{"id":6776,"date":"2015-09-29T12:19:33","date_gmt":"2015-09-29T11:19:33","guid":{"rendered":"https:\/\/www.farmhealthonline.com\/?page_id=6776"},"modified":"2016-04-09T22:13:45","modified_gmt":"2016-04-09T21:13:45","slug":"toxoplasmosis","status":"publish","type":"page","link":"https:\/\/www.farmhealthonline.com\/US\/disease-management\/sheep-diseases\/toxoplasmosis\/","title":{"rendered":"Toxoplasmosis"},"content":{"rendered":"<p><div class=\"printfriendly pf-button  pf-alignright\">\n                    <a href=\"https:\/\/www.farmhealthonline.com\/US\/disease-management\/sheep-diseases\/toxoplasmosis\/?pfstyle=wp\" rel=\"nofollow\" onclick=\"pfTrackEvent(&#039;Toxoplasmosis&#039;); return false;\" title=\"Printer Friendly, PDF & Email\">\n                    <img decoding=\"async\" class=\"pf-button-img\" src=\"https:\/\/cdn.printfriendly.com\/buttons\/printfriendly-pdf-email-button-notext.png\" alt=\"Print Friendly, PDF & Email\" style=\"width: 110px;height: 30px;\"  \/>\n                    <\/a>\n                <\/div><\/p>\n<h2>Sheep Diseases<\/h2><div id=\"gticontainer\"><div class=\"gti_clear\"><\/div><div id=\"gti_letterindex\"><ul><li><a href=\"#gti_all\">All<\/a><\/li><li><a id=\"gti_sel_A\" href=\"#\">A<\/a><\/li><li><a id=\"gti_sel_B\" href=\"#\">B<\/a><\/li><li><a id=\"gti_sel_C\" href=\"#\">C<\/a><\/li><li><a id=\"gti_sel_E\" href=\"#\">E<\/a><\/li><li><a id=\"gti_sel_F\" href=\"#\">F<\/a><\/li><li><a id=\"gti_sel_G\" href=\"#\">G<\/a><\/li><li><a id=\"gti_sel_H\" href=\"#\">H<\/a><\/li><li><a id=\"gti_sel_J\" href=\"#\">J<\/a><\/li><li><a id=\"gti_sel_K\" href=\"#\">K<\/a><\/li><li><a id=\"gti_sel_L\" href=\"#\">L<\/a><\/li><li><a id=\"gti_sel_M\" href=\"#\">M<\/a><\/li><li><a id=\"gti_sel_N\" href=\"#\">N<\/a><\/li><li><a id=\"gti_sel_O\" href=\"#\">O<\/a><\/li><li><a id=\"gti_sel_P\" href=\"#\">P<\/a><\/li><li><a id=\"gti_sel_R\" href=\"#\">R<\/a><\/li><li><a id=\"gti_sel_S\" href=\"#\">S<\/a><\/li><li><a id=\"gti_sel_T\" href=\"#\">T<\/a><\/li><li><a id=\"gti_sel_W\" href=\"#\">W<\/a><\/li><\/ul><div class=\"gti_clear\"><\/div><\/div><div class=\"tagindex\"><div id='gti_div_A'><div class='blockletter' id='gti_A'>A<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/acidosis-ruminal\/\">Acidosis - Ruminal<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/adenomatosis-pulmonary\/\">Adenomatosis - Pulmonary<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/arthritis-in-sheep\/\">Arthritis in Sheep<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_B'><div class='blockletter' id='gti_B'>B<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/barbers-pole-worm\/\">Barbers Pole Worm<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/sheep-blowfly-strike\/\">Blowfly Strike<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/border-disease\/\">Border Disease<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_C'><div class='blockletter' id='gti_C'>C<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/campylobacteriosis-2\/\">Campylobacteriosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/ccn\/\">CCN<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/cerebrocortical-necrosis\/\">Cerebrocortical necrosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/chlamydial-abortion\/\">Chlamydial Abortion<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/circling-disease\/\">Circling Disease<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/cobalt-deficiency-in-sheep\/\">Cobalt Deficiency<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/coccidiosis-in-lambs\/\">Coccidiosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/coenurosis\/\">Coenurosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/contagious-ecthyma\/\">Contagious Ecthyma<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/contagious-pustular-dermatitis\/\">Contagious Pustular Dermatitis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/contagious-respiratory-tumours\/\">Contagious Respiratory Tumours<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/copper-poisoning\/\">Copper Poisoning<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/cryptosporidiosis-in-lambs\/\">Cryptosporidiosis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_E'><div