E. Cotchin

Mammary neoplasms of the bitch.

n In this paper, the interrelationships of the neoplasms of the canine mammary gland are investigated. These neoplasms are a group of tumors of a great variety of histological structure and sometimes of uncertain histogenesis. Particular attention is given to the histogenesis of the mucoid, cartilaginous, and bony elements. From 1950-56, a macroscopic and histological examination of mammary neoplasms from 424 bitches (2-17 years of age) was made. The tumors from 381 bitches were removed surgically while the others came from 43 bitches who were examined postmortem. Of the 160 tumors whose location was recorded, 105 occurred in the 2 hinder glands, 19 in the middle glands, and 46 in one or another of the 2 anterior glands. 186 of the 424 bitches bore malignant mammary tumors (87 carcinomas, 73 sarcomas, 27 complex malignant tumors) and 249 had benign tumors (19 simple and 230 complex). 40 of the benign complex tumors contained bone, an additional 63 contained cartilage but no bone, and 67 showed mucoid tissue but no cartilage or bone. It is suggested that there is a predominant proliferation of myoepithelial cells which tend to become embedded in a mucoid or chondroid matrix. The bone in the tumors appears to be formed by endochondral ossification of preformed cartilage, or by intramembranous ossification in the connective tissue of the tumor. Metastases were present in 41 of the 424 bitches.n

Corynebacterium Equi in the Submaxillary Lymph Nodes of Swine

Summary The high loads were found to have the following main causes, which occured together in many work situations: 1. C. equi was isolated in eight cases from the supposedly tuberculous submaxillary lymph nodes of 86 pigs, being associated in five cases with tubercle bacilli. 2. From a series of apparently normal submaxillary lymph nodes from 50 pigs, C. equi was recovered in one instance. 3. Oral and intravenous administration of living suspensions of C. equi produced no observable lesions in swine. Subcutaneous inoculation led to local abscess formation. 4. Evidence is presented indicating that C. equi probably has no aetiological relationship to tuberculous-like lesions in the submaxillary lymph-nodes of swine.

Studies On Corynebacterium Renale: II. The Experimental Pathogenicity for Mice

Summary The sequence of events occurring in the kidneys which follows the intravenous inoculation of mice with C. renale has been studied histologically and bacteriologically. It has been shown that given in adequate dosage C. renale may cause the death of a proportion of mice and induce a pyelonephritis. Similar lesions may be found in some mice which survive. The changes in the kidneys are associated with actual multiplication of bacteria in the kidney tissue and the typical lesion occurs most frequently in the mice inoculated intravenously. Other routes of injection were tried and lesions were found in one only of those mice inoculated intraperitoneally, in one only given C. renale per vaginam, and in none of those inoculated subcutaneously. Although it is not suggested that these phenomena are peculiar to C. renale, these studies should form a useful basis for an extended investigation into C. renale and the disease it produces. A brief record is given of the effect C. renale produces after intravenous inoculation of guinea-pigs and rabbits and of the reaction in the developing egg.

Streptococcal endocarditis in a pig following intravenous injection of an organism from a natural case

Summary Two pigs were given a single intravenous dose of an alphahaemolytic streptococcus recovered from a natural case of porcine endocarditis, and two were given repeated intravenous doses. Lesions of endocarditis were found macroscopically in the first, and histologically in the second pig of the pair receiving the single doses. Arthritis was found in one pig of each pair.

Tubercle Bacilli in Lesions of the Submaxillary Lymph Nodes of Swine

Summary 1. From the submaxillary lymph nodes of 86 pigs, strains of tubercle bacilli were isolated in 68 cases. 2. Of these strains, 12 were of the avian type and a further 10 probably of the avian type, while 46 were of the mammalian, and probably bovine, type. l

Bacillus actinoides: Its association with pneumonia in cattle and its relationship to Streptobacillus moniliformis

Summary Twenty-six cases of bovine pneumonia, mainly in calves from different parts of England, were investigated. A pleomorphic organism closely resembling B. actinoides was present in 14 cases; it was isolated in pure culture from two and in mixed culture from twelve. In two cases the organism was found in adult bovines and in the other cases in calves. The organism proved to be identical with that isolated by Blakemore (1945) and very similar to that originally described by Smith (1918) . A study was made of its relationship with strains of Streptobacillus moniliformis isolated from mice and guinea-pigs. It is concluded that the two organisms are distinct species to be placed in the same group. The successful reproduction of the typical broncho-pneumonia in one goat by intratracheal inoculation of a suspension from a pneumonic lung suggests the possibility of using goats in further studies of the pathogenicity of the organism if calves are not available.

Studies on Corynebacterium Renale: III: Penicillin Treatment of Experimentally Infected Mice

Summary Strains of C. renale vary in their sensitivity in vitro to penicillin. Penicillin is of value in the treatment of experimentally produced C. renale pyelonephritis in mice when given early in the disease.

A Radiographic Study of the Normal Development of the Hock Joint of the Fowl

Summary The development of the normal hock joint of the fowl from. the age of four weeks onwards has been followed by means of radiographs.

Observations on Perosis Occurring in Chicks Used for Vitamin D3 Assay

Summary Perosis was found in 107 out of 5,720 chieks used for the assay of vitamin D 3 . An account is given of radiographic and histological studies of the early changes in the hock joint in perosis, together with a brief description of the symptoms and macroscopic features of the condition.

Studies on Corynebacterium renale. IV. Renal lesions in mice produced by other bacteria.

Summary The intravenous injection of mice with living suspensions of C. ovis, C. pyogenes, Bact. equirulis, Bact. colt and Staph. aureus produced renal lesions in a variable proportion of animals. These lesions differed in distribution from those which were observed after the similar administration of living suspensions of C. renale , as they were not confined to the medulla but were found also in the cortex. It is therefore concluded that, as far as our observations extend, the distribution of the lesions produced by C. renale are specific for that bacterium.