There is one standard CHECS programme for Neospora; Neospora Risk-level Certification Programme (beef and dairy).
Full rules are detailed in the CHECS Technical Document.
Neosporosis is a disease caused by infection with single-celled parasites and is one of the most common causes of bovine abortion in cattle. It can also cause abortion in other species such as goats, sheep and camelids but they’re thought to be less susceptible than cattle.
It’s transmitted in two ways; horizontally and, much more commonly, vertically. Dogs are the definitive hosts in horizontal transmission. They shed oocysts in their faeces, which survive for prolonged periods in water and soil. Cattle then become infected when they consume food or water from areas contaminated by the oocysts of an infected dog.
The disease is also spread vertically from dam to foetus during pregnancy and this is the primary route of transmission. Once a cow and calf are infected with Neospora, they remain infected for life. Infected dams are 3-7 times more likely to abort than uninfected cattle.
There are no clinical signs of infection seen in the dam other than abortion, anytime between three and nine months of gestation. Calves may be stillborn or premature and any surviving calves may have brain disease at birth. Heifers born live to infected dams have a higher probability than normal to abort when they join the breeding herd. Cows that have aborted before will possibly abort again in subsequent years.
Only a post mortem of aborted calves will confirm a diagnosis of Neospora.
It is worth pointing out that blood tests might indicate a cow is infected with Neospora, but she may abort because of another concurrent infection with, for example, BVD or Leptospirosis.
There are neither vaccines nor treatments of any proven benefit to control Neospora.
To prevent horizontal transmission it’s important to impose strict hygiene standards at calving to ensure that dogs do not have access to placental tissue or aborted/dead calves. Also, aim to store feedstuffs and mixed rations securely so there’s no risk of contamination from infected dog faeces. Erect signpost warnings to dog walkers on public footpaths crossing grazing land advising them to clean up after their dog.
When it comes to vertical transmission, identify cattle with antibodies to Neospora and cull them as they’re at increased risk of aborting and produce less milk than antibody negative cows. If possible, retain only blood test negative heifer calves for breeding thus reducing the number of congenitally infected replacements entering the breeding herd.
Where there are valuable genetics involved with seropositive cows, you could consider embryo transfer to seronegative surrogates, as this technique prevents vertical transmission.
Reducing Neospora transmission is a worthwhile goal but complete eradication from a herd is usually impractical.