Molineus barbatus

Molineus barbatus Chandler, 1942

ETYMOLOGY: Molineus for Dr. Molin of Padua, and barbatus for the hair-like nature of these worms.


HISTORY: This worm was originally described by Chandler (1942) from raccoons in East Texas. It has since been found on rare occasions in cats.

GEOGRAPHIC LOCATION: This parasite has been recorded as a parasite of raccoons, Procyonlotor, in North America. It has been found by Shoop et al. (1991) in cats from Arkansas. Out of thirteen random-source cats, seven were found to harbor worms. The cat with the most worms had 21 adults.

LOCATION IN HOST: Small intestine.

PARASITE IDENTIFICATION: The adults of this species are quite small and delicate (Chitwood, 1942). The worms are red. The females are 5.5 to 6.6. mm long, and the males are 4.3 mm to 4.7 mm long. The cuticle is finely striated with 24 to 28 longitudinal ridges. The anterior end has a cephalic inflation. The bursa is well developed, the spicules are 90 µm to 100 µm long, and there is a gubernaculum present. The vulva is about a mm from the posterior end of the female. The eggs are eliptical, 50 to 53 µm long by 32 µm to 37 µm wide (Chitwood, 1942). Gupta (1961) gave the dimensions of the eggs as 54 µm to 61 µm by 38 µm to 45 µm. Shoop et al. (1991) gave the size of the eggs as 60 µm long by 40 µm wide and similar to hookworm eggs in appearance. The eggs are passed in the morula stage. It would be interesting to perform careful observations to determine if the eggs can be readily separated. Schmidt (1965) presents a key to the different species of Molineus that have been described. The very small size of these worms may cause them to be overlooked at necropsy unless precautiions are taken to use procedures that will recover worms small that the feline hookworms.

LIFE CYCLE: Gupta (1961 and 1963) described the life cycle, including the free-living stages and in experimentally infected ferrets (Putoriusputorius). The egg is passed in the morula stage, and after around a day at 20C, the first-stage larva hatches from the eggshell. Two molts occur over the next 4 days, producing a sheathed third-stage larva 520 µm long. When these larvae were given orally to seven ferrets, eggs appeared in the feces of five of the ferrets 8 to 10 days later. When larvae were administered sucutaneously to seven ferrets, eggs appeared in the feces 13 days later. Following both forms of administration, the patent periods were very brief. Balasingam (1963) infected cats with larvae orally and subcutaneously and reported prepatent periods of 8 days and mote than 30 days, respectively.


TREATMENT: Not described.

EPIZOOTIOLOGY: These larvae are acquired most likely by the ingestion of material contaminated with infective third-stage larvae. Thus, if cats tend to eat grass or other matter in a yard shared by a raccoon, it s possible that the infection could be acquired by cats in this manner.

HAZARDS TO OTHER ANIMALS: The life cycle of this parasite is direct, and dogs and ferrets, as well as cats and raccoons could be infected. Thus, it is possible that if a cat does become infected, other household pets sharing the environment could become infected.

HAZARD TO HUMANS: It may be possible for humans to develop transient patent infections if the larvae were to be ingested.

CONTROL/PREVENTION: Prevent the contamination of areas with raccon feces where cats may hunt or graze.


Balasingham E. 1963. Experimental infection of dogs and cats with Molineusbarbatus Chandler, 1942, with a discussion on the distribution of Molineus spp. Canad J Zool 41:599-602.

Chandler AC. 1942. The helminths of raccoons in east Texas. J Parasitol 28:255-268.

Gupta SP. 1961. The life history of Molineusbarbatus Chandler, 1942. Canad J Zool 39:579-588.

Gupta SP. 1963. Mode of infection and biology of infective larvae of Molineusbarbatus Chandler, 1942. Exp Parasitol 13:252-255.

Schmidt GD. 1965. Molineus mustelae sp. n. (Nematoda: Trichostrongylidae) from the long-tailed weasel in Montana and M. chabaudi nom. n, with a key to the species of Molineus. J Parasitol 51:164-168.

Shoop WL, Haines HW, Michael BF, Eary CH, Endris RG. 1991. Molineusbarbatus (Trichostrongylidae) and other helminthic infections of the cat in Arkansas. J Helm Soc Wash 58:227-230.

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