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TUMOURS OF THE SALIVARY GLANDS. 
(6) TUMOURS OF THE SALIVARY GLANDS. 
The nature of new growths occurring in the salivary glands of 
animals has not hitherto been fully or sufficiently investigated. In 
man, connective tissue tumours, such as sarcomata, fibromata, and 
enchondromata, are most frequent. The tumours so common in grey 
horses are usually melano-sarcomata, and in cattle actinomycosis. As 
little is known of the causes of these new growths as of other tumours. 
Cohnhein refers the development of enchondroma to cartilaginous 
fragments of the branchial arch. Actinomycosis depends on infection. 
Their sharply defined appearance, slow development, and the absence 
of inflammatory symptoms, render the diagnosis of tumours compara¬ 
tively easy. Their precise nature, however, can usually only be deter¬ 
mined by microscopical examination. Actinomycosis will be referred 
to later. 
Treatment must clearly be of an operative character. Simple, sharply 
defined tumours can easily be removed with knife or scissors. By 
careful suturing and appropriate treatment of the wound, it is easy to 
avoid producing salivary fistulae. Large and extended tumours may 
necessitate removal of the entire gland. Total extirpation of the parotid 
is attended with danger, and therefore should only be resolved on in 
case of pressing necessity, as when dyspnoea is produced by the tumour, 
or when exceptionally valuable animals, which cannot be slaughtered, 
have to be dealt with. Leblanc is said to have first performed this 
operation, and to have employed it both for removal of tumours and for 
the cure of salivary fistulse. Important vessels and nerves—the carotid 
and jugular, with their branches—and the great nerve stems (nervus 
facialis) must be avoided. Provision must, however, be made for 
ligaturing vessels. The operating place should be well lighted, and 
antiseptic precautions are, of course, necessary. 
The skin is divided from the upper to the lower end of the parotid, and 
where adherent to the tumour, is removed. In large animals a second 
incision is usually carried in a backward direction perpendicular to the 
former, and starting from about its centre. The fascia underlying the 
skin is divided and separated as far as possible from the parotid. The 
gland, thus exposed, is now separated from its surroundings, beginning 
at the lower end, so that large bleeding vessels may be more easily 
dealt with. For the same purpose a thread may be passed around the 
carotid, which, in case of need, can be used as a ligature, though the pre¬ 
caution is almost unnecessary if two or three torsion forceps are at hand. 
As the recurrent nerve may easily be injured, it is better, in valuable 
horses, to avoid exposing the carotid. The gland should as far as possible 
be separated with blunt instruments, assisted by the fingers. Vessels 
