Bovine Trichomoniasis (Trich) Frequently Asked Questions
Bovine Trichomoniasis (Trich) is a complicated disease and the answers to the most frequently asked questions below are not meant to give in-depth knowledge of the disease.
What is Trich?
It is a veneral disease of all breeds of cattle that causes infertility, open cows, and occasional abortions in cows and heifers. It is a disease that can be economically devastating for infected herds.
How is Trich spread?
Bulls do not show signs and can be chronically infected. They carry the disease and transmit it to cows through breeding. Clean bulls can also become infected by breeding infected cows. This disease causes cows to abort and become temporarily infertile.
What are the signs of “Trich” in cattle?
Neither the cow nor the bull appears ill at any time when they are infected with this organism. The only sign of Trich is when there are reproductive problems in the herd. The first sign is usually an increase in the number of open and late calving cows.
How does Trich get into a herd?
Trich will most likely get into a herd by the addition of new animals,
either bulls or cows, that already have the disease. It also may be introduced from a neighbor’s herd that has the disease, if their bulls or cows inadvertently breed with your animals.
How is Trich diagnosed in my herd?
The organism is easier to find in bulls than in cows, because bulls become “carriers,” while cows can eventually clear themselves of the infection. Scrapings of preputial
(internal sheath) fluids of the bulls are taken to be cultured or have a PCR test. If even one bull is positive, you have to assume that the whole herd is infected. There is no test for live cows.
How does Trich affect bulls?
Bulls become infected by breeding infected cows, after which the organism lives on the tissue lining of the penis and sheath. Infected bulls show no symptoms and suffer no adverse health
effects, but the disease cannot be treated and bulls remain persistently infected.
How does Trich affect cows?
Infected cows and heifers, like bulls, show virtually no outward signs of the disease. In infected cows, the protozoa live in the vagina, cervix, uterus, placenta and fetus. Cows become
infected when bred by infected bulls. Cows generally clear the disease with an extended period (150 days) of sexual rest, but can become reinfected. Some cows may remain chronically infected and still be able to deliver a normal calf; this condition is rare and should be closely monitored, as such animals can continue be a source of infection to bulls from one breeding season to the next.
Can Trich be treated?
There is no effective, FDA-approved treatment for Trichomoniasis at this time.
How are Trich tests conducted?
The official test for Trichomoniasis is three negative weekly cultures or a single negative PCR (DNA) test performed by a Trich-certified veterinarian.
Are pooled tests acceptable for the Mississippi program?
Trich tests can be pooled at the veterinarian’s request only from animals originating in one herd. Individual samples must be submitted; the lab can then combine up to five bulls per pool. Samples from affected herds and from ongoing epidemiological investigations will continue to be run as single samples.
How long is a negative Trich test valid?
A negative test is valid until a bull is mingled with females. As long as a bull is kept separate from females, the test is valid for 60 days for bulls moving to other states, and 90 days for bulls sold within Mississippi.
Do bulls moving directly to a sale barn need a Trich test?
No, but non-virgin bulls without proof of an official negative test will be restricted to sale for slaughter only.
Can bulls be tested at the sale barn?
Yes, but not all sale barns have the facilities for the veterinarian to test bulls at sale day. The only options to buy bulls from these sale barns are for bulls to come to the sale barn with their valid negative Trich test.
Does Mississippi have any restrictions on open cows?
Open cow restrictions apply only to Trich-positive herds in Mississippi, and these animals are restricted to slaughter only unless they are verified to be more than 150 days bred.
What are the identification requirements for bulls undergoing Trich testing?
An approved official ID tag must be placed in the ear of all bulls at the time of their first official test, which is either a metal silver “brite” tag, an 840 RFID tag, or an 840 flap tag.
What is the definition of a virgin bull?
Sexually intact bulls less than 18 months of age are considered to be virgin bulls in Mississippi. By request from the State Veterinarian, farms holding bull sales with animals up to 20 months may be certified as virgin bulls providing the herd veterinarian can attest to the virgin bull status.
How does an owner write up an “affidavit” for a virgin bull?
The owner must individually list in writing each bull being certified as virgin, and sign and date the document, which must include an official identification number, breed and age. This certification can be stated on the CVI or can be an official state form that accompanies the CVI and sent to the MBAH office. The Virgin Bull Statement to use is as follows: “I certify that these bulls have not been exposed to female breeding animals since weaning.”
What happens when a bull tests positive for Trich?
Positive bulls must be sold for slaughter. All other non-virgin bulls in the herd are required to have three negative PCR tests performed.
What happens to cows or heifers from a positive herd?
All females exposed to positive bulls will be quarantined until they are confirmed to be 150 days pregnant. There are no restrictions on virgin heifers. Open cows must be consigned to slaughter due to the possibility of transmitting Trich to a bull.
For more information, please contact Dr. Nancy Jackson with the Mississippi Board of Animal Health at 662-418-7927 or firstname.lastname@example.org.