Med. Weter. 2019, 75 (7), 410-415
full text
ALEKSANDRA KIERBIĆ, MARIA WIECZORKIEWICZ,
ELŻBIETA ŻBIKOWSKA, JĘDRZEJ M. JAŚKOWSKI |
Neospora caninum infection in cattle:
Not only an economic problem |
Neosporosis is an infectious disease of cattle and other species with a worldwide distribution. In Poland, the
seropositivity rate for N. caninum among dairy cattle varies between 6% and 80%, with the highest number of
seropositive cows in central and north-eastern voivodeships. In the United States, in 2003 the total annual cost
of N. caninum infections was 657 million dollars, and in Great Britain in 2014 it was nearly 14 million pounds.
N. caninum results in severe economic losses caused by a decreased milk yield, an increased number of culled
cows, a higher newborn calf mortality rate and occasional birth defects. However, the most common result of
this disease is abortion, which usually occurs between the 5th and 7th month of gestation. The risk of aborting
is 3 times as high for seropositive cows as it is for seronegative cows; up to 21.6% vs. 7.3%, respectively. Cattle
can become infected by consuming food and water contaminated with N. caninum oocysts, but the principal
route is transplacental transmission usually between the 70th and 210th day of gestation. The ELISA test is
most often used to detect the presence of specific antibodies in blood serum. PAG-2 level in the bloodstream
can be a good marker for predicting Neospora-induced abortions – in seropositive cows, a level of more than
4.5 ng/ml on the 120th day of gestation means a 7-fold higher risk of pregnancy loss. According to research, live
attenuated vaccines are highly efficacious in preventing neosporosis. Unfortunately, the currently available
methods of prevention are based on the elimination of seropositive cows from the herd and the limitation of
contact with the final hosts of N. caninum. |
Keywords: bovine neosporosis, risk factors, abortions in cattle, cattle breeding, veterinary parasitology |