6,502
edits
Changes
Bovine Viral Diarrhoea Virus (view source)
Revision as of 11:10, 24 August 2010
, 11:10, 24 August 2010→Acute Infections: Pregnant Animals
Congenital defects can arise from transplacental infection between days 100 and 150. This is caused by an inappropriate inflammatory response mounted to BVDV by the immune system, which is undergoing the final phase of development at this stage<sup>33</sup>. Examples of common congenital abnormailites include defects of the thymus, occular changes and cerebellar hypoplasia<sup>34</sup>. Calves with cerebellar hypoplasia ataxic, reluctant to stand and may suffer tremors<sup>35</sup>, and occular pathology often causes blindness and cataracts. Localisation of virus to the vascular endothelium gives vasculitis, leading to oedema, hypoxia and cellular degeneration. Weak, stunted calves may also be produced by BVDV infection in the second trimester.
Congenital defects can arise from transplacental infection between days 100 and 150. This is caused by an inappropriate inflammatory response mounted to BVDV by the immune system, which is undergoing the final phase of development at this stage<sup>33</sup>. Examples of common congenital abnormailites include defects of the thymus, occular changes and cerebellar hypoplasia<sup>34</sup>. Calves with cerebellar hypoplasia ataxic, reluctant to stand and may suffer tremors<sup>35</sup>, and occular pathology often causes blindness and cataracts. Localisation of virus to the vascular endothelium gives vasculitis, leading to oedema, hypoxia and cellular degeneration. Weak, stunted calves may also be produced by BVDV infection in the second trimester.
Infection in the third trimester trimester (over 180-200 days) elicits a response from the fully-developed immune system, giving rise to normal but seropositive calves. an additional effect of foetal infection before 120 days gestation is the birth of persistently infected calves.
Infection in the third trimester trimester (over 180-200 days) elicits a response from the fully-developed immune system, giving rise to normal but seropositive calves. An additional effect of foetal infection before 120 days gestation is the birth of persistently infected calves.
====Persistent Infections====
====Persistent Infections====