EXOSTOSIS OF THE MANDIBLE OF THE CHICKEN COMPLICATING EDEMA OF THE WATTLES GEORGE MILTON SMITH, M.D.1 (AnutomioaZ Laboratory, Yale School of Medicine, New Haven, Connecticut) During the past year opportunity has been afforded to examine eleven chickens (Rhode Island Reds) suffering from the effects of a disease known as edema of the wattles. As five of these birds showed a bony mass formed in the lower jaw, of possible interest to investigators of chicken tumors, it seemed advisable to give a short description of this condition. Edema of the wattles is a disease characterized by an extensive acute edematous inflammatory swelling of one or both wattles. The infection progresses rapidly during the first few days after onset to an abscess formation of varying extent. Later, with or without rupture of the abscess, the disease continues as a chronic. inflammatory process with a characteristic shrinking and fibrous induration of the wattle. Veenendaal (1) describes the disease as occurring in Europe, Australia, and America. Davis (2), who haa had an opportunity of studying epidemics occurring in the poultry farms of California, states that edema of the wattles is primarily a disease of male birds. It was observed, however, in both the mature male and female. He found the disease in the cockerel as young as four and a half months, hut not in the pullet of that age. In flocks having a total number of 2000 male birds, approximately 40 per cent of that number were affected. The mortality, as such, was not high; but diseased birds are often attacked and destroyed by normal males and in this way the death rate is greatly increased. From the pathologic standpoint the infection map involve both wattles, but more frequently one alone is diseased. Davis (2) describes the inflammatory mass in the beginning as forming a soft nodule in the wattle the size of a marble. The inflammation soon spreads and map result in an enormous distention of the wattle. By upward extension the opposite wattle may be involved and even the sinuses of the head. Davis (2) finds that on the third day the contents of the wattle show a cloudy, yellowish material, which by the sixth day has become thickened and caseated. The caseous material is not adherent to adjacent tissue, so that it map be removed in one mass after incision. A shrivelling of the wattle 1 Aided by the Blaseoin Fund, Yale University. 616
EXOSTOSIS OF THE MANDIBLE OF THE CHICKEN 617 to one third or one half the normal size follow8 soon after the acute stage. The period of actual sickness of the bird is estimated by Davis (2) as between two and three weeks. Veenendaal (1) states that cholera-like bacilli may be found in the edematous content of the wattle at the beginning of the sickness. He believes that the cause of the disease is B. avisepticus (Pasteureh avicida). Later in the course of the disease other organisms may be isolated, as B. coli, B. pyocyaneus, and staphylococci. References to the bacteriology and experimental transmission of the disease may be found in the papers of Veenendaal (l), Davis (Z), Panisset and Verge (3), and Gwatkin (4, 5, 6, 7). FIQ. 1. MALE BIRD (RHODE ISLAND RED) SAOWINQ SHRUNKEN WATTLE AS RESULT OF INFECTIOUS 1)ISEABE KNOWN A8 EDEMA OF THE WATTLIB Tlic probe poiuts to the area occupied by an exostosis of the mandible The birds examined in connection with the present paper were approximately two years old. All were in the subacute and chronic stages of the disease, the period of illness, as far as could be determined, extending up to about three months after the beginning of the infection. An exostosis of the lower jaw occurred in five birds, four males and one female. The new bone formation was in each instance unilateral, although in two birds with exostosis of the mandible both wattles were infected. The exostosis in all birds involved the lower parts of the surfaces of the thin, flattened mandible, at a point just porterior to the anterior attachment of the wattle (Fig. 1). Althongli apparently small in size, the newly
