Title: Neospora caninum

{{short description|Species of Conoidasida in the apicomplex phylum}}
{{Speciesbox
| image = Neospora caninum (5256961091).jpg
| image_alt = &quot;Neospora caninum&quot;
| image_caption = ''Neospora caninum''
| status = 
| status_system = 
| status_ref = 
| genus = Neospora
| species = caninum
| authority = Dubey, Carpenter, speer, Topper &amp; Uggla, 1988
| synonyms = 
| synonyms_ref = 
| subdivision_ranks = 
| subdivision = 
}}

'''''Neospora caninum''''' is a [[coccidia]]n [[parasite]] that was identified as a species in 1988. Prior to this, it was misclassified as ''[[Toxoplasma gondii]]'' due to structural similarities.&lt;ref&gt;{{cite journal |author=Dubey JP |title=Neosporosis—the first decade of research |journal=Int J Parasitol |volume=29 |issue=10 |pages=1485–8 |date=Oct 1999 |pmid=10608433 |doi=10.1016/S0020-7519(99)00134-4 |url=https://zenodo.org/record/1259617 }}&lt;/ref&gt; The genome sequence of ''Neospora caninum'' has been determined by the [[Wellcome Trust Sanger Institute]] and the [[University of Liverpool]].&lt;ref&gt;{{cite journal |vauthors=Reid AJ, Vermont SJ, Cotton JA, Harris D, Hill-Cawthorne GA, Konen-Waisman S, Latham SM, Mourier T, Norton R, Quail MA, Sanders M, Shanmugam D, Sohal A, Wasmuth JD, Brunk B, Grigg ME, Howard JC, Parkinson J, Roos DS, Trees AJ, Berriman M, Pain A, Wastling JM |title=Comparative Genomics of the Apicomplexan Parasites Toxoplasma gondii and Neospora caninum: Coccidia Differing in Host Range and Transmission Strategy |journal=PLOS Pathogens |volume=8 |issue=3 |article-number=e1002567 |year=2012 |pmid=22457617 |doi=10.1371/journal.ppat.1002567 |pmc=3310773 |doi-access=free }}&lt;/ref&gt;  ''Neospora caninum'' is an important cause of [[spontaneous abortion]] in infected [[livestock]].

==Life cycle and transmission==
''Neospora caninum'' has a [[heteroxenous]] life cycle, with the sexually reproductive stage occurring in the intestine of a [[definitive host]].  Until 2004, the only known definitive host was the domestic [[dog]].&lt;ref&gt;{{cite journal |vauthors=McAllister MM, Dubey JP, Lindsay DS, Jolley WR, Wills RA, McGuire AM |title=Dogs are definitive hosts of ''Neospora caninum'' |journal=Int J Parasitol |volume=28 |issue=9 |pages=1473–8 |date=Sep 1998 |pmid=9770635 |doi=10.1016/S0020-7519(98)00138-6 }}&lt;/ref&gt; New research has determined that other canids such as [[coyotes]] (''Canis latrans''), [[Gray wolf|gray wolves]] (''Canis lupus''), and Australian [[dingos]] (''Canis lupus dingo'') are also definitive hosts.&lt;ref name=&quot;Dubey 2011&quot;&gt;{{cite journal|last=Dubey|first=JP|author2=MC Jenkins |author3=C Rajendran |author4=K Miska |author5=LR Ferreira |author6=J Martins |author7=OCH Kwok |author8=S Choudhary |title=Gray Wolf (Canis lupus) is a natural definitive host for ''Neospora caninum''|journal=Veterinary Parasitology|date=September 2011|volume=181|issue=2–4|pages=382–387|doi=10.1016/j.vetpar.2011.05.018|pmid=21640485|url=https://zenodo.org/record/1259437}}&lt;/ref&gt;&lt;ref name=&quot;Gondim et al 2004&quot;&gt;{{cite journal|last=Gondim|first=LFP|author2=MM McAllister |author3=WC Pitt |author4=DE Zemlicka |title=Coyotes (Canis latrans) are definitive hosts of Neospora caniinum.|journal=International Journal for Parasitology|date=February 2004|volume=34|issue=2|pages=159–161|doi=10.1016/j.ijpara.2004.01.001|pmid=15037103|url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1373&amp;context=icwdm_usdanwrc|url-access=subscription}}&lt;/ref&gt;&lt;ref name=&quot;King et al., 2010&quot;&gt;{{cite journal|last=King|first=JS|author2=Slapeta J |author3=Jenkins DJ |author4=Al-Qassab SE |author5=Ellis JT |author6=Windsor PA |title=Australian dingoes are definitive hosts of ''Neospora caninum''|journal=International Journal for Parasitology|date=July 2010|volume=40|issue=8|pages=945–950|pmid=20149793|doi=10.1016/j.ijpara.2010.01.008}}&lt;/ref&gt;

