Neospora is a single celled parasite of livestock and companion animals. It was not discovered until 1984 in Norway, where it was found in dogs. Neosporosis, the disease that affects cattle and companion animals, has a worldwide distribution. Neosporosis causes abortions in cattle and paralysis in companion animals. It is highly transmissible and some herds can have up to a 90% prevalence. Up to 33% of pregnancies can result in aborted fetuses on one dairy farm. In many countries this organism is the main cause of abortion in cattle.[1] Neosporosis is now considered as a major cause of abortion in cattle worldwide. Many reliable diagnostic tests are commercially available. Neospora caninum does not appear to be infectious to humans. In dogs, Neospora caninum can cause neurological signs, especially in congenitally infected puppies, where it can form cysts in the central nervous system.
The genome of Neospora caninum has been sequenced.[2] The results suggest a European origin for this parasite.
Effects of diseaseedit
Neospora caninum is a major pathogen of cattle and dogs that occasionally causes clinical infections in horses, goats, sheep, and deer as well. The domestic dog is the only known definitive host for N. caninum. In cattle, N. caninum is a major cause of bovine abortion in many countries and is one of the most efficiently transmitted parasites with up to 90% of some bovine herds infected. N. caninum causes abortion in both beef and dairy cattle. Another important factor is the gestational age and hence immunocompetence of the fetus at the time of infection.[3] Early in gestation, N. caninum infection of the placenta and subsequently the fetus usually proves fatal, whereas infection occurring in mid to late pregnancy may result in the birth of a congenitally infected but otherwise healthy calf. Recent studies have broadened the list of known intermediate hosts to include birds. N. caninum has recently been found to infect domestic chickens and house sparrows (Passer domesticus) which may become infected after ingesting parasite oocysts from the soil. [4] The presence of birds in cattle pastures has been correlated to higher infection rates in cattle.[5] Birds may be an important link in the transmission of N. caninum to other animals.
Epidemiologyedit
The life cycle is similar to Toxoplasma. An infected dog will pass the oocysts through its feces and infect food or water. A cow or other animal will then up take the parasite. The parasite will undergo asexual reproduction in the animal's muscle until it is eaten by a dog. There, sexual reproduction will occur and oocysts will be created and passed through the feces. Dogs are often the definitive host but can act as an intermediate host as well. Cows are usually the intermediate host. No horizontal cow-to-cow transmission have been shown, although salival interactions have been suggested. Vertical transmission can occur when an infected cow gives birth to an infected calf—the calf survives the infection and grows into an adult. Vertical route is the major route of transmission in cattle and is extremely efficient as the rate of transmission is usually between 80 and 100%. [6] A heifer calf that is born congenitally infected is capable of transmitting the infection to the next generation when she becomes pregnant, thus maintaining the infection in the herd. Transplacental transmission in cattle is considered the major route of transmission. The life cycle is typified by three infectious stages: tachyzoites, tissue cysts, and oocysts [7] Tachyzoites and tissue cysts are the stages found in the intermediate hosts, and they occur intracellularly.
Detection of diseaseedit
Detection: the presence of cerebral and cardiac lesions can be seen on aborted bovine fetuses originating from a single farm. The parasite is identified in the tissues of many bovine aborted fetuses but also of stillborn calves and, rarely, of clinically affected newborn calves. The diagnosis of the infection is assisted through histopathology and immunohistochemical examination of aborted fetuses and serologic testing of cattle for evidence of infection.[8] The abortion is the only clinical sign and can occur from the third month of pregnancy and onwards. Most of the abortions take place between the 5th and 6th months of pregnancy [9] The fetus is either resorbed, autolyzed, mummified, stillborn, born alive with clinical signs, or born clinically normal but chronically infected. At calving, infected calves may be clinically normal or may have neurologic signs, be underweight or unable to stand.
Prevention and controledit
Embryo transfer is recommended as a method of reproduction to reduce the chances of contracting the disease, as long as the disease status of the donor cow is checked. It is not recommended to rebreed heifers or cows that have this disease. Seropositive animals should be culled. To prevent horizontal transmission it is important to prevent the contamination of feed and water via the shedding of oocysts by dogs and possibly other canids like the fox. These animals should not have access to animal premises although this might be difficult to achieve. There are no drugs or vaccines available yet to prevent or control the disease.
