Veterinary tests help answer a simple but important question: what is happening inside your dog or cat’s body. Sometimes they confirm a suspicion. Sometimes they detect changes before symptoms are obvious. They also help choose treatment, monitor a chronic disease or check whether surgery or anesthesia can be planned more safely.
Not every pet needs the same tests. A puppy with diarrhea, a cat drinking more water, a senior dog losing weight and a dog about to have surgery all need different decisions. That is why veterinarians combine three pieces of information: what you describe, the physical exam and diagnostic tests.
This guide explains the most common veterinary tests, what they are used for and what information is worth keeping for future visits.
Important: this article is educational and does not replace veterinary diagnosis or treatment. If your pet has trouble breathing, seizures, heavy bleeding, severe pain, a swollen abdomen, collapse, vomiting or diarrhea with blood, go to an emergency veterinarian.
Editorial note: Written by the Dogtorcito team using veterinary references from the Merck/MSD Veterinary Manual for medical tests, lab work and urinalysis; AAHA for preventive monitoring in senior dogs and cats; and Cornell University College of Veterinary Medicine for diagnostic imaging. Last reviewed: May 19, 2026.
Quick overview: types of veterinary tests
| Type of test | What it can show | When it is often recommended | Common examples |
|---|---|---|---|
| Physical exam | General condition, pain, hydration, temperature, gums, heart, lungs, abdomen, skin and mobility | At almost any visit, including preventive checkups | Full exam, auscultation, palpation, weight, body condition score |
| Blood work | Blood cells, inflammation, anemia, platelets, organs, glucose and electrolytes | Sick pet, senior pet, before anesthesia or with changes in weight, thirst or energy | CBC, biochemistry, SDMA, T4, coagulation tests |
| Urinalysis | Kidney clues, hydration, urinary infection, crystals, glucose, protein and sediment | More thirst, more urine, accidents at home, kidney disease, diabetes or senior checkup | Dipstick, urine specific gravity, sediment, culture, protein/creatinine ratio |
| Fecal tests | Parasites, blood, digestion, bacteria or some infectious agents | Diarrhea, vomiting, weight loss, puppy or newly adopted pet | Fecal exam, Giardia test, fecal flotation, PCR in selected cases |
| Imaging | Bones, chest, abdomen, organs, masses, fluid, foreign bodies or internal injuries | Limping, trauma, cough, persistent vomiting, abdominal pain, internal masses or suspected foreign body | X-ray, ultrasound, CT, MRI |
| Cytology and histology | Cells or tissue under the microscope | New lump, non-healing lesion, internal mass, discharge or abnormal fluid | Fine needle aspirate, impression smear, biopsy, histopathology |
| Microbiology | Microorganisms and which antibiotics may work | Urinary, skin or ear infections that recur or do not respond to treatment | Urine culture, skin culture, antibiogram |
| Serology and rapid tests | Exposure, infection or immune response to selected agents | Suspected infectious disease, adoption screening or regional risk | Leishmania, FeLV/FIV, parvovirus, antigen or antibody tests |
| Cardiac tests | Heart rhythm, structure and function | Murmur, cough, fainting, arrhythmia, fast breathing or predisposed breeds | ECG, blood pressure, chest X-rays, echocardiography, NT-proBNP |
What test might a vet suggest based on the symptom?
This table does not replace a consultation, but it helps you understand the diagnostic logic. Your veterinarian may choose a different test depending on age, physical exam, severity and history.
| What you notice at home | Tests that may make sense | Why they help |
|---|---|---|
| Dog drinking and urinating a lot | Blood work + urinalysis | They help assess kidneys, glucose, urine concentration and possible metabolic disease |
| Senior cat losing weight | Blood work + urinalysis + T4 | They help investigate kidneys, liver, diabetes, inflammation and hyperthyroidism |
| Puppy with vomiting and diarrhea | Fecal tests + parvovirus test + blood work if weak | They look for parasites, infections and dehydration |
| New or growing lump | Cytology and sometimes biopsy | They help tell inflammation, cyst, infection and tumor apart |
| Persistent cough or unusual breathing | Exam + chest X-rays + cardiac tests when appropriate | They help separate respiratory, heart-related and other causes |
| Limping or pain when moving | Orthopedic exam + X-ray when appropriate | They help locate injury, arthritis, fracture or joint disease |
| Repeated ear or skin infections | Cytology + culture in selected cases | They help identify microorganisms, inflammation and better treatment choices |
When to worry and not wait
You do not need to know which test your pet needs to act in time. Seek urgent veterinary care if you see:
- Trouble breathing.
- Pale, bluish or very white gums.
- Collapse, fainting or seizures.
- Swollen and painful abdomen.
- Heavy bleeding or bleeding that does not stop.
- Inability to urinate, especially in cats.
