
Oral Lesions cb
Erosions of papillae
Malignant Catarrhal Fever

41. Malignant Catarrhal Fever
Oral Lesions
mvv
Malignant Catarrhal Fever

42. Erosions in squamous (anterior) portion of nasal cavitycb
Erosions in squamous (anterior) portion of nasal cavity
Malignant Catarrhal Fever

43. Enlarged and edematous
Lymph nodes become enlarged if the animal has survived more than a few days of the disease. On cross section the lymph nodes are edematous and sometimes hemorrhagic. M. van Vuuren
Enlarged and edematous
lymph nodes
Malignant Catarrhal Fever

44. Malignant Catarrhal Fever
Moist necrotic
dermatitis with
exudation and
encrustations
Skin lesions associated
with both sheep form
and wildebeest derived.
Resembles foot-and-mouth
disease
mvv
Malignant Catarrhal Fever

45. Malignant Catarrhal Fever
Mild diarrhea
sometimes seen
which is black and
tarry, but not
effusive
Malignant Catarrhal Fever

46. Malignant Catarrhal Fever
In terminal stages CNS
symptoms: falling, circling,
head pressing, high stepping
convulsions, then death
mvv
Malignant Catarrhal Fever

47. Clinical Signs in Swine
From a case in Norway:
Symptoms reported as: hyperemic conjunctiva, vomiting, restlessness and anorexia. The rectal temperature was 41° C, the respiratory rate was 33 per minute, and the heart rate was 110 per minute. Despite parenteral antibiotic treatment, the symptoms worsened and the pig died 5 days after onset of disease. Over a short period, three other adult swine in the same herd died after showing similar clinical signs.
LYken T, Aleksandersen M, Reid H, Pow I: Malignant catarrhal fever in swine caused by Ovine herpesvirus-2 in Norway. Vet Rec 143: , 1998
September 11, 2003 — Michael Meredith (ed. Harry Snelson)
Malignant catarrhal fever (MCF) is usually encountered as a fatal infectious disease of cattle and cervids (deer). The disease occurs world-wide but is not common except in some parts of Africa. Wild ruminants can be sub-clinical sources of MCF in Africa and sheep can be an important asymptomatic reservoir of the virus elsewhere.
Now the sheep-associated MCF virus, Ovine Herpesvirus 2 (OvHV-2), has been identified in Swiss pigs as the causative agent of a disease which has been termed Porcine Malignant Catarrhal Fever (PMCF). The Swiss researchers suggest that the disease may be "heavily underestimated" in swine because the clinical signs and diagnostic procedures are not generally known.
In sheep, MCF virus excretion occurs in semen and sexual transmission of OvHV-2 is believed to be important in the epidemiology of the virus.
Bratberg B: Acute vasculitis in pigs: a porcine counterpart to malignant catarrhal fever. Proc Congress Internatl Pig Vet Soc, Copenhagen, Denmark, p. 353, 1980
Kurtze H: Überträgung des “Bösartigen Katarrhalfiebers des Rindes” auf ein Schwein. (In German). Deutsche Tierärtzliche Wochenschrift 57:261, 1950
In sheep, MCF virus excretion occurs in semen and sexual transmission of OvHV-2 is believed to be important in the epidemiology of the virus.
Malignant Catarrhal Fever

48. Clinical Features Summary
Incubation period is LONG – weeks to months
Morbidity LOW
Clinical illness – weight loss, enlarged lymph nodes, corneal opacity, rhinitis
Mortality – 100%
Dr Corrie Brown
Malignant Catarrhal Fever

49. Malignant Catarrhal Fever
Diagnosis at Necropsy
The disease is systemic and lesions can be found in any organ
Inflammation and necrosis of the respiratory, alimentary and urinary mucosa
Generalized lymphoid proliferation and necrosis
Widespread vasculitis
Malignant Catarrhal Fever

50. Focally disseminated erosions and ulcerations in the GIT
Professor Moritz van Vuuren
Focally disseminated erosions and ulcerations in the GIT
Malignant Catarrhal Fever

51. Focally disseminated erosions and ulcerations in the GIT
Professor Moritz van Vuuren
Erosions ocurr from the esophagus to the rumen. Prominent lesions in the abomasum is common feature of MCF.
Focally disseminated erosions and ulcerations in the GIT
Malignant Catarrhal Fever

52. “button ulcers” 5-10 cm erosions
Professor Moritz van Vuuren
Focally disseminated erosions and ulcerations in the GIT
“button ulcers” 5-10 cm erosions
Malignant Catarrhal Fever

53. Malignant Catarrhal Fever
Professor Moritz van Vuuren
Frequently see erosions in the bladder mucosa
Malignant Catarrhal Fever

54. Malignant Catarrhal Fever
Professor Moritz van Vuuren
Lymphoid infiltration
Malignant Catarrhal Fever

55. Multifocal lymphoid infiltration
Professor Moritz van Vuuren
Prominent white nodules representing intramural and perivascular proliferation may be apparent. (Merck Veterinary Manual 9th Ed.)
Multifocal lymphoid infiltration
Malignant Catarrhal Fever

56. Multifocal lymphoid infiltration
Professor Moritz van Vuuren
Multifocal lymphoid infiltration
Malignant Catarrhal Fever

57. Malignant Catarrhal Fever

58. Enlarged lymphoid tissue – everywhere – looks like lymphoma
Dr Corrie Brown
Tonsils bulge
Lymph nodes – TOO BIG
Malignant Catarrhal Fever

59. Hemal nodes are prominent
Dr Corrie Brown
Spleen infiltrated
Malignant Catarrhal Fever

60. Peyer’s patches stand out
Dr Corrie Brown
Peyer’s patches stand out
Malignant Catarrhal Fever

61. Malignant Catarrhal Fever
Diagnosis
Dr Corrie Brown
Malignant Catarrhal Fever

62. Malignant Catarrhal Fever
Diagnosis
Dr Corrie Brown
Malignant Catarrhal Fever

63. Malignant Catarrhal Fever
Histopathology
T lymphocyte
hyperplasia,
cell necrosis
T lymphocyte hyperplasia, cell necrosis
Malignant Catarrhal Fever

64. Malignant Catarrhal Fever
Histopathology
Severe necrotizing
vasculitis
Perivascular
lymphoid infiltration
Malignant Catarrhal Fever

65. Malignant Catarrhal Fever
Histopathology
Perivascular lymphoid
infiltration of arterioles
Malignant Catarrhal Fever

66. Malignant Catarrhal Fever
Summary
Think Malignant Catarrhal fever when:
Only a few cattle are affected and they die
Cattle have been exposed to sheep during lambing season
Cattle have severe respiratory symptoms and conjunctivitis with cornel opacity
Lesions are on the ventral side of the tongue
Malignant Catarrhal Fever

67. Malignant Catarrhal Fever
This presentation is a collaborative effort
Malignant Catarrhal Fever