264 DISEASES OF THE NERVOUS SYSTEM 



Cachexia Strumipriva. — When the thyroid gland is removed, there 

 appear certain pathological phenomena that are the opposite to Basedow's 

 disease. In two or three days after removal of the gland, sometimes a 

 later period, the extremities become stiff, clonic muscular twitching and 

 convulsive movements of the muscles of mastication are seen with trem- 

 bling, dyspnoea, acceleration of the heart, stupor, albumen in the urine, 

 emaciation and death in al)out a month. In cases where only one-half 

 of the gland was removed, there is no systemic disturbance, and the same 

 occurs if there should be secondary thyroid glands which perform the func- 

 tions of the extirpated gland. It is possible to prevent a fatal termina- 

 tion by injecting the animal with thyroid preparations, or administering 

 the preparation internally. 



Bronchocele, Hypertrophy of the Thyroid Gland, Goitre, Struma. 



As Morbus basedowii and Cachexia strumipriva belong to the group 

 of true diseases of the nerves, and Goitre has so many characteristics in 

 common with these diseases, it, will be classed with them. Goitre is a 

 chronic hypertrophy of the thyroid gland. It may either be a simple hy- 

 perplasia of the gland (struma simplex, struma parenchymatosa, struma 

 f ollicularis) or it may be more or less of a cystoid degeneration with the 

 formation of cavernous cysts, filled with gelatinous contents (struma 

 cystica) or it may be of a fibrous character, united by connective tissue 

 (struma fibrosa) , or an enlargement of the veins (struma vasculosa, struma 

 varicosa) or finally we may have a carcinomatous or even sarcomatous de- 

 generation of the gland (struma maligna). One observer found ossifica- 

 tion of the gland (struma ossea). In young dogs when the first named 

 condition, simple hyperplasia, is found to be soft, it is termed struma 

 mollis, and it is said to be congenital, while in older dogs we more fre- 

 Cjuently find the hard fibrous goitre and the struma carcinomata. In 

 Switzerland 30 to 40 per cent, of all dogs over middle age are affected 

 with goitre, and generally of the cancerous type. Goitrous degeneration 

 generally involves the whole gland, but in fibrous or the malignant types 

 ■\ve frequently find only one-half is affected, or may be unequally distributed 

 over both halves of the gland. Malignant forms frequently involve not 

 only the gland but also the surrounding tissues, affecting the lungs, called 

 struma aberrans. In two such cases, the enlargement was in the mediasti- 

 num in one, and in the other, in the middle third of the neck. These growths 

 Avhich originated from the secondary thyroid were cancerous in structure. 



Etiology and Clinical Symptoms. — The true cause or origin of goitre 

 has not as yet been defined: In man, horses and cattle, it is supposed to 

 be due to the effect of mountains and the absence of sun in deep valleys, or 

 to the soil (rich in calcium and magnesia, and the absence of the iodides), 

 but in the dog this cause can hardly be said to hold good, as in canines, it 