- Vomiting or diarrhea with blood.
- Severe weakness or rapid worsening.
In these cases, the priority is not choosing a specific test at home. The priority is getting to a clinic that can stabilize and diagnose your pet.
The physical exam: the test that is never wasted
Before ordering blood work or an X-ray, the veterinarian usually starts with something that looks simple: looking, touching, listening and measuring.
A physical exam may include:
- Weight and recent trend.
- Temperature.
- Heart and respiratory rate.
- Gum color and capillary refill time.
- Hydration.
- Listening to the heart and lungs.
- Abdominal palpation.
- Skin, coat, ears, mouth and eye check.
- Mobility, lameness and pain assessment.
- Body and muscle condition.
The exam does not replace diagnostic tests, but it helps decide which test makes sense. Blood work for weight loss is not the same as blood work for vomiting, cough, itching, fever or excessive thirst.
Blood work: CBC and biochemistry
When people say “blood work”, they usually mean a combination of a complete blood count and a biochemistry panel.
Complete blood count
A CBC studies blood cells:
- Red blood cells: help detect anemia, dehydration or oxygen-carrying problems.
- White blood cells: can point toward infection, inflammation, stress, allergy or bone marrow problems.
- Platelets: help assess clotting ability.
A CBC does not usually say “your dog has this exact disease” by itself. It gives clues that the veterinarian interprets with symptoms, the physical exam and other tests.
Blood biochemistry
Biochemistry measures substances in the blood that give clues about organs and metabolism. It may include:
- Kidneys: urea, creatinine, SDMA, phosphorus.
- Liver and bile ducts: ALT, AST, ALP, GGT, bilirubin.
- Glucose: useful when diabetes, hypoglycemia or stress is suspected.
- Proteins: albumin, globulins, total protein.
- Electrolytes: sodium, potassium, chloride, calcium.
- Pancreas: specific tests when pancreatitis is suspected.
Biochemistry is useful in sick animals, senior checkups, pre-anesthetic screening and chronic disease monitoring.
Concrete examples:
- Dog drinking and urinating more: blood work and urine are often used to assess kidneys, glucose and urine concentration.
- Senior cat losing weight despite eating: CBC, biochemistry, urine and T4 may be needed to check for hyperthyroidism and other causes.
- Pet before surgery: blood work can reveal changes that may affect the anesthetic plan.
For older dogs, this connects closely with our guide to senior dog care.
Urinalysis: a small test with a lot of information
Urinalysis may seem less important than blood work, but it is often essential. It helps assess:
- Hydration.
- Kidney ability to concentrate urine.
- Glucose or ketones.
- Protein in urine.
- Blood or inflammation.
- Crystals.
- Bacteria.
- Abnormal cells.
It can also help investigate signs such as:
- Drinking more water.
- Urinating more often or in larger amounts.
- Accidents at home.
- Pain when urinating.
- Blood in urine.
- Weight loss.
- Suspected kidney disease, diabetes or urinary infection.
Urine is not always collected the same way. Sometimes a free-catch sample is enough. In other cases, the veterinarian may prefer a sterile sample by cystocentesis, especially if a culture is needed.
A common example: if a dog starts drinking a lot, urine helps show whether the kidneys are concentrating properly. If blood work also shows high glucose, the veterinarian may investigate diabetes. If there is protein, abnormal sediment or low urine concentration, the kidneys or urinary tract may need a closer look.
Fecal tests: parasites, diarrhea and prevention
Feces can reveal a lot about the digestive tract and some parasites. Fecal tests are common in puppies, newly adopted pets, diarrhea, vomiting, weight loss or preventive checkups.
They may look for:
- Intestinal parasite eggs.
- Giardia or other protozoa.
- Occult blood.
- Digestive changes.
- Some viruses, bacteria or parasites through specific tests.
If your dog has severe diarrhea, blood in stool, vomiting, weakness or is a puppy, do not just wait to “see if it passes”. Some digestive diseases progress quickly. You can read more in the guide to common dog diseases.
Imaging tests: X-ray, ultrasound, CT and MRI
Imaging tests allow veterinarians to see internal structures without opening the body. They are not all used for the same purpose.
X-ray
X-rays are one of the most common imaging tests in veterinary practice. They can help assess:
- Bones and joints.
- Fractures.
- Chest and heart size.
- Lungs.
- Abdomen.
- Foreign bodies.
- Some masses or fluid accumulation.
They are quick and very useful, but they do not always show soft tissues in detail. That is why they are sometimes combined with ultrasound or other tests.
Ultrasound
Ultrasound uses sound waves and is especially useful for abdominal organs and soft tissues. It can help study:
- Liver.
- Spleen.
- Kidneys.
- Bladder.
- Uterus and prostate.
- Intestine.
