Toxoplasmosis in Pregnancy: A Practical Veterinary Guide to Zoonotic Risk and Prevention

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is a globally prevalent zoonotic disease that affects all warm-blooded animals, including humans. For veterinarians, it represents a critical interface between animal health and human safety, especially when it comes to pregnancy. While the infection is often silent, its consequences during pregnancy can be severe, making early awareness and prevention essential¹. 

Transmission Pathways: Where Veterinarians Play a Key Role 

Cats act as the definitive hosts, shedding infective oocysts through feces. Humans and animals typically acquire infection through: 

• Ingestion of oocysts from contaminated soil, water, or surfaces  

• Consumption of undercooked or raw meat containing tissue cysts^1,2 

This highlights the veterinarian’s role in client education, particularly advising pregnant women on safe litter handling, hygiene, and food practices. 

Clinical Presentation: Subtle Yet Significant 

One of the biggest clinical challenges is that toxoplasmosis is often asymptomatic. When symptoms do appear, they are mild and non-specific, including: 

• Swollen lymph nodes  

• Fatigue  

• Mild fever^1,3 

These flu-like symptoms are frequently overlooked or misdiagnosed, delaying detection. Evidence shows lymphadenopathy and flu-like illness are the most common early warning signs during pregnancy, yet they are easily missed¹. 

Pregnancy Risks: Why Early Detection Matters 

Primary infection during pregnancy carries a high risk of vertical transmission to the fetus⁴. This can lead to¹: 

• Miscarriage or stillbirth  

• Congenital abnormalities such as hydrocephalus, intracranial calcifications, and chorioretinitis  

It is important to distinguish that mild maternal symptoms contrast sharply with potentially severe fetal outcomes. This gap makes early suspicion and testing crucial. 

Risk Factors: Practical Counseling Points 

The most significant risk factor is exposure to cat feces, but others include¹: 

• Eating undercooked meat  

• Poor food hygiene  

• Contact with contaminated soil  

• Unsafe water exposure  

Regional differences in diet, sanitation, and animal contact influence these risks. Veterinarians should actively counsel clients, especially pregnant women, on: 

• Avoiding direct contact with cat litter  

• Practicing strict hand hygiene  

• Ensuring proper cooking of meat⁵ 

Diagnostics: Beyond Basic Serology¹ 

Diagnosis primarily relies on serological tests like ELISA, but these cannot reliably identify recent infections. IgG avidity testing, though underused, is crucial for distinguishing acute from past infections. 

Advanced methods such as PCR provide direct evidence by detecting T. gondii DNA in blood or amniotic fluid, improving diagnostic accuracy. However, cost and infrastructure limit widespread use. 

Clinical Takeaway for Veterinarians 

Toxoplasmosis is a classic example of a “silent risk” where prevention is more effective than treatment. Early diagnosis enables timely interventions such as spiramycin therapy and fetal monitoring, reducing complications¹. 

Veterinarians play a vital role by: 

• Educating pet owners about zoonotic risks  

• Promoting preventive hygiene practices  

• Supporting early medical referral when risk is suspected  

Conclusion 

Toxoplasmosis in pregnancy may present with minimal symptoms but carries serious fetal risks. Given its zoonotic nature, veterinarians are in a unique position to bridge the gap between animal exposure and human health outcomes. Focused client education, risk awareness, and preventive guidance can significantly reduce the burden of congenital toxoplasmosis. 

References 

1. Tangus CJ, Maingi N, Nganga JC, Njuguna DK, Njaanake K, Lokonon BE, Addo KK, Mensah GI, Ndour AP, Bonfoh B. Early Warning Signs, Effects, Risk Factors, and Diagnostic Indicators of Toxoplasmosis in Pregnant Women: A Systematic Review. https://www.preprints.org/frontend/manuscript/681f6ea3ef7758c16bf8ebd92000c69f/download_pub 

2. Roy A, Gaucher L, Dupont D, Menotti J, Atallah A, de la Fournière B, Massoud M, Lina B, Tirard-Collet P, Wallon M. Epidemiological changes in Toxoplasma infection: a 7-year longitudinal study in pregnant women in Lyon, France, 2017–2023. Parasite. 2025 May 21;32:31. https://pmc.ncbi.nlm.nih.gov/articles/PMC12094578/ 

3. Sebaa S, Behnke JM, Labed A, Abu-Madi MA. Seroprevalence of Toxoplasma gondii and associated risk factors among pregnant women in Algeria. The American Journal of Tropical Medicine and Hygiene. 2024 Apr 30;110(6):1137. https://pmc.ncbi.nlm.nih.gov/articles/PMC11154063/pdf/ajtmh.23-0187.pdf 

4. de Dieu Rukamba J, Hakizimana T, Ishimwe MP, Adoch CO, Pius T, Baluku A, Musiime JN. Seroprevalence and factors associated with toxoplasmosis among pregnant women attending antenatal care clinic at a tertiary teaching hospital in Uganda: A cross-sectional study. Int J Reprod Contracept Obstet Gynecol. 2024 Feb 1;13:234-41. https://www.researchgate.net/profile/Theoneste-Hakizimana-2/publication/377178247_Seroprevalence_and_Factors_Associated_with_Toxoplasmosis_among_Pregnant_Women_Attending_Antenatal_Care_Clinic_at_a_Tertiary_Teaching_Hospitals_in_Uganda_A_Cross-_sectional_study/links/6598132e0bb2c7472b361390/Seroprevalence-and-Factors-Associated-with-Toxoplasmosis-among-Pregnant-Women-Attending-Antenatal-Care-Clinic-at-a-Tertiary-Teaching-Hospitals-in-Uganda-A-Cross-sectional-study 

5. Deganich M, Boudreaux C, Benmerzouga I. Toxoplasmosis infection during pregnancy. Tropical medicine and infectious disease. 2022 Dec 21;8(1):3. https://www.mdpi.com/2414-6366/8/1/3