ISSN 2398-2969      

Neosporosis

icanis

Synonym(s): Neospora caninum


Introduction

  • First recognized as a disease of dogs in Norway in 1984.
  • Cause:Neospora caninum Neospora caninum similar protozoal parasite toToxoplasma gondii Toxoplasma gondii.
  • Signs: typically paresis and mortality mainly affecting young dogs (but can produce a wide variety of signs in dogs of all ages).
  • Diagnosis: serology, demonstration of parasites in tissues with specific staining. 5-17% of dogs in the UK are seropositive.
  • Treatment: appropriate antibiotics.
  • Prognosis: fair.
  • Widespread cause of abortion in dairy cattle.
  • No natural infections reported in cats or humans.

Pathogenesis

Etiology

Predisposing factors

General
  • Immunosuppression may re-activate subclinical infection.

Specific

  • Administration of corticosteroids can exacerbate acute and chronic neosporosis.

Pathophysiology

  • Ingestion of tissue cysts and tachyzoites may occur in dogs fed uncooked meat (beef) → rapid multiplication of tachyzoites → kills host cells → tissue cyst rupture → host reaction.
  • Mononuclear cell infiltration into CNS and spinal nerves suggests immune-mediated pathology.
  • Lesions include hypo- or demyelination and inflammatory response but exact mechanism of paralysis unknown.
  • Immunosuppression may reactivate latent infection.
  • N. caninumcan be transmitted transplacentally and is a possible cause of abortion/resorption or stillbirth.
  • As well as vertical transmission (placenta and colostrum) horizontal transmission is considered possible, perhaps via oocyte shedding in feces, although this does not occur in significant numbers except in immunocompromised dogs.
  • In cattle, prevalence of antibodies can be high, eg up to 35% in New Zealand, but abortion is probably triggered by an immunomodulating event, eg infection with bovine viral diarrhea virus.

Timecourse

  • Clinical signs do not usually occur until puppies are 3-5 weeks old.
  • Neurological signs may progress over days to months → dysphagia and death.
  • Myocarditis may present as sudden collapse or death.

Epidemiology

  • Transmission by ingestion and transplacentally.
  • Chronically infected bitches may show recurrent parasitemia without clinical signs.
  • Not all puppies in a litter may be affected.
  • Full lifecycle is not known. The only stages identified are tachyzoites and tissue cysts.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Boyd S P, Barr P A, Brooks H W & Orr J P (2005) Neosporosis in a young dog presenting with dermatitis and neuromuscular signs. JSAP 46 (2), 85-88 PubMed.
  • Lorenzo V, Pumarola M & Siso S (2002) Neosporosis with cerebellar involvement in an adult dog. JSAP 43 (2), 76-79 PubMed.
  • Boydell P & Brogan N (2000) Horner's syndrome associated with Neospora infection. JSAP 41 (12), 571-572 PubMed.
  • Reichel M P (2000) Neospora caninum infections in Australia and New Zealand. Aust Vet J 78 (4), 258-261 PubMed.
  • Braund K G (1997) Idiopathic and exogenous causes of myopathies in dogs and cats. Vet Med 92 (7), 629-634 VetMedResource.
  • Barber J S & Trees A J (1996) Clinical aspects of 27 cases of neosporosis in dogs. Vet Rec 139 (18), 439-443 PubMed.
  • Dubey J P & Lindsay D S (1996) A review of Neospora caninum and neosporosis. Vet Parasitol 67 (1-2), 1-59 PubMed.
  • Ruehlmann D, Podell M, Oglebee M & Dubey J P (1995) Canine neosporosis - a case report and literature review. JAAHA 31 (2), 174-183 PubMed.

Other sources of information

  • Dubey J P (1992)Neospora caninum infections.In:Current Veterinary Therapy XI.Eds: R W Kirk & J D Bonagura. Philadelphia: W B Saunders. pp 263.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code