class='blockletter' id='gti_E'>E<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/e-coli-infection-in-lambs\/\">E. coli infection in lambs<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/eimeria-in-sheep\/\">Eimeria in sheep<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/encephalitis-listerial\/\">Encephalitis - Listerial<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/endoparasites-in-sheep\/\">Endoparasites in Sheep<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/enzootic-abortion-in-ewes\/\">Enzootic Abortion<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_F'><div class='blockletter' id='gti_F'>F<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/fasciola-hepatica-in-sheep\/\">Fasciola<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/fly-strike\/\">Fly Strike<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/foot-abcess\/\">Foot Abcess<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/foot-rot\/\">Foot Rot<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_G'><div class='blockletter' id='gti_G'>G<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/granuloma\/\">Granuloma<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/grass-staggers-in-sheep\/\">Grass Staggers in sheep<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_H'><div class='blockletter' id='gti_H'>H<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/haemonchus\/\">Haemonchus contortus<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/hairy-shaker-lambs\/\">Hairy-shaker lambs<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/hypomagnesaemia-in-sheep\/\">Hypomagnesemia in Sheep<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_J'><div class='blockletter' id='gti_J'>J<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/jaagsiekte\/\">Jaagsiekte<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/joint-ill-sheep\/\">Joint-ill<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_K'><div class='blockletter' id='gti_K'>K<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/ketosis\/\">Ketosis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_L'><div class='blockletter' id='gti_L'>L<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/listeriosis-in-sheep\/\">Listeriosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/liver-fluke-sheep\/\">Liver Fluke<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/louping-ill\/\">Louping-ill<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_M'><div class='blockletter' id='gti_M'>M<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/magnesium-deficiency-2\/\">Magnesium Deficiency<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/mange-psoroptic\/\">Mange - Psoroptic<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/myiasis\/\">Myiasis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_N'><div class='blockletter' id='gti_N'>N<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/nematodirus\/\">Nematodirus battus<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_O'><div class='blockletter' id='gti_O'>O<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/orf\/\">Orf<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_P'><div class='blockletter' id='gti_P'>P<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/parasitic-gastroenteritis\/\">Parasitic Gastroenteritis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/pen\/\">PEN<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/polioencephalomalacia\/\">Polioencephalomalacia<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/pregnancy-toxaemia-in-sheep\/\">Pregnancy Toxemia<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/pulmonary-adenomatosis\/\">Pulmonary Adenomatosis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_R'><div class='blockletter' id='gti_R'>R<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/roundworm\/\">roundworm<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/roundworms-in-sheep\/\">Roundworms in Sheep<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/ruminal-acidosis\/\">Ruminal Acidosis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_S'><div