|
|
Disease Author |
Dr Debra Bourne MA VetMB PhD MRCVS
(V.w5); Nikki Fox BVSc MRCVS (V.w103)
|
 |
Referees |
John Chitty BVetMed
CertZooMed MRCVS (V.w65);
Lord Soulsby of Swaffham Prior MA,PhD,DSc (H c: Mult) , AM(H c),DVM&S (H.c),DVMS(H.c) ,DVM(H,c) F.Med Sci.,Hon FRCVS F.Inst Biol. F.R.C.Path (H.c), DVSM, MRCVS
(V.w135) |
Major References /
Reviews
|
Code and Title List |
In Waterfowl
B11.39.w7:- BSAVA
Manual of Raptors, Pigeons and Waterfowl
B15:- Diseases
of Wild Waterfowl
B24:-
Helminths, Arthropods and Protozoa of Domesticated Animals
B36.28.w28:-
Field Manual of Wildlife Diseases
B37.x.w1:-
Handbook of Avian Medicine
J5.26.w1:-
Avian Diseases
P4.1993.w3:
- Proceedings Association of Avian Veterinarians
In Bears:
J11.84.w2, J212.5.w1
In Lagomorphs:
B529.15.w15, B601.11.w11; B603.3.w3;
B606.10.w10;
B614.10.w10
|
Other References
|
Code and Title List |
J1.12.w1, J1.13.w7, J1.15.w2, J1.17.w2, J1.17.w3, J1.17.w6, J1.26.w1, J1.27.w1:-
Journal of Wildlife Diseases
J3.70.w1:-
Veterinary Record
J4.99.w1:-
Journal of the American Veterinary Medical Association
J5.7.w2, J5.36.w5:- Avian
Diseases
In Bears:
J1.16.w11, J1.35.w6
P5.29.w5
In Lagomorphs:
J1.13.w16, J1.13.w17,
J1.16.w17, J1.18.w8,
J10.27.w2,
J40.7.w1, J381.37.w1,
J469.281.w1
|
Detailed Clinical and Pathological Characteristics
|
General |
WATERFOWL |
Usually asymptomatic in
waterfowl, with macrocysts as an incidental finding, particularly in the breast muscles,
at post mortem examination. |
Clinical
Characteristics
|
WATERFOWL |
- Usually asymptomatic.
- Lameness or weakness may be seen with severe infections; very rarely
paralysis.
- Heavy infections may increase susceptibility to predation and hunting.
(B11.39.w7,
B36.28.w28, B37.x.w1) |
| BEARS |
In two polar bears in a zoo in Anchorage,
Alaska: (J11.83.w1)
- Lethargy and anorexia. (J11.83.w1)
- Death after six days of illness, despite supportive treatment. (J11.83.w1)
In two-year-old American black bears (Ursus americanus - American black bear)
in a wild animal park in South Dakota:
- Clinical signs were "vague"; one bear died. (J212.5.w1)
|
| LAGOMORPHS |
- Asymptomatic in rabbits with light or moderate infections. (B614.10.w10)
- Lameness may be seen in very heavy infections. (B614.10.w10)
|
Incubation |
WATERFOWL |
At least three months
required for the development of visible cysts (B36.28.w28). |
| BEARS |
-- |
| LAGOMORPHS |
-- |
Mortality / Morbidity |
WATERFOWL |
Mortality due to this
disease is rare in waterfowl (B36.28.w28).
Mortality reported in a green-winged teal Anas crecca, which was emaciated at death
(J4.99.w1). |
| BEARS |
- Two polar bears in a zoo in Anchorage, Alaska, both died despite
supportive treatment. (J11.83.w1)
- In two-year-old American black bears (Ursus americanus - American black bear)
in a wild animal park in South Dakota, one bear died after a short
illness, one recovered after treatment, the third was lost to
follow-up. (J212.5.w1)
- No morbidity or mortality has been described in association with
sarcocysts in the muscle of Ursus americanus - American black
bears. (J1.35.w6,
J11.84.w2, J11.88.w2)
|
| LAGOMORPHS |
-
Clinical disease is often only seen in very heavy infections. (B614.10.w10)
- In the USA, this disease is endemic in wild Sylvilagus
rabbits. (B603.3.w3)
|
Pathology |
WATERFOWL |
Gross Pathology:Macrocysts are visible as white, cream or yellow ‘rice grain’
cylindrical lesions in breast muscles (most common site), other skeletal muscles, cardiac
muscle, in parallel streaks through the muscle. Muscle may have a gritty feel on cutting
due to calcification around cysts.
