Trichomoniasis—Trich for short—isn’t just another hard-to-pronounce disease. It’s a serious and costly problem that can infiltrate your herd and significantly impact your bottom line. We’re talking fewer calves on the ground, lower weaning weights, and a longer, more frustrating breeding season. And the worst part? You often don’t realize it’s there until it’s already done the damage.
Trich is a reproductive disease that spreads through breeding. It can leave cows temporarily infertile and cause early embryonic loss. That means open cows, delayed calving, and ultimately, fewer calves to sell at the end of the season. Bulls often carry it without any signs, passing it from one cow to the next without anyone realizing it.
But here’s the thing—Trich is preventable. Stopping it starts with awareness and a few simple, proactive steps. Whether it’s testing bulls before turnout, keeping a close eye on your fences, or tightening up your recordkeeping, you have the tools to protect your herd.
It may not be the most talked-about topic around the coffee pot, but understanding Trich and how to prevent it can save you thousands in lost production. So, before the breeding season gets underway, take the time to get ahead of it. A few smart decisions now can help you avoid a whole lot of headaches (and empty pastures) later.
In the sections that follow, we’ll break down exactly what Trich is, how it spreads, and the best steps you can take to keep it far away from your operation.
What Is Trichomoniasis, Really?
Trichomoniasis—commonly called Trich—is a venereal disease that spreads through breeding, kind of like an STD in cattle. It’s caused by a microscopic organism called Tritrichomonas fetus, and it can be found in the reproductive tracts of both bulls and cows. But bulls are the real troublemakers here—they’re the primary carriers. They can spread the disease from cow to cow without showing any symptoms themselves.
Here’s how it works:
- An infected bull breeds a cow.
- The organism gets transferred and settles into the cow’s reproductive tract.
- If the cow is already bred, Trich can cause her to abort.
- If she’s open, the infection can prevent her from getting pregnant at all.
The kicker? Once infected, cows can remain infertile for up to five months. Even if they do eventually clear the infection, they’re not in the clear right away.
You can’t consider a cow truly safe in calf until:
- She’s at least 120 days pregnant, or
- If open, she’s had 90 days of sexual rest (no exposure to bulls).
That’s a big chunk of your breeding season gone—and a significant hit to your calving numbers.
Because bulls show no visible signs of infection, the only way to determine if they’re carrying Trich is to have them tested by a veterinarian before turnout. It’s one of those diseases where an ounce of prevention is truly worth a pound of cure.
How It Spreads—and Why Bulls Are the Biggest Risk
Trichomoniasis spreads during breeding. When an infected bull breeds a cow, the tiny organisms on the surface of his penis are transferred into the cow’s reproductive tract. From there, they multiply fast—working their way up into the uterus and causing a nasty infection.
At first, a cow may still conceive, but that doesn’t mean everything is fine. After a couple of weeks, once the infection takes hold, it damages the uterine lining. That’s when things really go south. Most infected cows will either:
- Abort early in pregnancy or
- Fail to carry the calf to term
This early embryonic loss often goes unnoticed unless you’re checking pregnancies early or watching for sudden drops in your conception rates.
Here’s the real problem: bulls don’t show any signs of being infected. They don’t look sick, they don’t act differently, and unless you test them—you’d never know. Cows might show a little discharge, but even that isn’t consistent.
So, what are the warning signs? Honestly, the biggest red flag is when you start seeing a bunch of open cows or unexpected abortions. By the time you realize something’s off, the damage might already be done.
The only reliable way to know if Trich is in your herd is through a specific test done by your veterinarian. And it’s not part of a regular breeding soundness exam—you have to ask for it.
That’s why it’s crucial to test your bulls before turning them out to pasture. Trich can quietly cut your calf crop in half if it slips in undetected—and that’s a loss most of us can’t afford to take.
The Real Cost: How Trich Impacts Your Calf Crop
Let’s talk about what Trichomoniasis really costs you—not just in stress, but in actual dollars and cents. When a cow becomes infected, her chances of staying pregnant decrease rapidly. She may not conceive at all, or if she does, she’ll likely lose the calf early on. That means fewer calves on the ground and fewer dollars in your pocket come sale time.
