A Simple Fecal Flotation Method for Diagnosing Zoonotic Nematodes Under Field and Laboratory Conditions

Currently, a countrywide geolocation study of the zoonotic parasites of dogs is being carried out to put further control and prevention strategies for these diseases. The existence of a wide variety of ecosystems in Mexico influences the frequency of parasite infections in dogs. Therefore, it is necessary to carry out field work and identify these parasites to be able to propose region-specific deworming guidelines according to the epidemiology of each parasite.

The simple flotation technique is not sensitive enough to detect Cryptosporidium oocysts, Giardia cysts, or Trichuris eggs. We propose a concentration procedure for better coproparisitoscopic detection of these parasites. This technique can speed up and facilitate diagnosis of helminth infection in dogs in areas where no laboratory infrastructure or equipment are available.

Findings and deworming recommendations can be prescribed immediately after each microscopic examination. This protocol can be helpful in conducting routine fecal examinations under field or laboratory conditions to estimate the frequencies of Toxocara canis and Ancylostoma infections in dogs. To begin, collect at least two grams of the fecal sample from the ground immediately or within 10 minutes of defecation.

Seal the bags containing the fecal sample thoroughly. Refrigerate the bags at four degrees Celsius. To prepare the saturated salt solution, wash an empty, one liter soda bottle thoroughly with water.

Measure 420 grams of salt in a 12 to 14 ounce plastic cup and add it to the one liter bottle. Fill the bottle with water. Tighten the screw cap, and shake the bottle vigorously until the solution is saturated.

To begin, collect the fecal samples from the dogs and prepare the saturated salt solution in a one liter bottle. Place approximately three grams of feces in a plastic cup. Add one milliliter of the saturated salt solution to the cup and stir for one minute to obtain a paste.

Add 100 milliliters of saturated salt solution to the cup. Pass the suspension through a plastic strainer into a fresh plastic cup to remove coarse particles. Allow the suspension to stand for 15 to 20 minutes.

Heat an inoculation loop for one second to ensure it is free of eggs, cysts, or oocysts, and let it cool for five seconds. Take around three drops of the fecal suspension from the surface with the inoculation loop. Place three separate drops on a glass slide.

Observe each drop under the microscope with a 10X objective. Place a cover slip on the sample to visualize the sample at 40X magnification. The light microscopy images at 40X magnification showed the presence of Toxocara canis and Ancylostoma species eggs.