class='blockletter' id='gti_S'>S<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/scab\/\">Scab<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/scald\/\">Scald<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/sheep-scab\/\">Sheep Scab<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/shelly-hoof\/\">Shelly Hoof<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/suppurative-polyarthritis\/\">Suppurative Polyarthritis<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_T'><div class='blockletter' id='gti_T'>T<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/taenia-multiceps\/\">Taenia multiceps<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/teladorsagia-circumcincta\/\">Teladorsagia circumcincta<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/thiamine-deficiency\/\">Thiamine Deficiency<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/toxaemia\/\">Toxemia, Pregnancy<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/toxoplasmosis\/\">Toxoplasmosis<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/trichostrongylus\/\">Trichostrongylus<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><div id='gti_div_W'><div class='blockletter' id='gti_W'>W<\/div><ul><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/watery-mouth-disease\/\">Watery Mouth Disease<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/white-line-separation\/\">White Line Separation<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/white-liver-disease\/\">White Liver Disease<\/a><\/li><li style=\"width:100%;\"><a href=\"https:\/\/www.farmhealthonline.com\/US\/sheep-diseases\/\/worms-in-sheep\/\">Worms in Sheep<\/a><\/li><\/ul><div class='gti_clear'><\/div><\/div><\/div><\/div>\n<h4>Toxoplasmosis in Sheep<\/h4>\n<p><span class=\"responsive\"><\/p>\n<div id=\"attachment_4331\" style=\"width: 209px\" class=\"wp-caption alignright\"><a href=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2014\/10\/Sheep-eating-concentrate.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-4331\" class=\"size-medium wp-image-4331\" src=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2014\/10\/Sheep-eating-concentrate-199x300.jpg\" alt=\"Sheep eating concentrate\" width=\"199\" height=\"300\" \/><\/a><p id=\"caption-attachment-4331\" class=\"wp-caption-text\"><strong>Contaminated feed is considered to be the most likely source of infection for sheep. Keeping cats away from stored feed will minimize the risk of infection.<\/strong><\/p><\/div>\n<p><\/span><strong>Toxoplasmosis is caused by the protozoan parasite <em>Toxoplasma gondii<\/em>. The organism is an intestinal coccidium of cats, with a wide range of warm-blooded <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"A (second) host where an essential transitional part of the parasite lifecycle occurs\">intermediate hosts<\/a><\/span>, including sheep, in which it can cause considerable losses during pregnancy (<a href=\"#ref\">Buxton, 1991<\/a>). Toxoplasmosis causes heavy economic losses to the sheep industry worldwide (<a href=\"#ref\">Innes <em>et al<\/em>., 2000<\/a>).<\/strong><\/p>\n<p>Toxoplasmosis is a <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"The ability of an infectious disease to pass from animals to humans or vice versa\">zoonotic<\/a><\/span> disease and although not common in humans, it can present a food safety issue and infection in pregnant women can lead to abortion, stillbirth or serious disease in the newborn. As a provision, pregnant women should avoid close contact with sheep during the lambing period. (Further guidance about pregnant women and contact with sheep can be found here: <a href=\"http:\/\/www.nhs.uk\/chq\/pages\/934.aspx?CategoryID=54\">http:\/\/www.nhs.uk\/chq\/pages\/934.aspx?CategoryID=54<\/a>).<\/p>\n<p><em>Toxoplasma<\/em> can also cause severe disease in people with HIV, or other conditions\u00a0that suppress the immune system.<\/p>\n<h3>The Life Cycle of <em>Toxoplasma<\/em><\/h3>\n<p>The life cycle of <em>Toxoplasma<\/em> can be divided into two stages;<\/p>\n<ol>\n<li>The\u00a0<span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"Reproduction not involving female and male gametes\">asexual<\/a><\/span> cycle with little host specificity i.e.,\u00a0the stage that\u00a0occurs in <strong>sheep<\/strong>, humans, rodents and birds<\/li>\n<li>The\u00a0sexual stage of the life cycle, confined to the intestinal <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"The thin layer of cells lining the gut\">epithelial<\/a><\/span> cells of <strong>cats<\/strong>, which results in the production of oocysts.