Tritrichomonas fetus is a flagellate, pyriform protozoan parasite that can cause infertility in cattle. Tritrichomonas fetus resides in the preputial cavity of bulls, with some concentration in the fornix and around the glans penis, with little or no clinical signs. In bulls under 3–4 years old, infection may be transient. Chronically infected bulls show no gross lesions. For bulls older than 3–4 years, spontaneous recovery rarely occurs, resulting in a permanent source of infection in herds. In the infected cow, the initial lesion is a vaginitis and animals may exhibit irregular oestrous cycles. Cows usually clear their infection and generally become immune, at least for that breeding season. If infected cows become pregnant the organism may invade the cervix and uterus with various outcomes including placentitis leading to early abortion (1–16 weeks), uterine discharge, and pyometra. Not all infections result in abortion and a normal calf may be born. Transmission of infection occurs by coitus, by artificial insemination, or by gynaecological examination of cows. Bulls are the main reservoir of the disease as they tend to be long-term carriers, whereas most cows clear the infection spontaneously. For these reasons samples from bulls are usually preferred for diagnosing and controlling the disease in herds.
PCR provides a very sensitive and specific method for detection of Tritrichomonas fetus in clinical samples. The organisms do not need to be viable and PCR will detect very lower numbers.
The traditional method for diagnosis is culture and microscopic examination. The sensitivity of this method is relatively poor as it depends on a relatively uncontaminated sample being collected in a manner that maximises the number of organisms present, and for the sample to reach the lab in a viable state for culture.
Preputial scraping/washing and vaginal mucus. These samples can be collected with scraping device called a "Tricamper" (contact Gribbles Veterinary Pathology for supplies).
Sterile pot or plain tube.
Use the "Tricamper" to scrape the preputial lining or the vagina. The end of the "Tricamper" can then be clipped off into the pot or tube.
Special handling/shipping requirements: