Detailed Clinical and Pathological Characteristics
|
General |
- Infection may be
inapparent or cause severe disease with non-specific signs, neurological
signs, abortion and/or other signs, depending on the species affected. (Th3,
J4.205.w1)
- Clinical signs are variable; different tissues may be most affected.
(B22.32.w15)
|
| General |
WATERFOWL |
Infection usually
subclinical in waterfowl. Systemic disease causing non-specific and nervous signs. |
| BEARS |
Usually subclinical, but
clinical, fatal disease has been reported. |
| LAGOMORPHS |
In rabbits
- Infection is usually
subclinical and latent. (B601.11.w11)
In hares
|
| FERRETS |
- Stunted growth has been noted in neonatal ferrets that acquired
Toxoplasma gondii oocysts. (B626,
J10.34.w1)
|
| GREAT APES |
|
Clinical
Characteristics
|
WATERFOWL |
Listlessness, nervous signs
(e.g. paralysis of feet, opisthotonus,
nervousness, tremors),
diarrhoea,
ruffled feathers, pasted eyelids, emaciation, anorexia, diarrhoea (J5.6.w1, B13.46.w1, B16.19.w1) |
| BEARS |
Fatal infection in a
six-day-old Ursus maritimus - Polar bear.
(P5.31.w2) |
| LAGOMORPHS |
-
Acute, chronic and latent forms of toxoplasmosis have been described in
rabbits. (J63.8.w1)
-
Toxoplasma gondii infection in rabbits is usually
subclinical and latent (B601.11.w11,
J15.28.w1)
or causes only mild signs (transient fever). (J42.117.w1)
Acute toxoplasmosis
Clinical findings may include:
- Anorexia, central nervous system signs, raised temperature, death
within 2 - 8 days. (J63.8.w1,
J495.42.w3)
- Sudden anorexia (B603.4.w4,
B614.10.w10)
- Fever (>104 °F) (B601.11.w11,
B603.4.w4, B614.10.w10,
J15.28.w1)
- Lethargy (B601.11.w11,
B614.10.w10, B603.4.w4)
- Hepatosplenomegaly may occur; the spleen can become ten times its
normal size (B603.4.w4)
- Increased respiratory rate (tachypnoea) (B614.10.w10,
J42.117.w1)
- Serous or seropurulent nasal and ocular discharge (B614.10.w10,
J42.117.w1, J63.8.w1)
- Head tremors (B601.11.w11,
B602.20.w20, B609.2.w2,
B614.10.w10, J15.28.w1)
- Head tilt (B600.12.w12,
B606.13.w13, B609.2.w2)
- Note: toxoplasmosis is a rare cause of head tilt. (B603.1.w1)
- Ataxia (B601.11.w11,
B602.20.w20, B603.3.w3,
B606.13.w13,
B609.2.w2,
B614.10.w10, J15.28.w1)
- Dysuria (B603.1.w1)
- Muscle tremors (B603.4.w4,
B606.13.w13)
- Convulsions may occur within a few days of the onset of the clinical
signs listed above. (B603.4.w4,
B609.2.w2,
B614.10.w10, J63.8.w1)
- Posterior paresis (B602.20.w20,
B603.3.w3, B609.2.w2,
J15.28.w1)
- Paralysis in some cases, particularly in the hindquarters.
(B601.11.w11, B602.20.w20,
B603.4.w4, B606.13.w13,
B609.2.w2,
B614.10.w10, J63.8.w1)
- Tetraplegia (B602.20.w20,
B603.1.w1, B609.2.w2)
- Death will usually occur after two to eight days of illness. (B603.4.w4,
B614.10.w10, J15.28.w1,
J63.8.w1)
- In three pet French lop rabbits: (J495.42.w3)
- Anorexia, dehydration, tetraplegia and temperature 41.6 °C (J495.42.w3)
- Anorexia, ataxia, developing to muscle tremors, posterior
paresis, temperature 41.1 °C (J495.42.w3)
- Sudden death. (J495.42.w3)
- In experimentally infected Lepus europaeus - Brown hare.
(J32.93.w2)
- Lassitude, sitting in a corner, loss of shyness, ruffled fur and
reduced food consumption. (J32.93.w2)
- No behavioural changes in some hares before death. (J32.93.w2)
Chronic toxoplasmosis
This form of the disease is usually seen in older rabbits. (B614.10.w10)
- The course of the disease is protracted and the rabbit becomes
anorexic and emaciated. This commonly results in anaemia. Central
nervous signs may occur as the disease progresses, usually as
posterior
paralysis. Sudden death may occur but many animals recover. (B614.10.w10,
J63.8.w1)
Clinical pathology
- Haematology, biochemistry and urinalysis are usually normal unless the Toxoplasma
organisms have affected non-neural tissue. (B609.2.w2)
|
| FERRETS |
Clinical signs in ferrets that carry Toxoplasma gondii are uncommon, but are
usually seen when immunosuppressed. (J10.34.w1)
Clinical signs that may occur include:
Systemic signs;
- Anorexia. (B626,
J10.34.w1)
- Lethargy. (B626)
- Hepatitis with clinical jaundice. (B626)
- Respiratory distress, dyspnoeic. (B626)
- Diarrhoea. (B626)
- Pyrexia; individuals are known to reach 105.3°F. (B626,
J10.34.w1)
- Depressed.(B626)
- Dehydration. (B626)
- Tachycardia. (B626)
- Orthopnoea: difficulty breathing when lying down. (B626)
- In congenitally infected ferret kits, some died without obvious
clinical signs, while survivors showed stunted growth. (J10.34.w1)
Neuromuscular signs
- Posterior weakness and ataxia. (B626,
J10.34.w1)
Ocular signs
- Ocular lesions, such as retinitis or iritis can be present. (B626)
- Blindness has also been reported. (B626)
- Corneal oedema and ataxia.(B626)
|
| GREAT APES |
In a
Pan troglodytes - Chimpanzee
experimentally infected orally with about 2.5 million oocyts divided
over two days: (J258.2-5758.w1)
- Listlessness and anorexia for about a week. (J258.2-5758.w1)
- Superficial lymph nodes enlarged for about six weeks. (J258.2-5758.w1)
- No clinical signs in a similarly-infected chimpanzee which was
already seropositive. (J258.2-5758.w1)
|
Incubation |
WATERFOWL |
-- |
| BEARS |
-- |
| LAGOMORPHS |
In experimental infection
in Lepus
timidus- Mountain hare, clinical signs were seen in one hare seven days after oral
inoculation (J42.117.w1) |
| FERRETS |
-- |
| GREAT APES |
In a
Pan troglodytes - Chimpanzee
experimentally infected orally with about 2.5 million oocyts divided over
two days, less than a week. (J258.2-5758.w1) |
Mortality / Morbidity |
WATERFOWL |
Infection may be
common, but clinical disease is rare in waterfowl (J4.205.w1, B15). |
| BEARS |
Infection is relatively
common (seroprevalence rates as high as 80% detected in Pennsylvania black bears Ursus americanus - American black bear)
(J1.29.w14),
but clinical disease is rare: one, fatal case reported.