<\/li>\n<\/ol>\n<h5><strong>The <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"Reproduction not involving female and male gametes\">asexual<\/a><\/span> life cycle of <em>Toxoplasma<\/em><\/strong><\/h5>\n<p><strong>Tachyzoite stage:<\/strong><br \/>\n<span class=\"responsive\"><\/p>\n<div id=\"attachment_6781\" style=\"width: 549px\" class=\"wp-caption alignright\"><a href=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Toxoplasmosis-edited-Life-Cylce-from-elifesciences.org_.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6781\" class=\"wp-image-6781 \" src=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Toxoplasmosis-edited-Life-Cylce-from-elifesciences.org_-300x168.jpg\" alt=\"Toxoplasmosis edited Life Cycle from elifesciences.org\" width=\"539\" height=\"302\" srcset=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Toxoplasmosis-edited-Life-Cylce-from-elifesciences.org_-300x168.jpg 300w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Toxoplasmosis-edited-Life-Cylce-from-elifesciences.org_-1024x572.jpg 1024w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Toxoplasmosis-edited-Life-Cylce-from-elifesciences.org_.jpg 1382w\" sizes=\"(max-width: 539px) 100vw, 539px\" \/><\/a><p id=\"caption-attachment-6781\" class=\"wp-caption-text\"><strong><em>Toxoplasma gondii<\/em>\u00a0life cycle. The sexual stage\u00a0that occurs in the definitive feline host is shown\u00a0on the left,\u00a0with the non-host specific asexual stage on the right. This image is a modified image taken from <a href=\"http:\/\/www.elifesciences.org\" target=\"_blank\">www.elifesciences.org<\/a><\/strong><\/p><\/div>\n<p><\/span><\/p>\n<ol>\n<li>Cats shed millions of unsporulated oocysts in their feces, these take 1-5 days to sporulate depending on the climatic conditions<\/li>\n<li>The sheep ingests a sporulated oocyst<\/li>\n<li>In the gut the sporozoites are released and they penetrate the intestinal wall and\u00a0migrate via the lymphatic and portal systems<\/li>\n<li>Tachyzoites penetrate host cells and become surrounded by a <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"A membrane enclosed fluid bubble\">vacuole<\/a><\/span> \u2013 <em>Toxoplasma gondii<\/em> can infect cells in the reproductive system, central nervous system, lung, liver and muscle tissue<\/li>\n<li>The tachyzoites multiply <span class=\"tooltips\"><a href=\"#\" rel=\"tooltip\" title=\"Reproduction not involving female and male gametes\">asexually<\/a><\/span> by a process called \u2018budding\u2019<\/li>\n<li>Once 8 \u2013 16 tachyzoites have accumulated, the cell ruptures and new cells are infected<\/li>\n<\/ol>\n<p>Some cases result in the death of the host, but more usually\u00a0the host\u00a0develops immunity to the infection and chronic infection is established, which\u00a0is called the bradyzoite stage.<\/p>\n<p><strong>Bradyzoite stage:<\/strong><\/p>\n<ol>\n<li>Antibodies are produced by the host&#8217;s immune system and any extra cellular parasites are eliminated<\/li>\n<li>The antibodies limit the invasiveness of intracellular tachyzoites to new cells, resulting in the formation of cysts which are found most frequently in the brain and skeletal muscle<\/li>\n<li>These cysts contain between a few and many\u00a0thousands of organisms called bradyzoites, which grow very slowly \u2013 this is the latent form. If immunity wanes, cysts may rupture releasing bradyzoites.<\/li>\n<\/ol>\n<p>Adapted from (<a href=\"#ref\">Taylor <em>et al<\/em>., 2007<\/a>).<\/p>\n<h5><strong>The sexual stage of the\u00a0life cycle of <em>Toxoplasma<\/em><\/strong><\/h5>\n<ul>\n<li>The sexual stage of the life cycle starts when a (usually) young cat ingests food containing cysts, such as a rodent<\/li>\n<li>The walls of the cysts dissolve in the stomach and small intestine<\/li>\n<li>The released bradyzoites penetrate the epithelial cells of the small intestine and form gametocytes over the 3-15 days following infection<\/li>\n<li>The formed microgametes are released and swim to and penetrate macrogametes<\/li>\n<li>The resulting oocysts, each containing a fertilized gamete, are passed out of the cat and sporulate within 1 &#8211; 5 days (<a href=\"#ref\">Frenkel, 1973<\/a>; <a href=\"#ref\">Taylor <em>et al<\/em>., 2007<\/a>).