Many of us are unlikely to have heard of Neospora but it is something that all dog owners should be aware of. It can cause devastating effects across a wide range of species whilst typically remaining very much under the radar of detection. So what is Neospora and how can we combat it?

What is Neospora?

Neospora, or Neospora caninum to give it its full name, is a microscopic parasite that is ubiquitous in the environment of the UK countryside. Neospora is a specific type of single-celled parasite known as a protozoan who’s life cycle is divided between a definitive host and intermediate host species. 

How does this intermediate/definitive host relationship work?

Without getting too technical, definitive hosts are those in which the parasite completes its life cycle; intermediate hosts are those in which the parasite is supported until being passed onto the definitive host. In the case of Neospora, the intermediate hosts are large herbivores, especially cattle, with the definitive hosts being canines, typically dogs. Clinically, Neospora rarely causes any symptoms in dogs, but can be devastating to cattle. 

Neospora is most commonly transmitted through dogs ingesting the parasite when it is in its oocyst stage, present in the tissues of the intermediate host such as in raw meat or foetal membranes. The dog will then shed the eggs in their faeces. If the faeces are deposited in cattle fields, the cattle, upon eating the grass, will similarly ingest the parasite and become infected. An infected cow can also pass on Neospora to her offspring if infected in late pregnancy; either in her milk or even across the placenta while still pregnant. 

What is the problem with Neospora?

The main concern with Neospora infection is the awful effects it can have within a cattle herd. In these intermediate hosts, Neospora will infect the reproductive system. And it is one of the leading causes of infertility, abortion and calf mortality in the world. Because of the nature of its transmission, it is unlikely to simply affect one cow within a herd, but potentially could affect every cow that grazes in an infected field. It’s easy to see how this can be catastrophic for a farm. 

In dogs, the results are different. Although many dogs will have been exposed to Neospora, clinical disease is rare. When it does strike, it mainly affects young and immunosuppressed animals; where it can cause severe neurological symptoms such as an ascending paralysis, breathing difficulties and problems swallowing. If older dogs are affected, they can show weakness, lethargy, muscle atrophy and neurological signs. If a female dog is infected with Neospora, she can pass it onto her puppies in a similar manner to that in cows. 

How is Neospora treated?

Unfortunately, Neospora is very difficult to treat. In cattle, there is no treatment available. Cows that are known to be infected are often culled from the herd as they are prone to repeat abortions. (Abortion is 20 times more likely in cows that have previously been infected). In dogs, some antibiotic treatments have been used with variable success. But the duration of treatment is long (weeks to months) and it is rarely considered fair to allow the severe neurological symptoms to continue that long without a known positive outcome. 

How can we prevent Neospora?

The key to preventing Neospora infection is to break that life cycle transmission. Prevent dogs being able to pass it to cattle and prevent cattle being able to pass it to dogs. This is where dog owners need to step up and take responsibility as it is through their actions that this can be achieved. 

Firstly, always pick up your dog’s faeces

Not only does this prevent the spread of worms to other animals or even people, but could prevent the deposition of Neospora in a cattle field. 

Never feed your dog raw or undercooked meat

This can be a contentious issue for those who wish to ‘raw feed’ but be aware of the potential dangers to your dog and other animals. 

Never allow your dog to have access to, or eat, dead calves, foetal membranes or aborted material

Although unlikely in many areas, those living rurally or in or around farms ought to be particularly vigilant. 

Neospora is a prime example of how simple measures by one group of people can greatly assist another – although it will rarely cause problems in pet dogs, owners can put measures in place themselves that will help prevent the devastating impacts the infection can have for farmers. It’s about the countryside working together to keep harmony and health at the forefront of their relationship. 

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