Trichomoniasis in Cattle
Dr. Jeremy Powell, Associate Professor and Veterinarian
Dr. Tom Troxel, Professor, University of Arkansas Introduction Trichomoniasis, commonly referred to as “trich,” is a venereal disease of cattle caused by a protozoa organism, Tritrichomonas foetus. This small, motile organism is found only in the reproductive tract of infected bulls and cows. Infected cattle can lead to major economic losses due to infertility, low pregnancy rates, an extended calving season, diminished calf crops and occasional abortions in pregnant cows and heifers. It can also be very costly to eradicate from a herd. Trich is not a human health issue, but it is currently a reportable disease in Arkansas. Transmission and Clinical Signs Trich is transmitted from an infected bull to the cow’s reproductive tract during breeding and then migrates to the uterus. Infected cows will experience infertility and early embryonic death, causing the cow to return to estrus (heat) and subsequently leading to poor pregnancy rates and an extended breeding season. This disease causes very few outward signs in infected cows or bulls. An infected cow may show a very subtle, mild vaginal discharge 1 to 3 weeks after becoming infected, but in many cases no outward signs are apparent. Obviously, these signs can easily go unnoticed; therefore, trich can be present in a herd for a considerable time before it is suspected and diagnosed. Repeat breeding or infertility of individual cows can last up to 5 months. The reason for the open or late cows is the organism causes the loss of the calf a few weeks into the pregnancy. The majority of infected cows will clear the infection if given 120 to 150 days of sexual rest. Most cows will eventually settle, if given enough time, but their immunity to the disease is weak; therefore, they can be reinfected the next season. An infected bull has virtually no outward signs of infection, but the bull is the main source of transmission for the herd. In bulls, the organism lives on the tissue lining of the penis and preputial sheath. Once infected, bulls (especially bulls over 4 years of age) often stay infected for life. Trich typically gets introduced into a herd by the introduction of one infected animal, an infected bull. Diagnosis In spite of the fact that bulls do not show clinical signs of infection, the organism is easier to find in bulls than in cows. This is because bulls become long-term “carriers” of the disease while cows eventually shed the infection. Two weeks of sexual rest is recommended before a bull is tested. This allows organisms time to build up to a detectable level. A wash and scrapings from inside the preputial sheath are collected and placed into special growth media. This sample can be used for two types of test: a culture test or a polymerase chain reaction (PCR). Confirmation of infection can be identified by three separate culture tests (weekly intervals) or one PCR test. For more information about testing, contact your local veterinarian. Treatment and Prevention Currently, there is no approved treatment for cattle infected with trichomoniasis. However, cattle producers can do a lot to protect their herds from a trichomoniasis outbreak.
When purchasing bulls, purchase virgin bulls if possible.
If purchasing a bull that has prior breeding experience, or if you are renting or borrowing a bull for breeding, then isolate the bull and have it tested for trich before turning the bull out with the cows.
If you suspect a problem in your herd, test your current bull battery. Any positive bulls should be culled and sold for slaughter only.
Keep the neighbor’s bull out of your cow pasture. You don’t know if he may be a carrier of the disease.
Pregnancy check cows in a timely manner after the breeding season to identify a potential problem early.
When purchasing females, purchase virgin heifers and/or cows from a reputable source.
Keep fences in good repair to prevent accidental contact with potentially infected cattle. Monitor traffic in and out of the herd.
Keep good records of a herd’s reproductive efficiency. The records can help identify a possible problem.
Maintain a defined breeding season, perform pregnancy exams and cull open cows.
A vaccine is available to aid the control and prevention of this disease. The vaccine can be useful in cows but does not protect bulls from becoming infected. Vaccination requires two injections, typically administered 2 to 4 weeks apart. Consult with your veterinarian when starting a trichomoniasis vaccination program for your herd. Breeding Bull Shipment Regulations Cattle producers should be aware of trichomoniasis testing requirements prior to movement. The Arkansas Livestock and Poultry Commission is the governing body that sets and enforces such requirements. For the current trichomoniasis testing movement requirements, contact the Arkansas Livestock and Poultry Commission (www.arlpc.org) or your local veterinarian.