<\/li>\n<\/ul>\n<p><span class=\"responsive\"><\/p>\n<div id=\"attachment_6789\" style=\"width: 283px\" class=\"wp-caption alignright\"><a href=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Bella-the-kitten.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6789\" class=\" wp-image-6789\" src=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Bella-the-kitten-300x198.jpg\" alt=\"Bella the kitten\" width=\"273\" height=\"180\" srcset=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Bella-the-kitten-300x198.jpg 300w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Bella-the-kitten-320x210.jpg 320w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/Bella-the-kitten.jpg 448w\" sizes=\"(max-width: 273px) 100vw, 273px\" \/><\/a><p id=\"caption-attachment-6789\" class=\"wp-caption-text\"><strong>Cats (young strays in particular) are the primary source of infective oocysts as they shed millions in their feces.<\/strong><\/p><\/div>\n<p><\/span>Cats can shed millions of oocysts, but only for a period of about 8 days, after which they generally do\u00a0not excrete oocysts again. Ingested oocysts and tachyzoites can also infect cats, but in this case oocysts are produced in reduced numbers, and even then by only half the animals (<a href=\"#ref\">Buxton, 1991<\/a>; <a href=\"#ref\">Gethings <em>et al<\/em>., 1987<\/a>). A study in the USA reported that 60% of cats tested were serologically positive for Toxoplasmosis (<a href=\"#ref\">Taylor <em>et al<\/em>., 2007<\/a>).<\/p>\n<p>Oocysts can survive for months and contaminate pasture, grain, hay and water, which if consumed by pregnant sheep that have not\u00a0encountered <em>Toxoplasma<\/em> before, can trigger infection in the developing fetus (<a href=\"#ref\">Buxton, 1990<\/a>). Typically, a ewe produces a weak or stillborn lamb two to three days early, often accompanied by a small, mummified fetus. Weakly lambs do not usually survive, as they often have brain damage. The placental membranes will appear normal, but characteristically there will be multiple white spots 1-2 mm in diameter in the cotyledons (<a href=\"#ref\">Rodger and Buxton, 2006<\/a>). The outcome of infection depends largely on the stage of pregnancy when the ewe was infected\u00a0and the age of the fetus.<\/p>\n<div class=\"custom-table-1\">\n<table>\n<tbody>\n<tr>\n<td width=\"286\"><strong>Early Pregnancy<\/strong><\/td>\n<td width=\"858\">Infection in early gestation leads to fetal death and resorption, leaving the ewe barren.<\/td>\n<\/tr>\n<tr>\n<td width=\"286\"><strong>Mid Pregnancy<\/strong><\/td>\n<td width=\"331\">Infection in mid-gestation results in the parasite becoming established, first in the placenta and then in the fetus. The ability of the fetal immune system to resist the disease is age-dependent. Infection in mid-pregnancy may sometimes result in the death of a lamb but spare its twin and hence allow the pregnancy to survive. Infection will, however, be established in the surviving placenta and progressively damage the cotyledons. In some cases the placenta is so compromised the fetus dies. In others the lamb survives but is born with brain damage resulting from lack of oxygen due to a damaged placenta.<\/td>\n<\/tr>\n<tr>\n<td width=\"286\"><strong>Late Pregnancy<\/strong><\/td>\n<td width=\"331\">After 70 days,\u00a0the fetus\u00a0becomes progressively more able to combat the disease, and infection during the latter part of gestation would normally be successfully controlled in the fetus by its more advanced immune system. The placenta would become infected and damaged, but with less time before lambing, the degree of damage would not be sufficient to cause major issues.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"hr hr3\" style='margin:20px 0px 20px 0px !important;'><\/div>\n<h4>Control and Prevention of Toxoplasmosis<\/h4>\n<p><span class=\"responsive\"><\/p>\n<div id=\"attachment_6782\" style=\"width: 310px\" class=\"wp-caption alignright\"><a href=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/stacked-hay-in-a-barn-resized.