(P5.31.w2) |
| LAGOMORPHS |
- In Oryctolagus cuniculus domesticus - Domestic European rabbit:
- Exposure to this infection is
reported as widely prevalent in the domestic rabbit. However, infection is
usually subclinical and latent; clinical disease is rare. (B601.11.w11,
B603.4.w4,
J15.28.w1)
Fatal disease occurs occasionally. (J495.42.w3)
- Occurs in outbreaks with many deaths, particularly in young
rabbits. (J63.8.w1)
- High mortality with acute toxoplasmosis (50% mortality in two
weeks in one outbreak in 600 young rabbits. (J63.8.w1)
- In Lepus europaeus - Brown hare:
- A high incidence of acute fatal toxoplasmosis has been reported
in these hares in Scandinavia. (B208.17.w17d,
J1.30.w8)
- In experimentally infected Lepus europaeus - Brown hare,
all individuals given 10 oocysts or more died. (J32.93.w2)
|
| FERRETS |
Death can occur without clinical signs. (B626,
J10.34.w1)
|
| GREAT APES |
In
Pan troglodytes - Chimpanzees experimentally infected
orally with about 2.5 million oocyts divided over two days, no clinical
signs in an individual already seropositive, and mild clinical illness
in an individual previously seronegative. (J258.2-5758.w1) |
Pathology |
WATERFOWL |
Miliary white,
necrotic foci
in the liver, congestion
of the lungs, splenomegaly with areas of
necrosis, clear to sanguineous
exudate
in body cavity. Crescent-shaped Toxoplasma gondii organisms visible on
Giemsa-stained smears of liver and peritoneal fluid (J5.6.w1) |
| BEARS |
In a six-day-old Ursus maritimus - Polar bear.
(P5.31.w2)
- Generalised infection; lesions were most severe in the liver,
skeletal muscles and brain. There was necrosis of the liver and
pancreas. (B22.32.w15,
P5.31.w2)
Gross pathology
- Liver: Pinpoint necrotic foci, petechial haemorrhages.
- GIT: Mucosal haemorrhage.
- Skeletal muscles: Very pale and marbled.
- Lungs: Acute oedema
- Cardiac: Right ventricle dilated.
(P5.31.w2)
Histopathology
- Liver: localised areas of necrotising inflammation; at the
margins of such lesions, Toxoplasma tachyzoites and in cells,
pseudocysts containing Toxoplasma.
- Pancreas: Necrotising inflammation.
- Lung: Slight interstitial inflammatory reaction.
- Heart: Slight cellular proliferation.
- Skeletal muscles and diaphragm: Significant necrosis, with
pseudocycts in the area around the necrotic lesions.
- Thymus: Significant necrosis, with pseudocycts in the area
around the necrotic lesions.
- Retina: Slight accumulation of lymphoblastic cells in foci in
the retina, with Toxoplasma cysts present.
- CNS: Purulent meningitis, mainly per-ventricular lesions,
with oedema and Toxoplasma cysts. (P5.31.w2)
In four- to seven-month old Kodiak bears (Ursus arctos - Brown bear)
at Rostock Zoo. (P5.29.w5)
- CNS: Encephalitis, toxoplasma cysts present.
- Pulmonary: Interstitial pneumonia with Toxoplasma
present.
- Cardiac: Myocarditis.
(P5.29.w5)
|
| LAGOMORPHS |
Acute toxoplasmosis
Generalised lesions are seen characterised by extensive necrosis of
heart, lungs, liver, spleen and lymph nodes. (B614.10.w10)
Gross pathology:
- Swollen organs with multiple, necrotic foci.
