AMPUTATION OF THE TEAT

Amputation of the rudimentary teat is performed in the young animal in order to make the udder more symmetrical. It is a simple operation requiring only the removal with sharp scissors, washing with a mild antiseptic and painting over with tincture of iodine. Care should be taken, however, not to get too deep and injure the glandular tissue.

Amputation of the teat is also performed in those cases where there is abscess formation in the cistern or the glandular tissue and the pus cannot be forced out through the swollen teat. General septicemia is likely to result if the pus is not drained out from that quarter and the best drainage can be obtained by amputating the teat up near the udder where the opening is large. That quarter can be of no further value so it can do no harm to remove the teat. The hemorrhage may be controlled by passing sutures through the skin and connective tissue as well as the lining membrane and back through to the skin. This makes a mattress suture and serves to enlarge the opening into the milk cistern. As many of these sutures may be used as necessary to control the hemorrhage from the vessels. The pus may then be washed out through the opening which is at the bottom of the abscess.

ABSCESSES BETWEEN GLANDULAR TISSUE

There is a condition which may be mistaken for abscess of the udder but which does not involve the glandular tissue. An abscess may form in the supermammary lymph gland or between the two halves of the udder and produce considerable swelling but the flow of milk is not decreased and the character of the milk is not changed. These abscesses may be opened on the posterior side of the udder or they sometimes point down between the two halves of the udder and may be opened there. After opening, care should be taken that pus is not discharged over the ends of the teats and the infection pass up the teat canal. It is well to disinfect the teats frequently to prevent this infection of the quarters.

GANGRENOUS MASTITIS

Gangrenous mastitis differs from the other forms in that the part becomes cold, pits upon pressure, is dark bluish in color, and the secretion of milk ceases. In its place there is a watery, flaky exudate. It is very common in the ewe and is often associated with stomatitis in the young lamb. Whether the mastitis is the cause of the stomatitis or the stomatitis the cause of the mastitis has not been definitely decided.

Gangrenous mastitis is quite likely to produce septicemia and early death of the animal. If only one quarter is involved the skin over the part may become necrotic, the glandular tissue slough out and the animal make a recovery.

About the only treatment for gangrenous mastitis is the removal of half or the whole of the udder. This may be done under local anesthesia by injections along the median line and then injecting about two inches laterally from the teats. If one prefers, general anesthesia of chloral or chloroform may be used.

The principal blood vessels of the udder are the external pudic arteries and veins which come down through the so-called inguinal canal and the milk vein which passes anteriorly along the belly.

An incision is made first on the median line, being careful to keep between the two halves of the udder. There are but few nerves and blood vessels on the median line and if the dissection is done carefully the amount of pain and hemorrhage is slight. After the two halves are divided you can work around the superior border of the gland with blunt scissors or the hand until the blood vessels are reached. These should be ligated securely and then severed. The separation can then be continued around the outside of the gland and downward toward the teats. If the external pudic artery has been ligated there is but little hemorrhage when the milk vein is severed; the latter may be easily ligated if thought necessary. A skin incision is then made about two inches laterally from the teats and the gland drops out. The cavity is packed and sutured. If the whole gland is involved, the other half is removed by the same procedure.

LOCAL ANESTHESIA*

H. J. MILKS

Department of Materia Medica and Small Animal Clinic

It is needless for me to discuss the advantages of using some kind of anesthesia in veterinary surgery because we all believe that any operation should be performed with as little discomfort to the patient as possible. The days of brutal surgery are over as far as veterinarians are concerned, yet the subject of anesthesia is being quite actively agitated by the humane societies and there is considerable probability that some legal regulations will follow their propaganda. Veterinarians individually and through the different societies should join this movement and render such aid as they can to secure legislation founded on just and humane principles.

While some of the laity go so far as to recommend anesthesia for all operations we must realize that some judgment is necessary because in many cases the anesthetic would cause more discomfort than the operation. Another point to bear in mind is that animals do not suffer from the fear or dread of an operation as do people, so that short operations like opening abscesses, hematomes, etc., cause no more pain than accidental wounds which are comparatively painless even in people. In a general way it may be said that all major operations should be done under anesthesia. In minor ones the question must be decided in each case.

General anesthesia is often a difficult problem for the veterinarian because he cannot always call upon the services of a skilled anesthetist. In many cases the nearest colleague lives miles away, in others the owners are unwilling to pay for the services of an extra man, and in all operations there are times when the entire attention of the surgeon is needed for the operation. Consequently if he can operate under local anesthesia it is to his advantage to do so.

Quite severe operations can be painlessly performed under local anesthesia, provided the anesthetic is properly used, but unless a careful technic is followed the results will not be satisfactory. While there always have been and probably always will be limits to local anesthesia these limits are being gradually removed as can be seen from the statement of a prominent surgeon to the effect that with the increasing experience and better training we shall some day have to establish indications for general anesthesia. It will then seem no more reasonable to anesthetize the whole body for a strictly local operation than to splint and bind it for injury to an extremity. On the other hand the anesthetic should equal the operation and where it is fairly evident that local measures will not suffice, general anesthesia should be adopted.

