Non-infectious Causes of Abortion
In most cases, without a good history and physical examination of the aborting animal it is not possible to diagnose non-infectious causes of abortion in the laboratory.
Abortion may be caused by trauma (shock/sickness), high fever of the pregnant mother or accidental insemination of pregnant animals. The foetus is well protected by its surrounding of amniotic fluid so factors like high environmental temperatures and being pressed in a crush are not likely to cause abortion.
- Iodine deficiency has been associated with stillbirths and weak newborn calves. Lack of Iodine in the soil is known for certain areas of Kenya /East Africa
- Feeding of kale to livestock.
- Application of human sewage sludge to pasture.
- Selenium/Vitamin E deficiency has been associated with bovine abortions, soils in some parts of Kenya are Selenium deficient.
- Vitamin A deficiency, which can occur towards end of the dry period and during drought, may also interfere with pregnancy.
Various toxins, such as those which occur in a number of plants, may cause abortion.
Cattle frequently abort following an outbreak of nitrate/nitrite poisoning (after heavy fertilization of pastures with nitrogen fertilizer) which poisons the dam and subsequently also the foetus. Common sources of nitrate/nitrite on farms are commercial fertilizers but also certain plants
Signs of nitrate/nitrite poisoning
- Severe difficulty in breathing,
- Muscle twitching
- Brown mucous membranes and blood are likely to be present
Genetic abnormalities may result from high levels of inbreeding in the herd. Signs are congenital malformations, foetal death and abortion. Bulldog calves are one example. To prevent such genetic problems inbreeding should be avoided.