FAQ

Feces and blood samples should be processed within 60 minutes whenever possible. Depending on the sample matrix, temporary storage by refrigeration or freezing is possible. See: Storage & Handling

The light blue lines are important for internal quality control and can also serve as guide lines for the user (the location where the lines appear). They are washed away during the test run without affecting the test results. The test is valid.

Yes, even a faint test line is considered positive. The intensity of the control line (C) does not correlate with that of the test line.

If you suspect temperature exposure outside the range of 2–30 °C: Check the test using a control sample or run buffer (if available). Do not use if the C line is absent or if the run pattern is atypical.

Only the tip of the cotton swab should be covered with a thin layer of stool. To do this, mix the stool sample thoroughly (e.g., using a wooden spatula) and dab the tip of the cotton swab on at least 3 spots on the surface. Too much stool can block the test or cause the background to turn yellowish-brown.

Max. 5 minutes. Better: Mix the swab tip containing the stool sample thoroughly into the buffer and apply the fresh solution directly to the test.

Yes, this is possible—especially with crumbly stool—and it's very helpful. The material sticks better to the cotton swab this way and is easier to transfer.

• Store stool in the refrigerator (4–8 °C) for up to 3 days; freeze for longer-term storage
• Serum/plasma is stable when refrigerated for up to 48 hours; freeze for longer-term storage
• Whole blood remains stable for up to 48 hours only when refrigerated; freezing is not possible

• Temperatures below 2°C or above 30°C may impair test performance and buffer effectiveness.
• Bring to room temperature before starting the test. Tests that are too cold may result in faint or delayed lines.

Use within 30 minutes after opening and mixing. Old buffer solution may affect the test results.

If samples need to be transported, store them at a cool temperature to maintain antigen stability.

To prevent whole blood from seeping through or interfering with the test, wait until the blood has been completely absorbed before adding the run buffer. Adding the buffer too early can interfere with the test, especially with very thick or viscous blood.

Use of the product may cause background staining, which can complicate analysis and affect the results. Lipemic samples can affect test results because the fat can block the Ag/AK coupling, which may produce false-negative results.

Chemically treated litter in the sample-buffer mixture can skew the test results; therefore, sampling from contaminated areas should be avoided. A better approach: Split the fecal sample down the middle and take the sample from the inner portion.

Possible causes: sample is too viscous, sample volume is too large, mucus/contaminants.

Solution:

• Fecal sample: Gently dab the tip of the cotton swab only on the surface; if necessary, add a few drops of clear buffer solution.
• Serum: Do not test hemolyzed, lipemic, or icteric samples.
• Whole blood samples: Allow the blood to fully absorb into the sample well before adding buffer. (Delays may occur with viscous blood.)

Indicates too much fecal matter. Dilute the solution or use less material to ensure a clean run and avoid brown streaks. Alternatively, turn the buffer bottle upside down, allow the heavier components to settle, and discard the first drop.

The test is invalid; please repeat it. Check for any abnormalities in the sample or during the test run.

Read the results exactly within the specified time window. Reading the results too late often leads to nonspecific shadow lines (evaporation artifacts!).

• Only lines that appear within the 10-minute window AND remain visible are valid.
• Lines that disappear before the time expires or do not appear until after 10 minutes are not to be counted.

• The sample-buffer mixture is too viscous, which makes it difficult to perform a clean run.
  • Solution: Do not fully immerse the swab tip in the stool; instead, lightly dab the surface in several places so that only the tip is covered.
• Incorrect timing of the test: The sample was collected at a time when the disease was not yet or no longer detectable, e.g., FeLV (antigens are detectable only 2 to 4 weeks after infection) or CPV/FPV (very short shedding period, approx. 3–10 days)
• Testing immediately after treatment: For example, dead Giardia are still shed by the animal for about 3 weeks after treatment. Rapid tests do not distinguish between live and dead Giardia.
• Live vaccines, such as those against parvovirus, can still be detected by an antigen test up to 3 weeks later.

• Incorrect timing of the test: The time it takes for antibodies to develop after an infection can vary depending on the pathogen (see travel-related illnesses)
• Depending on the vaccine (especially live vaccines), do not test immediately! Seroconversion takes time (usually 3–4 weeks after the last dose).

• Sensitivity: The ability to correctly identify sick animals as positive.
• Specificity: The ability to correctly identify healthy animals as negative.
• TTP: Overall reliability of the test, taking into account sensitivity and specificity.

• Feces + urine or other substances → unexpected reactions, test disrupted.

• Lipemic, hemolytic, or icteric: May intensify background staining and/or interfere with the flow, thereby complicating the evaluation.
• Crumbly or very crumbly stool: Moisten the swab to collect the sample onto the cotton swab.

Cat litter, bedding/floor particles, or food scraps → will skew the test results. Always use clean fecal samples.

• Some animals (Giardia, parvovirus, FeLV) may shed antigens or antibodies for longer periods or intermittently.
• Interpretation may require multiple tests over time.

• After administration of a live vaccine, an antigen test may temporarily yield a positive result.
• Waiting period after live vaccination: antigen tests (e.g., parvo): at least 2–3 weeks; antibody tests: approximately 2–4 weeks, depending on the vaccine.

• Cryptosporidium or Giardia → Humans can also become infected. Practice good hygiene.

• Often, the micropores of the nitrocellulose membrane are clogged, or too much feces has been applied to the sample pad. Note: Some sample pads are thicker and may not filter viscous samples or excessive amounts of material as effectively.

• For stool samples, it is recommended to briefly homogenize the sample before collection (e.g., with a wooden spatula)
• Advantage: This increases the likelihood of actually detecting antigens in the sample.

• Too much of the stool/buffer mixture can distort the test line and/or interfere with the test; too little can lead to false-negative results.
• Tip: Always moisten the tip of the cotton swab; do not submerge it completely.

• In cases of very watery diarrhea, the virus or antigen may be flushed out → the test initially comes back negative, even though an infection is present.
• Solution: Wait 30 minutes after watery diarrhea and use firmer stool samples (→ dilution effect).

• Use gloves; keep sample containers clean.
• Cross-contamination (e.g., between animals) can produce false-positive results.

• Weak T-lines that are visible within the reading period are considered positive. If the line is weak and there is no clinical suspicion: Consider repeating the test and/or performing confirmatory testing (e.g., PCR, Western blot).
• The intensity of the control line has no effect on or significance for the test line.

• If a chronic or recurrent infection is suspected, it may be advisable to test for differential pathogens as a precaution (e.g., Giardia and CPE, or Giardia and Cryptosporidium).
• Example: Giardia or parvovirus—a negative individual test does not necessarily mean “no pathogen present.”

• Many antigen/antibody tests have specific time windows during which an infection can be detected.
  
  • e.g., parvovirus antigen: approximately 7–10 days; viral shedding occurs 3–4 days after infection and before symptoms appear
  • e.g., distemper virus antigen: detectable in infectious blood for 3–4 days and subsequently in feces for approximately 3 days
• Tests performed too early → false-negative results.
• Testing too late (e.g., after viral shedding) → also false-negative.

• Particularly useful after treatment or vaccination to monitor the patient’s progress.
• But be careful: Live vaccines can be detected by rapid tests (e.g., parvovirus antigen after vaccination). Be sure to observe the waiting period!