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6782\" class=\"size-medium wp-image-6782\" src=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/stacked-hay-in-a-barn-resized-300x200.jpg\" alt=\"stacked hay in a barn\" width=\"300\" height=\"200\" srcset=\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/stacked-hay-in-a-barn-resized-300x200.jpg 300w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/stacked-hay-in-a-barn-resized-1024x683.jpg 1024w, https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2015\/09\/stacked-hay-in-a-barn-resized.jpg 1536w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><p id=\"caption-attachment-6782\" class=\"wp-caption-text\"><strong>Infected cats shed millions of oocysts in their feces. A likely source of infection is a place where cats like to live, such as in a hay\u00a0or straw\u00a0barns. Pregnant ewes should be prevented from eating contaminated feed or bedding.<\/strong><\/p><\/div>\n<p><\/span>Cats play an essential role in the spread and prevalence of toxoplasmosis. It is difficult to explain the widespread infection in sheep, but it is thought that pregnant ewes are most commonly infected during periods of concentrate feeding\u00a0at breeding or lambing, when the stored food has become contaminated with cats&#8217; feces and millions of oocysts (<a href=\"#ref\">Taylor <em>et al<\/em>., 2007<\/a>). Therefore a primary control measure should be to protect feedstuffs from access by cats.<\/p>\n<p>Practical control measures depend upon the proportion of the flock that is infected. A &#8216;clean&#8217; flock should be prevented from ingesting food and bedding contaminated by cats, particularly young cats (<a href=\"#ref\">Gethings <em>et al<\/em>., 1987<\/a>). <strong><span style=\"font-weight: 400;\">Male cats should be neutered to limit the size of cat population and reduce numbers of young cats.\u00a0<\/span><\/strong>However, chronically infected ewes are resistant to subsequent challenges.<\/p>\n<p>In\u00a0the past, in flocks in which a large number of ewes were already infected, there was a case to be made for attempting to expose young, non-pregnant replacement stock and uninfected bought-in animals to a contaminated environment 2-3 months before breeding; however identification of a contaminated environment is difficult. It is likely to be an area where cats live, as well as pasture spread with manure from such areas (<a href=\"#ref\">Faull <em>et al<\/em>., 1986a, 1986b<\/a>). E<span style=\"font-weight: 400;\">xposing na\u00efve sheep to infected sheep\/environment relies on older sheep having been significantly exposed to have developed complete natural immunity. \u00a0This cannot be proven until the subsequent breeding season.<\/span><\/p>\n<p>It is safer and more cost effective to opt for a vaccination strategy, and there is a live vaccine now available, which induces very good immunity after only one injection (<a href=\"#ref\">Buxton, 1993<\/a>; <a href=\"#ref\">Buxton<em> et al.<\/em>, 1991b<\/a>).\u00a0<span style=\"font-weight: 400;\">The best advice is to talk to your vet about confirming diagnosis and planning a vaccination program. \u00a0Vaccinal immunity lasts several years, so a booster is not needed every year, but vaccinating incoming stock and replacement ewes will rapidly reduce disease incidence.<\/span><\/p>\n<p>However, the emphasis of prevention should still be on management measures, particularly\u00a0by ensuring the flock is not exposed to toxoplasmosis,\u00a0and preventing access to feedstuffs by cats.<\/p>\n<div class=\"hr hr3\" style='margin:20px 0px 20px 0px !important;'><\/div>\n<h4>Treating Toxoplasmosis<\/h4>\n<p>Once an outbreak of toxoplasmosis has started, there is little that can be done other than to observe sensible precautions by disposing of dead lambs and infected placentas and disinfecting contaminated pens.