Diagnostic Methods

CBC

complete blood count

What is a routine procedure in daily practice?

CBC

CBC Machine

assay/count of numbers of RBCs, White blood cells, and platelets

Purple top tube

EDTA (anticoagulant)

What does a chemistry panel typically analyze?

1. electrolyte levels

2. kidney values

3. liver enzymes

4. glucose

5. albumin

6. Globulins

7. pancreatic health indicators

What electrolyte levels are measured in a chemistry panel?

Sodium, potassium, chloride, and total calcium.

What kidney values are included in a chemistry panel?

Blood Urea Nitrogen (BUN) and creatinine levels.

Which liver enzymes are assessed in a chemistry panel?

ALT, ALKP, TBIL, GGT

What indicators of pancreatic health are included in a chemistry panel?

Amylase and lipase

What are the two types of samples that can be used for a chemistry panel?

Plasma or serum.

TBIL

Total Bilirubin

- Liver

What are rough, insensitive indicators of pancreatic health?

Amylase/lipase

What is the most common method for fecal analysis?

fecal floatation

fecal float

put feces in a floatation medium, let it sit, in theory...eggs rise to coverslip and can be assessed for presence or absence under the microscope

What is the advantage of fecal centrifugation before floatation?

better overall assay, takes better advantage of specific gravity by using centrifugal force

What does specific gravity measure?

relative density of a substance

How is specific gravity abbreviated?

SG

What device is used to measure specific gravity?

A refractometer.

Water has a SG of

1.000

Specific Gravity (SG)

Most parasite eggs have SG of 1.100 and 1.200.

Floatation Solution Requirement

Solution used for floatation must have a higher specific gravity than the parasite eggs to allow them to 'float' to the top.

Density Principle

Less dense things float, heavier things sink.

Common Floatation Solutions

Sodium nitrate - SG 1.200 to 1.250.

Sugar Solution Specific Gravity

Sugar solution - SG 1.330.

Zinc Sulfate Specific Gravity

Zinc sulfate - SG 1.180.

What are the 2 quantitative techniques used to determine overall parasite load in large animals?

1. The Wisconsin double centrifugation technique

2. McMaster technique.

What is the purpose of fecal assay methods in large animal herd health?

assess the degree of parasitism

What type of evaluation can be performed directly on fecal material?

A direct evaluation, which is insensitive but specific.

Which technique is used for detecting Cryptosporidium in fecal samples?

The Ontario College Puddle Technique.

What is the general approach to assessing parasite load in large animal herds?

Rather than a simple YES/NO answer, a quantitative assessment is preferred.

Baermann Technique

used to retrieve lungworm larvae from species

Baermann Technique time

takes 12-18 hours

What does ELISA stand for?

Enzyme Linked Immunosorbent Assay

What 3 substances can ELISA testing detect?

1. Antigens

2. antibodies

3. or other proteins in the blood

What is the primary use of ELISA testing?

identify the presence and amount of a target substance in a sample

What is the key to ELISA testing?

ability to bind specific antibodies or antigens and detect them using an enzyme-linked reaction

ELISA sample

blood serum, urine or tissue

What is the basis of the ELISA test?

The ELISA test relies on the specific interaction between an antigen and an antibody.

What role do antibodies play in the ELISA test?

Antibodies are proteins produced by the immune system to neutralize antigens, and they are used to detect the presence of specific antigens in a sample.

How does the enzyme-linked detection work in ELISA?

After the antigen or antibody binds, the enzyme linked to the antibody produces a measurable signal by converting a colorless substrate into a colored product.

What does the intensity of the color in an ELISA test indicate?

The intensity of the color correlates with the amount of the target substance present in the sample.

What is an antigen in the context of the ELISA test?

An antigen is a molecule capable of stimulating an immune response, such as a virus.

What is the first step in the ELISA process?

Coating the plate wells with an antibody or antigen, depending on the type of ELISA.

What is the purpose of the blocking step in ELISA?

To block unbound sites in the wells with a protein to prevent non-specific binding.

What is added to the wells during the sample addition step of ELISA?

The sample containing the antigen or antibody.

What is the role of the detection antibody in some ELISA formats?

To bind the target molecule and is linked to an enzyme.

What happens during the enzyme reaction step of ELISA?

A substrate is added, and the enzyme on the detection antibody converts it to a detectable signal, typically a color change.

How is the intensity of the color change measured in ELISA?

Using a spectrophotometer or ELISA reader to quantify the amount of target substance in the sample.

What is a key advantage of ELISA regarding accuracy?

ELISA has high sensitivity and specificity, making it highly accurate, especially with matched antibodies for the specific antigen.

What types of results can ELISA provide?

ELISA can provide both qualitative (yes/no) and quantitative (how much antigen or antibody is present) results.

What types of substances can ELISA detect?

ELISA can be adapted to detect various substances, including viruses, bacteria, hormones, and toxins.

SNAP 4Dx Plus Test

tests for

E. Canis, E. ewingii

A. phagocytophilum

A. platys

Heartworm

(D. immitis)

Lyme Disease

(B. burgdorferi)

What does PCR stand for?

Polymerase Chain Reaction

What is the primary purpose of PCR testing?

To amplify small segments of DNA for detection of specific genetic material.

In which field is PCR widely used for diagnosing infections?

Veterinary medicine

What types of DNA can PCR detect?

Viral, bacterial, or parasitic DNA.

Why is PCR particularly useful in diagnosing infections?

It allows for detection and analysis of genetic material even in very low amounts.

What are some applications of PCR in veterinary medicine?

Diagnosing infections, identifying genetic disorders, and monitoring disease outbreaks.

What is PCR used for in infectious disease diagnosis in animals?

PCR is used to detect pathogens such as bacteria, viruses, and parasites.

Name one viral disease that PCR can diagnose in dogs.

Canine Parvovirus

What genetic information can PCR help identify in animals?

Genetic disorders or hereditary traits, such as certain coat colors and predispositions to diseases.

How does PCR assist in disease surveillance and control?

PCR tracks outbreaks, such as rabies in wildlife or swine flu in farms.

What is one example of a viral disease that PCR can diagnose in cats?

Feline Immunodeficiency Virus (FIV)

Which virus associated with cattle can be detected using PCR?

Bovine Viral Diarrhea Virus (BVDV)

What is a key advantage of PCR regarding sensitivity?

PCR can detect very small amounts of DNA or RNA, making it extremely sensitive for early-stage infection detection.

How does PCR ensure specificity?

PCR primers are designed to target only the specific DNA sequence of the pathogen or gene of interest.

What is the speed advantage of PCR compared to traditional methods?

PCR can provide results within a few hours, making it much faster than traditional culture methods.

What is one key responsibility of vet techs in PCR testing?

Properly collecting, handling, and storing samples to avoid contamination.

How should vet techs prepare for sample collection in PCR testing?

By reading the instructions and wearing gloves.

What role do vet techs play in performing PCR tests?

They assist in performing PCR tests under supervision or in specialized laboratories.

What is a critical task for vet techs after PCR tests are performed?

Interpreting test results and communicating them with the veterinarian.

Why is it important for vet techs to communicate test results with veterinarians?

To ensure proper diagnosis and treatment planning.