**Collecting a urine or stool sample from a dog: doing it properly**

> How to catch urine cleanly, why the first morning sample is the useful one, why a culture needs a sterile sample, and why parasites may need three days.

Source: https://galen.vet/journal/collecting-a-urine-or-stool-sample-from-a-dog/ · updated: 2026-09-15

[Journal](https://galen.vet/) /Home care

Home care

# Collecting a urine or stool sample from a dog so the result is usable

A sample collected badly is not a slightly worse sample. It is a result that has to be discounted, and a visit that has to be repeated.

Written by the [Galen editorial team](https://galen.vet/about/). Reference material — not a diagnosis, a prescription or a dosing instruction.

Published 15 September 2026

![A person walking a dog on a lead across wet grass early in the morning holding a sample container](https://galen.vet/img/journal/collecting-a-urine-or-stool-sample-from-a-dog.webp)

*A person walking a dog on a lead across wet grass early in the morning holding a sample container*

## The short answer

- Use a clean, dry, sealable container from the practice. Household jars leave residues that interfere with the test.
- The first urine of the morning is the most concentrated and the most informative for most routine questions.
- Catch it mid-stream in a shallow, wide vessel held at a distance. Never collect from the ground — soil, grass and floor contaminate it completely.
- A urine culture needs a sterile sample, which normally means the practice collecting it directly from the bladder. Ask before you go, so you do not do the job twice.
- Get it there within a few hours, refrigerated. Cells break down, bacteria multiply and crystals form in a sample left at room temperature.

On this page

1. Ask what the sample is for before you collect it
2. Collecting urine
3. Collecting faeces
4. Storage and delivery
5. What else to bring
6. Bottom line

Being asked to bring a sample is one of the few genuinely useful jobs an owner is given, and it is also one of the easiest to do in a way that wastes everyone’s time. A contaminated urine sample does not produce a slightly less accurate result — it produces a result that has to be discounted, and a second appointment.

The rules are short, and each of them exists because of a specific way samples go wrong.

## Ask what the sample is for before you collect it

This is the step that saves the most repeated visits.

A **free-catch** sample — caught mid-stream at home — answers most routine questions: concentration, glucose, protein, blood, crystals, cells. It is what practices normally mean when they say “bring a urine sample”.

A **culture**, which identifies bacteria and the antibiotics that will work against them, is different. It requires a sample that cannot have been contaminated on the way out, which in practice means the practice collecting urine directly from the bladder with a fine needle — **cystocentesis**. It is quick, usually done with ultrasound guidance, and generally better tolerated than owners expect. A free-catch sample cannot answer a culture question, because organisms picked up from the skin and coat on the way out are indistinguishable from organisms in the bladder.

So the question to ask when the appointment is booked is: *is this something I can catch at home, or does it need to be taken here?*

***Two different samples, two different questions.** Everything on the left can tolerate contamination from skin and coat; nothing on the right can, which is why a culture is taken at the practice rather than brought in. Free to reuse with a link to this page.*

## Collecting urine

**The container.** Ask the practice — most supply a collection kit with a shallow scoop and a sterile pot, and many have a purpose-made ladle for bitches. If you must improvise, use something clean, dry and previously unused. A rinsed jam jar carries sugar residue that will show as glucose; a container washed in detergent carries surfactant; a bottle that held anything else carries that too.

**The timing.** First thing in the morning, before the dog has eaten or drunk. That urine has been in the bladder overnight and is the most concentrated the dog produces, which matters because concentration is itself one of the measurements.

**The technique.** Take the dog out on a lead so that you can be in position rather than following. Let the first second of the stream pass — it flushes the urethral opening — then slide a shallow, wide vessel into the flow from the side, at whatever distance the dog tolerates. Taping a container to a garden cane is a well-established solution for a dog that will not let you crouch beside it, and for a low-slung dog a wide flat tray works better than a deep pot.

Transfer into the sample pot, seal it firmly, and **label it**: the dog’s name, the date, and the time of collection.