Emergency Movement Requirements for Trichomoniasis in Cattle Dr. Tom Troxel, Professor, U of A On June 2 the Livestock and Poultry Commission passed an emergency regulation for testing bulls for trichomoniasis prior to intrastate movement. The regulation reads as follows. Intrastate Change of Ownership Requirements for Bulls A. Any bull changing ownership within the state of Arkansas shall have a negative official T. foetus test within thirty (30) days prior to change of ownership with no exposure to females from seven (7) days prior to the test at the time of change of ownership. B. Exceptions to this rule shall include the following: 1. A bull accompanied by an Arkansas Virgin Bull Affidavit; 2. A bull sold directly to slaughter; or 3. A bull sold for feeding and slaughter that will be castrated within seven (7) days of change of ownership. C. Any bull presented for sale at a livestock auction market without a virgin bull affidavit or verification of a negative official T. foetus test: 1. Shall be tagged for slaughter only and sold for slaughter on a VS 1-27 form; 2. May go to the purchaser’s destination so long as the market veterinarian takes a sample for an official T. foetus test and the purchaser agrees to keep the bull under quarantine at the destination until receipt of negative test results. D. A livestock auction market shall not be liable for a virgin bull affidavit verifying no sexual contact with females within seven (7) days prior to arrival at the livestock auction market, and shall not be liable for the results of a market veterinarian’s sampling and results for an official T. foetus test. E. The above requirements shall become effective June 15, 2011, as an emergency regulation. F. All bulls found to be positive for T. foetus must be taken to slaughter within two weeks on a VS-127. The Arkansas Livestock and Poultry Commission must be notified of all positive bulls and the disposition of these bulls.
In May 2009, Livestock and Poultry passed trichomoniasis testing requirements for bulls moving into Arkansas. Import Requirements for Bulls A. No bull that has tested positive for trichomoniasis shall be brought into this state for any purpose whatsoever. B. No bull may be brought into this state without being accompanied by a negative test for trichomoniasis except for the following animals: 1. Exhibition and rodeo bulls that are temporarily in the state only for the purpose of the event and will be leaving the state after the event; 2. Bulls consigned to go directly to slaughter; and 3. Virgin bulls (under twenty-four (24) months of age). C. A bull that is brought into this state without being accompanied by a negative test for trichomoniasis shall not be comingled with any cow unless the bull is tested and found to be negative for trichomoniasis prior to comingling. D. All bulls, except exhibition and rodeo bulls, brought into this state shall be identified by one or more of the following means prior to importation: 1. Brucellosis ear tag; 2. Official 840 radio frequency identification device (RFID); 3. Official 840 flap or bangle tag; 4. Official individual animal breed registry brand. E. Virgin bulls, other than exhibition and rodeo bulls, brought into this state shall, in addition to any other required documentation, be accompanied by a certification of virgin status signed by the owner of the bull, or the owner’s representative or a duly authorized veterinarian. The certification shall include the bull’s individual identification. If the owner seeking to import the virgin bull into this state acquired the bull from a breeder or another owner, a certification of virgin status signed by the breeder and each prior owner of the bull, or their representative, must also accompany the bull. The use of the Arkansas Virgin Bull Status form is required. F. The requirements for trichomoniasis testing shall be three separate culture tests, each conducted not less than one week apart, or one (1) polymerase chain reaction (PCR) test no more than thirty (30) days prior to entry of the bull into this state. All sample collections and inspection of bulls must be performed by a licensed and accredited veterinarian. Testing for trichomoniasis must be performed at/by an accredited/approved laboratory. G. All bulls found to be positive for T. foetus must be taken to slaughter within two weeks on a VS-127. The Arkansas Livestock and Poultry Commission must be notified of all positive bulls and the disposition of these bulls