276 CLINICAL VETERINARY MEDICINE AND SURGERY. 



Even the ophthalmic artery is often dilated. The membranes of 

 the eye, particularly the choroid and retina, are hypersemic ; the retinal 

 arteries and veins have been found dilated, the retina infiltrated with 

 blood and pigmented, the choroid strongly injected. 



Other lesions may exist in the principal viscera. The stomach, 

 intestine, liver, spleen, kidneys, and brain are sometimes hyperasmic. 

 In many cases hypertrophic cirrhosis has been noted ; in others renal 

 lesions, similar to those of Bright's disease. Such lesions, however, 

 are of secondary importance, for in most cases the viscera show 

 nothing special. 



Exophthalmic goitre is characterised by very special features, and 

 forms a well-defined condition. But what is its nature ? 



One theory regards it as a disease of nutrition, a cachexia. In the 

 obstinate and persistent form, in that which kills, the blood at length 

 undergoes change, nutrition languishes, anaemia sets in, and becomes 

 more or less rapidly accentuated. In the case I related nutrition was 

 evidently affected, wasting and visible weakness were extreme ; oedema 

 had occurred in the lower parts of the body, diarrhoea was permanent, 

 and finally, numerous purulent centres developed in the subcutaneous 

 connective tissue of different regions. In this form death generally 

 occurs from progress of the cachexia, though the nutritive change is 

 only an effect and not a cause of the disease. It is not seen in trifling 

 cases which develop slowly, remain stationary, or diminish. The 

 disease itself is therefore not a cachexia. 



Many persons still regard the disease as of nervous origin, and 

 consider it principally due to causes acting on the brain, such as severe 

 nervous excitement, depressing circumstances, or violent emotion. 

 Physiology, they say, has shown that local congestions may be caused 

 by purely nervous impulses. The congestive phenomena occurring in 

 the thyroid gland and in the eyes are said to result from " nervous 

 paroxysms," which, through the medium of the sympathetic, provoke 

 disturbance of circulation. They thus claim to prove that the three 

 main S3'mptoms result from one cause, that is to say, from primary 

 disturbance in the brain. They describe the disease as a " cerebro- 

 medullary disease, a congestive neurosis, w^iich progresses by 

 paroxysms." 



At the present day the tendency is to regard it as an auto-intoxica- 

 tion, produced by excessive activity or functional disturbance of the 

 thyroid gland itself. Certain symptoms, or even the entire group of 

 symptoms, peculiar to exophthalmic goitre can easily be produced in 

 animals b}- injecting certain toxic substances. M. Bouchard has 



