Transcript Epizootic of Mucopurulent Nasal Discharge in African Hoofstock

Epizootic of
Mucopurulent Nasal
Discharge in African
Hoofstock
L.J. Venter
South Africa
Addra Gazelle, Gazella dama
ruficollis
Cape Buffalo, Syncerus caffer
caffer
Black-faced Impala,
Aepyceros melampus petersi
Indian Guar, Bos Frontalis
Enclosures
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5 confirmed cases occurred in 4
enclosures
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Areas ranged from 300m2 to 2500 m2
All enclosures have night-quarter facilities
Enclosure 41
Enclosure 126 & 127
Enclosure 138
Enclosure 162
Black-faced Impala
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Clinical signs and history
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Intermittent episodes of weakness and
lethargy for 2 months
Admitted to hospital in a state of collapse and
died during initial treatment
Gross Necropsy Findings
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Mild icterus and mild fibrinous ascites in the
carcass
Severe, generalized lymphadenopathy
Abomasal ulceration
Moderate, diffuse, sub-acute hepatitis with
cholestasis
Mild nephrosis
Mild splenic atrophy
Diffuse, severe pulmonary congestion and
edema
Histopathology
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Severe, multifocal perivasculitis
Fibrinous necrotizing vasculitis
Lymphoid hyperplasia
Necrotizing enteritis
Severe purulent interstitial pneumonia
Pulmonary edema, hemorrhage,
microemboli, alveolar necrosis, atelectasis
Cape Buffalo-1
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Clinical Signs and history
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12 days listlessness, mucopurulent nasal
discharge, excessive lacrimation,
blepharospasm, corneal opacity, ataxia
Gross Necropsy Findings
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Mild cachexia
Focal ulcerations of buccal mucosa
Mild to moderate, diffuse, edema and
congestion of the lungs
Moderate, chronic, localized caseous
necrotis omasitis
Histopathology
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Focal to focally-extensive, severe, chronic
necrogranulomatous myositis
Brain, spinal cord, meninges: mild diffuse
congestion and edema
Mild, multifocal lymphocytic perivasculitis
Moderate, multifocal necrogranulomatous
lymphangitis of mesenteric lymph nodes
Multifocal interstitial lymphocytic nephritis
Cape Buffalo-2
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PCR indicated Wildebeest strain of MCF
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No wildebeest at Pretoria for 20 years
Test repeated 5 times on different tissues,
same results
Cape Buffalo-2
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Clinical Signs and history
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Coughing
Severe mucopurulent nasal discharge
Corneal opacity
Light sensitivity
Lacrimation
Cape Buffalo-2
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Diagnostics
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Animal immobilized
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Bronchoscopy
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Treatment
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Severe tracheobronchitis
with diptheritic membrane
Extensive antibiotic therapy for 2 weeks
Outcome
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Euthanasia for humane reasons
Gross Necropsy Findings
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Severe diffuse keratitis
Moderate conjunctivitis
Muzzle and nostrils:
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Mild, multifocal hyperkeratosis and exudative
dermatitis with crust formation
Severe, acute, diffuse fibrinopurulent
rhinitis with hyperemia of the mucous
membranes and turbinates
Gross necropsy Findings-con’t
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Severe, acute, diffuse fibrinohemorrhagic
pharyngitis, laryngitis, and tracheitis
Severe, diffuse congestion and edema
with fibrinopurulent bronchopneumonia of
the apical and cardiac lung lobes
Severe Sarcocystis sp. infection of the
gluteal muscle
Histopathology
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Brain: Mild, multifocal, subacute lymphocytic
perivasculitis
Eye: Severe, multifocal-to-coalescing subacute to
chronic rhinotracheitis with mucosal and vascular
necrosis.
