Lapis ISSN 2398-2969

Eimeria stiedai

Synonym(s): Hepatic coccidiosis

Contributor(s): Will Easson, Glen Cousquer, Susan Dawson

Introduction

Classification

Taxonomy

  • Phylum:Apicomplexa.
  • Class:Sporozoasida.
  • Order:Eucoccidiorida.
  • Family:Eimeriidae.

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Clinical Effects

Epidemiology

Lifecycle

  • Sexual phase of lifecycle takes place in the definitive host the rabbit.
  • Asexual phase can take place within the same host at the same time as the sexual phase.

Transmission

  • Rabbits become infected by the ingestion of sporulated oocysts from the environment.
  • Oocysts are shed by infected rabbits. In colonies this may be from carrier adult females.
  • Infected young rabbits will rapidly contaminate the environment with large quantities of oocysts.
  • Once a rabbit has been infected it will usually develop immunity and can become a carrier for the rest of the colony; clinical signs in immune carriers are rare.

Pathological effects

  • Clinical signs may vary as a function of the severity of infection and the immune status of the individual. Signs include weight loss, ascites, jaundice, diarrhea and hepatomegaly. Stunted growth may be seen in young rabbits surviving the disease but with significant liver damage.
  • Hepatic disease   Liver: disease   is seen; clinical signs are associated with bile duct obstruction.
  • Mortality can be high in groups of rabbits, where a significant disease challenge exists to naive young rabbits.
  • Animals from an enzootically infected colony may show few signs of infection. Disease may recrudesce, however, if animals are stressed, immunocompromised or subject to changes in husbandry.

Other Host Effects

  • Older animals are generally less severely affected.
  • Age resistance to hepatic coccidiosis is likely to be acquired.

Control

Control via animal

  • Good hygiene - prevent contact with feces and prevent fecal contamination of food and water. Feces should be removed regularly.
  • The use of an all in, all out system may be indicated.
  • Eradication of this protozoan from the colony, as practiced in commercial rabbitries, may be possible by detection and removal of infected rabbits. An eradication program will not, however, allow the development of protective immunity.
  • Incoming animals can be quarantined and tested repeatedly. Where subclinical infections are suspected, large quantities of feces (>1 kg) may need to be collected over several days to increase sensitivity.
  • Prophylactic use of in-feed antibacterials such as sulfadimethoxine, or sulfamerazine sodium.
  • One study reported the successful use of toltrazuril (+/- ivermectin   Ivermectin  ).
  • Treatment failure is to be expected where oral medication is supplied to inappetent or anorexic rabbits - such rabbits may be euthanized.
  • Response to treatment can be good when sulfa drugs are administered to rabbits that are active and eating well. Newly weaned animals that recover from hepatic coccidiosis possess lifelong immunity to the disease.
  • Another study investigated the efficacy of a single subcutaneous injection of diclazuril against coccidiosis in rabbits and concluded that it was effective in controlling clinical coccidiosis at a dose of 4 mg/kg BW.

Control via environment

  • Environmental control measures should not be neglected and every effort should be made to avoid the promotion of an unhealthy reliance on chemotherapeutic solutions.
  • Solar radiation plays a significant role in the elimination of coccidial oocysts from pasture through a process of dessication and the action of UV light. Under summer conditions, it is suggested that pasture be rested for 1-2 months.
  • Daily movement of rabbit grazing arks on pasture is likely to reduce the disease threat.

Vaccination

  • No vaccines are currently commercially available although some vaccines have been developed and used in a research setting.

Diagnosis

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Al-Matha E M (2008) Hepatic Coccidiosis of the Domestic Rabbit Oryctolagus cuniculus domesticus L. in Saudi Arabia. World J Zool (1), 30-35 VetMedResource.
  • Cam Y, Atasever A,  Eraslan G et al (2008) Eimeria stiedae: Experimental infection in rabbits and the effect of treatment with toltrazuril and ivermectin. Exper Parasitol 119 (1), 164-172 PubMed.
  • Pan B L, Zhang Y F, Suo X et al (2008) Effect of subcutaneously administered diclazuril on the output of Eimeria species oocysts by experimentally infected rabbits. Vet Rec 162 (5), 153-155 PubMed.
  • Grès V, Voza T, Chabaud A & Landau I (2003) Coccidiosis of the wild rabbit (Oryctolagus cuniculus) in France. Parasite 10 (1), 51-57 PubMed.
  • Hanada S, Umemoto Y, Omata Y et al (2003) Eimeria stiedai merozoite 49-kDa soluble antigen infuces protection against infection. J Parasitol 89 (3), 613-617 PubMed.
  • Hanada S, Omata Y,  Umemoto Y et al (2003) Relationship between liver disorders and protection against Eimeria stiedai infection in rabbits immunized with solube antigens from the bile of infected rabbits. Vet Parasitol 111 (2-3), 261-266 PubMed.
  • Singla L D, Juyal P D & Sandhu B S (2000) Pathology and therapy in naturally Eimeria stiedae-infected rabbits. J Protozool Res 10, 185-191 ResearchGate.
  • Varga I (1982) Large-scale management systems and parasite populations: coccidia in rabbits. Vet Parasitol 11 (1), 69-84 PubMed.
  • Barriga O O & Arnoni J V (1979) Eimeria stiedae: Weight, oocyst output, and hepatic function of rabbits with graded infections. Experi Parasitol 48 (3), 407-414 PubMed.
  • Gill B S & Ray H N (1960) The coccidia of domestic rabbit and the common field hare of India. Proc Zool Soc (Calcutta) 13, 128-143.
  • Lund E E (1954) Estimating relative pollution of the environment with oocysts of Eimeria stiedaeJ Parasitol 40 (6), 663-637 PubMed.
  • Litwer G M (1935) Der Einifluss von geringen Dosen der Ultraviolettstrahlen auf die Stabilität des Sporulationszyklus bei Kaninchen coccidien. Arch Protistenk 85, 395-341.
  • Pérard C (1925) Recherches sur les coccidies et coccidioses du lapin. II. Contribution à létude de la biologie des oocystes de coccidies. Ann Inst Pasteur Paris 39, 505-542.

Other sources of information

  • Quesenberry K E & Carpenter J W (2003) Ferrets, Rabbits and Rodents: Clincial Medicine and Surgery. 2nd edn. W B Saunders. pp 168-169. ISBN 0-7216-9377-6.

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