A cow with signs of a urinary tract infection was treated by a veterinarian and then later developed bumps on her vulva. The veterinarian diagnosed the cow with infectious bovine rhinotracheitis (IBR). Also known as “red nose,” IBR is a contagious viral disease caused by the bovine herpesvirus type 1 (BHV-1).
Kansas State University’s Beef Cattle Institute experts discussed the diagnosis and cattle herpes during a recent “Cattle Chat” podcast.
K-State veterinarian Bob Larson says herpes is a common and highly contagious virus in cattle. The virus typically creates vesicles (small bumps) in two primary locations — the respiratory tract and the reproductive tract. These vesicles appear on areas such as the nose, penis, prepuce and vulva.
While the virus is widespread, clinical symptoms are relatively rare due to existing immunity from vaccines and natural exposure. However, when symptoms do appear, they can be significant. The most concerning potential complication is abortion, which can occur weeks after the initial infection.
Brian Lubbers, K-State veterinarian, says like human herpes, the cattle herpes virus can become dormant in nerve roots after initial infection. This means the virus can remain inactive and then reactivate under stress, similar to how humans experience cold sore recurrences.
The discussion highlighted how herpes can enter a herd, particularly in closed herds. In this case, a recently purchased bull likely introduced the virus. Most cattle herds already have animals that are carriers, making transmission relatively common.
Diagnosing IBR
The K-State veterinarians emphasized the importance of proper veterinary diagnosis. While the veterinarian suspected herpes in the example mentioned, Lubbers notes the need to rule out other conditions like trichomoniasis, which can cause similar reproductive tract symptoms.
He says the key diagnostic considerations include:
- Examine the location and nature of bumps (external versus internal reproductive tract)
- Check for additional symptoms like discharge
- Conduct appropriate veterinary testing to confirm the specific disease
Management Strategies
The discussion included several management recommendations.
“Our vaccines for IBR herpes virus are pretty effective,” Larson says. “So, a lot of cattle have decent immunity to herpes virus, either from natural exposure or vaccines, or probably a little bit of both.”
If you suspect IBR after vaccination, Larson suggests reviewing and potentially updating current vaccination strategies.
“Recheck your vaccine protocol, make sure that you’re using the vaccines appropriately,” he explains.
He adds vaccinating during an active outbreak might not change the immediate outcome.
If a producer suspects IBR, they should closely watch the herd for potential abortion events in the weeks following the initial infection.
Selling Considerations
The experts addressed the concern about selling an infected cow.
“Lots of herpes carriers are getting sold,” Lubbers notes.
The K-State experts encourage producers not to sell one that is clinically ill and to consult sale barn regulations regarding disease-specific selling restrictions.
Proper understanding, veterinary guidance and proactive management can help producers effectively navigate cattle herpes.
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