FIQ. 2. SPEOIMEN OF &fandible, MALE BXaD, WITH SMALL FLATTENED EXOSTOSIS OF TISSUES) (PEEPARED BY MACERATION FIQS. 3 AND 4. WAX-PLATE MODEL BASED ON BERIAL &hcboscopio BECTIOXS OT Exosmsxs or THE MANDIBLE IN CASES or EDEMA or WATTLEB, OCCWEINQ IN A FEMALE AND MALE BIRD RESPECWVELY 618
ESOSTOSIS OF THE MANDIBLE OF THE CHICKEN 619 formed bone may actually represent a density more than three times the thickness of the normal mandible. Figure 2 is a photograph of the lower jaw of a male bird, prepared by maceration of tissues. The exostosis is somewhat flattened, occupies the outer and under surfaces of the bone, and is directed downward and outward. It was embedded in a thick, fibrous, shrunken wattle, showing marked evidence of chronic inflammation. Figure 3 is a wax-plate model of an esostosis occurring in a hen, based on serial microscopic sections. The bony swelling is A A B C C B D E D FIO. 5. NEWLY FORMED Sw- FIO. 6. NEW BONE AND CARTI- PERIOETEAL BONE, CD, RADIATINO LAOE, CDE, GROWINO FRO116 SITE OF FROM NORMAL BONE OF MANDIBLE, OLD BONE OF MANDIBLE, AB; AREA OF 88; SECTION TAKEN FROM TEE MASS CAETILAOE AT D: SECTION OF MASS ILLUSTRATED IN MODEL (m0. 3) REPREEENTED IN MODEL (ma. 4) somewhat fusiform and tapers down anteriorly and posteriorly to the normal dimensions of the mandible. A transverse microscopic section of this mass is shown in Figure 5. New subperiosteal bone (C) is laid down in fine trabeculae radiating chiefly from the lower and outer aspects of the old bone (AR). Figure 4 is another model based on serial microscopic sections of a bony mass found in the mandible of a male bird. This mass was larger than that of the female bird, very irregular with several projecting bosses and partly cartilaginous. A transverse microscopic section of the lesion is seen in Figure 6. The new bone (CDE) contains an area of cartilage at the point indicated at D. The periosteum is thickened. Tissues of the wattles were densely fibrous, with thickened blood vessels and scattered collections of lymphoid cells.
620 GEORGE MILTON SMITH In a study of serial sections of the bony lesions in four cases with exostosis, it was observed that a hyperplasia of the lymphatic tissue was present in the salivary glands overlying and in close re- 1at.ion to the affected bone. A small field of gland tissue is shown in Figure 7, illustrating this hyperplasia. Large collections of lymphoid cells, covered by a single layer of cuboidal epithelium, infiltrate areas of tubules. Whether the infection of salivary gland tissue is primary or secondary cannot be determined from the Flu. 7. I~YPERPLASIA OF LYMPHATIC TISSUE OF SALIVABY GLAND NEAR EXOSTOSIS OF TEE MANIIIBI~E AN present study. The fact, however, that infection of the salivary glands has occurred suggestr that a portal of entry for infection of the wattle and mandible may exist in these glandular structures in the floor of the mouth. SUMMUY Five instances of exostosis of the mandible were studied occurring among eleven chickens (Rhode Island Reds) diseased with an infection known as edema of the wattles. One exostosis contained, also, cartilage. Hyperplasitt of lymphatic tissue in adjacent salivary glands suggests that these glandular structures possibly represent a portal of entry for organisms infecting the wattle and mandible, with resulting formation of new bone.
EXOSTOSIS OF THE MANDIBLE OF THE CHICKEN 62 1 REFERENCES 1. VEENENDAAL, H. : Handbuch der Oefliigel Krankheiten der Geflugelzucht, pp. 502-503, Stuttgart, 1929. 2. DAVIS, D. L.: Edema of the wattles in cockerels, J. Am. Veterinary Med. Assoc. 66: 587-596, 1925. 3. PANISSET, L., AND VEME, J.: Oedeme des barbillons chez le coq, Rev. gkn. (1. mkd. vkt. 34: 371-372, 1925. 4. OWATKIN, RONALD: Edema of the wattles, Ontario Dept. of Agriculture, Report of the Ontario Veterinary College, 1924, pp. 6G-68. 5. OWATEIN, RONALD: Edema of the Wattles, Ontario Dept. of Agriculture, Bulletin 305, pp. 14-15, 1924. 6. GWATKIN, RONALD: Subacute infections in fowl due to Pa.deurellu auicida, Report of the Ontario Veterinary College, 1928, pp. 55-58, Toronto. 7. GWATKIN, RONALD : Further notes on Pusteurella avicicida, Ontario Dept. of Agriculture, Report of the Ontario Veterinary College, 1929, pp. 56-61, Toronto.