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| **the eggs are single (i.e. not in packets like Dipylidium) | | **the eggs are single (i.e. not in packets like Dipylidium) |
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− | T. ovis | + | 1) '''''T. ovis''''' |
− | Cysticerci occur in the musculature of sheep = condemnation of meat on aesthetic grounds.
| + | *Cysticerci occur in the musculature of sheep = condemnation of meat on aesthetic grounds. |
− | Common in some sheep-raising areas of the UK.
| + | *Common in some sheep-raising areas of the UK. |
− | Known as ‘sheep measles’ in Australasia, where it causes economic loss to the export industry.
| + | *Known as ‘sheep measles’ in Australasia, where it causes economic loss to the export industry. |
− | Consequently, a recombinant oncosphere antigen vaccine is available in New Zealand.
| + | *Consequently, a recombinant oncosphere antigen vaccine is available in New Zealand. |
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− | T. hydatigena | + | 2) '''''T. hydatigena''''' |
− | The commonest species in the UK.
| + | *The commonest species in the UK. |
− | Sheep are the most frequent intermediate host, but the cysticerci can establish in other animals.
| + | *Sheep are the most frequent intermediate host, but the cysticerci can establish in other animals. |
− | The oncosphere hatches out of the egg in the small intestine of the sheep.
| + | *The oncosphere hatches out of the egg in the small intestine of the sheep. |
− | Oncospheres travel to the hepatic portal system, where they transform to cysticerci.
| + | *Oncospheres travel to the hepatic portal system, where they transform to cysticerci. |
− | The grow rapidly while migrating through liver parenchyma, then to the peritoneal cavity.
| + | *The grow rapidly while migrating through liver parenchyma, then to the peritoneal cavity. |
− | The cysticerci in the peritoneal cavity are approximately 8cm long; often found adhering to the omentum.
| + | *The cysticerci in the peritoneal cavity are approximately 8cm long; often found adhering to the omentum. |
− | Usually, liver damage heals, forming fibrotic tracts, which leads to condemnation at meat inspection.
| + | *Usually, liver damage heals, forming fibrotic tracts, which leads to condemnation at meat inspection. |
− | If a sheep swallows a whole proglottid, it leads to liver damage, and ultimately death (“cysticercosis hepatica”), but this is a rare event affecting a single animal in a flock.
| + | *If a sheep swallows a whole proglottid, it leads to liver damage, and ultimately death (“cysticercosis hepatica”), but this is a rare event affecting a single animal in a flock. |
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− | T. pisiformis | + | 3) '''''T. pisiformis''''' |
− | It is similar to T. hydatigena, except that the cysticerci are pea-sized and are found on the omentum of rabbits.
| + | *It is similar to T. hydatigena, except that the cysticerci are pea-sized and are found on the omentum of rabbits. |
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− | T. multiceps (also known as Multiceps multiceps) | + | 4) '''''T. multiceps''''' (also known as Multiceps multiceps) |
− | Widespread distribution in the UK; particularly common in parts of mid-Wales.
| + | *Widespread distribution in the UK; particularly common in parts of mid-Wales. |
− | The eggs hatch in the small intestine of the sheep.
| + | *The eggs hatch in the small intestine of the sheep. |
− | The oncosphere enters the blood stream and travels to the brain, where it migrates through brain tissue.
| + | *The oncosphere enters the blood stream and travels to the brain, where it migrates through brain tissue. |
− | The metacestode (a coenurus) occurs inside the skull, lying on the surface of the brain.
| + | *The metacestode (a coenurus) occurs inside the skull, lying on the surface of the brain. |
− | It forms a 5cm long space occupying lesion.
| + | *It forms a 5cm long space occupying lesion. |
− | This leads to neurological signs, including gid – circling, ataxia and blindness.
| + | *This leads to neurological signs, including gid – circling, ataxia and blindness. |
− | It also causes softening of the skull above the lesion.
| + | *It also causes softening of the skull above the lesion. |
− | If a whole proglottid is ingested, it can lead to acute encephalitis (very rare).
| + | *If a whole proglottid is ingested, it can lead to acute encephalitis (very rare). |
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− | T. serialis | + | 5) '''''T. serialis''''' |
− | The coenurus forms in intermuscular connective tissues of rabbits, often causing a soft subdermal swelling.
| + | *The coenurus forms in intermuscular connective tissues of rabbits, often causing a soft subdermal swelling. |
− | Cases in pet rabbits probably originate from eggs shed by urban foxes.
| + | *Cases in pet rabbits probably originate from eggs shed by urban foxes. |
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