**What not to do:** do not collect from the floor, the grass, a puddle or a tray; do not soak it up with a cloth, kitchen paper or a nappy, all of which absorb the very thing being measured; do not top up a small sample with water; do not decant into a second container “to make it look tidier”.

**Do not withhold water to concentrate the sample.** It distorts the result you are trying to obtain, and in a dog that is already drinking excessively — which is often exactly why the sample was requested — withholding water is genuinely unsafe. If the practice wants a water-deprivation test, they will run it themselves, under supervision.

## Collecting faeces

**Fresh, and from the top.** Take the sample from the upper surface of the stool, not the underside that has been in contact with the ground. Grass, soil and gravel introduce free-living organisms and plant material that complicate a parasite examination.

**How much.** Roughly the size of a thumb is plenty for most tests. Practices supply pots, usually with a small spoon moulded into the lid.

**Three days, sometimes.** Parasites shed eggs intermittently, so a single negative sample does not exclude infection. If you have been asked for a three-day sample, it means collecting a portion on each of three consecutive days into the same pot, kept refrigerated between collections. Doing one day and hoping is how a false negative is produced.

**Note the appearance.** Colour, consistency, any blood or mucus, whether there is straining, and anything visible in it. And photograph it — an owner’s description of “a bit loose” covers a wide range, and a photograph does not.

## Storage and delivery

This is where good samples are commonly ruined after the hard part is over.

*What happens to a urine sample left at room temperature, and why the result then describes the container rather than the dog.*

| Change | Effect on the result |
| --- | --- |
| Bacteria multiply | A small, irrelevant contamination becomes an apparent infection |
| Cells break down | Red and white cells and casts disintegrate and are undercounted |
| Crystals form | Crystals appear that were not present in the bladder |
| Glucose is consumed | Bacteria metabolise it; a diabetic sample can read low |
| pH drifts | Rises as urea is broken down, which alters crystal interpretation |

So: refrigerate immediately — not the freezer — and deliver within a few hours, same day at the latest. If you cannot get there, telephone rather than storing it overnight and hoping; it is usually better to collect a fresh sample on the morning you can attend.

## What else to bring

The sample is one input. Bring the rest of the picture with it, because it is what turns a number into an interpretation.

Whether the dog is on any medication, including supplements and parasite treatments, with the strengths — several drugs alter urine and blood results directly. A measured water intake if increased drinking is the reason for the visit: fill the bowl from a marked jug, record what disappears over 24 hours, and bring the figure, which is far more useful than “seems to be drinking more” and is central to the picture described in [diabetes in dogs](https://galen.vet/journal/diabetes-in-dogs/). Any change in appetite, weight, energy or toileting habits, with dates.

What the numbers on the resulting report actually measure is a subject in itself, and it is set out in [what the abbreviations on a dog’s blood test mean](https://galen.vet/journal/dog-blood-test-and-ultrasound-terms/).

## Bottom line

Ask first whether the practice needs a free-catch sample or a sterile one, because a culture requires urine taken from the bladder and a home sample cannot answer that question. For a free catch: a clean dry pot from the practice, the first urine of the morning, caught mid-stream in a shallow wide vessel held at a comfortable distance, never collected from the ground and never soaked up with anything absorbent. Label it with the name, date and time, refrigerate immediately, and deliver within a few hours. For faeces: fresh, from the top of the stool, thumb-sized, sealed, refrigerated — and across three consecutive days if a parasite test was requested, because shedding is intermittent. Do not withhold water to concentrate a sample. And bring the medication list and the measured water intake, which are often worth as much as the sample itself.

## Questions readers ask

How do I collect a urine sample from a dog?

Ask the practice for a collection kit or a sterile pot. Use the first urine of the morning where possible. Take the dog out on a lead so you can position yourself, and slide a shallow wide vessel — the ladle or tray supplied in a kit, or a clean shallow container taped to a stick for a bitch — into the stream after the first second or so, catching mid-flow. Transfer it into the pot, seal it, label it with the dog's name, the date and the time, and refrigerate it until you leave.

Why does it have to be the morning sample?

