SALEM, Ohio – It’s a faceless and invisible disease, one that sneaks in through the front door even when local farmers are looking.
They don’t recognize it at first, don’t know where it came from, but the disease doesn’t wait for an invitation to join the herd.
And now it’s here, full-blown and killing cows and calves, and farmers only want it gone.
The most common strain of leptospirosis is challenging the best managers, the best dairies and the best veterinarians locally.
Common disease. There are more than 250 known strains of leptospirosis, and it’s not an uncommon disease.
The disease has been around for a long time, and most producers know about it, according to one local veterinarian.
But it may be more prevalent than those in the know had estimated: Michigan State University research says hardjo-bovis is the cause of leptospirosis in 57 percent of dairy herds across the country.
A whopping 91 percent of California dairy herds are infected.
But the most common five-way vaccines used on farms don’t protect against hardjo-bovis, leaving thousands of cattle wide open to the threat of infection.
Clinical cases. The disease causes abortions, stillbirths, problems with breeding back and infertility.
If a calf does make it, it faces weakness, slow growth and even death.
The organisms thrive where it’s warm and wet, and pass from animal to animal through urine and urine-contaminated feed and water.
A barn in the wintertime can be the perfect haven for whole-herd infection.
The organisms can survive in soil, streams, ponds and surface water for considerable periods of time, according to Pfizer Animal Health.
Once their inside the body, the leptospires hide from search-and-destroy antibodies: They head for the kidneys, brain eyes, uterus and genital tract.
Calves in utero can be infected. And once she’s got it, a cow may shed the organisms her entire life.
Local example. Things don’t look good on one Mahoning County farm, whose owner is devastated by the disease’s presence.
Dave Moff’s Holstein herd hadn’t shown good heats all last summer and fall. The cows just weren’t breeding well.
He double-checked his feeding regimen, his barn and pastures, his vaccine records.
He questioned his breeder, who was just five out of 15 in breeding attempts.
Nothing jumped out at him.
He went to his veterinarian, Eric Gordon of Lisbon Vet Clinic, for help. Urine collected from five cows showed the infection.
He hit his herd of more than 60 Holsteins with antibiotics to kill the leptospires, and followed up with a new Pfizer vaccine specifically for hardjo-bovis.
It’s a learning experience he wishes he’d never had, but he thought the worst was over.
Still going. Moff’s favorite cow calved a month ago. She milked three days before he was forced to put her down. The disease was rampant in her body.
Less than a week ago, a set of twins was aborted three weeks early, Moff said. One lived, the other didn’t.
It wasn’t the first time he’d seen it. He’s lost three mature cows and eight calves born weeks or months early since last summer.
“We’ve got a real time bomb here, and too many guys don’t realize it,” he said.
And in all honesty, he said he’s scared to death of what may come of his six-generation dairy farm.
Not only is his herd infected, but he fears his family may now have the disease, too.
Dealing with it. Not far away, another dairyman has a better grip in dealing with the same disease.
Steve Shoemaker, who milks 120 Holsteins and Jerseys near Salem, Ohio, was suspicious of his herd last summer.
Some of his cows were losing pregnancies in the early stages. Others were preg checked but then came back into heat.
He decided to test. In that random test group, eight of 15 were positive. None ever got sick, which is common for carrier animals.
Fight back. But Shoemaker fought back. He vaccinated the herd over the winter and continues to treat each cow with LA-200 as she dries off.
Young calves all get a single dose of the antibiotic.
He believes he’s got a handle on the problem now. Last month, only one animal tested positive, leaving Shoemaker with fewer headaches and worries.
“Between the frustration of losing calves and this affecting humans, we needed to get it taken care of,” he said.
Any cow that aborts her calf now gets tested right away as this dairyman watches his numbers.
“You’ve got to keep after it and don’t let your guard down,” he said.
Still hope. Herds won’t be destroyed by the disease, thanks to Spirovac, a Pfizer vaccine specifically for hardjo-bovis.
“Hardjo-bovis has been unstoppable until now, as current standard L5 vaccines do not cover hardjo-bovis,” said Sam Barringer, senior dairy veterinarian with Pfizer Animal Health.
“It’s reassuring to know that there’s a leptospirosis vaccine that prevents infection of the developing fetus and can stop the cycle of carrier calves being born,” Barringer said.
What to do. “Is this something to worry about? No. Is it something that affects your herd? Probably,” said veterinarian Eric Gordon.
“This disease is probably more ubiquitous than we think,” he added.
Gordon confirmed three or four client herds urine tested in the past six months have all identified hardjo-bovis at some level.
But there’s plenty producers can do to keep their barn doors closed to the disease, he said.
“If you think you have it, test to find out. Don’t just blindly treat for this. If you do have it, then vaccinate.
“To protect as best you can, test, treat and vaccinate,” he said.
He recommends good cleanliness around the herd, including measures such as wearing gloves and washing hands well to prevent human infection.
(Reporter Andrea Myers welcomes reader feedback by phone at 1-800-837-3419, ext. 22, or by e-mail at firstname.lastname@example.org.)
Signs of lepto hardjo-bovis
Hosts carry infection and shed leptospires to spread the disease through the whole herd, even if no clinical signs are shown.
Infected animals will express infertility as:
* Low conception rates
* Early embryonic deaths
* Delayed returns to heat
In utero infection can be associated with:
* Late-term abortions
* Premature, weak calves
* Retained placentas
* Persistently infected calves
Calves that survive the fetal infection become chronic carriers that are prone to succumb to other diseases.
(Source: Pfizer Animal Health Lepto Hardjo-bovis Technical Manual)
Humans can become infected with leptospirosis.
Who’s at risk
Those who come in contact with the contaminated urine
* Artificial inseminators
Signs of infection
* Flu-like illness
* Profound fatigue
* Severe headaches
* High fever, night sweats
* Muscular aches and pains
* Red eyes
* Abdominal pain
* Infected people can develop kidney damage, meningitis, liver failure and respiratory disease.
* Transmission between humans is possible but unlikely.
(Source: Pfizer Animal Health)
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