[[Oocyst]]s passed in the feces of the [[definitive host]], such as canines or canids, are ingested by an [[intermediate host]], such as cattle. After ingestion of an oocyst, motile and rapidly dividing tachyzoites are released. These tachyzoites disseminate throughout the host, and in response to the host immune response, differentiate into bradyzoites, which form cysts in muscle and tissue. Formation of these cysts results in chronic infection of the intermediate host.  Ingestion of infected intermediate host tissue by the definitive host completes the life cycle. A second route of transmission is the congenital transmission from mother to offspring.&lt;ref name=&quot;USDA&quot;&gt;{{cite web |url= http://www.ars.usda.gov/Main/docs.htm?docid=11007|archive-url= https://archive.today/20121214091649/http://www.ars.usda.gov/Main/docs.htm?docid=11007|archive-date= December 14, 2012|title=Neosporosis |author=&lt;!--Staff writer(s); no by-line.--&gt; |date=November 7, 2005 |website=United States Department of Agriculture Agricultural Research Service |publisher=USDA |access-date=26 November 2013}}&lt;/ref&gt;   [[Transplacental]] transmission (passage from mother to offspring during pregnancy) has also been shown to occur in dogs, cats, sheep and cattle. If the intermediate host acquires the disease during pregnancy, it activates these cysts, and active infection often causes spontaneous abortion.&lt;ref name=&quot;USDA&quot; /&gt;  In addition, if the aborted fetus and membranes are then eaten by the definitive host, they cause further infection and the cycle is complete.    Other [[carnivore]]s, for example the [[red fox]] (''Vulpes vulpes''), may also be intermediate hosts, but they are not known to be definitive hosts.&lt;ref&gt;{{cite journal |vauthors=Almería S, Ferrer D, Pabón M, Castellà J, Mañas S |title=Red foxes (''Vulpes vulpes'') are a natural intermediate host of ''Neospora caninum'' |journal=Vet. Parasitol. |volume=107 |issue=4 |pages=287–94 |date=Aug 2002 |pmid=12163240 |doi=10.1016/S0304-4017(02)00162-0 }}&lt;/ref&gt;  ''Neospora caninum'' does not appear to be infectious to humans.  In dogs, ''Neospora caninum'' can cause neurological signs, especially in [[congenital]]ly infected puppies, where it can form cysts in the [[central nervous system]].&lt;ref&gt;{{cite journal |vauthors=Barber JS, Payne-Johnson CE, Trees AJ |title=Distribution of ''Neospora caninum'' within the central nervous system and other tissues of six dogs with clinical neosporosis |journal=J Small Anim Pract |volume=37 |issue=12 |pages=568–74 |date=Dec 1996 |pmid=8981277 |doi=10.1111/j.1748-5827.1996.tb02332.x }}&lt;/ref&gt;

The discovery that coyotes are definitive hosts may increase the risk of transmission of ''N. caninum'' to domestic livestock as well as to wild [[ruminant]]s such as [[white-tailed deer]] (''Odocoileus virginianus'').&lt;ref name=&quot;Gondim et al, Dec. 2004&quot;&gt;{{cite journal|last=Gondim|first=LFP|author2=McAllister MM|author3=Mateus-Pinilla NE|author4=Pitt WC|author5=Mech LD|author6=Nelson ME|title=Transmission of ''Neospora caninum'' between wild and domestic animals|journal=[[Journal of Parasitology]]|date=December 2004|volume=90|issue=6|pages=1361–1365|url=https://pubag.nal.usda.gov/download/20958/PDF|archive-url=https://web.archive.org/web/20180223171321/https://pubag.nal.usda.gov/download/20958/PDF|archive-date=February 23, 2018|access-date=2018-02-23|jstor=3286228|doi=10.1645/GE-341R|pmid=15715229|bibcode=2004JPara..90.1361G |s2cid=15705809 |url-access=subscription}}&lt;/ref&gt; Coyote range now includes most of North and Central America.&lt;ref name=&quot;Gondim et al 2004&quot; /&gt;  Studies suggest that the parasite may be widespread among wildlife and that infection cycles cross over between wild and domestic animals.&lt;ref name=&quot;Gondim et al, Dec. 2004&quot; /&gt;

