It is that time of year again, the sun has returned to the sky and the grass has begun to grow, meaning that many of us, are looking forwards to grass day. In preparation for this it is a good idea to remind everyone of the importance of vaccine boosters before turnout.
Leptospirosis is caused by Leptospira Hardjo and infection most often occurs via contaminated urine or abortive material. Co-grazing with sheep is a risk unless they have tested negative. Contaminated watercourses allow the infection to spread over a long distances. It is a common cause of infertility and reproductive failure and may cause other issues such as flabby bags and milk drop. Once contracted cattle can remain infected for many years, intermittently shedding bacteria.
During housing, excretion is generally reduced, maybe as a result of the silage being fed acidifying the urine. At pasture excretion increases, peaking between June and October meaning disease is more common at the end of the summer. This is the reason most people vaccinate pre-turnout to limit this excretion peak.
Leptospirosis is a zoonosis and can cause severe illness in people including kidney disease and occasionally death. This is something worth considering if you have any people who are immunocompromised on the farm. If you have any concerns please discuss this with your GP.
It is possible to take blood samples or use milk samples in order to check if animals have been infected. Most of our dairies are registered with us to have their bulk milk checked quarterly for leptospirosis, and beef farmers have their youngstock checked on an annual basis. These are good practices in order to monitor what is
happening on the farm and picking up problems early, rather than waiting for disaster to strike.
Control is based mostly on excellent biosecurity, combined with vaccination as a method to reduce excretion and protect the uninfected. Vaccination has been around for 182 years and there are more vaccines appearing each year. Choosing the appropriate vaccines for your farm can only be done following testing to see what is present on farm and what risk there is to the herd. Many vaccination programmes can be likened to wearing a seat belt in the car – 99% of the time you don’t need it, but if you are not wearing it when you crash you can suffer major injury.
Other methods for reducing risk to your herd include the following:
- Stop access to streams or rivers where other livestock have access
- Protect food from wildlife access
- Clean, disinfect and dry pens between batches
- Rodent control and reduce rubbish which may attract rats.
- Keep a closed herd if possible
- Vaccinate animals
- AI cows rather than using a bull that could spread disease.
If you would like to discuss vaccinating your cows or having either a bulk milk or youngstock test done on your herd please contact the practice and ask to speak to one of the vets.