It’s tricky enough to get a cow in calf, and that’s before the worries that come with the gestation period itself.
Abortion in cattle is a big fear many farmers have at this time of year, and they can happen for the simplest of reasons.
A cow may ‘throw a calf’ after catching an infectious disease, or even if they have a small injury.
Stress can also result in the calf being lost. Here are a few of the more common diseases that bring about abortion in Irish Cattle
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Brucellosis
This disease normally causes abortion after the first five months of pregnancy. It is very contagious and it is required by law that you report it to government authorities.
Additionally, farmers are legally obliged to have any cow or heifer that aborts tested twice for the disease.
The placenta and fluids released at calving are highly infectious, so it is imperative that you treat a Brucellosis infection and abortion with the highest urgency.
Leptospirosis
This disease can cause an abortion at any stage of the pregnancy, and needs to be detected via a blood test. Tests on the foetus are unsatisfactory.
Leptospirosis is among the main causes of abortion in Irish suckler herds, so vaccination should be carried out to ensure the herd is free from the disease if it does appear.
It also causes infertility and poor milk yield, so it is cause for concern even if the cow is not in calf.
Leptospirosis affects humans causing influenza-like symptoms with severe headaches but can be treated effectively.
Salmonellosis
This disease causes abortions from the fourth month of pregnancy onwards, and can also cause other illnesses in the herd.
It is highly contagious and can be difficult to control, as many animals don’t show signs of having it.
However, unlike other infections, aborting animals can sometimes display signs of illness.
If this disease is confirmed (it can be detected from the aborted fetus, placenta or blood test) then the herd needs to be vaccinated.
Neosporosis
This disease is especially damaging, as once an animal is infected, they have it for life.
Neosporosis is caused by a parasite found in the faeces of dogs and foxes. It brings about abortion between the third and eighth months of gestation in the dam.
If a calf makes it through the full term alive, they may be born infected, and it will be able to pass from generation to generation.
There is no vaccine available for this infection, so prevention is the only cure. Infected animals should not be part of the breeding herd, and pets and wildlife shouldn’t have access to animals’ feed.
Mycotic Abortion
Mycotic Abortion in cattle typically occurs between the third and seventh month of pregnancy. It is caused by a fungus that can be found on silage that is poorly preserved.
There is also a slight risk of obtaining it from bedding, but the chances are significantly slimmer.
Silage can also carry the listeria and bacillus bacteria that were mentioned above. They are common in silage that has picked up soil during harvesting.
Bovine Viral Diarrhoea (BVD)
BVD abortion is more prone to happen in the early stages of gestation in suckler herds, however it can happen at any stage.
If the animal is persistently infected, the Animal Health Ireland recommend it be eliminated from the herd.
You can vaccinate the herd against BVD, but if a persistently infected animal is not removed, vaccination will not effectively protect it.
Tissue tagging will identify whether BVD caused the abortion, and all farmers in Ireland are required to carry is practice out.
Infectious Bovine Rhinotracheitis (IBR)
IBR is a highly infectious virus pneumonia that can be transmitted by the semen of infected bulls.
This disease can cause abortion in beef herds, and can be spread from animal to animal rapidly.
If the calf makes it through their full term alive, there’s a chance the mother may have passed it on. From there, it can be passed from one calf to another.
This disease can be controlled with a rigorous vaccination programme.
Prevention
As with most things, prevention is the most effective treatment. Cattle should be kept in clean, well ventilated and disinfected pens.
If there is a large variation in size and BCS, they should be separated (frailer cows are more prone to abortion if a larger cow rams into them in the pen).
Good hygienic practices should be adopted, especially when it comes to handling discharge from the aborting animal.
Teagasc advise to quarantine the aborting cow from other cattle, especially from other pregnant cows for 2-3 weeks until vaginal discharge has ceased.
If one of your cows aborts, you should keep a close eye on the rest of your pregnant herd. If you can vaccinate your animals to prevent the same thing from happening again, do.