Because it has been in the bladder overnight and is the most concentrated urine the dog produces. Concentration is itself a measurement — specific gravity tells a veterinarian how well the kidneys are conserving water — and a dilute sample taken after a dog has drunk and urinated several times cannot answer that question. A concentrated sample also gives cells, crystals and protein the best chance of being detectable.

Can I collect it from the floor or the grass?

No. Urine that has touched the ground, a floor, a litter tray or a puddle has picked up bacteria, soil, plant material and cleaning residues, and every one of those changes the result. A sample scooped off a surface can produce a false suggestion of infection or crystals. If a dog will not urinate on cue, going back the next morning is far better than submitting something collected from the floor.

Does a urine infection need a different kind of sample?

Usually yes. A culture identifies which bacteria are present and which antibiotics will work, and it is only meaningful if the sample cannot have been contaminated on the way out. That normally means the practice collecting urine directly from the bladder with a needle — cystocentesis — which sounds worse than it is and is quick and well tolerated. Ask what the sample is for before you collect anything, because a free-catch sample cannot answer a culture question.

How do I collect a faecal sample and how much is needed?

A fresh sample, collected from the top of the stool rather than the underside that touched the ground, roughly the size of a thumb, in a sealed pot — practices supply them, often with a small spoon in the lid. Do not include soil, grass, gravel or litter. Label it, refrigerate it, and take it in the same day. For some parasite tests you will be asked for samples on three consecutive days in one pot, because eggs are shed intermittently and a single sample can miss them.

How long can a sample be kept?

As little as possible. In urine at room temperature, cells break down, bacteria multiply, crystals form that were not there when it left the dog, and glucose is consumed — so the result describes the container rather than the dog. Refrigerate immediately and deliver within a few hours; same day at the latest. Faecal samples degrade more slowly but still need refrigeration and same-day delivery, and some tests require the sample to be genuinely fresh.

## Keep reading

- [How to take a dog's temperature at home and read the result A temperature is the first thing a practice asks for over the phone. It is only useful if it was taken in conditions you can repeat.](https://galen.vet/journal/how-to-take-a-dogs-temperature/)
- [Early signs of illness in cats and dogs: what to watch for Animals conceal illness competently. The signs that matter are usually changes in ordinary behaviour, and the useful question is what is different rather than what is wrong.](https://galen.vet/journal/signs-of-illness-in-cats-and-dogs/)
- [A first-aid kit for a dog: what belongs in it and what does not A kit is not for treating an injury. It is for controlling bleeding, protecting a wound and getting the dog to a practice without making anything worse.](https://galen.vet/journal/first-aid-kit-for-a-dog/)
- [Dog blood test and ultrasound terms: what each abbreviation measures A report is a list of measurements, not a list of verdicts. Knowing what each one measures makes the conversation with the vet a different conversation.](https://galen.vet/journal/dog-blood-test-and-ultrasound-terms/)
- [Caring for a dog after surgery: what the first two weeks require The dog feels well several days before the tissue has healed. Almost every post-operative complication lives in that gap.](https://galen.vet/journal/caring-for-a-dog-after-surgery/)

## Sources

1. [Dog owners — veterinary manual](https://www.merckvetmanual.com/dog-owners) — MSD/Merck Veterinary Manual
2. [The Merck Veterinary Manual](https://www.merckvetmanual.com/) — MSD/Merck Veterinary Manual
3. [Global guidelines for small animal practice](https://wsava.org/global-guidelines/) — World Small Animal Veterinary Association (WSAVA)
4. [Pet care resources for owners](https://www.avma.org/resources-tools/pet-owners/petcare) — American Veterinary Medical Association (AVMA)
5. [Parasite control guidelines for cats and dogs](https://www.esccap.org/guidelines/) — ESCCAP (European Scientific Counsel Companion Animal Parasites)

Galen publishes reference material on veterinary medicines. It describes how
products are labelled, stored and classified; it does not tell you what to give an
animal, in what amount, or for how long. Those decisions belong to a veterinarian
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exact product in front of them. Where national rules apply — to prescribing,
residues in food, or reporting a suspected reaction — the authority in your own
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