Take Action Against Leptospirosis
UK - For their own protection, cattle farmers and their vets are being reminded by Pfizer Animal Health that farmers are now the main group at risk for both Weil’s disease and cattle leptospirosis: the cattle form is a special risk for dairy farmers.A tragic reminder of the threat arises from the recent sudden death, from Weil’s Disease according to press reports, of a former Olympic gold medal rower aged 51. According to the HSE factsheet, both Weil’s Disease and the human form of cattle leptospirosis start with flu-like symptoms, with a persistent and severe headache. There may also be vomiting, muscle pains and ultimately jaundice, meningitis and kidney failure. Weil’s Disease can be fatal. The HSE advice to reduce the risks includes “get rid of rats” and “consult your vet”.
In 2007 and 2008, the most recent period for which information is available, the Health Protection Agency reports a 70 per cent increase in confirmed human cases of leptospirosis compared to the previous five year average.
These figures include all strains of leptospirosis, including those affecting cattle, in which one of the main consequences is impaired fertility, as well as abortions and milk drop.
A study comparing carrier ‘sero-positive’ and uninfected ‘sero-negative’ herds found:
- A 37 day penalty in the calving to conception interval of the carrier group and
- carriers requiring an additional 1.3 services per conception.
Financially, this impact on cow fertility can cause significant losses, according to Pfizer vet Matt Williams. At £3/day of calving interval and £20/service, he calculates the resulting cost to be £137/cow. Recovering this would be worth the equivalent of a 1.8p/litre milk price increase at 8,000litres/cow.
Among the HPA data, not all cases of leptospirosis in humans can be linked to a potential cause. But among the 28 where this was possible in 2007, one-in-four were farmers. Among the 2008 cases, two were known to be fatal, though the disease strain responsible is not available. An SAC overview of the disease states: “Dairymen working in the parlour are most at risk of exposure to infected urine. Herd owners must therefore be aware of their responsibilities under the COSHH regulations.” As long ago as 2003, a NADIS Cattle Disease Bulletin stated that “probably about 60 per cent of herds in the UK have been exposed to leptospirosis.”
In herds with sub-optimal fertility, where nutrition is sound and staff are well trained in heat detection, Mr Williams says leptospirosis could be a potential cause. “Testing should be carried out and vaccination implemented, include any breeding bulls on the farm, if deemed necessary by your vet,” he advises.
The leptospirosis vaccine from Pfizer Animal Health is Spirovac®. Mr Williams says February to March is a good time of year for vaccination in many herds, for at least three reasons:
- With a 12-month duration of action leptospirosis vaccine, uninfected animals will be protected in good time for the grazing season, when the infection risk can be elevated.
- Heifers and cows intended for calving next autumn and winter will be vaccinated before being served, avoiding the impact of leptospirosis on conception rates.
- This timing can help reduce immediate pre-turnout vaccine congestion in the spring.
TheCattleSite Newsdesk