Just Ask the Expert: How do you detect Physaloptera species eggs? - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


Just Ask the Expert: How do you detect Physaloptera species eggs?



Another useful method for Physaloptera species egg recovery is sedimentation in water, which is easy to do and recovers heavy eggs. And if enough eggs are present, direct fecal smears (wet mounts) in saline solution may work, although they are generally considered much less efficient because of the small sample size. One case study found that direct smears recovered more Physaloptera species eggs than did fecal flotation, but this was directly related to the low specific gravity of the flotation solution used (sodium nitrate solution at a specific gravity of 1.200).2

In most cases in which no eggs are present in the feces,3 antemortem diagnosis will not be possible except by endoscopy (or gastrotomy). In such cases, it is important to do a thorough endoscopic examination on a distended stomach, since small, single worms hiding underneath rugal folds may be missed.3 In such cases, using a videoendoscope has been suggested for improving detection of the worms.3

Kevin R. Kazacos, DVM, PhD
Department of Comparative Pathobiology
School of Veterinary Medicine
Purdue University
West Lafayette, IN 47907


1. Burrows CF. Infection with the stomach worm Physaloptera as a cause of chronic vomiting in the dog. J Am Anim Hosp Assoc 1983;19:947-950.

2. Clark JA. Physaloptera stomach worms associated with chronic vomition in a dog in Western Canada. Can Vet J 1990;31(12):840.

3. Theisen SK, LeGrange SN, Johnson SE, et al. Physaloptera infection in 18 dogs with intermittent vomiting. J Am Anim Hosp Assoc 1998;34(1):74-78.

4. Campbell KL, Graham JC. Physaloptera infection in dogs and cats. Compend Cont Educ Pract Vet 1999;21(4):299-314.

5. David ED, Lindquist WD. Determination of the specific gravity of certain helminth eggs using sucrose density gradient centrifugation. J Parasitol 1982;68(5):916-919.

6. Ehrenford FA. Diagnosis of Physaloptera in dogs by stool examination. J Parasitol 1954;40(Suppl):16.

7. Dryden MW, Payne PA, Ridley R, et al. Comparison of common fecal flotation techniques for the recovery of parasite eggs and oocysts. Vet Ther 2005;6(1):15-28.


Click here