Published in the Cornell Veterinarian, April, 1922.

There are two principal groups of local anesthetics: 1. Those which cause anesthesia through the production of cold, as ethyl chloride and ether, and 2, those which have a specific action on the sensory nerves or their endings as represented by cocaine and its substitutes.

This paper will deal only with those of the second group. Cocaine was the first member of the group discovered and with few exceptions represents the actions of the others. It produces anesthesia when brought into contact with any part of a nerve from the endings to the posterior root so that its action may be obtained by application to mucous membranes, injection into or beneath the skin, into or near a nerve and into the spinal canal which is called spinal analgesia. Anesthesia is caused only in those parts distal to the site of injection and parts central to it are not affected. Cocaine has no action upon the unbroken skin and consequently its application to this organ is illogical.

Mucous membranes. Cocaine anesthetizes mucous membranes when in any way it is brought into contact with them. It is usually applied to these structures by painting or spraying a solution upon them but in some particular cases a few of the crystals may be dropped on the part or applied with a swab or finger. The surfaces most easily reached are the mucous membranes of .the mouth, nose, pharynx, larynx, rectum, anus, vagina, urethra and in special cases the bladder. It may also be used to anesthetize the mucous membrane of the stomach of small animals to prevent persistent vomiting or gastritis. Absorption from the various mucosae is rapid and large doses may cause the same toxic symptoms as when administered in any other way. We have had sufficient absorbed from the anus of a small puppy to cause very serious symptoms. Poisonous effects are also sometimes encountered during the roaring operation and furthermore Macht, working with dogs, quickly produced symptoms of poisoning with intravaginal injections.

Injection into or beneath the skin. The solution of the anesthetic may be injected into the skin (intradermally) or beneath the skin (subcutaneously) but the latter is almost entirely used in veterinary surgery. The uses of this method are too well known to repeat. The solution of anesthetic is usually injected in a fanshaped or circular manner around the tumor or other operative area. The site of the contemplated field should be completely encircled, else pain will be shown when unanesthetized areas are reached. After selecting the operating area, introduce the needle through the skin and inject a small amount, advancing the needle slowly as the injection is made. When the entire length of the needle has been reached, reintroduce it for subsequent injections in a line with the previous puncture but within an already anesthetized area. In this way there will be no pain except for the first puncture of the skin. After the whole area has been blocked off a few deep injections in different parts of the tissue may be of advantage.

Intraneural or perineural injections - Blocking the nerve, or conduction anesthesia. Injections into a nerve are known as endoneural, those near one as perineural. It does not seem necessary to inject directly into a nerve in order to anesthetize it as any one will realize who has blocked a nerve for neurectomy or the diagnosis of lameness. Blocking a nerve anesthetizes its whole distribution. Of course if a part is supplied by two or more nerves its whole supply must be blocked. Endoneural injections are quite painful but if preceded by local infiltration or perineural injections cause little if any pain.

The extremities offer the best illustrations of blocking the nerves in veterinary medicine. The fore leg may be anesthetized from a few inches above the knee by injections into or near the median and ulnar nerves but is not complete unless both are blocked. If it is desired only to anesthetize parts below the fetlock, injections into or near the two plantars give complete insensibility to parts below the injection. The two digital nerves may be blocked in the same manner for operations upon the foot but the results are not quite so satisfactory and there is no reason for not employing the plantars.

Similar results may be obtained in the hind leg. Thus, for complete anesthetization of the limb from a point beginning a few inches above the hock, the anterior and posterior tibial nerves. must be blocked. The results from anesthetization of the plantars and digitals correspond exactly with those of the fore leg. These are but a few illustrations or applications of nerve blocking. The method may be adopted for other parts if the general principles are observed. Bemis has worked out a technic for nerve blocking in dental work in horses. Dental surgeons are using this method for extraction and other work on people and some surgeons are advocating local anesthesia for abdominal work in people. The general method for abdominal work is to use infiltration anesthesia for the abdominal parietes and then block the nerve supply of the viscera after the incision has been made.

Spinal analgesia. This consists of injecting the anesthetic beneath the spinal meninges. It has some advocates in human surgery although most surgeons consider it dangerous. Stovaine or stovaine and strychnine are the agents usually employed. Spinal analgesia has not been popular in veterinary medicine.

Strengths of solution. For mucous membranes 2 to 10 per cent solutions may be used. Solutions stronger than 4 per cent are generally regarded as liable to erode or dry the cornea with subsequent ulceration, yet it has been our practice to anesthetize the eye with a few crystals of cocaine and we have never observed any bad effects from it. For subcutaneous use a 4 per cent solution is most popular, although weaker ones serve as well. It is much better to use large amounts of a weak solution than small amounts of a strong one because more tissue can be reached and at the same time the benefits of the mechanical anesthesia caused