Sulfanilamide and Prontosil in the Treatment of Canine Distemper. ∗

Abstract

Sulfanilamide and prontosil have been found effective in otherwise apparently fatal cases of infection with meningococci 1 and hemolytic streptococci, 2 , 3 , 4 as well as in gonococci 5 infections, but curative value has not been shown in cases of infection with filtrable viri or with bacilli. It is now well established that canine distemper is caused by a filtrable virus. 6 The naturally occurring disease is, however, invariably complicated by infection with B. bronchisepticus and frequently with other secondary invaders. These greatly increase the mortality in distemper, and might be susceptible to the influence of sulfanilamide and its derivatives. We undertook to test this hypothesis in a naturally occurring epizoötic of distemper at the Whitney Kennels, Orange, Connecticut.

All the dogs exhibited typical distemper symptoms, including temperature curves. Moreover, two ferrets, injected with a suspension of the spleens of dogs which died during the epizoötic, developed severe distemper in 9 days; while 7 young dogs of known distemper-free history, vaccinated with a formolized suspension of the same spleens, have remained immune to distemper during a subsequent well-controlled exposure in other kennels.

Our experimental treatment was begun 6 days after distemper was first noted in the kennel, and a number of bloodhounds had already succumbed. Twenty-nine animals in various stages of the disease were divided into 4 groups as comparable for the purpose as possible. Four dogs received sulfanilamide, 9 prontosil, 4 both drugs, and 12 dogs served as untreated controls. Prontosil was injected subcutaneously as a 2.5% solution in 0.6% sodium chloride, while sulfanilamide was administered orally in the form of tablets of “Prontylin”. In all cases the drugs were given 3 times daily in the dosages indicated below.

Neither prontosil nor sulfanilamide appeared to have any definite beneficial effect.