From 2010, studies have broadened the list of known intermediate hosts to include birds.&lt;ref name=&quot;Darwich et al. Feb. 2012&quot;&gt;{{cite journal|last=Darwich|first=L|author2=Cabezón O |author3=Echeverria I |author4=Pabón M |author5=Marco I |author6=Molina-López R |author7=Alarcia-Alejos O |author8=López-Gatius F |author9=Lavín S |author10=Almería S |title=Presence of ''Toxoplasma gondii'' and ''Neospora caninum'' DNA in the brain of wild birds.|journal=Veterinary Parasitology|date=February 2012|volume=183|issue=3–4|pages=377–381|doi=10.1016/j.vetpar.2011.07.024|pmid=21831525}}&lt;/ref&gt; ''N. caninum'' has recently been found to infect domestic chickens and [[house sparrow]]s (''Passer domesticus'') which may become infected after ingesting parasite oocysts from the soil.&lt;ref name=&quot;Darwich et al. Feb. 2012&quot; /&gt;&lt;ref name=&quot;Gondim et al., Feb. 2010&quot;&gt;{{cite journal|last=Gondim|first=Leane S. Q. |author2=Kiyoko Abe-Sandes |author3=Rosângela S. Uzêda |author4=Mariana S.A. Silva |author5=Sara L. Santos |author6=Rinaldo A. Mota |author7=Sineide M.O. |author8=Vilela, Luis F.P. Gondim |title=''Toxoplasma gondii'' and ''Neospora caninum'' in sparrows (''Passer domesticus'') in the Northeast of Brazil|journal=Veterinary Parasitology|date=February 2010|volume=168|issue=1–2|pages=121–124|doi=10.1016/j.vetpar.2009.09.055|pmid=19879051 |doi-access=free }}&lt;/ref&gt;  Sparrows, which are common in urban and rural areas, may serve as a food source for wild and domestic carnivores.&lt;ref name=&quot;Gondim et al., Feb. 2010&quot; /&gt;  ''N. caninum'' has also been detected in [[common buzzard]]s (''Buteo buteo'') and magpies.&lt;ref name=&quot;Darwich et al. Feb. 2012&quot; /&gt;  The presence of birds in cattle pastures has been correlated to higher infection rates in cattle.&lt;ref name=&quot;Mineo et al., Dec 2011&quot;&gt;{{cite journal|last=Mineo|first=T.W.P. |author2=A.O.T. Carrasco |author3=T. F. Raso |author4=K. Werther |author5=A.A. Pinto |author6=R.Z. Machado|title=Survey for natural ''Neospora caninum'' infection in wild and captive birds|journal=Veterinary Parasitology|date=December 2011|volume=182|issue=2–4|pages=352–355|doi=10.1016/j.vetpar.2011.05.022|pmid=21680099 |hdl=11449/3157|hdl-access=free}}&lt;/ref&gt; Birds may be an important link in the transmission of ''N. caninum'' to other animals.&lt;ref name=&quot;Darwich et al. Feb. 2012&quot; /&gt;

==Clinical disease==
Neosporosis is an infectious disease for many different canids and cattle.&lt;ref name=&quot;USDA&quot; /&gt; Neuromuscular degeneration was first observed in canines in Norway, which led to hind limb paralysis.&lt;ref name=&quot;USDA&quot; /&gt;  Abortion in dairy cattle was also observed as a major cause of disease by neosporosis.&lt;ref name=&quot;USDA&quot; /&gt; Although this disease is worldwide, it is of major concern in the United States, Netherlands, and New Zealand.&lt;ref name=&quot;USDA&quot; /&gt;

