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Tritrichomonas foetus

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Tritrichomonas foetus is the causative agent of trichomoniasis which is characterized by infertility, early embryonic death, rare abortions and pyometra in cows and heifers
  • Most females eventually clear the infection, but infertility and infectivity may remain for 2-6 months following infection and chronic infections can occur
  • Pregnancy typically progresses for 60-120 days, then the fetus dies and is reabsorbed, resulting in an irregular return to estrus

Recognizing the problem in cows

  • Producers may notice excessive numbers of cows still cycling at the end of the breeding season
  • Most commonly seen as increases in the number of short-term pregnancies and open cows (up to 40% or more) at pregnancy evaluation
  • Subsequent calving season will be spread out
  • This evaluation can be made by graphing the gestational age of fetuses at pregnancy checks or calf birth dates the following calving season and dividing them into 21 day periods. An affected herd will show a low conception rate in the first 2-3 periods and a large percentage of open cows

Most commonly presents as asymptomatic infections in bulls
Occasionally see purulent preputial discharge during acute infection

Bulls may clear the infection, but often become carriers

  • Bulls >4-years-old are more likely to become carriers because they harbor the organism in penile crypts

Trichomoniasis is a reportable disease and there is no legal treatment for this infection; affected bulls and cows must be culled

Testing and importation requirements vary by state; currently there is no testing requirement in Iowa. Check with each state for specific requirements

Testing via InPouch™ TF (Biomed Diagnostics, see more information below) for culture and/or PCR

  • Sensitivity reported at 95-99% for InPouch™ TF if three separate samples 1 week apart are cultured; false negatives can occur with fewer cultures
  • PCR for Tritrichomonas foetus has been shown to be more sensitive than culture. In some cases, one negative PCR result may meet the requirement for interstate shipment. Check on specific regulations prior to transport
  • Preferred samples:
    • Bull:  vigorous back and forth scrapings of glans penis and prepuce using a sterile infusion pipette and negative pressure from a 12 cc syringe (Figure 1)
    • Cow:  cervical muscus or uterine fluid through an insemination or infusion pipette with negative pressure from a syringe
  • Avoid fecal contamination as feces contain non-pathogenic trichomonads that can lead to false positive culture results
  • Use separate, sterile pipettes and syringes for each animal tested

Figure 1. Diagrammatic representation of sampling method in the bull. (Adapted from BonDurant, R.H. Diagnosis, Treatment and Control of Bovine Trichomoniasis. Compendium on Continuing Education for Veterinarians, 7(3): March 1985, S179-S187.)

 

  • Using the InPouch™ TF
    • Inoculate InPouch™ TF top of the pouch with the sample and flush the pipette with the pouch media
    • Squeeze air out of the bottom of the pouch
    • Squeeze contents from the top of the pouch to the bottom
    • Roll down the top of the pouch, secure the pouch with the wire strips Do not use lactated ringers solution
    • Do not refrigerate, store at room temperature
    • This is the sample of choice for both culture and PCR
    • The Iowa State University Veterinary Diagnostic Laboratory will ship InPouch™ TF(s) for inoculation upon request for a small fee. Contact the ISU-VDL at 515-294-1950 for more information
  • Shipping instructions
    • Use overnight or 1 day shipping options
    • Double bag and ship in an insulated cooler
    • DO NOT SHIP ON ICE!!!
      • Only include ice packs if very hot summer conditions and protect pouches from ice pack using paper towels or newspaper
    • Ideally, temperature between 65°-75° F should be maintained
  • Management of affected herds
    • Cull all positive cows and bulls
    • Test all new non-virgin bulls before entering the herd
    • Use only bulls 3-years-old or younger (best) or keep bulls until 5-years-old with mandatory yearly testing
    • Cull all open cows and heifers
    • Cull cows and heifers with pyometra
  • Vaccines for cows are available for use at 8 and 4 weeks prior to breeding season; vaccination is not effective in bulls
  • Preventing Tritrichomonas foetus from entering the herd
    • Test all new bulls prior to entering herd as above
    • Maintain good fences
    • Don’t buy open replacement cows

Information compiled by Rachel Friedrich (fourth-year veterinary student) and Drs. Tim Frana, and Grant Dewell from the ISU College of Veterinary Medicine.

Contact Information:
ISU Veterinary Diagnostic Laboratory: 515-294-1950
ISU Beef Extension: 515-294-2822

To order large volume of Trich pouches:
Biomed Diagnostics
1-800-964-6466
Catalog # 11-1001 20 test kit
Catalog# 11-1003  100 test kit
 

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