A New Comestible Formulation of Parasiticide Fungi to Reduce the Risk of Soil-Transmitted Helminth Infections in a Canine Shelter

Abstract

Dogs cared for in a shelter are dewormed every three–four months, but they all become infected one–two months later by the soil-transmitted helminths (STHs) Toxocara canis, Toxascaris leonina, Trichuris vulpis, and Ancylostoma caninum. For the purpose of reducing their risk of infection by decreasing the survival of helminths’ infective stages in soil, chlamydospores of two parasiticide fungi, Mucor circinelloides (ovicide) and Duddingtonia flagrans (larvicide) were formulated as handmade edible gelatins and given three days per week for 17 months to 18 dogs (DRF, dogs receiving fungi); a second group was maintained without fungi (CD, control dogs). All individuals were dewormed at months 0, 3, 7, 10 and 13, and it was observed that the levels of helminths egg-output were reduced by 96–98% fourteen days after each treatment. Fecal egg counts of STHs were similar in both groups until the 6th–8th months, and then remained significantly lower in DRF than in CD (42–100% ascarids; 30–100% trichurids and ancylostomatids). According to the results, and considering that gelatin treats have always been fully accepted, it is concluded that this new formulation offers an efficient solution to decrease the risk of infection among dogs maintained in shelters, and is therefore recommended.

Isolation of saprophytic filamentous fungi from avian fecal samples and assessment of its predatory activity on coccidian oocysts

“…Finally, since all Mucor strains were isolated from avian fresh fecal samples, and showed interesting lytic activity on coccidian oocysts, it can be suggested that these strains resisted to the gastrointestinal passage in chickens and peacocks, and maintained both their germination and predatory capacities, as previously demonstrated in birds for the ovicidal fungus P. chlamydosporia 50 and larvicidal fungi D. flagrans and Monacrosporium thaumasium 51 . The fact that all Mucor isolates were obtained from feces belonging to healthy birds, allows also to suggest their innocuity to immunocompetent birds, as demonstrated by other researchers for horses 37 , sheep 20 , dogs 28 and wapitis 19 .…”

“…Their isolation from fecal matter, which frequently also harbours environmental forms of intestinal parasites, proves that fungi and parasites naturally establish relationships in the fecal and soil microenvironment, with the formers being a nutritional source for predatory fungi 17 , 29 , 36 . Also, the isolation of this type of fungi from feces belonging to healthy animals demonstrates the equilibrium in which these microorganisms are within the intestinal environment, and thus their innocuity to immunocompetent animals 17 , 19 , 20 , 28 , 37 – 39 .…”

“…The biocontrol of animal gastrointestinal parasitic infections using predatory fungi has already proved to be an accurate and sustainable complement to antiparasitic drugs, achieving efficacies of up to 97% in reducing the parasite egg shedding (number of eggs per gram of feces, EPG) in horses and ruminants 11 – 23 . However, only a few in vitro and in vivo studies have assessed the performance of predatory fungi against parasites affecting other animal hosts, namely birds, dogs, raccoons and wapitis 10 , 19 , 24 – 28 .…”

Reflecting on the past and fast forwarding to present day anthelmintic resistant Ancylostoma caninum–A critical issue we neglected to forecast

“…Therefore, good faecal hygiene and prompt faecal removal from the environment provides one mechanism to break the life cycle. In addition, use of oral administration of chlamydospores of two parasiticide fungi, Mucor circinelloides (ovicide) and Duddingtonia flagrans (larvicide) demonstrated a significant reduction in hookworm EPG values at the 9th month when comparing two groups of dogs receiving similar anthelmintic treatments in a dog shelter environment ( Viña et al, 2022 ). Maciel et al (2010) specifically looked at the impact of D. flagrans on Ancylostoma spp.…”

Assessing the efficacy of the ovicidal fungus Mucor circinelloides in reducing coccidia parasitism in peacocks

“…R.C. Cooke (1969), Arthrobotrys oligospora Fresen., (1850), and Monacrosporium thaumasium (Drechsler) de Hoog & Oorschot (1985), which are able to destroy nematodes’ infective larvae (L3) (larvicidal fungi), whereas Pochonia chlamydosporia (Goddard) Zare & W. Gams (2001) and Mucor circinelloides Tiegh (1875) present ovicidal activity towards helminth eggs and coccidian oocysts (ovicidal/coccidicidal fungi) 18 , 25 , 26 .…”