Veterinary post-mortem technic

Preface

The scientific study of jjathology without proper postmortem technic is impossible. Before a pathologic lesion can be studied it must be brought to light. To avoid the oversight of some obscure though important disease process an exact and painstaking system of technic must be developed. Technic is, in fact, the foundation of the science of patholog}^ and therefore demands deep study and much actual practice.

This book is written in an endeavor to fill a gap in the American veterinary literature which has long been felt by the writer in teaching post-mortem pathology. It is with the earnest hope that it may help those who do make postmortem examinations, encourage those who should but do not perform autopsies, and that it may facilitate the inclusion of the subject post-mortem pathology in the cun'iculi of other schools of veterinary medicine.

The illustrations of technical methods in the text were prepared from original photographs of fresh specimens instead of line drawings. Good photographs more forcibly portray to the student mind the reality of the subject, and establish a closer personal association with the actual work. They provide an unexaggerated object for the student to attain to, and an encouraging stimulus to his best efforts.

Koch, E. A. Benbrook, C. C. Whitney, Herbert Lienhart, H. ISl. Martin, and ]Mr. Albert Herbert for their assistance in preparing the photographs, and to Doctors John Reichel, Fred Bourner, and C. S. Rockwell, and J. B. Lippincott Company for material used in illustrating the technic on cattle and hogs.

Walter J. Crockee

PlIILADELPHIA, PA.

l^eceniber, 1917

Contents

CHAPTER PAGE

I. General Considerations 1

Definition, Complete Autopsy, Incomplete Autopsy, Object, Authority, Time, Date, Light and Weather, Place, Clinical History, Destruction of Animal, Description of Cadaver, Witnesses, Dress, Care of Instruments, Care of Hands, Notes, Specimens for Laboratory Examination, Express Companies' Regulations, Mailing and Parcel Post Regulations, Diseased Tissues in the Mails, Milk or Urine.

Chapter I General Considerations

Definition. — The systematic exposure and critical examination of a cadaver for the study of pathologic changes in any or all their relations and extent, and in many cases with the object of determining the cause of death, may be called a post, postmortem, autopsy, necropsy, necroscopy, mortopsy, sectio-anatomica, sectio-cadaveris or section. Obduction means a medicolegal postmortem which is not different from an ordinary autopsy, except that the results are used in court to settle a dispute concerning cause of death or accident, or duration of some pathologic condition to establish the fact that the animal was diseased or unsound prior to the date of purchase. A cosmetic postmortem is one conducted with the very least disfigurement, and in which the parts are replaced, and the cadaver sewed together, washed, the hair dried, and in general made to appear as nearly intact as possible. It is usually accomplished by making an incision on the median line of the ventral side from the xiphoid cartilage to the pubis, incising the diaphragm and eviscerating the thorax and abdomen. The organs are then compressed to free them from fluid, replaced, packed tight with paper, cloths, cotton or oakum, and the incision closed with a baseball stitch.

Complete Autopsy. — A complete autopsy must be effectuated in cases where the cause of death is not known. Every detail of technic must be completed and every organ or part carefully examineii to make j^ossible a correct postmortem diagnosis.

Incomplete Autopsy. — A short autopsy (removal of front leg and side of the large animal) may be done w^hen the piu'pose of the postmortem is to corroborate a positive laboratory or clinical diagnosis. Should the trouble not be disclosed, one must continue the autopsy to completion.

Object.^ — In no other branch of veterinary science is there demanded more sound knowledge, accurate scientific and systematic technic, and keen powers of observation, discrimination and interpretation.

In many cases the purpose of an autopsy is to establish the cause of death or the length of time a disease process has existed, or its area of anatomical distribution. The information obtained may be used in legal proceedings and should therefore be exact and complete in every detail.

