What is a fecal Baermann test?
A fecal Baermann is a specialized test for detecting certain types of parasites or “worms” in stool material. Many parasites pass their eggs in the host’s stool, and infection is easily diagnosed by examining the stool for the presence of parasite eggs. (see handout “Fecal Flotation”). However, some parasites pass larvae instead of eggs; larvae cannot be detected by routine stool examination, and a special technique called a fecal Baermann is required to find them.
How does the test work?
Stool material is mixed with water in a special filtering apparatus, and allowed to stand for 1-2 hours. The larvae sink to the bottom of the apparatus, where they are collected and examined. The type of parasitic infection can be determined by identifying the larvae.
What sample is needed?
A small amount of fresh stool material is all that is needed; ideally the stool sample should be no more than 24 hours old, and should be as free as possible of grass, gravel, kitty litter etc. The sample can be collected in any clean container with a tightly fitting lid; this may be a container brought from home, such as a clean margarine tub, or a container provided by your veterinarian.
When should a fecal Baermann be performed?
A fecal Baermann should be performed whenever there is a suspicion that a pet is infected with a parasite that passes larvae, rather than eggs, in the stool. The most common parasitic infection diagnosed using a Baermann test is lungworm, which typically causes signs of coughing. This parasitic worm lives in the lung, and releases larvae into the lung tissue. The host then coughs up the larvae and swallows them, ultimately passing them out in the stool. A fecal Baermann is necessary to diagnose this parasitic infection.