The Challenge of L. hardjo-bovis

USDA approves two vaccines already available for preventing the disease.

Leptospirosis has long been a health challenge in cattle. Leptospira, which often infect calves at a young age and easily spread within herds, ultimately can cause reproductive failure and significant economic loss. Extensive research to better understand this costly disease has identified that Leptospira borgpetersenii hardjo-bovis is the only species of L. hardjo found in the United States.

Once cattle have L. hardjo, which colonizes in the kidneys and reproductive tract, they can shed the organism in urine, placental fluids, milk and other infected fluids for weeks to months after infection. As herdmates come in contact with these fluids — or even contaminated water or small cuts in the skin of infected animals — infections can spread quickly.

"What's particularly challenging about leptospirosis is that it is so difficult to diagnose, since the signs often are mild or similar to other health problems," says Charlie Higdon, business unit manager for AgriLabs. "Infertility is the most significant symptom. Additional signs can include decreased reproduction efficiency and milk production, abortions, stillbirths and calves that are weak. Herds rarely experience a rash of abortions to signal an L. hardjo problem, even when the disease is widespread."

Since a combination of tests is needed to obtain the sensitivity and specificity for an accurate diagnosis, controlling disease caused by L. hardjo-bovis through vaccination is an important consideration for both dairy and beef operations.

L. hardjo-bovis vaccines
Because cattle themselves are L. hardjo-bovis carriers and even calves can be a host when born, vaccination is the most commonly used method for control and prevention. The goals of an effective vaccination protocol are to provide long-lasting immunity, prevent clinical signs and prevent renal colonization and urinary shedding.

"Research shows that there are differences among vaccines, which is why it's so important for producers to work with their veterinarians to examine which one is right for their herd," says Higdon, announcing USDA approval of Titanium® 5 L5 and Master Guard® 10 vaccines to aid in preventing disease caused by L. borgpetersenii hardjo-bovis in beef and dairy cattle.

"Dairy and beef producers are well-aware of just how expensive abortions and other reproductive problems caused by 'lepto' can be," says Higdon. "Research estimates that at least 59% of dairy herds1 and 42% of cow-calf operations2 have cattle with L. hardjo-bovis. Since the organism is spread within herds through urine and milk, and the disease it causes is difficult to diagnose, prevention through vaccination is smart business."

Now producers can vaccinate cattle that are not pregnant or nursing with Titanium 5 L5, and all cattle 5 months of age or older with Master Guard 10, to protect against this costly organism. Both vaccines are available exclusively from AgriLabs distributors. The newly labeled Titanium 5 L5 HB is packaged in 5-, 10- and 25-dose boxes, and Master Guard 10 HB is available in 10- and 25-dose boxes.

"While we are adding 'HB' to the names of Titanium 5 L5 and Master Guard 10 to call attention to the new USDA approval, the vaccines themselves remain the same," says Higdon. "This means that people can continue using the Titanium 5 L5 and Master Guard 10 vaccines already in their refrigerators, knowing the cattle they vaccinate will receive the same protection against L. hardjo-bovis."

Master Guard 10 HB is a combination modified-live and killed vaccine that provides five-way viral and five-way Leptospira protection in a single dose. Its killed bovine viral diarrhea (BVD, types 1 and 2) and infectious bovine rhinotracheitis (IBR) fractions offer safety at any stage of lactation; its modified-live parainfluenza3 (PI3) and bovine respiratory syncytial virus (BRSV) fractions maximize immune response.

Titanium 5 L5 HB is a modified-live vaccine that provides five-way viral and five-way Leptospira protection. It protects against both type 1 and type 2 BVD, IBR, PI3 and BRSV, as well as L. borgpetersenii hardjo-bovis. See label directions for both vaccines before administering.

Sources:
1Bolin C. Leptospirosis: Clinical signs and pathophysiology. Bovine Conference on Investigating Pregnancy Wastage, Kansas State University, May 3, 2003.

2Powell J. Hardjo-bovis in beef cattle – A new challenge. University of Arkansas, Cooperative Extension Service. Beef Champs. February 2005.

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