pyrantel-tartrate and Rodent-Diseases

Haemonchus contortus- and Trichostrongylus colubriformis-infected jirds (Meriones unguiculatus) are useful for anthelmintic studies. With concurrent infections of these parasites established in the jird, questions of not only anthelmintic activity, but to some extent spectrum, could be assessed in a single model system. This report outlines a model using immunosuppressed (0.02% hydrocortisone in feed) jirds concurrently infected with H. contortus and T. colubriformis. Immunosuppressed jirds were inoculated with approximately 1,000 exsheathed infective larvae of each species, treated per os on day 10 postinoculation (PI), and killed on day 13 PI. Stomachs and small intestines were removed, opened longitudinally, incubated in distilled water at 37 C for 5 hr, fixed in formaldehyde solution, and stored for subsequent examination. Contents of both organs were examined using a stereomicroscope (15-45 x). Various standard anthelmintics were evaluated in the model; modern broad-spectrum ruminant anthelmintics (benzimidazoles, febantel, ivermectin, levamisole hydrochloride, and milbemycin D) are active uniformly and in most cases at doses comparable to those required for efficacy against these parasites in ruminants. This model, using worms of 2 genera living in distinct sites, allows preliminary evaluation of anthelmintic activity and spectrum for experimental compounds in a single cost- and resource-efficient experiment.

Topics: Animals; Anthelmintics; Anti-Bacterial Agents; Benzimidazoles; Bithionol; Diethylcarbamazine; Gerbillinae; Guanidines; Haemonchiasis; Macrolides; Piperazine; Piperazines; Pyrantel Tartrate; Rodent Diseases; Trichostrongyloidiasis

Oral inoculation of mice with 340 embryonated eggs of the nematode, Baylisascaris procyonis, proved uniformly fatal as early as 13 days after inoculation and as late as 48 days. Mice given either 0.5% or 0.25% of pyrantel tartrate in dry feed were protected from cerebral migrations of the worm for 55 days. Treatment with pyrantel pamoate in the feed at the concentration of 0.2% given 7 days before inoculation and 5 days after inoculation also protected mice from migrations throughout the 55-day experiment. Embryonated eggs stored in 0.5% formalin in a 4-C refrigerator for 9 years have proved fatal to mice given doses of 340 eggs each.

Topics: Animals; Ascariasis; Ascaris; Female; Locomotion; Mice; Pyrantel; Pyrantel Pamoate; Pyrantel Tartrate; Raccoons; Rodent Diseases