''N. caninum'' infections have been reported from most parts of the world with studies in the United States, New Zealand, the Netherlands, Estonia, Germany, and Portugal.&lt;ref&gt;{{cite journal | last1 = Maia | first1 = C. | last2 = Cortes | first2 = H. | last3 = Brancal | first3 = H. | last4 = Lopes | first4 = A. P. | last5 = Pimenta | first5 = P. | last6 = Campino | first6 = L. | last7 = Cardoso | first7 = L. | year = 2014 | title = Prevalence and correlates of antibodies to ''Neospora caninum'' in dogs in Portugal | journal = Parasite | volume = 21 | page = 29 | doi = 10.1051/parasite/2014031 | pmid = 24972327 | pmc=4073620}}&lt;/ref&gt;&lt;ref&gt;{{cite journal | last1 = Lassen| first1 = B. | last2 = Orro| first2 = T. | last3 =  Aleksejev | first3 = A. | last4 = Raaperi | first4 = K. | last5 = Järvis | first5 = T. | last6 = Viltrop | first6 = A. | year = 2012 | title = Neospora caninum in Estonian dairy herds in relation to herd size, reproduction parameters, bovine virus diarrhoea virus, and bovine herpes virus 1 | journal = Vet Parasitol | volume = 190| issue =1–2 | pages = 43–50 | doi = 10.1016/j.vetpar.2012.05.021 | pmid = 22721941}}&lt;/ref&gt; 12-45% of aborted fetuses from dairy cattle are infected with the organism.  Exposure is common in US dairy herds, ranging from 16% to 36% of dairy cows testing positive on serum.&lt;ref&gt;{{cite web|last1=Arnold|first1=M|title=Neospora caninum Abortion in Cattle {{!}} Animal &amp; Food Sciences|url=https://afs.ca.uky.edu/dairy/neospora-caninum-abortion-cattle|website=afs.ca.uky.edu}}&lt;/ref&gt; The majority of calves that acquire a ''Neospora'' infection during gestation are born clinically normal except that they have precolostral antibody titers to ''Neospora caninum''.&lt;ref name=&quot;Dubey 2007&quot;&gt;{{cite journal|last1=Dubey|first1=JP|last2=Schares|first2=G|last3=Ortega-Mora|first3=LM|title=Epidemiology and control of neosporosis and Neospora caninum.|journal=Clinical Microbiology Reviews|date=April 2007|volume=20|issue=2|pages=323–67|doi=10.1128/CMR.00031-06|pmid=17428888|pmc=1865591|url=https://journals.asm.org/doi/10.1128/cmr.00031-06}}&lt;/ref&gt;

