Trypanosoma evansi (Surra) RT-PCR
Trypanosoma evansi RT-PCR is a blood test that looks for the DNA of the parasite that causes surra in cows, buffaloes and dogs. It can find low-level infections that a blood smear can miss.
- Sample
- Whole blood (EDTA)
- Quantity
- As advised
- Report
- Confirmed when you book
- Collection
- Free in Bhopal
What this test checks
- DNA of Trypanosoma evansi, the parasite that causes surra, in EDTA blood
- Low-level infections that a blood smear or wet film may miss
- Long-lasting or hidden infections in animals that show few signs
- Infection in dogs with fever, weakness or swelling, when the vet suspects surra
Benefits of this test
- Can find low-level infections that a blood smear can miss.
- Helps when a smear is negative but the signs still suggest surra.
- Looks for one named parasite, which helps your vet tell surra apart from other blood infections.
- Works for cows, buffaloes and dogs from a small blood sample.
- Can help your vet check other animals in a herd or area where surra has been found.
When your vet may advise it
- A cow or buffalo with a fever that comes and goes, weight loss or pale gums.
- Swelling of the lower body, a drop in milk, abortion or nervous signs such as circling.
- A dog with fever, weakness, swelling of the face or legs, or cloudy eyes.
- A dog that falls ill with fever after eating raw meat.
- A blood smear was negative but your vet still suspects surra.
- After a surra case in the herd or area, when your vet wants to check other animals.
About this test
Surra is a blood infection caused by Trypanosoma evansi, a tiny single-celled parasite that swims in the blood. Biting flies, such as horse flies and stable flies, carry it from one animal to another as they feed. Dogs can also catch it by eating raw meat from an infected animal. In cows and buffaloes, signs may include a fever that comes and goes, weakness, weight loss, pale gums, swelling of the lower body and a drop in milk. Some animals abort or show nervous signs such as circling. In dogs, signs may include fever, weakness, swelling of the face or legs, and cloudy eyes.
The number of parasites in the blood rises and falls in waves. When the number is low, as in long-lasting or hidden infections, the parasites can be missed on a blood smear or a wet film (a drop of fresh blood) seen under the microscope. PCR (polymerase chain reaction) finds the parasite's genetic material, called DNA, by copying it many times, so it can pick up these low-level infections. The test uses blood collected in an EDTA tube, which stops it from clotting.
A positive result means the parasite's DNA was found. A negative result makes infection less likely, but your vet may still repeat the test or add an antibody test if the signs continue. A registered veterinarian reads the result together with the animal's signs, history and other tests, such as a blood count, and then decides on treatment or further checks. Because flies spread the parasite between animals, your vet may also suggest testing other animals in the same herd or area.
How to prepare
No fasting is needed; blood is collected into an EDTA tube, and the vet should know about any medicine already given, because recent treatment can affect the result. The lab confirms the method, sample needs and reporting time when you book.
Reading the result
A registered veterinarian reads the result together with the animal's signs, history and other tests. A positive result means the parasite's DNA was found. A negative result makes infection less likely but does not always rule it out, because parasite numbers rise and fall, so your vet may repeat the test or add an antibody test.
Questions about Trypanosoma evansi (Surra) RT-PCR
What is surra in buffaloes, cows and dogs?
Is PCR better than a blood smear for surra?
Can dogs get surra?
Why might the surra test be negative when my animal seems ill?
Before you book this test
Why this notice: so you know, before you book, how a test is done, what its limits are and who is responsible.
- Where it is tested. Some tests are done wholly or partly by an independent partner laboratory. The lab tells you before booking if this test is sent out, and the report names the laboratory that did it.
- What a result can and cannot tell you. No test is right every time. A normal result does not rule out every disease, and an abnormal result does not prove one. A registered veterinarian should read the report with the animal’s signs and history before any treatment is started, changed or stopped.
- The sample. A sample that is clotted, too small, wrongly labelled, leaking or too old may be rejected or reported with a note, and the lab may ask for a fresh one.
- Reporting time. Confirmed when you book. Times are estimates, not guarantees, and the lab confirms the time when you book.
- Emergencies. A booking or a pending report must not delay urgent care. If an animal has collapsed, struggles to breathe, has fits or bleeds heavily, call a veterinarian at once.
Please read our Terms of Service, Medical Disclaimer, Privacy Policy and Refund and Cancellation Policy. Pashupatinath Vet Lab is operated by Duaji Healthcare and Tech Private Limited. This page is general information and does not replace a veterinarian’s advice.
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More RT-PCR tests
Trypanosoma evansi (Surra) RT-PCR: Bhopal and the big cities of Madhya Pradesh
Free sample collection anywhere in Bhopal. From the other cities, send the sample by courier, bus parcel or through your local veterinarian, and the report comes to you online.
Free collection in these Bhopal areas
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Surra is a blood infection of horses caused by Trypanosoma evansi and carried by biting flies. A smear, an antibody ELISA and RT-PCR can help detect it, and a single smear can miss it.
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