PHOTO: SUPPLIED
By Rosemary Longuett-Higgins | Veterinarian, King Country Vets
THIS month, discussions with farmers around slow, fading and dying stock have been a theme.
After investigation, we found many of these animals were suffering from anaemia (a reduction in red blood cells).
The two main causes were: Barber’s Pole (also called Haemonchus) in sheep and Theileria in cattle.
In early November, monitor faecal egg counts identified an early rise in Barber’s Pole, and in the first week of December we began receiving reports of ewes and lambs clinically affected by it.
LONG AUTUMN Traditionally, Barber’s Pole has been an autumn, or at least post-Christmas problem.
Unfortunately, last season set us up with a long autumn and mild winter that has led into an exceptionally early Barber’s Pole problem on some farms, reminiscent of the 2021/22 season.
Barber’s Pole can cause disease in any class of sheep.
However, lambs are more severely affected as they haven’t had time to develop effective immunity, so carry a higher burden of worms.
Unlike other sheep worms, Barber’s Pole sucks blood directly from the gut lining of the sheep, leading to pale gums, a lack of energy, and potentially death.
On farm you’ll notice slow animals lagging behind at mustering or running out of breath quickly, then sitting down to ‘sulk’ rather than keeping up with the mob.
CHECK Check the colour of the inside bottom eyelid if you have any of these cases- a white or pale pink colour is an indication the sheep is anaemic.
This is called ‘FAMACHA’ scoring and provides a guide to when drenching is necessary. Your vet can provide resources for you.
Luckily, Barber’s Pole is an easy target for most drenches. Talk to your vet about drench and grazing management options for controlling Barber’s Pole in your flock this season.
Another anaemia-causing disease we have been diagnosing this season is Theileria.
Theileria is an organism that infects cattle via tick bites and results in the destruction of red blood cells.
The disease was identified in Northland in 2014 and has been making its way down the North Island ever since. The clinical signs of Theileria are very similar to those of Barber’s Pole in sheep. Post-calving cows become weak or go down, and calves or weaner cattle are lethargic and tire easily when moved.
DEAD GIVEAWAY Pale pink, white, or yellow membranes in these animals may indicate Theileria, however in more extensive outbreaks dead youngstock may be the only sign.
There is no single easy treatment for animals unwell with Theileria, but your vet can provide advice and prescription medications to help improve recovery.
It is also important to remember that diagnosing Theileria does not always mean it is the cause of an animal’s illness, as some animals cope with a Theileria burden better than others.
MANAGEMENT Management of Theileria is a complicated subject and it is worth a discussion with your vet.
Eradication of Theileria is generally accepted as impractical, and with time cattle develop good immunity to the disease on their own.
Therefore, a range of techniques can be employed to help the herd build immunity.
These may include: • Targeted tick treatments at critical times of the year and/or tick life cycle • Grazing management to reduce severity of tick burdens on calves and cows • Ensuring other elements of stock health are optimal, including body condition, trace element supplementation, internal parasite control, facial eczema protection • Carefully planned exposure of healthy cattle to ticks to help develop immunity • Purchasing cattle from areas likely to have Theileria and thus some immunity already • Managing feral deer populations, or consider their location when planning grazing • As always, there are many causes of poor performance in stock, so get in touch with your vet if you have questions.
