Line 10: |
Line 10: |
| }} | | }} |
| <br> | | <br> |
| + | |
| + | ==Neospora== |
| + | *2 main species |
| + | **''Neospora caninum'' in the dog |
| + | **''Neospora hughesi'' in the horse |
| + | |
| + | *Sporulated oocysts measuring just 10μm |
| + | |
| + | *Oocyst contains 2 sporocysts with 4 sporozoites |
| + | |
| + | *Route of transmission not fully understood |
| + | |
| + | *Often misdiagnosed as ''Toxoplasma gondii'' |
| + | **''Sarcocystis'' cysts have thicker walls |
| + | |
| + | *Infection diagnosed by IFAT, ELISA or PCR |
| + | **Identification of lesions and organisms in tissue using immunohistochemical staining |
| + | **Eliminate other causes of abortion first |
| + | |
| + | '''Life cycle''' |
| + | *Life cycle similar to ''Toxoplasma gondii'' |
| + | |
| + | *Limited range of warm-blooded intermediate hosts |
| + | **Asexual reproduction occurs in intermediate host forming tissue cysts |
| + | |
| + | *Host range of sexual stage is unknown for ''N.caninum'' |
| + | **Intermediate host for ''N.hughesi'' is the horse, but the definitive host is unknown |
| + | |
| + | *Final host |
| + | **Dogs pass oocysts |
| + | **Role not fully understood in pathogenesis |
| + | **5 day prepatent period |
| + | **Other wild canids may also act as final definitive hosts |
| + | |
| + | *Intermediate host |
| + | **Mostly cattle |
| + | **Natural infection has been documented in other herbivores |
| + | |
| + | *Transmission |
| + | **Transplacental infection occurs in all intermediate hosts and in the canine final host |
| + | ***Transplacental can occur in '''successive pregnancies''' |
| + | **In cattle, vertical transmission occurs |
| + | ***Post-natal infection occurs but is less common |
| + | |
| + | '''Pathogenesis''' |
| + | *Dogs |
| + | **Occurs mainly in puppies |
| + | **Causes ascending paralysis, especially of hind limbs, with muscle wasting |
| + | **Causes sudden collapse due to myocarditis |
| + | **More than puppy in a litter may be affected, although this may not occur simultaneously |
| + | **Successive litters affected |
| + | |
| + | *Cattle |
| + | **Commenest cause of infectious abortion in dairy cattle |
| + | **Congenitally infected calves can have encephalomyelitis and paresis |
| + | **Abortion usually occurs between 5-7 months of gestation but can occur as early as 3 months |
| + | **No other clinical signs in the cow |
| + | **Repeat abortions possible in same cow (persistently infected) |
| + | |
| + | *Horses |
| + | **Myeloencephalitis |
| + | **Transplacental infection occurs |
| + | **Disease only diagnosed in USA |
| + | |
| + | *''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]] |
| + | |
| + | '''Prevention and Control''' |
| + | *Do not allow dogs access to calving cows, placental membranes and aborted or dead calves |
| + | |
| + | *Do not allow dogs to defecate in cattle feeding areas |
| + | |
| + | *Identify and cull seropositive cattle, or do not breed from them or their progeny |
| + | |
| + | *Select seronegative cattle for breeding |
| + | |
| + | *Vaccinate |
| + | **Only in the USA |
| + | **Neoguard or Intervet |
| + | **Killed protozoal vaccine for healthy, preganant cows |
| + | **Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation |
| + | **Revaccination with 2 doses during each subsequent pregnancy |
| + | |
| + | ==Sarcocystis== |
| + | [[Image:Sarcocystis Life Cycle.jpg|thumb|right|150px|''Sarcocytis'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]] |
| + | [[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]] |
| + | *Most infections are asymptomatic |
| + | |
| + | *Heavy infections are causes of chronic wasting in large animals, hide sondemnation and downgrading of carcasses |
| + | |
| + | *''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia |
| + | |
| + | *There are many species of ''Sarcocystis'' which differ in size from microscopic to several centimetres in length |
| + | **''S.neurona'' is an important equine pathogen in the USA |
| + | |
| + | *Infective cyst in the intermediate host is called a '''sarcocyst''' |
| + | |
| + | '''Life Cycle''' |
| + | *Individual life cycles incompletely misunderstood |
| + | |
| + | *Indirect life cycle |
| + | |
| + | *Life cycle alternates between the final and the obligatory intermediate host |
| + | |
| + | *Only '''one''' final and '''one''' intermediate host |
| + | |
| + | *Sporulated oocyst has 2 sporocysts containing 4 sporozoites |
| + | **Naked oocyst usually seen in faeces as the oocyst wall is very delicate |
| + | **Oocyst measures 15μm in length |
