Toxoplasmosis in Captive Ring-Tailed Lemurs (Lemur catta)

Area of Science:

• Veterinary Pathology
• Parasitology
• Wildlife Health

Background:

• Toxoplasma gondii is a widespread protozoan parasite affecting warm-blooded animals.
• Ring-tailed lemurs (Lemur catta) are susceptible to severe, lethal toxoplasmosis.
• Captive wildlife populations face unique health challenges.

Purpose of the Study:

• To document the pathological, immunohistochemical, serological, and molecular findings of a fatal toxoplasmosis outbreak in ring-tailed lemurs.
• To identify the causative strain of T. gondii.
• To assess the risk to co-habiting animals and captive populations.

Main Methods:

• Necropsy and histological examination of affected lemurs.
• Serological testing using a modified agglutination test (MAT) for anti-T. gondii antibodies.
• Immunohistochemistry to detect tachyzoites in tissues.
• Polymerase Chain Reaction (PCR) for parasite DNA and genotyping.

Main Results:

• Acute death in three captive ring-tailed lemurs.
• Histological evidence of necrotic lesions in spleen, liver, kidneys, and interstitial pneumonia.
• High antibody titers (IgM 1:1280, IgG 1:640) and presence of tachyzoites confirmed infection.
• PCR identified the parasite as clonal type II T. gondii.
• Co-habiting lemurs tested seronegative.

Conclusions:

• This is the first reported outbreak of acute disseminated toxoplasmosis in captive ring-tailed lemurs in Italy.
• Ring-tailed lemurs exhibit high susceptibility to T. gondii infection.
• Toxoplasmosis poses a significant threat to the viability of captive ring-tailed lemur populations.