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{{Taxobox

{{Taxobox

|name              = Isospora spp.

|name              = Isospora spp.

|species            = There are many e.g. ''Isospora suis''.

|species            = There are many e.g. ''Isospora suis''.

}}

}}

 

[[Image:Isospora suis (pig).jpg|thumb|right|150px|''Isospora suis'' from a pig - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

[[Image:Isospora suis (pig).jpg|thumb|right|150px|''Isospora suis'' from a pig - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

[[Image:Isospora.jpg|thumb|right|150px|''Isospora'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

[[Image:Isospora.jpg|thumb|right|150px|''Isospora'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

 

There are many different species of ''Isospora'', all of which are host specific. The most commonly seen of all the ''Isospora'' species is ''Isospora suis'' in the pig.  

There are many different species of ''Isospora'', all of which are host specific. The most commonly seen of all the ''Isospora'' species is ''Isospora suis'' in the pig.  

==Identification==

==Identification==

Each oocyst measures 20-50μm. The eggs are subspherical, and the wall is colourless and thin.  When sporulated each one contains two sporocyts each with four sporozoites.

Each oocyst measures 20-50μm. The eggs are subspherical, and the wall is colourless and thin.  When sporulated each one contains two sporocyts each with four sporozoites.

==Life Cycle==

==Life Cycle==

There are essentially three stages in the ''Isospora'' life cycle.  The first is called '''Sporogony''' and is the asexual stage of the parasite development. It occurs exogenously, and leads to the development of ''sporozoites'' in the oocysts. After this occurs, the oocysts are now deemed infective.

There are essentially three stages in the ''Isospora'' life cycle.  The first is called '''sporogony''' and is the asexual stage of the parasite development. It occurs exogenously, and leads to the development of ''sporozoites'' in the oocysts. After this occurs, the oocysts are now deemed infective.

The host then ingests the infectious oocyst, and the digestive enzymes break down the oocyst wall, and release the infective sporozoites, which then go on to penetrate the intestinal villus epithelium, namely the jejunum and the ileum. Each sporulated oocyst contains 2 sporocysts each with 4 sporozoites. This stage will occur relatively quickly under optimal conditions of high humidity and temperatures between 20 and 40 degrees.

The host ingests the infectious oocyst and the digestive enzymes break down the oocyst wall causing the release of infective sporozoites. The sporozoites then go on to penetrate the intestinal villus epithelium, namely the jejunum and the ileum. Each sporulated oocyst contains 2 sporocysts each with 4 sporozoites. This stage will occur relatively quickly under optimal conditions of high humidity and temperatures between 20 and 40⁰C.

The next step is '''Schizogony'''. This is an asexual process which occurs endogenously. After the sporozoites invade the epithelia, they then form ''trophozoites''. These trophozoites then form ''merozoites'', which is known as ''merogony''.

The next step is '''schizogony'''. This is an asexual process which occurs endogenously. After the sporozoites invade the epithelia, they then form ''trophozoites''. These trophozoites then form ''merozoites'', which is known as ''merogony''.

''Gametogony'', which is sexual division occurs endogenously, namely in the intestinal cells. Merozoites then form either microgamonts (male) or macrogamonts (female). Invasion of macrogametocytes containing cells by microgametocytes leads to fertilization, and the cycle continues.

''Gametogony'', which is sexual division occurs endogenously, namely in the intestinal cells. Merozoites then form either microgamonts (male) or macrogamonts (female). Invasion of macrogametocytes containing cells by microgametocytes leads to fertilization, and the cycle continues.

==Clinical Signs==

==Clinical Signs==

Clinical signs are due to '''destruction of the intestinal epithelium''' and sometimes the underlying connective tissue of the mucosa.  

Clinical signs are due to '''destruction of the intestinal epithelium''' and sometimes the underlying connective tissue of the mucosa.  

There may be haemorrhage into the lumen of the intestine, catarrhal inflammation and diarrhoea. There may be '''dysentry, tenesmus and dehydration'''. Anaemia is only seen in severely affected animals.

There may be haemorrhage into the lumen of the intestine, catarrhal inflammation and diarrhoea. There may be '''dysentry, tenesmus and dehydration'''. [[Anaemia]] is only seen in severely affected animals.

==Diagnosis==

==Diagnosis==

The number of oocysts in a sample can vary and must be related to clinical signs and lesions, and the species observed must be found to be pathogenic to that host. Other causes of diarrhoea should be ruled out before ''Isospora'' infection is diagnosed.

The number of oocysts in a sample can vary and must be related to clinical signs and lesions, and the species observed must be found to be pathogenic to that host. Other causes of diarrhoea should be ruled out before ''Isospora'' infection is diagnosed.

Many '''nonpathogenic species''' can be found during episodes of diarrhoea, which will non allow a diagnosis of coccidiosis in that species.

Many '''nonpathogenic species''' can be found during episodes of diarrhoea, which will not allow a diagnosis of coccidiosis in that species.

==Treatment==

==Treatment==

==Isospora in Cats and Dogs==

==Isospora in Cats and Dogs==

''Isospora'' species in cats are ''I. felis'' and ''I. rivolta'' which can be identified by size and shape.

''Isospora'' species in cats are ''I. felis'' and ''I. rivolta'' which can be identified by size and shape. Four species infect the dog: ''I. canis'', ''I. ohioensis'', ''I. burrowsi'' and ''I. neorivolta''.

 

Four species infect the dog: ''I. canis'', ''I. ohioensis'', ''I. burrowsi'' and ''I. neorivolta''.

Clinical illness is uncommon but heavy infections have been reported in kittens and puppies. In kittens, infection is usually seen at weaning.

Clinical illness is uncommon but heavy infections have been reported in kittens and puppies. In kittens, infection is usually seen at weaning.

The illness can be associated with other infections and immunosuppression.

The illness can be associated with other infections and immunosuppression.

Cats usually '''spontaneously eliminate''' the infection, but if they are clinically infection: '''trimethoprim-sulfa''' can be given.

Cats usually '''spontaneously eliminate''' the infection, but if they are clinically ill, '''trimethoprim-sulfa''' can be given.

{{Learning

{{Learning

[[Small Animal Abdominal and Metabolic Disorders Q&A 12]]

[[Small Animal Abdominal and Metabolic Disorders Q&A 12]]

}}

}}

==References==

==References==

Merck and Co (2008) '''Merck Veterinary Manual''' ''Merial''

Merck and Co (2008) '''Merck Veterinary Manual''' ''Merial''

[[Category:Coccidia]]

[[Category:Coccidia]]

[[Category:Expert_Review]]

[[Category:Expert_Review]]