Leptospirosis Tests in Dogs and Cattle
Short answer
Leptospirosis in dogs and cattle is checked with antibody tests, which show that the body has met the germ, and RT-PCR, which looks for the germ in blood or urine. A vet picks the test by timing and signs.
By Pashupatinath Vet Lab Share
Leptospirosis tests for dogs and cattle fall into two groups. Antibody tests show that the body has met the germ, while RT-PCR (real-time PCR) looks for the germ's genetic material in blood or urine. A registered veterinarian picks between them based on the animal's signs and how long it has been unwell.
How does leptospirosis spread?
Leptospirosis is an infection caused by thin, spiral-shaped bacteria called Leptospira. Infected animals pass the germ out in their urine, and rats can carry it without looking ill. The bacteria survive in wet soil, puddles and slow, muddy water. The risk rises in the rainy season, when dogs wade through flooded lanes and cattle stand in wet, dirty sheds or drink from village ponds.
The germ can enter through cuts or through the soft lining of the mouth, nose and eyes. Leptospirosis can pass from animals to people too. Wash your hands well after handling an animal, its urine or its bedding, wear gloves and boots when you clean a shed or collect a sample, and speak to a doctor if you feel unwell, mentioning your work with animals.
Which signs make a vet think of it?
In dogs, a vet may think of leptospirosis when there is fever, tiredness, vomiting, a change in how much water the dog drinks, or a yellow colour in the gums and eyes. Kidney or liver trouble may follow. In cows, it may be one of several causes the vet considers when there are abortions, poor breeding or a sudden fall in milk. Some animals carry the germ with no obvious signs at all.
These signs match many other illnesses, so they cannot settle the question alone. A sick animal should see a vet at once. Please do not wait for a test result before asking for help.
What do the antibody tests show?
Antibodies are proteins the body makes after it meets a germ. They take time to appear, so a very early case can test negative. Both tests below use serum, the clear liquid left after blood clots.
- The Leptospira IgM / IgG ELISA is a plate-based test that measures two kinds of antibody. IgM tends to point to recent contact, while IgG can stay for longer.
- The Leptospira MAT (Microscopic Agglutination Test) mixes serum with several types of live Leptospira and watches under a microscope for clumping. It is the long-standing reference antibody test and shows which types the antibodies react with.
A second blood sample taken some time later may be asked for, to see whether the antibodies are rising. Tell your vet about any vaccination, because vaccines can also raise antibodies.
When do RT-PCR and the rapid kit help?
RT-PCR looks for the DNA of the germ itself, not the body's reaction to it. The Leptospira RT-PCR can use whole blood in an EDTA tube or urine. Blood is more useful early in the illness, and urine later on. The sample should be taken before any antibiotic medicine is started, because that can make the germ harder to find. A negative result does not always rule leptospirosis out, since the germ may be missing from the sample at the stage it was taken.
For dogs there is also the Canine Leptospira (Rapid Test), a quick kit made for dogs only. It gives a first answer, and your vet may confirm it with another test. It is not used for cattle.
How is testing different for a dog and a herd?
A dog is usually tested because it is ill, and the vet may add blood counts and kidney and liver checks to see how far the illness has gone. In a herd the question is often different. The vet may want to know whether the germ is moving among animals that have breeding trouble.
Results from one cow do not describe the whole herd, so a vet may sample several animals. For cows, the vet usually draws the blood or collects the urine.
Read next
Brucellosis is another germ that can pass from herd animals to people, and Brucellosis in Herds: Testing, Safety and What to Tell the Vet explains the safety steps and the tests. If breeding problems are your worry, Bull Semen Evaluation for Better Breeding Results shows what a semen check looks at.
Testing in Bhopal
Blood, serum or urine can be brought to the lab at C-200, C Sector, Shahpura, or collected free anywhere in Bhopal, and for cows the vet usually takes the sample first. Owners in other districts can send it by courier, bus parcel or through their local vet. Call or WhatsApp +91 88175 01118, and the lab confirms the method, sample needs and reporting time when you book.
This article is general information and does not replace a veterinarian’s advice. Please talk to a registered veterinarian about your animal’s signs, tests and treatment.