- Abdominal fluid.
- Internal masses.
It can also guide a fine needle aspirate or sample collection.
CT and MRI
CT and MRI are advanced tests. They are used when more detail is needed or when the problem is in an area that is difficult to assess with X-ray or ultrasound.
They may be useful for:
- Neurologic problems.
- Complex injuries.
- Tumors.
- Surgical planning.
- Difficult fractures.
- Nasal disease, middle ear disease or spinal problems.
Many pets need sedation or anesthesia for these tests to prevent movement. Your veterinarian will explain the benefit, risk and alternatives.
Cytology and biopsy: looking at cells or tissue
When a lump, skin lesion, discharge, internal mass or abnormal fluid appears, the veterinarian may recommend studying cells or tissue.
Cytology
Cytology analyzes cells under a microscope. Samples may be collected by:
- Fine needle aspirate.
- Impression smear.
- Scraping.
- Swab from ear, skin or discharge.
- Fluid sample.
It can suggest inflammation, infection, allergy, some tumors or lesion type. Sometimes it gives a clear diagnosis. Other times it says, in effect, “this needs a biopsy”.
Biopsy and histopathology
A biopsy takes a piece of tissue. A laboratory then examines it under a microscope. It is often more informative than cytology when a tumor, complex inflammatory disease or a lesion that does not respond to treatment is suspected.
If your pet has a new lump, one that grows, changes color, bleeds or bothers them, do not monitor it for months without asking a vet.
Practical rule: new lump = appointment; growing lump = appointment soon; bleeding, painful or fast-changing lump = priority appointment.
Microbiology: cultures and antibiogram
A culture tries to identify bacteria or other microorganisms from a sample. An antibiogram helps show which antibiotics are more likely to work.
It can be especially useful for:
- Recurrent urinary infections.
- Infected wounds.
- Ear infections that do not improve.
- Deep or repeated skin infections.
- Pneumonia or selected respiratory infections.
This matters because not all infections are treated with the same antibiotic, and using antibiotics blindly when they are not appropriate can contribute to resistance or delay the correct diagnosis.
Serology, rapid tests and PCR
Some diseases are investigated with tests that detect antigens, antibodies or genetic material from the infectious agent.
Common examples:
- Parvovirus test in puppies with vomiting and diarrhea.
- Leishmania testing in risk areas.
- FeLV/FIV testing in cats.
- Tick-borne disease tests.
- PCR for selected viruses, bacteria or parasites.
These tests are not interpreted in isolation. A positive, negative or unclear result can mean different things depending on symptoms, vaccination, region, time since exposure and sample type.
Cardiac tests: ECG, blood pressure and echocardiography
The heart may need specific tests when there is a murmur, cough, fainting, exercise intolerance, fast breathing, arrhythmia or a breed predisposition.
Common tests include:
- Electrocardiogram (ECG): studies the heart’s electrical rhythm.
- Blood pressure: useful in kidney disease, feline hyperthyroidism, eye problems, senior pets and patients with certain signs.
- Chest X-rays: assess heart size, lungs and signs of congestion.
- Echocardiography: heart ultrasound to see structure and function.
- NT-proBNP: a blood marker that can support heart disease investigation in some contexts.
AAHA recommends considering tests such as blood pressure, T4, CBC, biochemistry and urine regularly in senior dogs and cats, always adjusted to the individual patient and clinical judgment.
Tests before anesthesia or surgery
Before anesthesia, the veterinarian may recommend preoperative tests. They do not guarantee zero risk, but they help detect problems that could change the plan.
They may include:
- Physical exam.
- Blood work.
- Urinalysis.
- Coagulation tests.
- X-rays or ultrasound if clinical signs are present.
- ECG or echocardiography if there is a murmur, arrhythmia or heart concern.
In a young healthy animal, the panel may be simple. In a senior, brachycephalic patient or a pet with kidney, heart, liver or endocrine disease, the workup may need more detail.
When a vet may request tests
It is worth asking about veterinary tests if you notice:
- Unexplained weight loss or gain.
- More thirst or more urine.
- Repeated vomiting or diarrhea.
- Blood in stool, urine or vomit.
- Persistent cough.
- Unusual tiredness.
- Limping, pain or stiffness.
- Itching, wounds, hair loss or recurrent skin infections.
- Strong bad breath, pain while eating or loose teeth.
- Behavior changes.
- Seizures, fainting or weakness episodes.
- New or changing lumps.
- Loss of appetite.
If the problem seems urgent, see the guide to pet emergencies.
Preventive tests: not only when there are symptoms
Tests are not only for sick animals. They can also be part of preventive medicine.
They may be useful for:
- Newly adopted puppies or kittens.
- Pets starting vaccination or parasite prevention.
- Annual checkups.
- Senior dogs and cats.
