Veterinary Cytology, Microbiology, and Urinalysis Review

Comprehensive flashcards covering veterinary cytology, microbiology, and urinalysis concepts, including staining techniques, malignancy criteria, and culture methods.

Preferred Cytology Fixative

$95\%$ methanol is the preferred fixative to ensure high-quality preparation.

Mast Cell Diff-Quik Preparation

To improve staining of granules, the fixative time should be increased to at least $15$ minutes.

Starfish Smear

A technique involving dragging the aspirate peripherally in several directions with a syringe needle; also known as the needle spread technique.

Standard Fixation Duration

Prepared cytology slides should remain in the fixative for a minimum of $2$ to $5$ minutes.

Compression Preparation

A technique where an aspirate is expelled onto a slide and a second slide is slid smoothly across it to spread the sample; also called a squash prep.

Papanicolaou Stain

A staining technique that requires the specimen to be wet-fixed before cells have dried to provide the best nuclear detail.

Cytology Concentration Threshold

Mandatory when a fluid sample has a cell count of less than $500/\mu L$.

Gravitational Sedimentation

The concentration method most commonly used for cerebrospinal fluid (CSF) evaluations.

New Methylene Blue (NMB)

A useful adjunct stain providing excellent detail of the nucleus and nucleolus.

Line Smear

A technique used to concentrate cells in a fluid sample that cannot be centrifuged.

Tissue Scraping Technique

Primary advantage is the collection of a large number of cells from firm lesions.

Centesis

In cytology, this refers to the collection of fluid from body cavities.

Neoplastic Lesion Samples

Typically characterized by a homogeneous population of cells.

Criteria of Malignancy

A specimen is generally identified as malignant if it displays at least three nuclear criteria.

Anisokaryosis

A nuclear criterion of malignancy characterized by significant variation in the size of the nuclei of cells of the same type.

Macronucleoli

Nucleoli that are increased in size, typically $\ge 5\,\mu m$.

Epithelial Cell Tumors

Commonly known as carcinoma; these typically exfoliate in clumps or sheets.

Mesenchymal Cell Tumors

Commonly known as sarcomas; these typically exfoliate as individual spindle cells.

Melanoma

A discrete round cell tumor characterized by cells with prominent dark black granules.

Suppurative Inflammation

Inflammation characterized by more than $85\%$ neutrophils; also called purulent.

Pyogranulomatous Inflammation

Defined by a sample containing more than $15\%$ macrophages.

Karyolysis

A nuclear change representing rapid cell death, appearing as a swollen, ragged nucleus with reduced staining intensity.

Obligate Aerobes

Bacteria that require oxygen to survive.

Gram-Negative Bacteria Appearance

Appear reddish-orange after a proper Gram stain procedure.

KOH Test

Uses potassium hydroxide to produce a sticky strand in Gram-negative bacteria.

Ziehl-Neelsen Stain

A specific staining procedure used to identify acid-fast organisms like Mycobacterium.

Beta Hemolysis

Characterized on a blood agar plate by a clear zone around the colony.

MacConkey Agar

A culture medium used to differentiate bacteria based on their ability to lactose ferment.

Culture Plate Incubation Orientation

Stored and incubated in an inverted position to prevent moisture condensation from settling on the agar surface.

Minimum Inhibitory Concentration (MIC)

The lowest concentration of an antibiotic that prevents the visible growth of a specific bacterium.

Bacterial Culture Incubation Standards

First growth is typically checked after $18$ to $24$ hours at $37^\circ C$.

Antimicrobial Sensitivity Measurement

Calipers are used to measure the zone of inhibition.

Cystocentesis UTI Confirmation

Confirmed if a sample contains more than $1,000$ colony-forming units (CFUs) per milliliter.

Dermatophyte Test Medium (DTM)

The most common medium used for dermatophyte testing in veterinary clinics.

Microsporum canis

Only about $50\%$ of cases will show an apple-green fluorescence under a Wood's lamp.

Fungal Culture Collection Site

Samples should be collected from the periphery (outer edge) of the lesion.

Urine Sample Analysis Timeline

Should ideally be analyzed within $30$ to $60$ minutes of collection.

Isosthenuria

Urine specific gravity that approaches that of glomerular filtrate, ranging from $1.008$ to $1.012$.

Refractometer

The most reliable instrument for measuring urine specific gravity in a clinical setting.

Urochromes

Pigments primarily responsible for normal urine color.

Bilirubinuria Significance

Considered a significant finding in cats.

Urine Sediment Centrifugation

Involves spinning $10\,\text{mL}$ of urine for $3$ to $6$ minutes at $1,000$ to $2,000\,\text{rpm}$.

Pyuria

The presence of excessive white blood cells in the urine, indicating an inflammatory or infectious process.

Calcium Carbonate

Urine crystals commonly found in normal horse and rabbit urine, making it appear milky.

Campylobacter Appearance

Gram-negative, slender, spiral, or curved rods on fecal cytology.

Break Point

The dilution of the antimicrobial where the bacterium begins to show resistance.

Mueller-Hinton Agar

The specific agar standardly used for the Kirby-Bauer disc diffusion test.

Binary Fission

The process by which bacteria reproduce.

Refractile Artifact

A staining problem caused by moisture in the fixative, specifically affecting RBCs in Diff-Quik.

Pleomorphism

Variability in the size and shape of the same cell type.

Nuclear Molding

Deformation of nuclei by other nuclei within the same cell or adjacent cells.

Hemosiderin in Macrophages

Indicates that hemorrhage occurred at least a day prior to the collection of a centesis sample.