J. COMPo PATH. 1962. VOL. 72. 245

EXPERIMENTAL LATHYRISM IN AYLESBURY DUCKLINGS

By

J. MALCOLM CAMERON*

Department of Pathology, Southern General Hospital, Glasgow

INTRODUCTION

Experimental lathyrism has been produced by a number of com­pounds, including semicarbazide hydrochloride, which when fed to weanling rats (Dasler, 1958; Milliser and Dasler, 1959; Ramamurti and Taylor, 1959) produces gross skeletal lesions identical to those originally produced by Gieger, Steenbock and Parsons (1933). Similar changes have been produced in chicks (Cameron, 1960, 1961), but to date ducklings have not been used for semicarbazide lathyrogenic experiments.

MATERIALS AND METHODS

Newly hatched Aylesbury ducklings were used. A control group of 10 ducklings was given a normal diet of chickens crumb and to the test group, also of 10 ducklings, o· 1 per cent of semicarbazide hydrochloride was added. The food and fresh tap water were unrestricted.

RESULTS

Although they appeared more resistant than chicks to experi­mental lathyrism, marked retardation in body growth was soon obvious. From the 14th day of feeding, the test animals were noted to have red, swollen, painful tibia-tarsal joints which had a very restricted passive and active range of movement. Eventually they were so crippled that they were walking on these joints as their feet did not touch the ground (Figs. I & 2). It was noted that when put in deep water they could not paddle, as they were partially paralysed. At the end of three weeks all the animals were killed with ether and by that time the paresis was more marked. The average weight of the control animals was 630 g. while that of the test was 190 g. This difference in size is well.seen when the animals are examined radio­logically (Fig. 3). Histological examination failed to reveal any pathological change in the aorta or skeleton. Examination of the spinal cord in the lumbar region, however, showed degeneration and fragmentation of the anterior motor horn cells with necrosis in the region of the neurons and a surrounding low grade inflammatory reaction (Figs. 4 & 5).

DISCUSSION

Paralysis of the rear legs is a phenomenon frequently seen in rats suffering from advanced experimental lathyrism. Dasler (1954)

*Present Address: University Department of Pathology, Glasgow Royal Infirmary, Glasgow.

EXPERIMENTAL LATHYRISM IN DUCKLINGS

interprets this as a result of mechanical injury to the spinal cord resulting from a severe kyphoscoliosis, while others (Vivanco and Diaz, 1951; Diaz, Vivanco, Ramos and Sanchez-Martin, 1957) ascribe it to a specific neurological effect of the toxin. The latter assumption is supported by the fact that the Spanish workers per­formed decompression laminectomies in rats before the appearance of kyphosis without any effect on the development of lameness and paralysis.

Milleser and Dasler (1959), and Cameron (1961) have noted additional symptoms which appear to be neurological in nature, namely a high incidence of paraphimosis, urinary retention and atony of the colon. Lalich, Barnett, Bird and Strong (1956) pro­duced leg paralysis with degeneration of the anterior motor neurons in the spinal cord in turkey poults, and Sanchez-Martin (1959) produced similar changes in rats after chronic parenteral adminis­tration of a lathyrogenic compound. The neurological changes pro­duced by semicarbazide in the Aylesbury ducklings and the absence of vertebral deformities show that the drug has a direct neurotoxic action.

CONCLUSIONS

Aylesbury ducklings on a diet containing o· 1 per cent. semi carb­azide developed partial leg paresis. At the end of three weeks there was degeneration of the anterior motor horn cells and necrosis of spinal motor neurons with a surrounding low grade inflammatory reaction.

ACKNOWLEDGMENTS

The author thanks Mr. G. F. Headden for technical and photomicro­graphic help, Mr. H. H. Bridges for the other photographs, and Miss H. Scott for secretarial assistance.

REFERENCES

Cameron, ]. M. (1960). IV Congreso Internac de Patlogia Clinica; Madrid; (1961). J. Path. Bact., 82,519.

Dasler, W. (1954), J. Nutrit, 53, 105; (1958). Proc. Soc. expo BioI. & Med., 97, 112.

Diaz, C. ]., Vivanco, F., Ramos, S., and Sanchez-Martin,]. A. (1957). Rev. din. Espan., 67, 295.

Geiger, B. ]., Steenbock, H., and Parsons, H. T. (1953). J. Nutr., 6, 417. Lalich, ]. ]., Barnett, B. D., Bird, H. R., and Strong, F. M. (1956).

Circulation, 14, 499. Milliser, R. V., and Dasler, W. (1959). A.M.A. Arch. Path., 67,427. Ramamurti, 0., and Taylor, H. E. (1959). J. Bone & Jt. Surg., 41B, 590. Sanchez-Martin,]. A. (1959). Exper. Med. & Surg., 17, 155. Viva nco, F., and Diaz, C. ]. (1951). Rev. din. Esp., 40, 157. Bull. Inst.

Med. Res., Madrid, 4, I.

[Receivedfor publication, January 16th, 1962]

J. MALCOLM CAMERON

Fig. I. Normal 3 week old duckling (X 1). Fig. 2. Three week old duckling fed semicarbazide. Note that the tibio-tarsal joint is

weight-bearing ( x i ). Fig. 3.

Radiograph of ducklings in Figs. I and 2 showing the marked difference In

size. Note subluxation of the right tibio-tarsal joint in the test animal (left). To face page 246

EXPERIMENTAL LATHYRISM IN DUCKLINGS

Fig. 4.

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Photomicrograph of anterior motor horn duckling. (Unna-Pappenheim X 300).

of the spinal cord in a normal

Fig. 5.

Photomicrograph showing degeneration and fragmentation of the anterior motor horn of the spinal cord of a duckling following administration of semi carbazide. Low grade inflammatory reaction, although present in other fields, is not shown in this figure. (Unna-Pappenheim x 300).