- Before anesthesia.
- Chronic disease monitoring.
- Pets taking long-term medication.
- Animals that travel or live in areas with specific diseases.
Frequency depends on age, species, breed, symptoms, history, lifestyle and local risks. For example, vaccination schedules are individualized by age and exposure. You can learn more in the dog vaccination schedule.
How to understand a result without panicking
A result outside the reference range does not always mean serious disease. And a “normal” result does not always rule everything out.
There are several reasons:
- Values are interpreted with symptoms and the physical exam.
- Some changes are mild or temporary.
- Age, breed, medication and stress can influence results.
- A sample may be hemolyzed, contaminated or taken at a less-than-ideal moment.
- Some diseases require repeat testing or more specific tests.
The useful question is not only “is it normal?”. Ask:
- What does this result mean for my specific pet?
- What changes in the treatment or monitoring plan?
- When should it be repeated?
- What signs should I watch for at home?
What information to keep from each test
After a veterinary test, keep:
- Date.
- Reason for the test.
- Symptoms present.
- Full result, not just “fine” or “bad”.
- Values outside the reference range.
- Diagnosis or main suspicion.
- Treatment prescribed.
- Follow-up date.
- Home monitoring recommendations.
- Attachments: report, images, PDF or photos.
This prevents loss of context. A kidney value, liver enzyme or mass is not interpreted the same way if it appeared suddenly as if it has been stable for two years.
How Dogtorcito helps with tests and diagnoses
Dogtorcito works as an organized health record for your pet.
You can use it to:
- Store lab work, reports and results.
- Record symptoms before and after the visit.
- Track weight, appetite, thirst, stool and medication.
- Schedule review reminders.
- Keep a clear history if you change clinics or go to emergencies.
- Share trends with your veterinarian.
A single test is a snapshot. An organized history shows the whole movie.
Keep your pet’s tests easy to find
Store lab results, reports, diagnoses, symptoms, medication and reminders in one place so you arrive better prepared for each visit.
FAQ
What are the most common veterinary tests?
The most common are physical exam, CBC, biochemistry, urinalysis, fecal tests, X-rays, ultrasound, cytology, cultures and rapid tests for infectious diseases.
Can blood work detect everything?
No. Blood work provides a lot of information, but it does not detect every problem. Some diseases require urine tests, imaging, cytology, biopsy, hormone tests, cultures or specific infectious disease tests.
When does my dog need blood work?
It may be recommended if your dog is sick, losing weight, drinking more, vomiting, having diarrhea, going under anesthesia, taking chronic medication or becoming senior. The decision depends on the case and veterinary judgment.
What is urinalysis for in dogs and cats?
It helps assess urine concentration, protein, glucose, blood, sediment, crystals, bacteria and other clues related to kidneys, bladder, hydration and some metabolic diseases.
Are X-rays and ultrasound used for the same thing?
Not exactly. X-rays are very useful for bones, chest, lungs, heart size and some abdominal problems. Ultrasound usually gives more detail for soft organs such as liver, spleen, kidneys, bladder, intestine or uterus.
Why repeat a test if it was normal before?
Because some diseases change over time. Repeating a test helps compare trends, confirm whether treatment is working or detect a change that was not visible yet.
Can I interpret the results at home?
You can read them, but it is not wise to draw conclusions without context. Results are interpreted with symptoms, exam findings, age, breed, medication, diet and history.
References
-
Merck Veterinary Manual. Veterinary Medical Tests. Reviewed/Revised Dec 2025.
https://www.merckvetmanual.com/special-pet-topics/diagnostic-tests-and-imaging/veterinary-medical-tests -
Merck Veterinary Manual. Urinalysis. Modified Jun 2025.
https://www.merckvetmanual.com/clinical-pathology-and-procedures/diagnostic-procedures-for-the-private-practice-laboratory/urinalysis -
Merck Veterinary Manual. Clinical Hematology.
https://www.merckvetmanual.com/clinical-pathology-and-procedures/diagnostic-procedures-for-the-private-practice-laboratory/clinical-hematology -
Merck Veterinary Manual. Clinical Biochemistry.
https://www.merckvetmanual.com/clinical-pathology-and-procedures/diagnostic-procedures-for-the-private-practice-laboratory/clinical-biochemistry -
AAHA. Diagnostic Tests and Recommended Frequencies for Senior Dogs and Cats. 2023 AAHA Senior Care Guidelines. Published Dec 12, 2022.
https://www.aaha.org/resources/2023-aaha-senior-care-guidelines-for-dogs-and-cats/diagnostic-tests-and-recommended-frequencies-for-senior-dogs-and-cats/ -
Cornell University College of Veterinary Medicine. Imaging Service.
https://www.vet.cornell.edu/hospitals/services/imaging-service
