Sample collection and prep methods

What are common veterinary sample types?

Blood, urine, feces, skin scrapings, cytology, biopsies, swabs, and fine needle aspirates.

What tests are commonly performed on blood samples?

CBC, chemistry, and serology.

What can urine samples be collected for?

Urinalysis to evaluate kidney function and urine characteristics.

What are three methods of urine collection?

Free-catch/manual bladder expression, catheterization, and cystocentesis.

What is the purpose of a fecal sample?

Testing for parasites and performing cultures.

What is cytology?

Microscopic evaluation of cells shed from body surfaces.

What can cytology identify?

Types and numbers of cells, bacteria, fungi, and parasites.

What can cytology help differentiate?

Inflammation versus neoplasia.

What determines the method of cytology sample collection?

Sample consistency, sample location, and the test being performed.

How are superficial solid masses sampled for cytology?

Swab, scrape, or imprint.

What is a fine needle biopsy (FNB) used for?

Sampling subcutaneous solid masses.

What is a tissue biopsy used for?

Sampling the deepest sites of solid masses.

What is a fine needle aspiration (FNA) used for?

Sampling fluids from subcutaneous sites.

What is centesis used for in cytology?

Collecting fluid from the deepest sites.

When should cytology slides be made and stained?

Immediately after sample collection for best results.

What are five methods of cytology slide preparation?

Feathered edge smear, line smear, compression smear, wet mount, and rolling.

When is heating a cytology slide necessary?

When melting ear wax or performing a Gram stain.

Why is mineral oil used on skin scrapings?

It traps mites and debris and improves visibility under low magnification.

Why are skin scrape slides not stained?

Mineral oil interferes with cytology stains; the goal is parasite detection.

Which microscope objectives are used to examine skin scrapings?

4× or 10× objectives.

How should the microscope be adjusted for skin scrapings?

Partially close the iris diaphragm and lower the condenser for contrast.

What should you do if tissue or fluid samples for cytology cannot be tested immediately?

Refrigerate them.

How soon must fresh, chilled cytology specimens be analyzed?

Within 24 hours of collection.

Should tissue or fluid samples for cytology be frozen?

No, never freeze them.

When may tissue or fluid samples be frozen?

For virology, toxicology, and certain other tests.

What is microbiological testing used for?

Identifying bacteria and determining drug susceptibility for treatment.

What are four common culture media in veterinary practice?

Blood agar, MacConkey agar (MAC), DTM, and Mueller-Hinton agar.

What is blood agar used for?

Bacterial culture.

What is MacConkey agar (MAC) used for?

Bacterial culture.

What is DTM used for?

Detecting dermatophytes.

What is Mueller-Hinton agar used for?

Antimicrobial sensitivity testing.

What is the first step in preparing a microbiology sample for evaluation?

Inoculate the appropriate culture media.

How long are culture media typically incubated?

24-48 hours.

What tests may follow microbiological culture?

Gram stain and biochemical tests.

What are three biochemical tests used in microbiology?

KOH, catalase, and coagulase.

What are the ten steps to prepare a sample for evaluation?

Confirm patient ID, review test requirements, prepare materials, label containers, collect aseptically, handle properly, complete lab form, package/store, log sample, communicate with lab.

What information confirms patient identification?

Name, species, and breed.

What information belongs on a sample label?

Patient name, date, time, and your initials.

Why should samples be collected aseptically?

To minimize contamination.

What information should be included on a laboratory form?

Patient history, clinical signs, and medications.

How should samples be packaged and stored for transport?

Use biohazard bags and ice packs when appropriate.

Why should samples be logged?

To document them in clinic records and record the submission date.

What should you do if laboratory requirements are unclear?

Communicate with the laboratory for clarification.

What is urinalysis (UA) used to evaluate?

Basic kidney function and urine characteristics.

What three characteristics are evaluated during urinalysis?

Physical, chemical, and cellular characteristics.

When should urine be collected for urinalysis relative to treatment?

Before any treatments are given.

When is the ideal time to collect urine for urinalysis?

In the morning before the pet eats or drinks.

Why is morning urine preferred for urinalysis?

It is less affected by diet and is usually more concentrated.

What does concentrated morning urine do for USG?

It provides the highest urine specific gravity (USG).

Why does concentrated morning urine help preserve cellular characteristics?

Higher concentration and more acidic pH help preserve cellular characteristics.

How long should you wait after eating or drinking if morning urine cannot be collected?

Wait 3-6 hours.

What information must be recorded when collecting urine?

The collection date and time.

How much urine is needed for most urinalysis testing?

Approximately 5 mL (about 1 teaspoon).

Should urine samples collected throughout the day be combined?

No, never combine them into one sample for testing.

What is the first step when performing urinalysis?

Evaluate physical characteristics using a well-mixed sample.

How are chemical urine characteristics measured?

Using a chemistry strip.

When should urine be centrifuged before chemical testing?

If the sample is cloudy, turbid, or flocculent.

How are cellular urine characteristics evaluated?

Using a microscope.

What are two urine slide preparation methods?

Wet mount and dry mount (line smear preparation).