<\/p>\n<div class=\"hr hr3\" style='margin:20px 0px 20px 0px !important;'><\/div>\n<h4>Good Practice Based on Current Knowledge<\/h4>\n<p>Abortion in sheep due to toxoplasmosis must be differentiated from other infectious causes of abortion, including infections with chlamydia (enzootic abortion), salmonella, border disease and Bluetongue. Toxoplasmosis infection in sheep can be confirmed by\u00a0immunofluorescent staining of antigens in fetal tissues.<\/p>\n<ul>\n<li>Control the farm cat population by treating with drugs to suppress oocysts shedding<\/li>\n<li>In the case of an outbreak, dispose of dead lambs and infected placentas and disinfect contaminated pens<\/li>\n<li>A &#8216;clean&#8217; flock should be prevented from ingesting food and bedding contaminated by cats, particularly young cats<\/li>\n<li>In flocks in which a large number of ewes are already infected, <strong><span style=\"font-weight: 400;\">a whole flock vaccination programme should be started and\u00a0<\/span><\/strong>susceptible young, non-pregnant replacement stock <strong><span style=\"font-weight: 400;\">should be vaccinated prior to the breeding period<\/span><br \/>\n<\/strong><\/li>\n<\/ul>\n<p><a id=\"ref\"><\/a>\u00a0<\/p>\n<div class=\"toggle\">\n<div class=\"toggle-title active\">Toxoplasmosis References<span><\/span><\/div>\n<div class=\"toggle-inner\">\n<div id=\"zotpress-e15bb06eea053fb3466b3f823f6fdaa7\" class=\"zp-Zotpress zp-Zotpress-Bib wp-block-group\">\n\n\t\t<span class=\"ZP_API_USER_ID\" style=\"display: none;\">254757<\/span>\n\t\t<span class=\"ZP_ITEM_KEY\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_COLLECTION_ID\" style=\"display: none;\">PRPCNHR3<\/span>\n\t\t<span class=\"ZP_TAG_ID\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_AUTHOR\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_YEAR\" style=\"display: none;\"><\/span>\n        <span class=\"ZP_ITEMTYPE\" style=\"display: none;\"><\/span>\n        <span class=\"ZP_ITEM_TYPE\" style=\"display: none;\">items<\/span>\n\t\t<span class=\"ZP_INCLUSIVE\" style=\"display: none;\">1<\/span>\n\t\t<span class=\"ZP_STYLE\" style=\"display: none;\">apa<\/span>\n\t\t<span class=\"ZP_LIMIT\" style=\"display: none;\">0<\/span>\n\t\t<span class=\"ZP_SORTBY\" style=\"display: none;\">author<\/span>\n\t\t<span class=\"ZP_ORDER\" style=\"display: none;\">asc<\/span>\n\t\t<span class=\"ZP_TITLE\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_SHOWIMAGE\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_SHOWTAGS\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_DOWNLOADABLE\" style=\"display: none;\">1<\/span>\n\t\t<span class=\"ZP_NOTES\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_ABSTRACT\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_CITEABLE\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_TARGET\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_URLWRAP\" style=\"display: none;\"><\/span>\n\t\t<span class=\"ZP_FORCENUM\" style=\"display: none;\"><\/span>\n        <span class=\"ZP_HIGHLIGHT\" style=\"display: none;\"><\/span>\n        <span class=\"ZP_POSTID\" style=\"display: none;\">6776<\/span>\n\t\t<span class=\"ZOTPRESS_PLUGIN_URL\" style=\"display:none;\">https:\/\/www.farmhealthonline.com\/wp-content\/plugins\/zotpress\/<\/span>\n\n\t\t<div class=\"zp-List loading\">\n\t\t\t<div class=\"zp-SEO-Content\">\n\n\t\t\t<\/div><!-- .zp-zp-SEO-Content -->\n\t\t<\/div><!-- .zp-List -->\n\t<\/div><!--.zp-Zotpress-->\n\n\n<\/div>\n<\/div>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p> [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":6562,"parent":1605,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-fullwidth.php","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/pages\/6776"}],"collection":[{"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/comments?post=6776"}],"version-history":[{"count":45,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/pages\/6776\/revisions"}],"predecessor-version":[{"id":10772,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/pages\/6776\/revisions\/10772"}],"up":[{"embeddable":true,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/pages\/1605"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/media\/6562"}],"wp:attachment":[{"href":"https:\/\/www.farmhealthonline.com\/US\/wp-json\/wp\/v2\/media?parent=6776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}