Referencesedit
^Haddad J; Dohoo I; VanLeewen J. 2005. "A review of Neospora caninum in dairy and beef cattle, a Canadian perspective". Can Vet Journal. 46:230-243.
^Khan A, Fujita AW, Randle N, Regidor-Cerrillo J, Shaik JS, Shen K, Oler AJ4, Quinones M4, Latham SM5, Akanmori BD, Cleaveland S, Innes EA, Ryan U, Šlapeta J, Schares G, Ortega-Mora LM, Dubey JP, Wastling JM, Grigg ME (2019) Global selective sweep of a highly inbred genome of the cattle parasite Neospora caninum. Proc Natl Acad Sci USA
^Innes E, Wright S, Bartley P (2005) The host-parasite relationship in bovine neosporosis. Vet Immunopathology. 108:29-36
^Darwich, L;Cabezón O, Echeverria I, Pabón M, Marco I, Molina-López R, Alarcia-Alejos O, López-Gatius F, Lavín S, Almería S (2012) Presence of Toxoplasma gondii and Neospora caninum DNA in the brain of wild birds. Veterinary Parasitology 183: 377–381
^Mineo T, Carrasco A, Raso T, Werther K, Pinto A, Machado R (2011) Survey for natural Neospora caninum infection in wild and captive birds. Veterinary Parasitology 182: 352–355.
^Anderson M; Reynolds J; Rowe J. 1997. "Evidence of vertical transmission of Neospora sp in dairy cattle". JAVMA. 210:1803-1806.
^Dubey, J. 2003. "Neosporosis in cattle". Journal of Parasitology 89:42-56
^Anderson, M; Andrianarivo, A; Conrad, P. (2000). “Neoporosis in cattle”. Animal Reproduction Science. 60: 417-431.
neospora, single, celled, parasite, livestock, companion, animals, discovered, until, 1984, norway, where, found, dogs, neosporosis, disease, that, affects, cattle, companion, animals, worldwide, distribution, neosporosis, causes, abortions, cattle, paralysis,. Neospora is a single celled parasite of livestock and companion animals It was not discovered until 1984 in Norway where it was found in dogs Neosporosis the disease that affects cattle and companion animals has a worldwide distribution Neosporosis causes abortions in cattle and paralysis in companion animals It is highly transmissible and some herds can have up to a 90 prevalence Up to 33 of pregnancies can result in aborted fetuses on one dairy farm In many countries this organism is the main cause of abortion in cattle 1 Neosporosis is now considered as a major cause of abortion in cattle worldwide Many reliable diagnostic tests are commercially available Neospora caninum does not appear to be infectious to humans In dogs Neospora caninum can cause neurological signs especially in congenitally infected puppies where it can form cysts in the central nervous system Neospora Neospora caninum Scientific classification Domain Eukaryota Clade Diaphoretickes Clade SAR Clade Alveolata Phylum Apicomplexa Class Conoidasida Order Eucoccidiorida Family Sarcocystidae Genus Neospora Species Neospora caninum Neospora hughesi Contents 1 Genome 2 Effects of disease 3 Epidemiology 4 Detection of disease 5 Prevention and control 6 References 7 External linksGenome editThe genome of Neospora caninum has been sequenced 2 The results suggest a European origin for this parasite Effects of disease editNeospora caninum is a major pathogen of cattle and dogs that occasionally causes clinical infections in horses goats sheep and deer as well The domestic dog is the only known definitive host for N caninum In cattle N caninum is a major cause of bovine abortion in many countries and is one of the most efficiently transmitted parasites with up to 90 of some bovine herds infected N caninum causes abortion in both beef and dairy cattle Another important factor is the gestational age and hence immunocompetence of the fetus at the time of infection 3 Early in gestation N caninum infection of the placenta and subsequently the fetus usually proves fatal whereas infection occurring in mid to late pregnancy may result in the birth of a congenitally infected but otherwise healthy calf Recent studies have broadened the list of known intermediate hosts to include birds N caninum has recently been found to infect domestic chickens and house sparrows Passer domesticus which may become infected after ingesting parasite oocysts from the soil 4 The presence of birds in cattle pastures has been correlated to higher infection rates in cattle 5 Birds may be an important link in the transmission of N caninum to other animals Epidemiology editThe life cycle is similar to Toxoplasma An infected dog will pass the oocysts through its feces and infect food or water A cow or other