Lungs: Severe, multifocal to coalescing, subacute to
chronic bronchointerstitial pneumonia with alveolar,
bronchial, and vascular necrosis
Kidneys: Mild to moderate, subacute lymphocytic
nephritis with interstitial and periglomerular infiltration of
lymphoid cells
Skeletal Muscle: Hemorrhage, necrosis, and edema as
well as scattered Sarcocystis spp. parasites
Addra Gazelle
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Clinical Signs and history
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Listlessness
Anorexia
Regurgitation of rumenal fluid
Abnormal high stepping gait, chewing gum fits
over a period of 4 days
Outcome
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Humane euthanasia
Gross Necropsy Findings
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Moderate congestion of the carcass
Severe, acute, locally extensive necrotic
bronchopneumnia involving the right
cranioventral lung lobe.
No gross lesions of the upper alimentary
system
Histopathology
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Lungs: Acute bronchopneumonia
Liver: Focal hepatocellular necrosis
Kidneys: moderate nephrosis and cast
formation
Indian Guar
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Clinical Signs and history
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No history of illness
Animal found dead in the enclosure with two
penetration wounds cranial to the scrotum
Gross Necropsy Findings
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Penetration wounds present cranial to
scrotum, portions of the small intestines
had herniated through one of the holes
Herniated small intestine was intensly
congested with frank blood in the lumen
Another penetrating wound was found in
the left flank
Gross Necropsy findings-con’t
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A large blood clot and rumenal contents were
present in the abdomen
Fibrin strands were visible on the serosal
surface of the abdominal organs
Penetrating wounds were seen in the rumen and
in the portion of herniated intestine
A single penetrating wound was seen in the
rectal wall
Histopathology
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CNS: Mild, subacute meningitis
Lymph nodes: Peripheral nodes exhibited
marked follicular atrophy, with medullary
histiocytosis
Cardiac: Myocardium had multifocal
interstitial accumulations of lymphocytes
were visible as well as focal areas of acute
myocardial necrosis
Five PCR Confirmed Cases
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Addra Gazelle
Cape Buffalo (2)
Black Faced Impala
Indian Guar
Background
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1990-2003
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21 Cases of MCF reported in 9 different
species in the National Zoological Gardens of
South Africa
5 Asia Deer
 4 Cape Buffalo
 3 Indian Guar (Asiatic Ox)
 2 American Bison, Pere David Deer
 1 each of Barbary Sheep, European Bison, Addra
Gazelle, Black Faced Impala, Kudu
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Background
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Five cases were confirmed as MCF by
PCR
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Highly specific and sensitive for MCF
These cases will be discussed
Remainder of the cases were diagnosed
based on:
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Clinical signs
Macroscopic pathology
Histopathology
Malignant Catarrhal Fever
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Acute, sporadic, invariably fatal disease of
Bovidae and Cervidae
Agents implicated in causing disease
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Alcephaline herpes virus I (AHV-I)
Associated with the wild blue wildebeest
 Occurs only in Africa
 “Wildebeest-derived” MCF
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Ovine herpes virus II (OHV-II)
Occurs worldwide
 “Sheep-associated” MCF
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MCF-Transmission
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AHV-I
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Horizontally and vertically in wildebeest herds,
calves may be infected in utero
Wildebeest develop no clinical signs
Fomites are largest source of disease
transmission
Virus excreted in nasal/ocular discharge and
feces
MCF-Transmission--con’t
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Similar mode of transmission in sheep
Susceptible ruminants are end-hosts which develop
clinical signs of the disease but DO NOT spread the
disease horizontally within susceptible population
Sub-clinical infection in cattle and deer has been
described with clinical manifestations under severe
stress
Close contact with wildebeest is NOT a prerequisite for
the development of the disease in cattle
Minimum separation distance of 1000m is suggested
between wildebeest and cattle
MCF-Clinical Signs
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Varies from sub-acute to chronic
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Deer: Per-acute disease
Cattle: Acute disease
Signs in acute form
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Fever, depression, lymphadenopathy, serous to
mucopurulent nasal and ocular discharge, oral
ulcerations and erosions, corneal opacity, diarrhea,
ulceration of the skin of the perineum, vulva, coronet,
and interdigital area, epithelial necrosis, interstitial
infiltration of organs by lymphocytes and widespread
angiitis
CNS signs: hyperaesthesia, hypermetria, tremors and
convulsions
MCF-Diagnosis
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Relies on observation of clinical signs and
herd signalment
Macroscopic necropsy examination
Histologic observation
Serologic investigation and PCR are
added diagnostic modalities
Control
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2 Sheep kept 30m behind the buffalo enclosure
(126 & 127) in the petting zoo
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Sold, no PCR tests performed
Movement of ungulates in and out of zoo was
restricted
Relevant personnel have been informed about
characteristics of MCF and are on heightened
alert for signs of the disease in all ungulate
species
PCR is part of the tests before any buffalo are
moved, not yet required by law
MCF-Prevention
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Separation of susceptible animals from
source of infection is the ONLY RELIABLE
way of preventing the disease
Comments and Discussion
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Interesting that Guar showed no clinical
signs
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Killed by the bull in the enclosure
Did the animal have the per-acute form that
lead to a change in behavior that caused the
bull to attack it? This is reported to happen in
wild animals.