Histopathology:
- Focal granulomatous myositis, sometimes severe, may develop in association with
degenerating cysts: initial infiltration of lymphocytes and plasma cells, later also
macrophages, with necrotic muscle fibres adjacent, through to granulomas with caseous
necrotic core, surrounded by epithelioid and giant cells, with lymphocytes and plasma
cells peripherally.
(J5.26.w1,
B15, B36.28.w28, B37.x.w1) |
| BEARS |
Gross
In two Ursus maritimus - Polar
bears in a zoo in Anchorage, Alaska:
- General: jaundice, occasional petechiae and ecchymoses on the
viscera. (J11.83.w1)
- Hepatic: liver slightly swollen and mottled tan/red. In one bear, the gall bladder wall was
oedematous. (J11.83.w1)
Histopathology
In two polar bears in a zoo in Anchorage, Alaska:
- Hepatic: Acute hepatocellular necrosis. In the liver parenchyma, numerous foci of acute hepatocellular lytic necrosis, varying in size and random in distribution. Foci were haemorrhagic a few had low numbers of lymphocytes and
neutrophils. At the borders of some necrotic foci were swollen hepatocytes with slight vacuolation of the cytoplasm, mild nuclear pleomorphism and
occasionally developing protozoan parasites. (J11.83.w1)
- Morphologically the parasites found were identified as Sarcocystis. They
divided by endopolygeny, not endodyogeny, and merozoits lacked
rhoptries. (J11.83.w1)
- The parasites did not react by immunohistochemistry to Toxoplasma
gondii, Neospora caninum or Sarcocystis neurona.
(J11.83.w1)
In one two-year-old Ursus americanus - American black bear
in South Dakota:
- Hepatic: Acute random hepatic necrosis, moderate to severe. There was a mild mononuclear cell infiltrate, mainly in the portal zones. There was inflammation of some portal veins, and portal zone haemorrhage associated with this.
In the parenchyma, some necrotic foci had associated congestion and
haemorrhage.
In several hepatocytes, various developmental stages of a protozoan parasite were present, in and near necrotic foci. Infected hepatocytes generally appeared normal except for distended cytoplasm, and no inflammation was associated with the infected cells, rather, it appeared that inflammation and necrosis were associated with maturation and rupture of the
schizonts. (J212.5.w1)
- Developing schizonts, in the cytoplasm of hepatocytes, were described as large, basophilic, which occupied 50-80% of the cytoplasm of the hepatocyte when mature, causing peripheral displacement of the nucleus. The earliest schizont detected was 6 x 4
µm and its nucleus had a prominent nucleolus. later stages had a larger nucleus,
prominent nucleolus and clefts in the cytoplasm. Often, merozoites budded peripherally to leave a
residual body, up to 15 µm diameter, not condensed. Mature
schizonts, containing up to 36 merozoites, were up to 20 x 30 µm. Within the necrotic foci were numerous
merozoites, many degenerating. (J212.5.w1)
- Electron microscopy revealed schizonts free in the hepatocyte cytoplasm, not within host parasitophorous vacuole. Merozoites were found to contain a nucleus, conoid and
micronemes, but no rhoptries. (J212.5.w1)
- Parasites did not react to Toxoplasm gondii or Neospora caninum
but did react to Sarcocystis cruzi. (J212.5.w1)
Muscular sarcocystis:
- In a bear with Sarcocystis sp. sarcocysts in muscle, there
were no associated histopathological lesions. (J11.84.w2)
- There were no associated lesions associated with Sarcocystis
sp. sarcocyts found on microscopic examination of muscles in two Ursus americanus - American black bear
from Florida, during a survey in 1998-2000. (J11.88.w2)
- Sarcocysts were an incidental finding in striated muscle of a wild Ursus americanus - American black bear
in Minnesota. (J1.16.w11)
- In the tongues of two of 46 Ursus americanus - American black
bears from Oregon, one sarcocyst was 240 x 60 µm, the other
84 x 60 µm. (J1.35.w6)
- By electron microscopy, the wall of one cysts measured about 0.9
µm in thickness. (J1.35.w6)
- Sarcocysts were found in skeletal muscle of a 114-day-old Ursus
arctos - Brown bear at Rostock zoo. (P5.29.w5)
|
| LAGOMORPHS |
- Sarcocystosis lesions are
seen in cardiac and skeletal muscle, particularly in the flanks,
loins and hind legs.