(B614.10.w10)
- In experimentally infected Lepus europaeus - Brown hare,
peritoneal exudate in some individuals. (J32.93.w2)
- Hepatic:
- Splenic:
- Lymph nodes:
- Pulmonary:
- GIT:
- Cardiac:
Histopathology:
- The vascular connective tissue and the
reticuloendothelial elements are most often affected. There is
pronounced cellular necrosis with or without inflammatory cell
infiltration. (B614.10.w10)
- Toxoplasma gondii trophozoites may be seen intra-
and extracellularly. (B614.10.w10)
- In experimentally infected Oryctolagus cuniculus domesticus - Domestic rabbit
killed at eight days post inoculation, lesions were minor, mainly
focal mononuclear cell accumulations in the liver, (J42.117.w1)
- Brain:
- Focal necrotic areas. (B609.2.w2)
- Non-suppurative meningoencephalitis. (B609.2.w2)
- Hepatic:
- Focal interstitial granulomatous hepatitis. (B603.3.w3)
- In Lepus
timidus - Mountain hare, areas of necrotic
hepatocytes, small amount of macrophage infiltration, Toxoplasma
gondii organisms found in groups or singly in association
with lesions. (J42.117.w1)
- In three French Lop rabbits, multifocal necrosis and
granulomatous reaction, with both tachyzoites and tissue
cysts. (J495.42.w3)
- In experimentally infected Lepus europaeus - Brown hare,
irregular foci of coagulative necrosis. (J32.93.w2)
- Lymph nodes:
- Splenic:
- In Lepus
timidus - Mountain hare, focal necrosis. (J42.117.w1)
- In three French Lop rabbits, multifocal necrosis and
granulomatous reaction, with both tachyzoites and tissue
cysts. (J495.42.w3)
- In experimentally infected Lepus europaeus - Brown hare,
irregular foci of coagulative necrosis, slight peripheral
inflammatory reaction, and slight follicular lymphocyte
depletion. (J32.93.w2)
- Pulmonary:
- In Lepus
timidus - Mountain hare, focal necrosis. (J42.117.w1)
- In three French Lop rabbits, multifocal necrosis and
granulomatous reaction, with both tachyzoites and tissue
cysts. (J495.42.w3)
- Bone marrow:
- Cardiac:
- GIT:
- In Lepus
timidus - Mountain hare, foci of necrosis in the
mucosa. (J42.117.w1)
- In experimentally infected Lepus europaeus - Brown hare,
in the small intestines, epithelial cell necrosis and
desquamation, in the lamina propria hyperaemia and
haemorrhages, and in the submucosa a mixed inflamatory
exutdate. Toxoplasma gondii tachyzoites were present in
the epithelial lining. (J32.93.w2)
- Skeletal muscles:
- Diaphragm:
- Immunohistochemistry:
- In Lepus
timidus - Mountain hare, Toxoplasma gondii
demonstrable in multiple organs, particularly liver,
mesenteric (and popliteal) lymph nodes, small intestine,
spleen, lung and bone marrow. (J42.117.w1)
- In Oryctolagus cuniculus domesticus - Domestic rabbit,
organisms rarely detected at eight days post-inoculation. (J42.117.w1)
- In three French Lop rabbits, positive reaction to anti-Toxoplasma
gondii serum but not to anti-Neospora caninum
serum. (J495.42.w3)
Chronic toxoplasmosis
- Gross pathology: the gross lesions are more variable in this
form of the disease. Various organs may have oedematous enlargement
and scattered necrotic foci. (B614.10.w10,
J63.8.w1)
- Histopathology: marked reticuloendothelial hyperplasia
especially in the lymph nodes, liver, spleen, and central nervous
system. Toxoplasma gondii organisms are more difficult to isolate than in the
acute disease. (B614.10.w10,
J63.8.w1)
Latent disease
- Lesions are primarily in the central nervous system in the form of
cysts with or without reaction. Gliosis and granulomatous encephalitis
with perivascular cuffing and nonsuppurative meningitis. These lesions
may be confused with Encephalitozoonosis.
(B614.10.w10)
|
| FERRETS |
Gross pathology:
- Pulmonary: Multiple white foci (necrotic areas) in lung tissue. (B626,
B627.16.w16,J10.34.w1)
- Cardiac: multiple necrotic areas may be present. (B626,
B627.16.w16)
- Hepatic: multiple necrotic areas may be present. B626,
B627.16.w16)
Histopathology:
- Hepatic: Multiple foci of coagulated necrosis, lightly
infiltrated by macrophages. (J10.34.w1)
- Myocardium: Multiple foci of coagulated necrosis were present,
with diffuse interstitial infiltration with moderate numbers of
lymphocytes. A small number of protozoa
were found and
intrascarcoplasmic Toxoplasma-like colonies. (J10.34.w1)
- Lung: Diffuse pneumonia with macrophages within the alveoli.
Also foci of coagulative necrosis and protozoal colonies within the
macrophages. (J10.34.w1)
- CNS:
- Cysts have been found in the brains of ferrets
that are serologically positive for Toxoplasma gondii. (J10.34.w1)
- Mengingoencephalitis or meningoencephalomyelitis has been found in
ferrets that showed posterior weakness and ataxia. (B626)
- Immunohistochemistry: Immunohistochemistry confirmed that the
protozoan detected associated with lesions in various organs in ferret
kits in New Zealand was Toxoplasma gondii. (J10.38.w1)
|
| GREAT APES |
|
Disease / Agent has been reported in either the wild or in
captivity in:
|
Disease has
been reported in:
- Domestic ducks (J5.1.w1).
- Geese (B16.19.w1).
- In Hedgehogs:
Infection has also been reported in:
- Mallard Anas platyrhynchos, Common pochard Aythya ferina,
Tufted duck Aythya fuligula (J6.21.w3, B15).
