Leptospirosis is a bacterial infection which is endemic in most herds, meaning most herds have some levels of infection or exposure to the disease in the country. It can cause abortions, low fertility and, in dairy cows, milk drop or cows going off form.

It can also infect humans and can be spread in cows’ urine, which means a risk for farmers particularly at milking time.

It is a significant economic, cow and human health risk, so my advice has always been to vaccinate your herd. With two vaccine options on the market and it being one of the cheaper shots, it has always been straightforward. This year, shortages in vaccine availability have complicated the situation.

A huge amount of farmer queries in the last month have been regarding what to do now. The vaccine letpavoid H has been out of stock and the alternative spirovac seems now to be out of stock due to increased demand.

So herds which have been using letpavoid H have been saying Spirovac can be used as a booster substitute this year and then resume Leptavoid H next year. Both these vaccines require two shots initially (primary course) and then a yearly booster given in advance of breeding.

Where issues arise with lepto vaccine is when we go beyond one year for the booster shot. So it would make sense we have a window of 14 to 15 months with boosters. Although this is not ideal, we must be practical that this is a target. Beyond 15 months, farmers and their vets will have to discuss the need to begin the primary course of two shots four weeks apart again.

I think this year farmers should prioritise young heifers for vaccination if supplies are short. If you can’t get any vaccines on board before breeding, then keeping the disease out is the priority.

Personally, I wouldn’t purchase animals this year from unvaccinated herds if you can’t vaccinate your own stock. Remember that herds which are grazing with sheep also have an added risk. If you get vaccine mid-breeding, common sense would say that you might be better waiting until after breeding to inject animals. Is it worth stressing animals during breeding getting them in for a vaccine?