- Sometimes they may be found in oesophageal striated muscle. (J1.18.w8)
Gross pathology
- In heavy infections, cysts (up to 5 mm long) may be seen as multiple
white streaks that run in the direction of the muscle fibre. (B614.10.w10)
Histopathology
- Usually intact cysts are seen in the muscle without any accompanying
inflammation. However, if the cyst wall degenerates, the invasion of
the released trophozoites can lead to severe focal myocarditis and
myositis. This is characterised by mineralisation and infiltration of
plasma cells, lymphocytes, macrophages and eosinophils. Scarring may
be prominent. (B614.10.w10)
|
Disease / Agent has been reported in either the wild or in
captivity in:
|
- Mortality reported in a green-winged teal Anas crecca, which was
emaciated at death (J4.99.w1).
- Macroscopic cysts have been reported frequently in dabbling ducks such as
mallard (Anas platyrhynchos, northern pintail Anas acuta, northern shoveler Anas
clypeata, (green winged) teal Anas crecca, American black duck Anas rubripes,
gadwall Anas strepera, mottled duck Anas fulvigula and American wigeon Anas
americana) with other ducks being more likely to have only microscopic cysts; cysts
are found infrequently in geese and swans (B15, B36.28.w28)
- Mallard Anas platyrhynchos, Northern shoveler Anas clypeata,
blue-winged teal Anas discors, green-winged teal Anas crecca, gadwall Anas
strepera, Northern pintail Anas acuta (J5.26.w1).
- Mottled duck Anas fulvigula in Louisiana, USA (J1.27.w1).
- American black ducks Anas americana in New Jersey, USA (J1.26.w1).
- Wild northern shoveler Anas clypeata in southwest Texas, USA (J1.13.w7).
- Magpie goose Anseranas semipalmata, Pacific black duck Anas
superciliosa and grey teal Anas gracilis (Anas gibberifrons gracilis) in
Australia (J1.15.w2)
- Wild green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
- Mallard Anas platyrhynchos in Texas, USA (J5.36.w5).
- Mallard Anas platyrhynchos, Northern shoveler Anas clypeata,
Pintail Anas acuta, American wigeon Anas americana, blue-winged teal Anas
discors, green-winged teal Anas crecca in North Dakota (J1.12.w1).
- Redhead Aythya americana, canvasback Aythya valisineria,
common goldeneye Bucephala clangula, green-winged teal Anas crecca, wood
duck Aix sponsa, greater scaup Aythya marila, bufflehead Bucephala
albeola, American widgeon Anas (Mareca) americana, blue-winged teal Anas
discors, northern shovelers Anas clypeata, mallard Anas
platyrhynchos, pintail
Anas acuta (J5.7.w2).
- Bufflehead Bucephala albeola recently imported to the UK from
North America, with note that the condition has also been seen in the mallard Anas
platyrhynchos, American black duck Anas rubripes, gadwall Anas strepera,
blue-winged teal Anas discors and northern shoveler Anas clypeata (J3.70.w1)
IN BEARS
- Sporozoan cysts, probably
Sarcocystis sp., were detected by histology in the heart and skeletal muscle of 11% of 53 bears during a survey of
Ursus americanus - American black bear
from six states in the southeastern USA, July 1973-November 1976. (J1.14.w10)
- Clinical (fatal) hepatic sarcocystosis was diagnosed in two polar bears in a zoo in Anchorage, Alaska.