- In Hedgehogs:
IN HEDGEHOGS:
IN ELEPHANTS:
- Antibodies against Toxoplasma gondii have been documented in
captive Elephas maximus
- Asian Elephants and free-living Loxodonta africana
- African Elephants. (J1.11.w8,
J4.189.w7, J11.85.w1,
J11.87.w1)
- In the USA, one of three tested Elephas maximus
- Asian Elephants , a three-year-old female, was seropositive
using the indirect haemagglutination test (IHA) (titre 524,288) and
the complement-staining fluorescent antibody test (titre at least
4,096). (J4.189.w7)
- In Thailand, 45.5% of captive Elephas maximus
- Asian Elephants sampled from four locations during 1994 -
1999 were positive (titre > 1: 50) with the modified
agglutination test (MAT) and 25.6% were positive (> 1:64)
with the latex agglutination test (commercial kit, Eiken, Japan). (J11.87.w1)
- A seroprevalence study of Toxoplasma gondii in East
African free-living mammals detected antibodies in four of
63 Loxodonta africana
- African Elephants tested, using the indirect
haemagglutination test (titre of >1: 64 considered
positive). Positive titres varied: 1:128, 1:4,096 (two elephants)
and 1:8192. (J1.11.w8)
- Antibodies against Toxoplasma gondii were found in two of
19
Loxodonta africana
- African Elephants ( 10.5%) from game Parks in
Zimbabwe. (J11.85.w1)
- In Sri Lanka, antibodies to Toxoplasma gondii were detected
in the sera of 14 of 45 privately owned elephants (32%) at titres of
1:25 to 1: 400 using the modified agglutination test (MAT); the
elephants were all older than 20 years of age. All of eight
elephants tested from the Pinnawala Elephant Orphanage were
seronegative. (J32.137.w1,
P75.9.w1)
IN BEARS:
- A survey of wildlife in Ontario, Canada, using the Sabin-Feldman dye test, detected antibodies to
Toxoplasma gondii in one of three (33%) Ursus americanus - American black bear
tested. (J1.12.w10)
- A survey of wildlife in Central Ontario, Canada, using the Sabin-Feldman dye test, detected antibodies to
Toxoplasma gondii in seven of 16 (43.8%) Ursus americanus - American black
bears
tested. (J1.12.w11)
- Antibodies to Toxoplasma gondii were detected by indirect
haemagglutination test (IHA) using RH strain in 23/303 sera (8%) from 265 Ursus americanus - American black bear
from northcentral Idaho, 1971-1975. (J1.16.w12)
- A serological survey of Pennsylvania black bears Ursus americanus - American black bear
detected Toxoplasma gondii antibodies in 80% of bears (535/665 bears) using the agglutination test at dilutions of 1:25 (10%), 1:50
(37%) and 1:500 (33%). Seroprevalence did not vary significantly between
males and females but was significantly higher in adults (83%) than in
juveniles (65%). (J1.29.w14)
- A survey using a commercially available latex agglutination test
detected antibodies to Toxoplasma gondii at a titre of > 64 in 87 of 480 grizzly bears
Ursus arctos - Brown bear)
(18%), ranging from 9% on Kodiak Island to 28% in northern Alaska, and in six of 40 (16%)
Ursus americanus - American black bear
from Interior Alaska (where the prevalence in grizzly bears was 13%, five of 40. No grizzly bears under two years of age were
seropositive. (J1.31.w12)
- A survey of blood samples from 892 grizzly bears (Ursus arctos - Brown bear), collected
1973-1987 from Alaska, using the modified agglutination test, detected titres >25 (the minimum threshold
titre) in 25% of 220 sera. In different areas, prevalence varied: from 9% in southern areas (18 of 196 sera positive) to 37% in northern areas (162 of 433 sera).
(J1.33.w13)
- Antibodies to Toxoplasma gondii were detected in 13/34 bears Ursus americanus - American black
bears in Florida, 1980-1987: in one of three from Calhoun county,
4/6 bears from Columbia/Baker counties, 3/13 bears from Putnam county, 4/8
bears from Marion county, 1/1 bear from Orange county, none of three bears
from Lake county. (B419.14.w14)
- A survey of wild animals in Florida, USA found all four Ursus americanus - American black bear
tested from Columbia/Baker counties to be seropositive for Toxoplasma gondii. (J4.175.w1)
- Antibodies to Toxoplasma gondii were detected by microtitre latex
agglutination test in 37/66 sera (56%) from free-ranging Ursus americanus - American black bear
from Florida, USA, 1994-1995. (J1.34.w11)
- A serological survey in wildlife in Alaska, using a modified
agglutination test (MAT), detected antibodies in 62/143 (43%) Ursus americanus - American black bear
tested. (J1.36.w7)
- Antibodies to Toxoplasma gondii were detected in 13% of 38 Ursus americanus - American black
bears, 0% of 36 grizzly bears (Ursus arctos - Brown
bear) and 0% of 60 Ursus maritimus - Polar bear
in Canada, from 1994-2001. (J3.155.w2)
- Antibodies to Toxoplasma gondii were detected, using a commercially
available latex agglutination test (Eiken Chemical Co.), in 6% of Ursus maritimus - Polar bear
from the Beauford and Chukchi seas, from samples collected 1982-1999. (J3.156.w2)
- A survey of blood samples from wildlife from Alaska, collected 1976-1996, using the modified agglutination test, detected Toxoplasma antibodies in 62 of 1443 (43%)
Ursus americanus - American black bear; prevalence was highest in bears from the southeastern area of Alaska.
(J1.36.w7)
- Using an indirect haemaglutination test (IHA), antibodies to Toxoplasma gondii
were detected in 40 of 149 sera (40%) from Ursus americanus - American black
bears trapped during a population study in California,
USA. [1982](J4.181.w4)
- Antibodies to Toxoplasma gondii were detected in one of two
tested polar bears (Ursus maritimus - Polar bear),
but not in a single tested Asiatic black bear Selenarctos thibetanus
(Ursus thibetanus - Asiatic black bear)
in the USA. (J4.189.w7)
- Fatal toxoplasmosis was diagnosed in a six-day-old Ursus maritimus - Polar bear.
(P5.31.w2)
- Fatal acute to subacute toxoplasmosis was diagnosed as the main cause
of death in nine of 20 juvenile (four- to seven-month-old) Kodiak bears
(Ursus arctos - Brown bear)
at Rostock Zoo, and was an additional finding in a further seven cubs. (P5.29.w5)
- Toxoplasma infection is common in bears in Pennsylvania. Serum (from heart blood) of 28
Ursus americanus - American black
bears from Pennsylvania was tested by several serological tests:
Sabin-Feldman dye test (DT), modified agglutination test (MAT), latex agglutination test (LAT) and indirect haemagglutination test
(IHA). Antibodies were detected in the MAT at titres >1:40 in 22 bears; the DT detected antibodies (>1:10) in 21 bears,
the LAT (>1:32) detected antibodies in nine bears and the IHA (>1:64) in 6 bears. All bears negative by MAT were also negative by other serological tests. Bioassay of heart muscle in mice
detected viable Toxoplasma gondii in samples from three of 11
bears, while bioassay in cats detected viable Toxoplasma gondii
in eight bears (including one which was also detected by mouse bioassay), giving a total of 10 bears in
which viable
Toxoplasma gondii were detected. All these bears were seropositive with the MAT and the DT but only six were LAT positive and five IHA positive.