| + | |
| + | *No schizogony in final host |
| + | |
| + | *Gametogeny occurs deep in subepithelial tissue |
| + | |
| + | *Faecal oocyst count is low |
| + | |
| + | *Oocysts are sporulated when passed |
| + | **Difficult to find on faecal examination as the sporocysts are few in number and small |
| + | |
| + | *Ingestion of sporocyst by intermediate host |
| + | **2 phases of rapid asexual reproduction in vascular endothelial cells |
| + | **Slow multiplication of bradyzoites in muscle tissue |
| + | **Sarcocyst forms with bradyzoites inside, surrounded by a cyst wall and divided into compartments |
| + | |
| + | '''Epidemiology''' |
| + | *Final hosts are carnivores and omnivores |
| + | |
| + | *Intermediate hosts are herbivores and omnivores |
| + | |
| + | *Humans are the final host for some species and the intermediate hosts for others |
| + | **Final host for species infecting cattle and pigs |
| + | |
| + | *Dogs are final hosts for species infecting cattle, sheep, goats, pigs and horses |
| + | |
| + | *Cats are final hosts for species infecting cattle, sheep and pigs |
| + | |
| + | '''Pathogenesis''' |
| + | *Widespread infection but mostly asymptomatic |
| + | |
| + | *Cause meat inspection losses |
| + | |
| + | *''Sarcocystis'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]] |
| + | |
| + | *Experimental infections cause severe, acute pyrrhexic disease when the organism multiplies in the vascular endothelium |
| + | |
| + | *Can cause chronic wasting disease in cattle and horses |
| + | **Causes abortion and post-natal disease in sheep |
| + | |
| + | *Equine protozoal myeloencephalitis |
| + | **Necrotising encephalomyelitis affecting the grey and white matter of the CNS |
| + | **Caused by ''S.neurona'' |
| + | **Opossum thought to be the definitive host |
| + | **Horses thought to be accidental hosts |
| + | **Natural intermediate hosts currently unknown |
| + | **Western Blotting shows 50% of horses in the USA are seropositive |
| + | **Risk factors poorly understood |
| + | **Causes spinal cord dysfunction |
| + | ***Ataxia and paralysis |
| | | |
| ==Toxoplasma== | | ==Toxoplasma== |
Line 151: |
Line 308: |
| ***14 weeks before lambing | | ***14 weeks before lambing |
| **The best method of protection is to prevent cats from contaminating the pasture, lambing sheds and feed stores | | **The best method of protection is to prevent cats from contaminating the pasture, lambing sheds and feed stores |
− |
| |
− | ==Sarcocystis==
| |
− | [[Image:Sarcocystis Life Cycle.jpg|thumb|right|150px|''Sarcocytis'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
| |
− | [[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
| |
− | *Most infections are asymptomatic
| |
− |
| |
− | *Heavy infections are causes of chronic wasting in large animals, hide sondemnation and downgrading of carcasses
| |
− |
| |
− | *''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia
| |
− |
| |
− | *There are many species of ''Sarcocystis'' which differ in size from microscopic to several centimetres in length
| |
− | **''S.neurona'' is an important equine pathogen in the USA
| |
− |
| |
− | *Infective cyst in the intermediate host is called a '''sarcocyst'''
| |
− |
| |
− | '''Life Cycle'''
| |
− | *Individual life cycles incompletely misunderstood
| |
− |
| |
− | *Indirect life cycle
| |
− |
| |
− | *Life cycle alternates between the final and the obligatory intermediate host
| |
− |
| |
− | *Only '''one''' final and '''one''' intermediate host
| |
− |
| |
− | *Sporulated oocyst has 2 sporocysts containing 4 sporozoites
| |
− | **Naked oocyst usually seen in faeces as the oocyst wall is very delicate
| |
− | **Oocyst measures 15μm in length
| |
− |
| |
− | *No schizogony in final host
| |
− |
| |
− | *Gametogeny occurs deep in subepithelial tissue
| |
− |
| |
− | *Faecal oocyst count is low
| |
− |
| |
− | *Oocysts are sporulated when passed
| |
− | **Difficult to find on faecal examination as the sporocysts are few in number and small
| |
− |
| |
− | *Ingestion of sporocyst by intermediate host
| |
− | **2 phases of rapid asexual reproduction in vascular endothelial cells
| |
− | **Slow multiplication of bradyzoites in muscle tissue
| |
− | **Sarcocyst forms with bradyzoites inside, surrounded by a cyst wall and divided into compartments
| |
− |
| |
− | '''Epidemiology'''
| |
− | *Final hosts are carnivores and omnivores
| |
− |
| |
− | *Intermediate hosts are herbivores and omnivores
| |
− |
| |
− | *Humans are the final host for some species and the intermediate hosts for others
