{"id":1240,"date":"2025-04-14T14:38:13","date_gmt":"2025-04-14T11:08:13","guid":{"rendered":"http:\/\/daminvet.com\/?p=1240"},"modified":"2025-04-15T14:44:04","modified_gmt":"2025-04-15T11:14:04","slug":"neosporosis-induced-abortion-in-cattle","status":"publish","type":"post","link":"https:\/\/daminvet.com\/en\/neosporosis-induced-abortion-in-cattle\/","title":{"rendered":"Neosporosis-Induced Abortion in Cattle"},"content":{"rendered":"\n

Neospora caninum<\/strong> is a protozoan parasite recognized as a major infectious cause of weak calf births and abortion in cattle. Infections with N. caninum<\/em> have been reported worldwide, including studies in the United States, New Zealand, the Netherlands, and Germany. These studies suggest that 12% to 45%<\/strong> of aborted bovine fetuses are infected with this organism. In the U.S., exposure is common<\/strong>, with 16% to 36%<\/strong> of dairy cattle testing seropositive.<\/p>\n\n\n\n

A distinguishing feature of this disease is that abortion typically occurs between the 4th and 6th month of gestation<\/strong>, which is a unique timeframe among infectious causes of bovine abortion. The parasite is efficiently transmitted, and in some herds, the infection rate can reach up to 90%<\/strong>. Cattle can become infected by one of two routes:<\/p>\n\n\n\n

    \n
  1. Horizontal transmission<\/strong>: through ingestion of feed or water contaminated with feces from infected dogs (or other canids) containing oocysts.<\/li>\n\n\n\n
  2. Vertical transmission<\/strong>: from a dam to the fetus during pregnancy.<\/li>\n<\/ol>\n\n\n\n

    An important characteristic of N. caninum<\/em> is that once a fetus is infected\u2014either through an infected dam or bull\u2014the infection persists for life. An infected cow can transmit the organism via the placenta to the fetus during every pregnancy<\/strong>. In some cases, this congenital infection<\/strong> leads to abortion or the birth of weak calves. Although many congenitally infected calves appear clinically normal, they remain persistently infected for life<\/strong>. Female calves born with the infection can transmit it to their offspring during gestation, thus perpetuating the infection within the herd<\/strong>.<\/p>\n\n\n\n

    Vertical transmission is considered the main route of infection in cattle<\/strong>, though both horizontal and vertical routes are critical for parasite survival in nature.<\/p>\n\n\n\n

    \n\n\n\n

    Pathogenesis and Mechanism of Abortion<\/strong><\/h3>\n\n\n\n

    The mechanism by which Neospora<\/em> causes abortion is complex and not yet fully understood<\/strong>. Abortion can result from the primary infection<\/strong> (e.g., ingestion of oocysts) but is more often linked to reactivation of a persistent infection<\/strong> during pregnancy. Once the organism reaches the bloodstream of a pregnant cow (parasitemia<\/strong>), it can invade the placenta and fetus.<\/p>\n\n\n\n

    Abortion may result from:<\/p>\n\n\n\n

      \n
    • Direct damage to the fetus or placenta<\/strong>, or<\/li>\n\n\n\n
    • Placental dysfunction<\/strong>, which can stimulate the release of maternal prostaglandins<\/strong>, leading to luteolysis<\/strong> and subsequent abortion.<\/li>\n<\/ul>\n\n\n\n

      A definitive diagnosis<\/strong> is achieved by detecting N. caninum<\/em> in fetal tissues, particularly the brain<\/strong>. A killed vaccine<\/strong> (e.g., NeoGuard) is available, but studies show it has limited efficacy<\/strong> in reducing abortion risk, and its overall reliability remains questionable.<\/p>\n\n\n\n

      Control strategies focus on:<\/p>\n\n\n\n

        \n
      • Culling positive animals<\/strong><\/li>\n\n\n\n
      • Preventing the introduction<\/strong> of infected replacement heifers<\/li>\n\n\n\n
      • Avoiding potential sources<\/strong> of horizontal transmission<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n

        Life Cycle and Transmission of Neospora caninum<\/em><\/strong><\/h3>\n\n\n\n

        Horizontal transmission<\/strong> occurs when cattle ingest oocysts shed in the feces<\/strong> of dogs, coyotes, or other wild canids. Once ingested, the oocysts excyst and release tachyzoites<\/strong>, which rapidly multiply and enter the bloodstream (parasitemia<\/strong>).<\/p>\n\n\n\n

        Tachyzoites can:<\/p>\n\n\n\n

          \n
        • Cross the placenta to infect the fetus, or<\/li>\n\n\n\n
        • Become encysted by the host\u2019s immune response, forming tissue cysts<\/strong>.<\/li>\n<\/ul>\n\n\n\n

          These tissue cysts<\/strong>, primarily located in the brain, spinal cord<\/strong>, and muscles<\/strong>, may also be found in the placenta<\/strong>. When canids<\/strong> consume infected tissues\u2014such as the placenta, aborted fetus, or carcasses\u2014they can become infected and begin shedding oocysts<\/strong> in their feces, thus restarting the cycle.<\/p>\n\n\n\n

          Deer<\/strong> have also been shown to harbor Neospora<\/em> cysts, serving as an additional infection source for dogs.<\/p>\n\n\n\n

          Notably, direct transmission between cattle does not occur<\/strong>, and although not conclusively ruled out, transmission through natural breeding or embryo transfer is considered highly unlikely.<\/p>\n","protected":false},"excerpt":{"rendered":"

          Neospora caninum is a protozoan parasite recognized as a major infectious cause of weak calf births and abortion in cattle.<\/p>\n","protected":false},"author":2,"featured_media":1089,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[57,1],"tags":[],"class_list":["post-1240","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","category-1"],"acf":[],"_links":{"self":[{"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/posts\/1240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/comments?post=1240"}],"version-history":[{"count":2,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/posts\/1240\/revisions"}],"predecessor-version":[{"id":1242,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/posts\/1240\/revisions\/1242"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/media\/1089"}],"wp:attachment":[{"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/media?parent=1240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/categories?post=1240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/daminvet.com\/en\/wp-json\/wp\/v2\/tags?post=1240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}