==Treatment and control==
[[File:Footpath sign and small footbridge - geograph.org.uk - 1739368.jpg|thumb|A notice at the entrance to the field reminds dog owners to keep their pets on leads, keep to the footpath and collect up all dog faeces.  Pregnant cattle which eat hay made from grass in these fields have been aborting their calves due to a disease called neosporosis, caused by ''Neospora caninum''. This type of abortion in young cows is very painful, and at present there is no vaccination.]]
In addition to being an important cause of cattle abortions,&lt;ref name=&quot;USDA&quot; /&gt; neosporosis is a significant disease in dogs throughout the world.&lt;ref name=&quot;Dubey et al., August 1998&quot;&gt;{{cite journal|last=Dubey|first=J.P.|author2=Dorough, K.R. |author3=Jenkins, M.C. |author4=Liddell, S. |author5=Speer, C.A. |author6=Kwok, O.C.H. |author7=Shen, S.K. |title=Canine neosporosis: clinical signs, diagnosis, treatment and isolation of ''Neospora caninum'' in mice and cell culture|journal=International Journal for Parasitology|date=August 1998|volume=28|issue=8|pages=1293–1304|doi=10.1016/s0020-7519(98)00099-x|pmid=9762578|url=https://zenodo.org/record/1259615}}&lt;/ref&gt;  If the disease is caught early, dogs may be successfully treated with [[clindamycin]] and other antiprotozoan drugs.&lt;ref name=&quot;Dubey et al., August 1998&quot; /&gt; However, the disease is often fatal to young puppies.&lt;ref name=&quot;Dubey et al., August 1998&quot; /&gt;  Preventative vaccines have been tested on cattle.&lt;ref name=&quot;Andrianarivo et al., 2000&quot;&gt;{{cite journal|last=Andrianarivo|first=AG |author2=Rowe, JD |author3=Barr, BC |author4=Anderson, ML |author5=Packham, AE |author6=Sverlow, KW |author7=Choromanski, L |author8=Loui, C |author9=Grace, A |author10=Conrad, PA|title=A POLYGEN-adjuvanted killed ''Neospora caninum'' tachyzoite preparation failed to prevent foetal infection in pregnant cattle following i.v./i.m. experimental tachyzoite challenge|journal=International Journal for Parasitology|date=August 2000|volume=30|issue=9|pages=985–990|doi=10.1016/S0020-7519(00)00088-6|pmid=10980287 }}&lt;/ref&gt;&lt;ref name=&quot;Romero et al., 2004&quot;&gt;{{cite journal|last=Romero|first=JJ|author2=Pérez, E |author3=Frankena, K. |title=Effect of a killed whole ''Neospora caninum'' tachyzoite vaccine on the crude abortion rate of Costa Rican dairy cows under field conditions|journal=Veterinary Parasitology|date=September 2004|volume=123|issue=3–4|pages=149–159|doi=10.1016/j.vetpar.2004.06.016|pmid=15325041|hdl=11056/23266|hdl-access=free}}&lt;/ref&gt; An inactivated vaccine was made commercially available but had mixed results.&lt;ref name=&quot;Reichel, 2009 (vaccine)&quot;&gt;{{cite journal|last=Reichel|first=MP|author2=Ellis, JT|title=''Neospora caninum'' – How close are we to development of an efficacious vaccine that prevents abortion in cattle?|journal=International Journal for Parasitology|date=September 2009|volume=39|issue=11|pages=1173–1187|doi=10.1016/j.ijpara.2009.05.007|pmid=19497326|hdl=10453/9478|hdl-access=free}}&lt;/ref&gt;  A live vaccine using attenuated ''N. caninum'' [[Apicomplexa lifecycle stages|tachyzoites]] has been more successful but is expensive to produce.&lt;ref name=&quot;Reichel, 2009 (vaccine)&quot; /&gt;  Other treatment options aim at prevention of the disease. Prevention requires an understanding of the transmission cycle, especially the connection between cattle and dogs (canids). Canids may pick up the parasite from eating infected material and spread the disease through contaminated feces.&lt;ref name=&quot;Reichel, 2009 (vaccine)&quot; /&gt;  One control method is to test for the disease and remove infected cattle from the herd.&lt;ref name=&quot;Reichel, 2009 (vaccine)&quot; /&gt;  Another method of control is preventing canids from entering the cattle holding area.&lt;ref name=&quot;Reichel, 2009 (vaccine)&quot; /&gt;

==Etymology and History ==
From the ''neo''- ([[Latin language|Latin]], &quot;new&quot;) + ''spora'' ([[Greek language|Greek]], &quot;seed&quot;) and ''canis'' (Latin, &quot;dog&quot;), ''Neospora caninum''  is a sporozoan parasite that was first described in 1984.&lt;ref&gt;{{cite journal |last1=Henry |first1=Ronnie |date=June 2019 |title=Etymologia: Neospora caninum |journal=Emerg Infect Dis  |volume=25 |issue=6 |page= 1228|doi=10.3201/eid2506.et2506|pmc=6537716 |quote= citing public domain text from the CDC|doi-access=free }}&lt;/ref&gt;

== References ==
{{Reflist}}

== External links ==
* [http://www.sanger.ac.uk/sequencing/Neospora/caninum/ ''Neospora caninum'' genome project]
* [http://www.wvdl.wisc.edu/PDF%5CWVDL.Info.Recognizing_and_Preventing_Neosporosis_Infections.pdf Neosporosis in cattle]
* [http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51600.htm Neosporosis]
* [http://awp.eduwikis.co.za/index.php/Neospora_caninum  Neosporosis in wildlife]

{{Taxonbar|from=Q1431408}}

[[Category:Protists described in 1988]]
[[Category:Conoidasida]]
[[Category:Dog diseases]]
[[Category:Apicomplexa species]]