A study of diseases of the skin of domestic animals

McCusker, Hugh Brian (1967) A study of diseases of the skin of domestic animals. PhD thesis, University of Glasgow.

Abstract

Section I: A study of the histology and histochemistry of skin samples from sixteen body areas of the cat gave results which in general were in agreement with those of previous workers. However, phospholipids were not detected in the sebaceous glands of the cat and cholesterol was absent from the epidermis. In addition, contrary to previous reports, the guard hair was found to erupt from the epidermis through a single opening. The structure and staining affinities of the sweat glands conformed closely to that described by Montagna (1962) and Munger (1962). An Investigation of the histamine-mast cell content of feline skin showed that the mast cells were numerous in the upper part of the dermis and that there was an associated high level of histamine in the tissue. The histamine-mast cell values were similar to those of Riley (1959). The staining characteristics of the mast cell in the cat differed from those of the dog in that adult cells of this type were PAS-positive and metachromatic when stained by toluidine blue. In contrast, canine mast cells were PAS-negative and metachromatic with toluidine blue. The results of differential staining of mast-cell granules by other techniques is included in the text. In the third part of this section the response of normal skin and its historaine-mast cell component to parenteral administration of corticosteroids was studied. It was found that administration of cortisone acetate produced easily recognised changes in the epithelial components vis. thinning of the epidermis and atrophy of the sweat and sebaceous glands. In addition a few mast cells showed evidence of degranulation and vacuolation of the cytoplasm hut there was no significant change in histamine-mast dell values between treated and control animals. However, administration of beta-methasone over a period of fourteen days at a rate of 3 mg. dally caused more severe degranulation and vacuolation of the mast cells and a significant fall in the histamine content of the skin. Section II: In this section miliary eczema, a common skin condition of cats, was described. The aetiology of the disease is obscure and in a series of fifty oats no precise correlation could be made between the incidence of the disease, the sex of the animal and the presence or absence of ectoparasites. Vesiculation was hot a feature of eozema in the cat as it is in man. The predominant changes on histological examination in the acute phase were fibrinous exudation, a heavy neutrophil infiltration and ulceration and erosion of the epidermis. Intercellular oedema and thickening of the epidermis were also present. In the dermis there was separation of collagen fibres by oedematous fluid and a perivascular mononuclear reaction. In chronic eczema the main changes in the epidermis were acanthosis and parakeratosis. The mast cell population of the upper dermis at this stage was markedly increased and there was a four-fold rise in skin-histamine values. The effect of betamethasone therapy on miliary eczema was investigated. While a pronounced clinical improvement was noted in nine of ten animals there was no appreciable alteration in the mast cell population of the skin. A decrease in the amount of histamine in the skin of the cats in the group did occur but was of doubtful significance. Section III: A series of experiments was carried out in order to study the precipitin response of oats immunized by various methods with bovine serum albumin, bovine gamma globulin and heterologous sera. Procedures used included antigen elimination, immunodiffusion, Immunoelectrophoresis and quantitative precipitation. Cutaneous hypersensitivity to bovine serum proteins was elicited in the cat by appropriate immunization procedures. In time course and histological features the reactions took the form of either local cutaneous anaphylaxis or an Arthus reaction. The best results were obtained by the use of bovine normal serum and bovine gamma globulin as antigens while the results were negative with bovine aerum albumin. Passive cutaneous anaphylaxis reactions wore demonstrated in the guinea- pig using eat antiaern to bovine normal serum and bovine gamma globulin but in normal oats only with antiserum to bovine gamma globulin could sensitivity be transferred. General anaphylaxis was produced in two cats in response to bovine serum proteins the main clinical features of which wore severe respiratory embarrassment and general collapse. Pulmonary emphysema, haemorrhage and oedema were the principal post-mortem findings; histological examination showed the arterioles to be packed with leucocytes and the lung tissue to be devoid of mast cells. Three observations suggest that the lung is the "shook organ" in the cat.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Advisers: J W Emelie; R SF Campbell
• Keywords: Veterinary science
• Date of Award: 1967
• Depositing User: Enlighten Team
• Unique ID: glathesis:1967-72606
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 11 Jun 2019 11:06
• Last Modified: 11 Jun 2019 11:06
• URI: https://theses.gla.ac.uk/id/eprint/72606