Neosporosis In Dogs – Neospora Caninum Symptoms & Treatments

Canine neosporosis is caused by the intracellular, coccidian, holoparasite-Neospora caninum with worldwide distribution.

Neospora caninum is similar in form to Toxoplasma gondii and the two infections share many of the same symptoms. But, the N. caninum infection impact on a dog's muscular and neurological system is more severe than T. gondii.

N- canine infection is often observed in puppies and dogs less than six months of age, but still, dogs of any age can be affected. Adult dogs may also get infected with N.caninumor recurrence of an existing infection due to immune-compromising conditions or pregnancy. 

The medical term for the diseased state due to this protozoal infection is called ‘Neosporosis’ which results in the premature death of cells and living tissues (necrosis). Prior to this, cell damage happens from the rupture of a cyst resulting in the invasion of intracellular tachyzoites (rapidly multiplying phase of the sporozoite organism). And now, the neosporosis becomes official. Eventually, tissue cysts containing bradyzoites start to form in the host after 3 weeks.

Although Neospora caninum is not considered zoonotic, still immunocompromised individuals should limit their contact with known N.caninum infected animals. No clinical cases have been identified yet; however, seropositive humans have been documented.

Some Adult dogs with neosporosis can be carriers but have no symptoms Few of the common signs:

• Muscular rigidity
• Dermatitis
• Ulcers in the skin
• Skin sores or inflammation
• Respiratory infections such as bronchitis and pneumonia
• Abortion
• Decreased muscle mass
• Damage to the liver

Severe infections in adult dogs:

• Incoordination
• Polymyositis and/or meningoencephalomyelitis
• Trembling or shaking
• Difficulty swallowing
• Myocarditis
• Pneumonia
• Diffuse peritonitis with peritoneal effusion
• Abnormal behavior
• Slowed reflexes
• Severe diarrhea
• Walking in circles
• Vision trouble including blurriness or even blindness in severe cases
• Paralysis of the legs
• Muscle inflammation

Puppies:

• Forelimbs paralysis
• Multifocal pulmonary consolidation
• Necrosis
• Cervical weakness
• dysphagia
• megaesophagus
• Articular deformation
• Joint curvature
• Fibrinohemorrhagic enteritis
• Myocarditis

As of now, canine neosporosis has no approved or curative treatments.

Management of clinical signs is best achieved in the promptness of the treatment. Treatment should be initiated before the event of paralysis or contracture.  Most Puppies typically die even with treatment and some adult dogs survive even without treatment. 

Treatment includes a course of antibiotics, anti-inflammatory drugs, and pain relievers.

Clindamycin - Antirobe/ClinCaps/ClinTabs (11-25 mg/kg PO) for 4 weeks, every 12 hours.

Trimethoprim sulfadiazine- (15-30 mg/kg PO) for 4 weeks, every 12 hours.

In combination with sulfadiazine or sulfamethoxazole or pyrimethamine (15 mg/kg PO for 4 weeks/ every 24 hours).

When there is no noticeable clinical improvement, treatment should be extended for another two weeks or until clinical signs have plateaued.

If there are affected puppies in a litter, then it is better to treat all littermates regardless of clinical signs.

Follow the appropriate monitoring schedule for your pet given by the Veterinary neurologist, as recommendations may vary for each individual.

Discuss home treatments with your vet to ensure they’re won’t mess with other medications.

This may include dietary changes, exercise, supplements to administer, and other holistic treatments.

• Herding dogs’ access to the feeding areas should be restricted, and pastures should be reduced.
• Takes steps to avoid contamination of livestock feed or feeding area with canine feces.
• Do not allow dogs to ingest raw meats from suspected sources, fetal membranes, and bovine placental tissues.
• Do not breed dogs that have whelped affected pups in the past or previously developed clinical neosporosis.
• Do not administer glucocorticoids or other immunosuppressive drugs to Seropositive dogs.

Puppies

Stages of Neospora caninum

• Oocysts: Unsporulated, noninfectious stage formed in the canine intestinal epithelium and passed with the feces.
• Tachyzoites: Stage found in intermediate hosts and they occur intracellularly. rapidly dividing stages that actively invade tissues.
• Bradyzoites: Slowly dividing stage in the intermediate host that encyst within their tissues.

Transmission is in two ways

Horizontal:

• Pathogens are spread through non-hereditary means to other members of the same or different species.
• Ingestion of sporulated oocysts that may be present in soil and water sources contaminated with dog feces. 
• Through infected tissues of intermediate hosts or with undercooked or raw meat, fetal membranes contaminated with sporulated oocysts or tissue cysts.

Vertical:

• Pathogen transmitted to baby from mother during the period immediately before and after birth.
• Transplacental transmission with fetal infection during Terminal stages of gestation.
• Transmammary transmission- postnatal transmission of tachyzoites via milk.

Environmental resistance:

N. caninum oocysts are the only pathogen reported to date that can shed environmentally resistant oocysts. They can survive in the environment for months to years. Oocysts become infective (sporulate) in the environment within 1-3 days. 

Morbidity:

Neosporosis has a worldwide distribution; depending on the country, the serologic prevalence in domestic dogs ranges from 0 – to 100%.

Dogs residing in the presence of cattle, Free-roaming dogs, sports, and hunting dogs are more commonly seropositive.

Diagnosis:

• Serologic assays include IFA of CSF or serum.
• Microscopically detecting tachyzoites in tissue aspirates.
• Bradyzoites in biopsy samples of affected muscles.
• Serum biochemistry profile, and urinalysis.

Mortality:

Neosporosis is a destructive disease with a high case fatality rate in puppies and leading to serious sequelae (long-term complications). The mortality rate decreases with age.

Prognosis:

The prognosis for puppies is poor.

In adult dogs, neurologic signs (such as central nervous system involvement), pneumonia inflammation of the liver and heart as well as skin inflammation with sores may occur. The prognosis deteriorates in dogs that are not treated promptly or with severe signs.

Emergency — Immediate Veterinary Assistance Needed

• Severe unsteadiness or loss of muscle control, Confusion or disorientation.
• Abnormal levels of aggression or agitation.
• Seizures

Nutrition guidelines you may like to consider:

• 40% Protein – Animal meat(avoid raw meat), Lean boiled meats, seafood, eggs
• 50% Fresh vegetables
• 10% Carbohydrates – Brown rice, Barley (pearled), grains
• Fatty acids – Cooked egg yolks, plant oils, sunflower, corn
• Avoid trans fat, a small amount of beef fat, steak fat
• Calcium – Powdered or crushed eggshells, supplements
• Antioxidant foods

Treatment of neosporosis is typically hard and partially, temporarily or entirely unsuccessful. Long periods (>2 months) of treatment may be needed. Treatment of Neosporosis Dogs that exhibit neurological symptoms is long term but has a poor prognosis. Early diagnosis and promptness of treatment is effective in many cases. In cases of muscular contracture, early diagnosis will yield successful results.