Parasitism of the gerbil rarely causes clinical disease problems. Alopecia in aged or debilitated gerbils may be due to demodicosis. Scrapes of affected areas may reveal hamster demodectic mange mites, Demodex aurati or Demodex criceti. Endoparasites of the gerbil may include mouse pinworms (Syphacia obvelata) which can be found in the cecum and a small intestinal gerbil pinworm. Dentostomella translucida. Syphacia ova can be recovered on a cellophane tape test, while Dentostomella ova are identified by the fecal floatation test.
Gerbils also are commonly colonized by intestinal flagellated protozoa (Giardia and Tritrichomonas sp.). No clinical signs of disease are usually associated with naturally occurring helminthes infections in gerbils. Please refer to the appropriate section elsewhere in this handbook for details on diagnosis, treatment, and control if any of these parasites are suspected or diagnosed. Identification of intestinal protozoa can be made by performing examination of feces for protozoal cysts or by preparing wet mount preparations of intestinal contents at necropsy. The hard fecal pellet of gerbils can be softened in saline, and a flotation performed to look for protozoal cysts. Metronidazole at 10 mg/ 100 ml water may be effective in controlling protozoal infections.
Tapeworm infections (Hymenolepis nana or H. diminuta) have been infrequently reported to cause clinical signs of dehydration and diarrhea during heavy infections in a wide variety of rodents. Tapeworm infections have not been reported in the gerbil, but the lack of host specificity of H. nana makes the risk of infection possible in any rodent. Because of the concern for human infection, tapeworm infections in gerbil should be definitively diagnosed.