There has been a “significant increase” in the number of redwater cases this year, according to Shane McCarvill, a vet at Farm Vets in Balla, Co Mayo.

“In the last week I have had at least 20 cases of redwater. I think I used five bottles of Imizol already this year, in a small practice. In the last two years I wouldn’t have used five bottles altogether for treatment. It is a lot worse this year,” he said.

“Redwater is caused by the Ixodes ricinus tick. They lice the red blood cells of the animal, giving you a wine-coloured urine – this is the breakdown of the red blood cells.”

ADVERTISEMENT

The vet puts the increase down to the cutting down of trees and deer displacement.

“What we are seeing over here is a lot of forestry is being harvested, which is displacing the deer. They are a reservoir for the tick, and they are spreading it to clean ground – ground that would never have had the redwater tick before."

At-risk stock

If an animal is born on the farm, they generally become immune to it themselves, according to McCarvill.

But he said that in his area, there are a lot of farmers that are contract-rearing dairy heifers for farms in the midlands, and that it is these introduced animals – stock bulls, contract-reared dairy heifers and replacement heifers – that are being brought in which are most at risk.

Early signs of redwater in cattle include high temperature, reduced appetite, straying away from the herd, and reddish-brown coloured urine which can be a bit frothy, the vet said.

In the advanced stages, they go anaemic, the gums go white, they develop jaundice, become weak, stagger and can die as a result.

Prevention and treatment

“In terms of prevention, there is a pour-on product called Bayticol, which has to be applied every 14 days to be effective.

“The Imizol injection can be used for treatment and prevention. It has a long withdrawal period of 213 days, so you have to be very wary of the food chain when using it.

“If you suspect redwater, get in as early as possible and get the vet to give the injection and an injection of B vitamins to help the synthesis of new red blood cells,” he advised.

“Generally, the farmers around here are very good at identifying it, and they will call you sharply. In a bad case you would have to do a blood transfusion from a healthy animal to an affected one.”

However, he warned that it can be fatal, with a mortality rate of around one in 12 or one in 15.

'Reduce tick habitats'

“If you have it on your ground, you would want to be breeding your own replacements and bringing in as few cattle as possible.

“If you are particularly bad you can reduce tick habitats by spreading lime, clearing rushes, furs and bushes, and graze the ground with a horse to get a tight grazing low to the ground.”