(J11.81.w1)
- A serological survey of mammals in Czech and Slovak zoos detected
antibodies to Toxoplasma gondii, using a commercially available
indirect fluorescent antibody test (Sevatest toxoplasma NIFR, Sevapharma,
Prague, Czech Republic) in the single tested Ursus maritimus - Polar bear
and in all three tested Ursus americanus - American black
bears. (J32.136.w1)
- Serological testing of Ursus americanus - American black
bears from Florida detected antibodies to Toxoplasma
gondii by the indirect haemaglutination test in 17/38 bears (45%). (B419.14.w14)
- Serological testing of samples from hunter-killed Ursus americanus - American black
bears from North Carolina, 1996-1997, detected antibodies to Toxoplasma
gondii in 120/143 individuals (83%). Titres were significantly
higher in females than in males, and increased with age. (J11.84.w3)
IN LAGOMORPHS:
There have been many reports of spontaneous
toxoplasmosis in the domestic rabbit from many parts of the world as well as in
wild rabbits and hares. (B614.10.w10)
- In Oryctolagus cuniculus - European rabbit
in New Zealand. (J194.25.w2)
- In Oryctolagus cuniculus domesticus - Domestic European rabbit:
- Toxoplasmosis was first reported in the domestic rabbit in 1908.
(B614.10.w10)
- Exposure to this infection is
reported as widely prevalent in the domestic rabbit. However, infection is
usually subclinical and latent. Clinical disease is rare. (B601.11.w11,
B603.4.w4)
- Antibody prevalence figures in clinically normal rabbits have been
reported as up to 50 %. (B614.10.w10)
- Fatal toxoplasmosis was reported in a domestic rabbit in the USA (1992). (B614.10.w10)
- In Lepus europaeus - Brown hare:
- Toxoplasmosis has been diagnosed in hares in the wild in Europe. (J63.8.w1)
- Acute fatal toxoplasmosis is common in this species in
Scandinavia. (J1.30.w8)
- In Sweden the incidence of acute disease among free-living
hares that were examined at post mortem has been reported at 12
% (1961) and 10 % (1988). (J1.30.w8)
- Subclinical toxoplasmosis:
- The prevalence of subclinical infection in this species is
reportedly low in Sweden. No toxoplasma antibodies were found in
serum samples from 176 brown hares ("Lepus europaeus P.")
that were shot in three different areas of south and central
Sweden (1984 - 1985). (J1.30.w8)
- Studies have also indicated a very low prevalence in
Australia, Austria, and the Netherlands. (J1.30.w8)
- In a study of Lepus europaeus - Brown
hares in Schleswig-Holstein, Germany, 1997-1999, antibodies
to Toxoplasma gondii were detected in 46% (147/318 hares). (J1.39.w8)
- Lepus timidus -
Mountain hare
(J1.30.w8)
- Sylvilagus
floridanus - Eastern Cottontail
- A study in Maryland found 21/95 (22.1%) seropositive, with dye
test titres ranging from 16 - 256. (J11.48.w1)
- In a study of Lepus europaeus - Brown
hares in Schleswig-Holstein, Germany, 1997-1999, antibodies
to Toxoplasma gondii were detected in 46% (147/318). (J1.39.w8)
- A survey in California found antibodies in 1/16 Sylvilagus bachmani - Brush rabbit
and 3/39 Lepus californicus
- Black-tailed jackrabbit. (J4.167.w5)
IN FERRETS:
- 30% of 750 neonatal ferrets that were raised for fur died without
clinical signs due to Toxoplasma
gondii infection. (B627.16.w16,
J10.34.w1,
J10.38.w1)
- Chronic Toxoplasma gondii
infection has been found in both free-living and captive mustelids
(Mustelidae - Weasels (Family)). (J10.34.w1)
IN GREAT APES
- Rarely reported. (B22.31.w31g)
- Experimental infection reported in a
Pan troglodytes - Chimpanzee; another chimpanzee was
already seropositive, indicating previous (natural) infection. (J258.2-5758.w1)
Further information on Host species has
only been incorporated for species groups for which a full Wildpro
"Health and Management" module has been completed (i.e. for which
a comprehensive literature review has been undertaken). Host species with
further information available are listed below:
|
Host Species
List |
BIRDS:
MAMMALS:
(List does not contain all other species groups affected by this
disease)
|
Disease / Agent has been specifically reported in
Free-ranging populations of:
|
| Clinical disease not
reported in wild waterfowl (B15).
Infection has been reported in:
- Mallard Anas platyrhynchos, Common pochard Aythya ferina,
Tufted duck Aythya fuligula (J6.21.w3, B15).
- In Hedgehogs:
IN ELEPHANTS:
IN BEARS:
- A survey of wildlife in Ontario, Canada, using the Sabin-Feldman dye test, detected antibodies to
Toxoplasma gondii in one of three (33%) Ursus americanus - American black bear
tested. (J1.12.w10)
- A survey of wildlife in Central Ontario, Canada, using the Sabin-Feldman dye test, detected antibodies to
Toxoplasma gondii in seven of 16 (43.8%) Ursus americanus - American black
bears
tested. (J1.12.w11)
- Antibodies to Toxoplasma gondii were detected by indirect
haemagglutination test (IHA) using RH strain in 23/303 sera (8%) from 265 Ursus americanus - American black bear
from northcentral Idaho, 1971-1975. (J1.16.w12)
- A serological survey of Pennsylvania black bears Ursus americanus - American black bear
detected Toxoplasma gondii antibodies in 80% of bears (535/665
bears) using the agglutination test at dilutions of 1:25 (10%), 1:50
(37%) and 1:500 (33%). Seroprevalence did not vary significantly between
males and females but was significantly higher in adults (83%) than in
juveniles (65%). (J1.29.w14)
- A survey using a commercially available latex agglutination test
detected antibodies to Toxoplasma gondii at a titre of > 64 in 87 of 480 grizzly bears
Ursus arctos - Brown bear)
(18%), ranging from 9% on Kodiak Island to 28% in northern Alaska, and in six of 40 (16%)
Ursus americanus - American black bear
from Interior Alaska (where the prevalence in grizzly bears was 13%, five of 40. No grizzly bears under two years of age were
seropositive. (J1.31.w12)
- A survey of blood samples from 892 grizzly bears (Ursus arctos - Brown bear), collected
1973-1987 from Alaska, using the modified agglutination test, detected titres >25 (the minimum threshold
titre) in 25% of 220 sera. In different areas, prevalence varied: from 9% in southern areas (18 of 196 sera positive) to 37% in northern areas (162 of 433 sera).
