Neosporosis in Dogs: Causes, Symptoms & Treatment Guide

Neosporosis in dogs is a parasitic disease caused by the protozoan Neospora caninum, which primarily affects puppies and young dogs, although it can occasionally occur in older dogs. This parasite is an important cause of neuromuscular disease in dogs and also affects cattle, causing reproductive losses. Dogs act as definitive hosts, shedding infectious oocysts in their faeces, which can contaminate the environment[1][2][3].

The Causes and Transmission of Neosporosis

Neosporosis is caused by the obligate intracellular coccidian parasite Neospora caninum. Dogs become infected through various routes:

• Vertical transmission: infected pregnant bitches may pass the parasite to their developing puppies transplacentally, often leading to abortion or infection of survivors.
• Oral ingestion of oocysts: dogs may ingest oocysts shed in the faeces of infected dogs contaminating food, water, or the environment.
• Consumption of infected tissues from intermediate hosts such as cattle can also infect dogs.

Puppies are most frequently affected because the infection can occur before birth, but older dogs with immune suppression can also experience reactivation of the infection from tissue cysts, although this is uncommon[1][3].

Identifying Symptoms of Neosporosis in Dogs

The clinical signs primarily affect puppies and younger dogs, with symptoms resulting from neuromuscular damage. Common signs include:

• Muscle atrophy, particularly in the hind legs
• Partial paralysis progressing to rigid contracture of muscles
• Overextended back legs with absence of the patellar reflex
• Severe cases can cause difficulty breathing and swallowing (dysphagia), which may be life-threatening

In older dogs, although rare, symptoms can be more diverse and may include:

• Polymyositis (inflammation of multiple muscles)
• Meningoencephalitis (inflammation of the brain and its membranes)
• Neurological issues such as seizures or behavioural changes
• Nodular dermatitis (skin nodules and inflammation)

Diagnosing Neosporosis: What to Expect at the Vet

If neosporosis is suspected, a vet will take a thorough medical history, including the dog's ancestry, to identify risk factors such as maternal infection. Clinical examination will focus on neuromuscular signs, and the vet may recommend specialised laboratory tests. These can include serological tests to detect specific antibodies against Neospora caninum or PCR tests to identify parasite DNA. Early and accurate diagnosis is essential for improving treatment outcomes[4].

Treatment Options and Prognosis for Dogs with Neosporosis

Treatment primarily involves prolonged courses of specific anti-parasitic drugs prescribed by a vet, typically over an 8-week period or longer. Supportive care may also be needed depending on the severity of clinical signs. The prognosis is generally guarded; puppies diagnosed and treated early in the course of the disease have a better chance of recovery. Unfortunately, delayed treatment often results in a poor outcome, especially in severe cases with respiratory or swallowing difficulties[2][4].

Preventing Neosporosis and Promoting Responsible Pet Ownership

Since no vaccine currently exists for neosporosis, prevention focuses on responsible management and reducing exposure risks. Key measures include:

• Avoid feeding dogs raw or undercooked meat, especially from livestock that may be infected.
• Prevent dogs from scavenging or hunting potential intermediate hosts.
• Keep pregnant bitches away from contaminated environments and ensure they receive regular veterinary checks.
• Maintain good hygiene when handling puppies and breeding stock to reduce vertical and environmental transmission.

Responsible breeders can help reduce the incidence of congenital infection by screening bitches for exposure and avoiding breeding affected animals. This promotes healthier litters and reduces suffering associated with this disease.

What Is Neosporosis in Dogs?

Quick Answer: Neosporosis is a parasitic infection caused by Neospora caninum, mainly affecting puppies with neuromuscular symptoms like paralysis and muscle wasting. It is transmitted vertically and via ingestion of contaminated food or tissues.

Neosporosis is a disease caused by the protozoan parasite Neospora caninum. Dogs are the definitive hosts, meaning the parasite completes its life cycle within them. Puppies are most severely affected, often showing hind limb paralysis and muscle contractures due to nerve and muscle damage. The disease is not zoonotic, so it does not infect humans.
Transmission typically occurs when pregnant bitches pass the parasite to their unborn puppies, or when dogs consume contaminated food or tissues. Affected dogs shed infectious oocysts into the environment, contributing to its spread. Early diagnosis and treatment by a vet improve puppy survival chances, but prognosis worsens if treatment is delayed.