PYRETHRUM AS AN ANTHELMINTIC FOR ASCARIDIA LINEATA.

                                                                         BY

                                                            R. E. REBRASSIER,

                         Columbus, Ohio College of Veterinary Medicine, Ohio State University.*

(Reprinted from Journal of the American Veterinary Medical Association, N. S. Vol. 37, No. 4, April 1934.

Over a century ago, it was discovered that flowers from certain species of the
pyrethrum plant would kill various forms of insect life. The powdered flowers of
this plant have been exported under various names from certain provinces of Persia
and Dalmatia into European countries for use as insecticides. The drug was intro-
duced into America first about the year 1850.

The pyrethrum plant belongs to the genus Chrysanthemum, of the family Com-
positae. Ginsburg¹ lists the following species as being toxic for insects : (1) roseum,
(2) carneum and (3) cinerariaefolium. The last-named species is cultivated espe-
cially for insecticidal purposes because it is higher in insecticidal properties and
gives a larger yield of flowers.

Pyrethrum is very poisonous to insects and cold-blooded animals, but it is not
toxic to man or other warm-blooded animals. Although all parts of the plant are
toxic to insects, most of the toxic principle is found in the flower-head. The toxi-
city is due to two chemical compounds named pyrethrin I (C₂₂H₃₀O₅). These com-
pounds are highly insoluble in water but dissolve readily in most organic solvents
such as alcohol, acetone, ether and kerosene. The total pyrethrin content of the
dried flowers varies from 0.3 to 1.2 per cent. The term pyrethrum refers to the
entire plant, while pyrethrin designates only the active principle. Within recent
years, pyrethrum has become one of our most valuable insecticides and large
quantities of the flowers are imported annually into this country from Japan, Italy
and other countries where this plant is cultivated.

Staundiger and Ruzicka² described the active principles of pyrethrum and the
toxic action on cold-blooded animals, and stated that oral administration to warm-
blooded animals was without danger.

Chevalier³ began internal medication with this drug in man and domestic
animals. He found it to be very efficacious in removing ascarids and tenia from
dogs, and stated that young dogs would withstand large doses of this drug without
apparent discomfort. A dose of 10 mg. was found to be sufficient to remove all
tenia and ascarids from the dog.

* In co-operation with the Ohio Agric. Expt. Stn., Animal Disease Laboratories, Raynoldsburg, Ohio.

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