Neosporosis in Highland Cattle: a member's experience
At the Highland Cattle Society, we are committed to sharing knowledge and experiences that help our members maintain the health and welfare of their herds. Neosporosis is a relatively common but significant disease that can impact cattle fertility, and raising awareness is crucial for responsible breeding and herd management. In this personal account, Society member Mellissa Curran of the Pollok fold shares her experience of encountering Neospora in her herd, the steps she took to investigate its presence, and the difficult decisions she now faces. Her story highlights the importance of proactive health testing and the considerations breeders must take to protect their herds and fellow buyers.
Neosporosis is a disease in cattle caused by the protozoan parasite Neospora Caninum. It’s a major cause of abortion in cattle and can cause reduced milk yield and fertility problems.
Pollok fold with their various show prizes
How it spreads:
Dogs are the definitive host for the parasite
Infected dogs shed oocysts in their faeces, which can contaminate feedstuffs
Cattle become infected by ingesting contaminated feed
The parasite can be transmitted vertically from infected cow to their calves via the blood supply to the placenta
Once it is in the bloodline it will pass to every calf from the infected dam
It can not be transmitted from an infected bull to their offspring, as there is not direct contact with blood supply of the sire
In November 2024, I received a call from a buyer who had purchased one of our heifers at Oban the previous month. The call was not a welcome one when I was informed that the heifer had tested positive for Neospora, a disease that I was aware of but didn’t know very much about.
After the call, I contacted our farm vet and hit Google hard, thinking there must be a mistake and that she couldn’t have got it at Pollok, as we had never had an issue with abortions or cows getting in calf in the first instance. Since 2020, we have only had one dead calf and that was due to a breech at 4am that we didn’t catch on the camera.
I contacted our vet who we do an annual health report with and explained my concerns, asking if it should be something that we should have been testing for during our annual herd test but she said as we hadn’t had any signs in the past there was never any need.
Luckily, we were getting ready for our annual herd test so I decided to add the test just for peace of mind. We tested every female on site over the age of one-year old and waited anxiously for the results to come back.
When the results came back it showed one female line as showing positive, two separate dams and a 2-year-old heifer - three animals in total. Both adult cows had calved every year with fit, strong calves that had thrived and had gone on be some of our best performing calves, in terms of growth and weight gain, so this was a surprise. Again, I called our vet and deep dived into their back pedigree. The original cow had been brought into Pollok in the 90s from another farm.
Through process of elimination I have surmised that the original cow must have been a carrier and passed the disease down the female line, that’s the only explanation that makes sense to me as, if Neospora was present here at Pollok, we would have multiple positives from other female lines.
We are now left with a decision to make: do we continue to breed with the positive animals, knowing that we have never had an issue? Leaving us with another decision of what to do with the offspring? I wouldn’t like to knowingly pass it on to another farm. Or do we cull the affected animals, regrettably killing off one of our best lines?
All the while this has been happening, in the background we have had the opportunity to take part in embryo collection for an American breeder. After discussion with the vets and Biobest, who run our herd testing, we have come to the conclusion that after the cows calf this year, we will take sexed embryos off them and insert them into heifers. Effectively keeping the bloodlines going and eliminating the Neospora from the fold. The positive animals will then be culled once their calves are weaned.
I have asked the society to ask the membership to test all females going to the Oban show and sale, going forward, as buyers get a guarantee on breeding bulls in February via the NBA Breeding warranty. So I feel that any females sold should be, on paper, free of a disease that would cause fertility issues.
The test itself is relatively cheap at about £7 per animal.
Mellissa Curran
Pollok fold
