Leptospirosis is one of the most common causes of abortion in dairy and beef herds in Ireland and according to Richard Ryan from Ormonde Veterinary Hospital, now is the ideal time to take control of the disease through an effective vaccination programme.
“With the breeding season just around the corner, we have to watch out for key diseases that are going to impact herd fertility. Leptospirosis can be detrimental to fertility as it can contribute to decreased conception rates as well as abortions weeks after the initial infection.”
One farmer who has seen the benefits of implementing a vaccination programme against Leptospirosis is Kilkenny farmer, Patrick Darmondy. A fourth-generation farmer, Patrick runs a dairy and beef enterprise alongside his mother and wife.
Achieving optimum herd health, fertility and survival are key priorities for Patrick. His herd is made up of 50% Holstein Friesian, British Friesian crosses to promote hybrid vigour and 100% AI is carried out on the farm in order to maintain a closed herd policy.
Clinical signs of Leptospirosis
The first step in protecting against any animal disease is identifying the cause of the problem. There are two serovars of Leptospirosis commonly found in cattle in Ireland – Leptospira interrogans hardjo and Leptospira borgpetersenii hardjo. Leptospirosis circulates in a herd by direct transmission from infected animals (new infections or carrier animals) or by indirect transmission through urine, birth fluids, milk, contaminated water, or other species.
According to Richard, Leptospirosis can affect cows in a variety of ways. “Similar to what was happening on Patrick’s farm, your herd may experience milk drop syndrome. However, one of the biggest problems we see on farm is decreased conception rates and also abortions, which can typically occur 6-12 weeks after the initial infection.”
Diagnosis of the disease is based on blood sampling and looking for high antibody levels in affected animals, however this can prove difficult. Often the infection is present 6-to-12 weeks before clinical signs become apparent (e.g. low pregnancy rates picked up at scanning).
It can also be based on the culturing of urine samples. In addition, leptospiral abortion diagnosis is best based on the identification of bacteria in the foetus.
Failure to control the disease can not only have a detrimental effect on the health and production of the herd, but it can affect people too as it is a zoonotic disease – it can cause disease in humans. Common forms of transmission include contact with urine, afterbirth or the aborted foetus of an infected animal.
Vaccination is the number one control strategy
Vaccination is the most reliable way of protecting your herd from Leptospirosis and according to Richard, “We vaccinate to protect your herd but also to help to protect you.”
It is essential to vaccinate heifers before their first pregnancy. The primary vaccination course consists of 2 injections 4-6 weeks apart, and thereafter, an annual booster before turnout and at least 2 weeks before breeding. It is a 2 ml dose, given under the skin to all cattle greater than one month of age. The correct use and timing of vaccination are vital to their success and always read the manufacturers recommendations.
Why vaccinate with Leptavoid-H?
Vaccination is a crucial part in controlling this highly infectious disease, however to provide full protection, it is vital to vaccinate against both strains of bacteria that cause the disease.
Leptavoid-H is unique in the fact that it is the only vaccine licensed to protect against both strains of Leptospira hardjo. It is also the only vaccine that is licensed to improve conception rates where Leptospirosis has been diagnosed as a cause of infertility. Another additional benefit of Leptavoid-H is that it can be used on the same day as Bovilis BVD (to cattle greater than eight months of age).
According to Patrick, “Since vaccinating with Leptavoid-H, there has been no going back. I know the vaccine works; fertility has improved, we have had no milk drops and with Leptospirosis being a zoonotic disease, there is reduced risk to anyone working here on the farm.
“We also find it extremely convenient that we can vaccinate with Leptavoid-H at the same time as vaccinating against BVD using Bovilis BVD.”