How Swabs and Samples Are Taken for RT-PCR Tests

For an RT-PCR test, the sample is usually a swab from the nose, throat or eye, a little fresh dung, or a small amount of blood, depending on where the germ lives. A veterinarian or a trained person should take it. Clean hands, clear labels and a cool pack matter nearly as much as the swab itself.

Which samples are used for RT-PCR?

The sample comes from the place where the germ is found. For germs that cause coughs and runny noses, that means the nose, the back of the throat or sometimes the eye. For gut germs it means dung. Some tests use blood. The tests below show the range, and the lab confirms the exact sample for each one when you book.

• The Canine Respiratory Disease RT-PCR Panel (Kennel Cough) is for dogs with kennel cough signs, and swabs from the nose or throat are common for it.
• The Feline Respiratory Disease RT-PCR Panel (Cat Flu) is for cat flu, where swabs from the nose, throat or eye are common.
• The Strangles (Streptococcus equi) RT-PCR is for horses and may use a nasal swab, a wash from a space behind the throat called the guttural pouch, or pus from an abscess.
• The Bovine Respiratory Disease RT-PCR Panel is for cows and buffaloes with breathing problems.

How is a swab taken?

A swab is like a long cotton bud with a soft tip made for sampling. The person touches the tip only to the area being sampled, rolls it gently against the lining for a few seconds and puts it straight into the tube supplied. The stick is then snapped or cut so that the cap closes.

Ask the lab before sampling which swab and tube to use. Some tubes hold a special liquid that keeps the germ in good condition, and the wrong tube can spoil the sample.

Who should take the sample?

For dogs and cats, a vet or a trained lab person should take it, usually with a helper holding the animal calmly. A frightened pet can scratch or bite, and a forceful swab hurts. For horses, cows and buffaloes the vet takes the sample, because large animals need safe handling and deeper samples such as the guttural pouch wash need a vet's skill and tools.

Owners should not push a swab deep into the nose or throat of any animal. Some animal germs can pass to people, so wear gloves, wash your hands after handling any sample and speak to a doctor if you feel unwell.

How do you keep the sample in good condition?

• Label every tube with the animal's name or tag number, the owner's name, the species, the body site and the date and time, using a marker that does not rub off.
• Use one tube for one animal. Change gloves between animals, because RT-PCR is so sensitive that a trace of germ from another animal can mislead.
• Keep the closed tube cool and out of the sun, inside a sealed bag in case it leaks. Heat can break down the genetic material the test looks for.
• Write down when the signs began, which animals are sick and any recent vaccine, and give the note to the vet or the lab.

If your vet has not yet started antibiotics, taking the sample first gives a clearer picture of what is there. This matters more for tests that grow bacteria than for RT-PCR. A sick animal must never wait for a sample, though, so your vet decides what comes first.

What can spoil a sample?

A swab that only touches the skin outside the nose, a swab left to dry in the open, a tube kept in hot sun, two animals' samples mixed up and a leaking tube are the common problems. Cleaning the area or putting anything on it just before the swab can also remove the germs the test looks for, so follow your vet's advice.

A spoiled sample can give a negative result even when the germ is present, and an unlabelled tube may not be accepted at all. A registered veterinarian reads every result with the animal's signs and history, so a clean sample and a clear note make that easier.

Read next

Some infections also need the germ to be grown in the lab, and Culture and Sensitivity: What It Tells Your Vet explains that test and why the timing of the sample matters. If you live outside the city, Sending Samples to the Bhopal Lab From Indore, Jabalpur and Gwalior walks you through packing, labelling and sending samples by courier or bus parcel.

Testing in Bhopal

Book first, then sample. When you call or WhatsApp +91 88175 01118, the lab at C-200, C Sector, Shahpura confirms the method, sample needs and reporting time, and tells you which swab and tube to use. In Bhopal, sample collection is free. Outside Bhopal, samples can come by courier, bus parcel or through your vet. For horses, cows and buffaloes, your vet usually takes the sample.