| |
− | **Final host for species infecting cattle and pigs
| |
− |
| |
− | *Dogs are final hosts for species infecting cattle, sheep, goats, pigs and horses
| |
− |
| |
− | *Cats are final hosts for species infecting cattle, sheep and pigs
| |
− |
| |
− | '''Pathogenesis'''
| |
− | *Widespread infection but mostly asymptomatic
| |
− |
| |
− | *Cause meat inspection losses
| |
− |
| |
− | *''Sarcocystis'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
| |
− |
| |
− | *Experimental infections cause severe, acute pyrrhexic disease when the organism multiplies in the vascular endothelium
| |
− |
| |
− | *Can cause chronic wasting disease in cattle and horses
| |
− | **Causes abortion and post-natal disease in sheep
| |
− |
| |
− | *Equine protozoal myeloencephalitis
| |
− | **Necrotising encephalomyelitis affecting the grey and white matter of the CNS
| |
− | **Caused by ''S.neurona''
| |
− | **Opossum thought to be the definitive host
| |
− | **Horses thought to be accidental hosts
| |
− | **Natural intermediate hosts currently unknown
| |
− | **Western Blotting shows 50% of horses in the USA are seropositive
| |
− | **Risk factors poorly understood
| |
− | **Causes spinal cord dysfunction
| |
− | ***Ataxia and paralysis
| |
− |
| |
− | ==Neospora==
| |
− | *2 main species
| |
− | **''Neospora caninum'' in the dog
| |
− | **''Neospora hughesi'' in the horse
| |
− |
| |
− | *Sporulated oocysts measuring just 10μm
| |
− |
| |
− | *Oocyst contains 2 sporocysts with 4 sporozoites
| |
− |
| |
− | *Route of transmission not fully understood
| |
− |
| |
− | *Often misdiagnosed as ''Toxoplasma gondii''
| |
− | **''Sarcocystis'' cysts have thicker walls
| |
− |
| |
− | *Infection diagnosed by IFAT, ELISA or PCR
| |
− | **Identification of lesions and organisms in tissue using immunohistochemical staining
| |
− | **Eliminate other causes of abortion first
| |
− |
| |
− | '''Life cycle'''
| |
− | *Life cycle similar to ''Toxoplasma gondii''
| |
− |
| |
− | *Limited range of warm-blooded intermediate hosts
| |
− | **Asexual reproduction occurs in intermediate host forming tissue cysts
| |
− |
| |
− | *Host range of sexual stage is unknown for ''N.caninum''
| |
− | **Intermediate host for ''N.hughesi'' is the horse, but the definitive host is unknown
| |
− |
| |
− | *Final host
| |
− | **Dogs pass oocysts
| |
− | **Role not fully understood in pathogenesis
| |
− | **5 day prepatent period
| |
− | **Other wild canids may also act as final definitive hosts
| |
− |
| |
− | *Intermediate host
| |
− | **Mostly cattle
| |
− | **Natural infection has been documented in other herbivores
| |
− |
| |
− | *Transmission
| |
− | **Transplacental infection occurs in all intermediate hosts and in the canine final host
| |
− | ***Transplacental can occur in '''successive pregnancies'''
| |
− | **In cattle, vertical transmission occurs
| |
− | ***Post-natal infection occurs but is less common
| |
− |
| |
− | '''Pathogenesis'''
| |
− | *Dogs
| |
− | **Occurs mainly in puppies
| |
− | **Causes ascending paralysis, especially of hind limbs, with muscle wasting
| |
− | **Causes sudden collapse due to myocarditis
| |
− | **More than puppy in a litter may be affected, although this may not occur simultaneously
| |
− | **Successive litters affected
| |
− |
| |
− | *Cattle
| |
− | **Commenest cause of infectious abortion in dairy cattle
| |
− | **Congenitally infected calves can have encephalomyelitis and paresis
| |
− | **Abortion usually occurs between 5-7 months of gestation but can occur as early as 3 months
| |
− | **No other clinical signs in the cow
| |
− | **Repeat abortions possible in same cow (persistently infected)
| |
− |
| |
− | *Horses
| |
− | **Myeloencephalitis
| |
− | **Transplacental infection occurs
| |
− | **Disease only diagnosed in USA
| |
− |
| |
− | *''Neospora caninum'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
| |
− |
| |
− | '''Prevention and Control'''
| |
− | *Do not allow dogs access to calving cows, placental membranes and aborted or dead calves
| |
− |
| |
− | *Do not allow dogs to defecate in cattle feeding areas
| |
− |
| |
− | *Identify and cull seropositive cattle, or do not breed from them or their progeny
| |
− |
| |
− | *Select seronegative cattle for breeding
| |
− |
| |
− | *Vaccinate
| |
− | **Only in the USA
| |
− | **Neoguard or Intervet
| |
− | **Killed protozoal vaccine for healthy, preganant cows
| |
− | **Dosed in first 3 weeks of pregnancy and then every 3-4 weeks during gestation
| |
− | **Revaccination with 2 doses during each subsequent pregnancy
| |