Observations on Fowl Paralysis (Neurolymphomatosis) ∗

Abstract

There are many reports on transmission experiments with fowl paralysis. Some workers have found a greater incidence of paralysis in chickens inoculated with tissues from paralyzed chickens than in uninoculated controls; e. g., Pappenheimer, Dunn and Seidlin 1 found paralysis in 25% of the inoculated chickens and 7% of the uninoculated controls. Similar but somewhat more successful were the transmission experiments of Dalling and Warrack. 2 Biely, Palmer and Asmundson 3 found that the incidence of paralysis depends on inherited susceptibility, and is not conspicuously influenced by inoculation with tissues from paralyzed chickens. There is no report of a readily transmissible strain of fowl paralysis and the relation of fowl paralysis to leukosis is not clearly defined in the literature.

Two transmissible strains of fowl paralysis have been isolated. Of one strain (Strain 5) 15 successful passages were made, of the other (Strain 6) 10 passages were made. Chart 1 shows only the results of inoculations of the first 5 passages of Strain 5.

The inoculations were made in most instances by intravenous injections of blood from paralyzed chickens, into healthy young chickens. The transmitting agent circulates in the blood of paralyzed chickens throughout the course of illness as shown by the following experiment:

No. 3946 was inoculated and showed beginning paralysis of legs and wings 42 days later. At this time three chickens were injected with 0.5 to 5 cc. of its blood. Two of these chickens developed paralysis and the third remained healthy. Eighteen days later the signs of paralysis were more conspicuous and another two chickens were injected with 0.5 to 5 cc. of blood of chicken No. 3946. Both of these chickens developed paralysis. Thirteen days later both extremities and one wing of No. 3946 were completely paralyzed, and the chicken was killed in extremis; two more chickens were injected with 0.5 cc. of its blood and both died with neurolymphomatosis.