Diagnosis: Other Research Methods

In previous articles of Pond Life we ​​discussed how to start an investigation and as a follow-up how a microscopic investigation works ( part 1 , part 2 and Part 3 ). At this stage, we've already completed part of the Anamnesis form and performed various checks (water, technique, physical, and behavioral). However, after the microscopic examination, there are still more options available to arrive at a conclusive diagnosis. While not always necessary, it's good to know if you're still unsure after the microscopic examination. You can perform some of these methods yourself, while others require assistance.

Bacterial (pressure) measurement

This includes a general measurement that determines the total number of free-floating bacteria in the pond and more specific bacterial tests focused on pathogens. A general bacterial pressure measurement is a simple and inexpensive way to determine the bacterial pressure in the pond. If it is high, it could be a cause of the problem. While we don't know which bacteria is responsible, we do know that there may be a bacterial problem, the cause of which we can try to find (for example, a buildup of debris in the pond or the plumbing). Specific bacterial tests will have to be outsourced, although much can be done by mail, keeping the costs down. A swap agreement must be created for this.

Swap

In the case of a bacterial infection, you might consider a swab. This involves collecting a sample of wound fluid using a cotton swab, which can then be sent to a laboratory in a solution containing nutrients for the bacteria to create an antibiogram. A swab can also be performed by a veterinarian or lab technician, but this will incur travel costs and additional labor costs.

Antibiogram

An antibiogram involves spreading the fluid from the swab containing the wound fluid over a culture medium in a Petri dish. Antibiotic tablets are then placed on top, and the whole thing is placed in an incubator to stimulate bacterial growth. The results are checked after 24 or 48 hours. Where the bacteria are not growing well (due to the influence of the antibiotic tablet), antibiotics can be prescribed to combat the bacterial infection in the fish.

Autopsy

This involves opening a dead fish to see if there is an internal problem that can be used to make a diagnosis.

Ultrasound/X-ray

This type of equipment allows you to look inside the fish without having to open it. This can be done by a veterinarian, for example, after anesthesia.

Author: Joop van Tol (www.koitoday.nl)