(J11.83.w1)
- Hepatic sarcocystosis was confirmed by histopathology in one Ursus americanus - American black bear
at a wild animal park in South Dakota. (J212.5.w1)
- During a survey of muscles (diaphragm, abdominal muscle or carcass muscle) from 92 hunter-killed
Ursus americanus - American black bear
from North Carolina in November 1996, Sarcocystis sp. was detected in one bear. Two sarcocysts were found and identified structurally as
Sarcocystis. There were no associated lesions and the species was unknown; the structure of the sarcocyst wall was different form that of known
Sarcocysis spp. (J11.84.w2)
- Sarcocystis sp. was detected in the tongues of two of 46 Ursus americanus - American black
bears from Oregon, May-June 1995 and 1996. (J1.35.w6)
- Sarcocystis sp. sarcocyts were found on microscopic
examination of muscles in two of 132 Ursus americanus - American black bear
from Florida, 1998-2000. There were no associated lesions. (J11.88.w2)
- Sarcocysts were an incidental finding in striated muscle of a wild Ursus americanus - American black bear
in Minnesota. (J1.16.w11)
- Protozoal cysts which were identified by immunohistochemical
staining as Sarcocytis sp. were an incidental finding in the
cerebral neuropil of a nine-year-old free-living male Ursus americanus - American black bear
from Labrador, Canada which died from valvular endocarditis. (J1.36.w8)
IN LAGOMORPHS
|
Host Species
List |
WATERFOWL
LAGOMORPHS
|
Disease / Agent has been specifically reported in
Free-ranging populations of:
|
- Mallard Anas platyrhynchos, Northern shoveler Anas clypeata,
blue-winged teal Anas discors, green-winged teal Anas crecca, gadwall Anas
strepera, Northern pintail Anas acuta (J5.26.w1).
- Mottled duck Anas fulvigula in Louisiana, USA (J1.27.w1).
- American black ducks Anas americana in New Jersey, USA (J1.26.w1).
- Wild northern shoveler Anas clypeata in southwest Texas, USA (J1.13.w7).
- Magpie goose Anseranas semipalmata, Pacific black duck Anas
superciliosa and grey teal Anas gracilis (Anas gibberifrons gracilis) in
Australia (J1.15.w2)
- Wild green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
- Mallard Anas platyrhynchos in Texas, USA (J5.36.w5).
- Mallard Anas platyrhynchos, Northern shoveler Anas clypeata,
Pintail Anas acuta, American wigeon Anas americana, blue-winged teal Anas
discors, green-winged teal Anas crecca in North Dakota (J1.12.w1).
- Redhead Aythya americana, canvasback Aythya valisineria,
common goldeneye Bucephala clangula, green-winged teal Anas crecca, wood
duck Aix sponsa, greater scaup Aythya marila, American widgeon Anas
(Mareca) americana, blue-winged teal Anas discors, northern shovelers Anas
clypeata, mallard Anas platyrhynchos, pintail Anas acuta (J5.7.w2).
IN BEARS
- Sporozoan cysts, probably
Sarcocystis sp., were detected by histology in the heart and skeletal muscle of 11% of 53 bears during a survey of
Ursus americanus - American black bear
from six states in the southeastern USA, July 1973-November 1976. (J1.14.w10)
- Clinical (fatal) hepatic sarcocystosis was diagnosed in two polar bears in a zoo in Anchorage, Alaska.
(J11.83.w1)
- Hepatic sarcocystosis was confirmed by histopathology in one Ursus americanus - American black bear
at a wild animal park in South Dakota. (J212.5.w1)
- During a survey of muscles (diaphragm, abdominal muscle or carcass muscle) from 92 hunter-killed
Ursus americanus - American black bear
from North Carolina in November 1996, Sarcocystis sp. was detected in one bear. Two sarcocysts were found and identified structurally as
Sarcocystis. There were no associated lesions and the species was unknown; the structure of the sarcocyst wall was different form that of known
Sarcocysis spp. (J11.84.w2)
- Sarcoscystis sp. was detected in the tongues of two of 46 Ursus americanus - American black
bears from Oregon, May-June 1995 and 1996. (J1.35.w6)
- Sarcocystis sp. sarcocyts were found on microscopic
examination of muscles in two of 132 Ursus americanus - American black bear
from Florida, 1998-2000. There were no associated lesions. (J11.88.w2)
- Sarcocysts were an incidental finding in striated muscle of a wild Ursus americanus - American black bear
in Minnesota. (J1.16.w11)
- Protozoal cysts which were identified by immunohistochemical
staining as Sarcocytis sp. were an incidental finding in the
cerebral neuropil of a nine-year-old free-living male Ursus americanus - American black bear
from Labrador, Canada which died from valvular endocarditis. (J1.36.w8)
IN LAGOMORPHS
|
Host Species
List |
WATERFOWL
LAGOMORPHS
|
