By Jennifer Hopkins

Leptospirosisin Cattle

“Leptospirosis is a bacterial infection of animals that is responsible for significant economic loss in livestock, particularly through abortion and stillbirth, and for zoonotic infection in people.”

Floyd Jr., J. G. (n.d.). Leptospirosis in Cattle. Alabama cooperative Extension system. Retrieved April 11, 2011, from www.aces.edu/pubs/docs/A/ANR-0858/ANR-0858.pdf

Microscopic bacteria

Has over 180 subclassifications called serovars

3 most common that infect cattle are Leptospira Hardjo, Leptospira Pomona, and Leptospira Grippotyphosa

Each serovar is adapted to a particular host species.

The serovar adapted to certain species tend to cause less severity in that species than in species that are not adapted to it. Ex. Serovar Pomona, the type that pigs are adapted to causes more of a severe disease in cattle because they aren’t adapted to it.

The kidney’s, liver, lungs and reproduction tract of pregnant cows can be infected

Etiology

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The infection is spread when the animal comes in contact with infected urine, urine contaminated feed, water and leptospires that penatrate mucosal surfaces and infect blood with the bacteria.

It accumulates in the urinary and reproductive tracts and gets passed in large numbers in urine in the early stages of the disease and can stop for a long periods of time then infect again later.

The spread of the infection is higher during grazing seasons

The infection is usually introduced to the herd through an addition of cattle to the herd, but can also be carried by pigs, horses and sheep.

It can also be introduced by water courses that are run through other farms

Is Zoonotic!

Pathogenesis

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http://www.youtube.com/watch?v=_HdeLzd93hM

Video on pathophysiology of Lepto

Depend on the degree of resistance or immunity within the herd

When there is adequate resistance, usually when you have good vaccination programs, some of the herd may be infected but not show signs.

With herd’s that have low resistance, the cows that are infected may show signs

There are three forms: acute, sub-acute or chronic

Clinical Signs

Often affects calves

High fever with dullness and anorexia

Jaundice

Nursing cows milk yield drops, for a week of longer the milk can be thick and yellow

there can be hemorrhaging under the mucous membranes

Hemoglobinuria

There has also been meningitis recorded

Usually death

Acute

Signs are milder

Nursing mother has reduced milk yield and is dull.

Some jaundice

Some hemoglobinuria

With some cases abortion occurs about a month later

Sub- acute

Affects pregnant cows

Causes abortions

Causes stillbirths

Birth of weak calves

Most economically important form In dairy cows due to the mastitis there is a decrease in milk

production More cost if farmer, family member of farmer or ranch hand get

infected with the disease

Chronic http://www.raisingcountrykids.com/2008/02/motherhood.html

www.kosvi.com/courses/vpat5215_1/vpat5310/fetus/fet07.htm

Microscopic agglutination test- most common used serologic test to diagnose

Measures antibodies to leptospirosis that appear about 12 days after initial infection

Two blood samples should be taken, one close to the time of the abortion or disease as possible, then a second one about 2-3 weeks later

Immunofluorescent staining- detects organisms in tissues or fluids of aborted fetuses or others that are infected

Grow organism on culture plate-difficult and usually unsuccessful

The best way to diagnose an abortion caused by the disease is to have the aborted fetus and the placenta taken to a lab.

Diagnosis

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Sometimes blood transfusions help

Antibiotics: Streptomycin and Tetracyline

Treatment after an abortion is too late

Treatment

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Quarantine any new cow that comes into the herd

Separate infected cows from non infected

Annual vaccinations of all serovars

Lepto vaccines in the US include 5 serovars: Hardjo, Pomona, Icterohaemorrhagiae, Canicola, and Grippotyphosa This vaccine is known as five-way lepto vaccine

Replacement heifers and young bulls should be vaccinated twice ASAP after entering the herd

Management methods to reduce transmission from rodents and wildlife

Control

1. Andrews, A. H., Blowey, R. W., & Boyd, H. (2007). Bacterial conditions, Mastitis, Fetal Loss. Bovine Medicine: Diseases and Husbandry of Cattle. (2nd ed., pp. 335,580,581,734,735). Chichester: John Wiley & Sons, Ltd..

2. Animal Production, Animal Feed, Poultry and Pig Industry, Dairy Cattle, Mycotoxins, Equines. (2009, March 12). Viral & Bacterial Diseases in Beef & Dairy Cattle – Natural Products. Retrieved April 30, 2011, from http://en.engormix.com

3. Floyd Jr., J. G. (n.d.). The Alabama Cooperative Extension System. Leptospirosis in cattle. Retrieved April 30, 2011, from http://www.aces.edu

4. Shapiro, L. (2001). Dairy Industry. Introduction to animal science (pp. 154, 155). Upper Saddle River, N.J.: Prentice Hall.

Bibiliography