Toxoplasmosis

Description

Cats and other felines are definitive hosts of the coccidian parasite Toxoplasma gondii, with sexual stages in the gut resulting in oocysts shed in faeces. The cat when first infected excretes large numbers of oocysts in the faeces for about 10 days and thereafter may only excrete small numbers on an intermittent basis.  Clinical disease is not common in cats.

Pregnant ewes and does are infected by ingestion of sporulated oocysts from cat faeces or by ingestion of T. gondii cysts in infected intermediate host tissues (e.g. infected placenta). Infection is more common in sheep kept under intensive systems of management where cats are present.

While infection appears to be common in mammals and birds relatively few individuals develop overt disease, with the exception of marsupials that seem to be much more sensitive.

Systemic toxoplasmosis occurs most often in young animals, especially immunologically immature neonates and in immunocompromised hosts.

Diagnosis and tests available

Diagnosis

Diagnosis is based on history, clinical signs, serology and histopathology.  A histopathologic diagnosis is based on the detection of tissue cysts with associated necrosis and inflammation.

Tests available

Test

Sample(s) required

Days of the week test is conducted

Turnaround time1

Histopathology examination

Fixed tissue

Monday –Friday

Up to 5 days

Necropsy examination

Aborted foetus

Monday – Saturday2

Same day

Toxoplasma latex test

Clotted blood (red top tube)

Monday – Friday

Up to 5 days

Toxoplasma agglutination test

Clotted blood (red top tube)

On request

2 days

1 Turnaround times are provided as a guide only. For specific information about your submission please contact Customer Service.
2 Prior approval of delivery and testing on Saturday is required. Please contact Customer Service on 1800 675 623 to seek approval.

Specimen requirements

Aborted foetus

  • Whole foetus and foetal membranes
    • Submit chilled in an insulated container

Blood (without anti-coagulant)

  • 10 ml of blood (including at least 2ml of serum) from aborting animals and 5-10 in-contact animals.
    • Submit chilled
    • Collected into a plain red top tube
    • Clearly document on the specimen submission form of each animal samples and clearly identify which animal aborted.

Fixed tissue

  • For cats collect brain, lung, heart, skeletal muscle, liver, lymphoid tissues and adrenal gland.
    • Submit fixed in neutral buffered formalin at a 10:1ratio of formalin: tissue
  • For ewes/does submit a range of fixed tissues as recommended for sheep abortions, but particularly placental cotyledons and foetal brain.
    • Submit fixed in neutral buffered formalin at a 10:1 ratio of formalin: tissue