Now, you might be thinking, “Okay, but how big of a deal is this really?“
According to research from Washington State, Trich transmission rates can be as high as 42% in a herd. That’s nearly half of your calf crop wiped out in a single season. Imagine running 100 cows and only getting 58 calves. That’s a gut punch no operation wants to take.
Here’s what makes it worse:
- Infertility can last up to 5 months, so infected cows are out of commission for nearly half the year.
- Even after they clear the infection, they’re more vulnerable to getting it again.
- You’ll need to separate infected cows from bulls for 120–150 days, which is a significant management challenge.
And the bulls? That’s the most challenging part. Since they’re the leading carriers and show zero symptoms, you often won’t know a bull is infected until it’s too late. Once confirmed, there’s no treatment, and most producers have no choice but to cull them. Selling to slaughter might be your only option—because no one wants to risk introducing Trich to their herd.
Bottom line: Trich doesn’t just hit your herd—it hits your bottom line hard. Prevention isn’t just smart. It’s essential.
There is no Cure, So Prevention Matters Most
Let’s get the hard truth out of the way—there’s no approved treatment for cows infected with Trichomoniasis. Once it finds its way into your herd, your hands are pretty much tied. Infected cows have to be culled; what about bulls? Same story. You’ll likely have to sell them for slaughter. Depending on how widespread the infection is, that can take a big chunk out of your herd—and your wallet.
But here’s the good news: you don’t have to sit back and wait for Trich to strike. While there’s no cure, prevention is 100% in your control. And that’s where innovative management comes in.
It may take a little more effort on the front end, but trust me—it’s a whole lot cheaper than dealing with a full-blown outbreak. With the right strategy, you can keep Trich out of your herd—and your stress level in check.
Simple, Practical Ways to Keep Trich Out
✅ 1. Buy Virgin Bulls (If You Can)
Virgin bulls have the lowest risk of carrying Trich. If you’re able to purchase one, this is your best first step toward keeping your herd clean.
🩺 2. Test Non-Virgin Bulls Before Buying
Can’t buy a virgin bull? No problem—just make sure the bull gets tested before you turn him out.
- Ask your vet for a Trich test specifically (it’s not part of a standard breeding soundness exam).
- Most reputable seedstock producers will already do this, but always ask if it’s not mentioned.
- What is the best time to do it? During the soundness exam.I talk more about the importance of this exam in “How to make your bull ready for breeding season.”
🚧 3. Keep Those Fences Tight
A good fence keeps bulls where they belong—and keeps unknown bulls out. Stray bulls can carry Trich, and it only takes one to cause significant problems.
📒 4. Track Your Records
Knowing your average calf crop percentage helps you spot changes fast.
- A sudden drop in bred cows?
- Lower than normal weaning numbers?
- It could be a red flag that Trich has slipped in.
📆 5. Stick to a Defined Breeding Season
This plan helps in two significant ways:
- It makes your calf crop more uniform (better at sale time)
- Easier to preg-check on time and catch any issues early
- If cows come up open after breeding, don’t ignore it—test, cull, and protect the rest of the herd.
Is the Vaccine Worth It? Here’s What to Know
Now, before you lose hope completely—there is one tool that might help in your battle against Trichomoniasis: a vaccine. While it’s not a cure (especially not for bulls), it can be part of a smart prevention game plan for your cows.
Here’s how it works: the Trich vaccine helps cows build some level of resistance to the organism Tritrichomonas fetus. It’s not a magic fix, but it can reduce the chances of long-term infection and early embryonic loss. To be effective, it requires two doses, spaced one month apart, and ideally should be given before breeding season begins.
But let’s be real for a second—this vaccine isn’t perfect. It doesn’t provide 100% protection, and it does not treat bulls at all. If a bull is infected, you’re still facing the hard reality of having to cull the bull to stop the spread.
That said, when combined with other prevention strategies—such as testing all bulls before turnout, purchasing virgin bulls, maintaining strong fences, and adhering to a strict breeding season—the vaccine can be a valuable tool in your herd health toolkit.
Just remember:
- It’s a supplement, not a substitute.
- It works best as part of a broader plan.
- And it won’t save the day if Trich is already in full swing.
So, while the vaccine shouldn’t be your only line of defense, it’s worth discussing with your veterinarian. In the end, a layered approach is your best bet to keep Trich off your place and your calf crop on track.