(J1.33.w13)
- Antibodies to Toxoplasma gondii were detected by microtitre latex
agglutination test in 37/66 sera (56%) from free-ranging Ursus americanus - American black bear
from Florida, USA, 1994-1995. (J1.34.w11)
- A serological survey in wildlife in Alaska, using a modified
agglutination test (MAT), detected antibodies in 62/143 (43%) Ursus americanus - American black bear
tested. (J1.36.w7)
- Antibodies to Toxoplasma gondii were detected in 13% of 38 Ursus americanus - American black
bears, 0% of 36 grizzly bears (Ursus arctos - Brown
bear) and 0% of 60 Ursus maritimus - Polar bear
in Canada, from 1994-2001. (J3.155.w2)
- Antibodies to Toxoplasma gondii were detected, using a commercially
available latex agglutination test (Eiken Chemical Co.), in 6% of Ursus maritimus - Polar bear
from the Beauford and Chukchi seas, from samples collected 1982-1999. (J3.156.w2)
- A survey of wild animals in Florida, USA found all four Ursus americanus - American black bear
tested to be seropositive for Toxoplasma gondii. (J4.175.w1)
- A survey of blood samples from wildlife from Alaska, collected 1976-1996, using the modified agglutination test, detected Toxoplasma antibodies in 62 of 1443 (43%)
Ursus americanus - American black bear; prevalence was highest in bears from the southeastern area of Alaska.
(J1.36.w7)
- Using an indirect haemaglutination test (IHA), antibodies to Toxoplasma gondii
were detected in 40 of 149 sera (40%) from Ursus americanus - American black
bears trapped during a population study in California. (J4.181.w4)
- Toxoplasma infection is common in bears in Pennsylvania. Serum (from heart blood) of 28
Ursus americanus - American black
bears from Pennsylvania was tested by several serological tests:
Sabin-Feldman dye test (DT), modified agglutination test (MAT), latex agglutination test (LAT) and indirect haemagglutination test
(IHA). Antibodies were detected in the MAT at titres >1:40 in 22 bears; the DT detected antibodies (>1:10) in 21 bears,
the LAT (>1:32) detected antibodies in nine bears and the IHA (>1:64) in 6 bears. All bears negative by MAT were also negative by other serological tests. Bioassay of heart muscle in mice
detected viable Toxoplasma gondii in samples from three of 11
bears, while bioassay in cats detected viable Toxoplasma gondii
in eight bears (including one which was also detected by mouse bioassay), giving a total of 10 bears in
which viable
Toxoplasma gondii were detected. All these bears were seropositive with the MAT and the DT but only six were LAT positive and five IHA positive.
(J11.81.w1)
- in all three tested Ursus americanus - American black
bears. (J32.136.w1)
- Serological testing of Ursus americanus - American black
bears from Florida detected antibodies to Toxoplasma
gondii by the indirect haemaglutination test in 17/38 bears (45%). (B419.14.w14)
- Serological testing of samples from hunter-killed Ursus americanus - American black
bears from North Carolina, 1996-1997, detected antibodies to Toxoplasma
gondii in 120/143 individuals (83%). Titres were significantly
higher in females than in males, and increased with age. (J11.84.w3)
IN LAGOMORPHS:
- There have been many reports of spontaneous toxoplasmosis in wild
rabbits and hares [species not specified]. (B614.10.w10)
- In Oryctolagus cuniculus - European rabbit
in New Zealand. (J194.25.w2)
- In Lepus europaeus - Brown hare:
- Acute fatal toxoplasmosis is common in this species in
Scandinavia. (J1.30.w8)
- In Sweden the incidence of acute disease among free-living
hares that were examined at post mortem has been reported at 12
% (1961) and 10 % (1988). (J1.30.w8)
- Subclinical toxoplasmosis:
- The prevalence of subclinical infection in this species is
reportedly low in Sweden. No toxoplasma antibodies were found in
serum samples from 176 brown hares that were shot in three different areas of south and central
Sweden (1984 - 1985). (J1.30.w8)
- Studies have also indicated a very low prevalence in
Australia, Austria, and the Netherlands. (J1.30.w8)
- In a study of Lepus europaeus - Brown
hares in Schleswig-Holstein, Germany, 1997-1999, antibodies
to Toxoplasma gondii were detected in 46% (147/318 hares). (J1.39.w8)
- Lepus timidus
(J1.30.w8)
- In a study of Lepus europaeus - Brown
hares in Schleswig-Holstein, Germany, 1997-1999, antibodies
to Toxoplasma gondii were detected in 46% (147/318). (J1.39.w8)
- A survey in California found antibodies in 1/16 Sylvilagus bachmani - Brush rabbit
and 3/39 Lepus californicus
- Black-tailed jackrabbit. (J4.167.w5)
IN FERRETS:
Further information on Host species
has only been incorporated for species groups for which a full
Wildpro "Health and Management" module has been completed (i.e.
for which a comprehensive literature review has been undertaken). Host
species with further information available are listed below:
|
Host Species
List |
BIRDS:
MAMMALS:
(List does not contain all other species groups affected by this
disease)
|
General Information on Investigation / Diagnosis
|
- In the definitive host (domestic cats and other felines) examination
of faeces for three weeks post infection may reveal the presence of
oocysts. (B22.32.w15)
- In other species, paired serum samples can show a rising antibody
titre. (B22.32.w15)
- Goats and other laboratory animals have been found to transmit
toxoplasmosis congenitally to their offspring. (B627.16.w16)
|
| WATERFOWL |
- Romanowski-stained impression smears of
peritoneal fluid, liver, other
tissues (J5.6.w1,
J4.205.w1).