animal will then up take the parasite The parasite will undergo asexual reproduction in the animal s muscle until it is eaten by a dog There sexual reproduction will occur and oocysts will be created and passed through the feces Dogs are often the definitive host but can act as an intermediate host as well Cows are usually the intermediate host No horizontal cow to cow transmission have been shown although salival interactions have been suggested Vertical transmission can occur when an infected cow gives birth to an infected calf the calf survives the infection and grows into an adult Vertical route is the major route of transmission in cattle and is extremely efficient as the rate of transmission is usually between 80 and 100 6 A heifer calf that is born congenitally infected is capable of transmitting the infection to the next generation when she becomes pregnant thus maintaining the infection in the herd Transplacental transmission in cattle is considered the major route of transmission The life cycle is typified by three infectious stages tachyzoites tissue cysts and oocysts 7 Tachyzoites and tissue cysts are the stages found in the intermediate hosts and they occur intracellularly Detection of disease editDetection the presence of cerebral and cardiac lesions can be seen on aborted bovine fetuses originating from a single farm The parasite is identified in the tissues of many bovine aborted fetuses but also of stillborn calves and rarely of clinically affected newborn calves The diagnosis of the infection is assisted through histopathology and immunohistochemical examination of aborted fetuses and serologic testing of cattle for evidence of infection 8 The abortion is the only clinical sign and can occur from the third month of pregnancy and onwards Most of the abortions take place between the 5th and 6th months of pregnancy 9 The fetus is either resorbed autolyzed mummified stillborn born alive with clinical signs or born clinically normal but chronically infected At calving infected calves may be clinically normal or may have neurologic signs be underweight or unable to stand Prevention and control editEmbryo transfer is recommended as a method of reproduction to reduce the chances of contracting the disease as long as the disease status of the donor cow is checked It is not recommended to rebreed heifers or cows that have this disease Seropositive animals should be culled To prevent horizontal transmission it is important to prevent the contamination of feed and water via the shedding of oocysts by dogs and possibly other canids like the fox These animals should not have access to animal premises although this might be difficult to achieve There are no drugs or vaccines available yet to prevent or control the disease References edit Haddad J Dohoo I VanLeewen J 2005 A review of Neospora caninum in dairy and beef cattle a Canadian perspective Can Vet Journal 46 230 243 Khan A Fujita AW Randle N Regidor Cerrillo J Shaik JS Shen K Oler AJ4 Quinones M4 Latham SM5 Akanmori BD Cleaveland S Innes EA Ryan U Slapeta J Schares G Ortega Mora LM Dubey JP Wastling JM Grigg ME 2019 Global selective sweep of a highly inbred genome of the cattle parasite Neospora caninum Proc Natl Acad Sci USA Innes E Wright S Bartley P 2005 The host parasite relationship in bovine neosporosis Vet Immunopathology 108 29 36 Darwich L Cabezon O Echeverria I Pabon M Marco I Molina Lopez R Alarcia Alejos O Lopez Gatius F Lavin S Almeria S 2012 Presence of Toxoplasma gondii and Neospora caninum DNA in the brain of wild birds Veterinary Parasitology 183 377 381 Mineo T Carrasco A Raso T Werther K Pinto A Machado R 2011 Survey for natural Neospora caninum infection in wild and captive birds Veterinary Parasitology 182 352 355 Anderson M Reynolds J Rowe J 1997 Evidence of vertical transmission of Neospora sp in dairy cattle JAVMA 210 1803 1806 Dubey J 2003 Neosporosis in cattle Journal of Parasitology 89 42 56 Anderson M Andrianarivo A Conrad P 2000 Neoporosis in cattle Animal Reproduction Science 60 417 431 Losson B 2006 Neosporosis in Cattle World Buiattrics Congress http www ivis org proceedings wbc wbc2006 losson pdf LA 1External links editNeospora at the U S National Library of Medicine Medical Subject Headings MeSH nbsp This Apicomplexa related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Neospora amp oldid 1114181772, wikipedia, wiki, book, books, library,
