D351 - Leptospira spp.

Description:

Leptospirosis is a disease that occurs worldwide. There are 7 pathogenic (capable of causing disease) species of Leptospira but there are more than 200 serovars, which are akin to subspecies and are different enough to be recognized as unique by an animal's immune system. In general, these bacteria become adapted to living in a specific host animal species, which is termed the "maintenance host." Infections in animals of the maintenance host species often cause either mild disease or do not cause disease signs at all because the bacteria and animal have become adapted to living together over many generations. When a host from a different species becomes infected (the so-called "incidental host") disease may result because the new host species has not adapted to harboring the bacteria. Two specific serovars of the L. interrogans species, icterohemorrhagiae and canicola, were traditionally thought to be responsible for most cases of leptospirosis in dogs. Therefore, a vaccine was developed against these 2 serovars and the number of cases in dogs declined. Recently, 3 serovars, not included in canine vaccines (grippotyposa, pomona, and bratislava), have emerged as significant agents of disease in dogs. Feline leptospirosis was once thought to be quite rare, although it is now known that cats can serve as incidental hosts for many of the serovars affecting rodents, small mammals, livestock, and dogs.
Dogs can acquire leptospirosis by coming in direct contact with soil or water contaminated with animal urine. The most likely reservoirs of transmission are wildlife such as raccoons, opossums, skunks, and less likely, rats. It is extremely rare for cats to contract the disease.

Diagnosis:

Leptospirosis can be very difficult to diagnose with certainty so veterinarians must have an index of suspicion for the disease in all cases of acute kidney failure. This is especially important because of the risk of spread to humans. It is possible in some instances to visualize the spiral-shaped bacteria in the urine of infected patients. This is difficult, however, because it requires a dark-field microscopy. The leptospiral bacteria are not continuously shed into the urine, and therefore, dark-field microscopy sometimes gives falsely negative results. The other method of diagnosis is serology. It relies on the detection of antibodies against the leptospiral organism in the blood of the patient. Because it takes time for the animal to mount a complete antibody response to the bacterial invader, diagnosis sometimes requires paired blood samples several weeks apart. The more specific and sensitive PCR test can detect the genetic material from most of Leptospira serovars in urine and blood samples.

Sample:

1. Urine (3 ml) in a sterile container.
(2. Whole blood (3ml) in a lavender top (EDTA) tube.)

Special Handling:

Store samples at 4°C until pick up or shipment.

Test Code:

D351