- Mouse inoculation (B15).
- Serological tests indicate infection but not necessarily disease, unless
a rising titre is demonstrated (J4.205.w1, B13.46.w1).
|
| BEARS |
- Serological tests. A study in which serum (from heart blood) of 28 Ursus americanus - American black
bears from Pennsylvania was tested by several serological tests:
Sabin-Feldman dye test (DT), modified agglutination test (MAT), latex agglutination test (LAT) and indirect haemagglutination test
(IHA) found that the modified agglutination test is the most sensitive serological test for detection of
T. gondii in bears. (J11.81.w1)
- Antibodies were detected in the MAT at tites >1:40 in 22 bears; the DT detected antibodies (>1:10) in 21 bears,
the LAT (>1:32) detected antibodies in nine bears and the IHA (>1:64) in 6 bears. All bears negative by MAT were also negative by other serological tests. Bioassay of heart muscle in mice
detected viable Toxoplasma gondii in samples from three of
11 bears, while bioassay in cats detected viable Toxoplasma
gondii in eight bears (including one which was also detected by mouse bioassay), giving a total of 10 bears in
which viable
Toxoplasma gondii were detected. All these bears were seropositive with the MAT and the DT but only six were LAT positive and five IHA positive.
The study indicated (J11.81.w1)
- The presence of viable Toxoplasma gondii can be detected by
bioassay in mice or cats. (J11.81.w1)
- In four- to seven-month old Kodiak bears (Ursus arctos - Brown bear)
at Rostock Zoo, diagnosis was made on the basis of the pathological
findings, and histological findings of toxoplasma tachyzoites in the
parenchyma of organs, the brain and lymph nodes, and in one case also
by electron microscopy. (P5.29.w5)
|
| LAGOMORPHS |
Diagnosis can be difficult; definitive diagnosis is usually made at post
mortem. (B603.4.w4)
- Cytology of impression smears or histopathology. (B603.4.w4,
B614.10.w10)
- Identification of Toxoplasma organisms by light and electron
microscopy.
- Samples must be taken from a fresh carcass (less than a few
hours) or the organism becomes unidentifiable. (B603.4.w4)
- Wright-Giemsa stained smears of mesentery, omentum, or
peritoneal exudate can be examined for the organisms in the acute
form of the disease. (B614.10.w10)
- Toxoplasma organisms have a strong uptake of haematoxylin
stain and this is a useful feature to differentiate this organism
from Encephalitozoon cuniculi. (B603.3.w3,
B609.2.w2)
- Toxoplasma gondii organisms can also be differentiated
from Encephalitozoon cuniculi by the following
characterisitics: gram negative, non birefringent when viewed with
polarised light, and they do not stain with Goodpasture's carbol
fuchsin. (B602.20.w20)
- Toxoplasma sporozoites ultrastructurally resemble Plasmodium
and coccidia. (B614.10.w10)
- Peroxidase techniques can be used to identify Toxoplasma organisms
in tissue sections using antiserum specific to this protozoa. (B614.10.w10)
- Serological methods
- Serological testing is available. (B601.11.w11,
B603.3.w3)
- "anecdotal reports of using serum antibody titres
available for testing in dogs and cats to support diagnosis in
rabbits exist; however, no data exist to direct proper
interpretation of results". (B609.2.w2)
- "Sabin-Feldman dye, indirect immunofluorescence antibody,
carbon immunoassay, and agglutination tests are currently the most
widely used for toxoplasmosis in rabbits". (B614.10.w10)
|
| FERRETS |
- Faecal examinations are necessary to positively identify toxoplasma.
(B602.2.w2)
- Antibody titers to Toxoplasma gondii can be found in carrier
ferrets. (B626)
- Usually diagnosed by possible exposure. (B626)
- Antibody ELISAs can
detect Toxoplasma
gondii specific immunoglobulin G (IgG) and immunoglobulin
M (IgM) and antigen ELISA can detect specific antigens in the serum. (B626,
B627.16.w16)
- Histological examination or inoculation is used for diagnosis. (B627.16.w16)
- In ferret kits in New Zealand, immunohistochemistry confirmed that
the protozoan detected associated with lesions in various organs was
indeed Toxoplasma gondii. (J10.38.w1)
- Blood results:
Neutrophilia, leukocytosis, microcytic, non-regenerative anaemia, and
decreased serum albumin. (B626)
|
| GREAT APES |
- Consider in an individual with hepatosplenomegally, atypical
pulmonary infection, chorioretinitis, myocardial inflammation or CNS
signs. (B22.31.w31g)
- Detection of tachyzoites in blood of a previously seronegative
Pan troglodytes - Chimpanzee one week after experimental
infection. (J258.2-5758.w1)
- Detection of antibodies using the Sabin Feldman dye test, complement
fixation test and indirect fluorescent anitibody test in naturally and
experimentally infected
Pan troglodytes - Chimpanzee. (J258.2-5758.w1)
- Detection of the organism by mouse inoculation of biopsy specimens
from inguinal lymph node and from thigh muscle, 11 weeks post infection
in a previously seronegative
Pan troglodytes - Chimpanzee. (J258.2-5758.w1)
|
| Related Techniques |
|
 |
Specific Medical Treatment
|
- Sulfamerazine, 30 mg/kg every six hours, plus pyrimethamine, 1 mg/kg
orally every 24 hours, for 14 days. (B22.32.w15)
|
| WATERFOWL |
- 30 days course pyrimethamine, 0.25-0.5 mg/kg orally, twice daily (B11.X.w11).