Comments and Discussion
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The pathologists report for the Addra
comments mainly on the
bronchopneumonia and few “classic” signs
of MCF are described.
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As this diagnosis was made on PCR could it
be possible that the animal was a carrier?
Comments and Discussion
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Except for the one, buffalo all PCR results
indicated OHV-II as the cause of the
disease
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This unexpected PCR result causes one to
speculate on the existence of a possible AHVI carrier apart from wildebeest in the zoo.
SPECIES
Aepyceros melampus petersi
COMMON NAME
Black-faced impala
ID
AGE
909803 4m
SEX
DATE OF DEATH
14.05.2003
DIAGNOSTIC
METHOD
PCR
Syncerus caffer caffer
Syncerus caffer caffer
Bos frontalis
Gazella dama ruficollis
Bos frontalis
Bison bonasus bonasus
Axis axis
Bos frontalis
Axis axis
Axis axis
Tragelaphus strepsiceros
Axis axis
Syncerus caffer caffer
Axis axis
Syncerus caffer caffer
Bison bison
Bison bison
Elaphurus davidianus
Elaphurus davidianus
Ammotragus lervia
Cape Buffalo
Cape Buffalo
Indian Gaur
Addra Gazelle
Indian Gaur
European Bison
Axis deer
Indian Gaur
Axis deer
Axis deer
Kudu
Axis deer
Cape Buffalo
Axis deer
Cape Buffalo
American bison
American bison
Pere David's deer
Pere David's deer
Barbary sheep
905220
902064
906964
900148
903849
900047
904496
903716
900106
902764
900208
900098
901322
900809
900067
900042
900043
901076
900123
900976
M
F
M
M
F
F
F
F
F
F
F
M
M
F
F
M
F
M
F
M
06.06.2003
06.03.2003
29.07.1998
11.07.1998
20.05.1998
05.12.1995
01.10.1994
04.07.1994
11.05.1994
11.09.1992
03.06.1992
15.11.1991
06.11.1991
01.11.1991
16.09.1991
04.05.1991
30.03.1991
12.03.1991
27.02.1991
22.11.1990
PCR
PCR
PCR
PCR
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
Histopathology
12y,3m
11y,4m
5m
10y,2m
4y,7m
8y,2m
1m
3y,1m
13y,9m
2m
4y,5m
11y,10m
8m
1y,2m
2y,7m
16y,4m
16y,2m
5m
13y,1m
2m
COMMENT
Ovine strain
Wildebeest
strain
Ovine strain
Ovine strain
Ovine strain
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
SND
Pathologist
Neser
Neser
Neser
Pearson
vd Lugt
Williams
Williams
Collett
Pearson
Nesbit
Nesbit
Nesbit
Nesbit
Nesbit
Nesbit
Nesbit
Williams
Nesbit
Kriek
Nesbit
Unknown