- Sulfamethazine 0.2-0.25% in drinking water or feed (B13.46.w1).
|
| LAGOMORPHS |
Prognosis
- The prognosis is guarded because there is often a varied response to
treatment. Residual deficits are likely (particularly neurological);
however it is not possible to predict the severity of the deficits
until after the course of treatment. (B609.2.w2)
Treatment options
- Trimethoprim-sulfonamide (B601.11.w11,
B602.20.w20, B603.4.w4,
J15.28.w1)
- This is the drug of choice. (B609.2.w2)
- Use at 15 to 30 mg/kg orally every twelve hours. (B609.2.w2)
- Sulfadiazine in combination with pyrimethamine (B601.11.w11,
B602.20.w20)
- This is another recommended option for treatment of
toxoplasmosis. (B609.2.w2)
- Use for two weeks at feline doses. (B609.2.w2)
- Precautions: this combination can cause depression, leucopaenia,
thrombocytopaenia and anaemia in cats; toxicity in rabbits has not
been described. (B609.2.w2)
- Doxycycline (B601.11.w11,
B602.20.w20, J15.28.w1)
- This has also been used in rabbits to treat toxoplasmosis;
efficacy uncertain. (B609.2.w2)
- 2.5 mg/kg orally every 12 hours. (B609.2.w2)
- Sulfadiazine, sulfones, pyrimethamine,
tetracyclines,1,2-dihydrotriazones, and spiramycin have been
reportedly used to inhibit trophozoites and cysts of toxoplasmosis. (B614.10.w10)
Contraindications
- Clindamycin
- Oral administration of this drug has been reported as a
treatment option of toxoplasmosis in other species, e.g. cats.
However, it should not be used in the rabbit because it can cause
a fatal enteric dysbiosis and enterotoxaemia. This also applies to
other oral antibiotics that select primarily against Gram-positive
bacteria (penicillins, cephalosporins, macrolides and lincosamides).
(B603.3.w3,
B609.2.w2)
|
| FERRETS |
Note: Suphaquinoxaline is toxic to ferrets. (B626)
- Treatment is with sulphonamides, for at least two weeks four times
daily until clinical signs have stopped. (B626)
- Pyrimethamine (0.5-0.1 mg/kg per day) plus sulfadiazine (60 mg/100
mL drinking water or 60 mg/100 g in food). These drugs will destroy the
tachyzoites, but not the cyst stage. (B626)
- Suphadiazine at 60 mg/kg per day for four times daily, given for one
to two weeks and given a few days after improvement. (B627.16.w16)
- If treatment is prolonged, folinic acid
or folic Acid
and bakers yeast should be
given as supplements to promote haematopoiesis. (B626,
B627.16.w16)
- Monitoring of bone marrow activity is essential. Haemograms (complete blood
cell counts) should
be performed before and during treatment. (B627.16.w16)
- Clindamycin hydrochloride has been used in cats at 25-50 mg/kg per
day. This may not kill Toxoplasma gondii, but it stops their
replication. (B626)
|
| GREAT APES |
Recommended treatments based on human dosages: (B22.31.w31g)
- Sulfadiazine (Sulphonamides) 25-50 mg/kg four times daily, orally, up to 6 g
plus Pyrimethamine 2 mg/kg per day orally, up to 100 mg, for
three days, then reducing to 1 mg/kg per day, up to 25 mg daily, for
four weeks. (B22.31.w31g)
|
| Related Techniques |
|
|
Environmental
and Population Control Measures
|
| General Environment Changes, Cleaning and
Disinfection |
WATERFOWL |
Keep cats away from
enclosures and stored feed (J4.205.w1). |
| BEARS |
- Stray cats were removed from the premises. (P5.31.w2)
- Meat fed to pregnant females was changed to boiled beef. (P5.31.w2)
- Fruit and vegetables were stored in a manner ensuring they would not
become contaminated. (P5.31.w2)
|
| LAGOMORPHS |
- Keep rabbits separated from cats. (B614.10.w10)
- Ensure water, food or bedding for lagomorphs are not contaminated with cat
faeces. (B602.20.w20,
B603.4.w4, B606.13.w13, B609.2.w2, B614.10.w10)
- Cover feed containers. (B601.11.w11,
J15.28.w1)
- Wash fresh vegetables before feeding. (B603.4.w4,
B606.13.w13)
- Prevent cats from accessing hay stores. (B601.11.w11)
- Heating and drying will inactivate the oocysts, however most
disinfectants will not result in inactivation. (B614.10.w10)
- Feed rabbits on food which has been processed to at least 66 °C (to
kill oocysts). (J495.42.w3)
- Ensure rabbits are not given access to an environment where cat
faeces may have been deposited. (J495.42.w3)
|
| FERRETS |
- If ferrets are housed away from cats, this should reduce the chance
of infection via faecal-oral cross-contamination. (B626)
- Ferrets could be fed indoors or in an outdoor cage, to prevent
contamination of their food. (B626)
- Cat litter trays should be placed high up, this is to prevent
ferrets from using the same tray and cross-contamination. (B626)
- Boarding kennels/catteries should have a separate area for boarding
ferrets. (B626)
- In zoos, ferrets should be housed away from other animals, to reduce
the risk of infection. (B627.16.w16)
|
| GREAT APES |
- Good hygiene to prevent access of cats to stored food and bedding,
and rodent control to prevent potentially infected rodents being eaten
by apes. (V.w5)
|
| Population Control Measures |
WATERFOWL |
-- |
| LAGOMORPHS |
-- |
| FERRETS |
Ideally cat wards should be separate from a ferret ward, to
stop cross contamination of Toxoplasma gondii. (B626) |
| GREAT APES |
-- |
| Isolation, Quarantine and Screening |
WATERFOWL |
-- |
| LAGOMORPHS |
If toxoplasmosis is present
in a rabbit colony then only the seronegative rabbits should be bred from
because toxoplasmosis can be transmitted transplacentally. (B614.10.w10) |
| FERRETS |
-- |
| GREAT APES |
-- |
| Related Techniques |
|
|