The practitioner should, whenever possible, autopsy every case lost. Through such study of post-mortem pathology he imquestionably comes to a more thorough knowledge of the interpretation of symptoms, the efficiency and proper selection of remedies, and in general, becomes a better diagnostician and safer therapist. He may frequently desire to corroborate his own or another's clinical diagnosis and justify the treatment used, on his own account or as a consultant, by conducting an autopsy in the owner's presence. Systematic tedmic and sound logic in such cases do much toward the establishment of an enduring reputation, and one is assured of a greater pecuniarj^ return than should he neglect such opportunities of study and demonstration of morbid processes. In addition it affords an excellent opportunity for the review of anatomy, and in animals killed by accident, for the study of the physiological character of the various parts, which better enables one to differentiate the normal, pathologic and post-mortem decomposed tissues. The practice of surgical operations on cadavers after an autopsy is commendable and tends to increase one's efficiency in surgery.

In many instances the services of State livestock sanitary boards have been sought to determine the specificity of a disease supposed to be present on premises where three or four animals died within a short length of time. Frequently, in these instances, a knowledge of systematic post-mortem technic would have shown the veterinary physician that the trouble in each animal was purely local and very remote from the nature of a communicable disease.

State veterinaries, commissioners of health, agents of State boards of health. State livestock sanitary boards, government field veterinarians, and laboratory pathologists should be thoroughly trained in post-mortem technic, as their duties may necessitate instruction, supervision, or actuation of autopsy of animals dead of contagious or infectious diseases, for the purpose of diagnosis, scientific research, or food sanitation.

Clinicians should follow cases which terminate fatally to the post-mortem table and there review the study of those morbid processes which they were endeavoring to correct. This strengthens their ability in diagnosis and treatment and makes them better teachers.

Regular systematic postmortems should be made and accurately recorded at every veterinary school and hospital for the accumulation of valuable data which are of great scientific and geographical interest.

Autopsy work for students in schools of veterinary medicine is indispensable. The student should first have a thorough training in general pathology and special pathology, the latter particularly studied from the standpoint of the pathology of the organs and systems of organs, as well as the contagious and infectious diseases. Too few of our profession have had a firm foundation laid in the pathology of the various systems of organs. With a good theoretical knowledge of the morbid processes of which an organ or part is susceptible, one may be, and often is, totally unable to recognize the conditions when confronted with them. Pathology taught at the autopsy table trains the student, as he can be trained in no other way, in distinguishing between the normal, pathological and postmortem decomposed tissues. It stimulates deep thinking, \ logical reasoning power, and the development of a keen mind. Post-mortem changes have, all too frequently, been accused of constituting pathologic changes which have never existed in the subject. Students and graduates not infrequently fail to identify various parts of organs or are unable to distinguish one organ from another, yet may speak most learnedly of the Malpighian corpuscles and the islands of Langerhans.

Ample opportunity is had in most of our veterinary schools for regular systematic courses in post-mortem pathology. The writer has taught the sub j ect in this manner for a nmnber of years and is thoroughly convinced that in no other way can a student be taught pathology with enough proficiency to enable him to consistently recognize, accurately describe, and logically give the pathogenesis of the many various morbid processes. Illustrations, museum specimens, word pictures, and discussions are valuable accessories, but when not used in conjunction with regular systematic post-mortem study they fail in their purpose, because, to the student mind, they are not real and they lack the association of other tissues and those processes which are primary and secondary to them. The teaching of pathology by lectures without systematic study at the post-mortem table would be no less impressive, convincing, or efficient than lectures in medicine without clinic, or the theory of surgery without surgery practicum. At the post-mortem table a j^atliologic process gives the student a full appreciation of its true significance. The presence of the cadaver itself bears mute witness of the malignancy of many morbid processes. The primary lesion and many of the subsequently changed tissues when handled, inspected and discussed in their full relationships so interest the student that he is much less apt to forget, and exercise of the functions of seeing, hearing, smelling and feeling during the examination and description of diseased tissues in their proper environment establishes an acquaintanceship so close that one experiences little difficulty in recognizing the processes when next met. Scientific systematic post-mortem technic should be used whenever possible to facilitate the teaching of pathology at the post-mortem table.

Authority. — Secure proper authority for conducting an autopsy before it is begun. State laws may prohibit the post-mortem examination of animals dead of communicable diseases, or place certain restrictions upon such examinations. Some owners object to an autopsy being performed upon an animal, especially if it has been a pet.

Time, Date, Light and Weather. — Perform the autopsy in daylight and as soon after the death of the animal as possible. Colors cannot be properly determined in artificial light, and post-mortem decomposition sets in very soon after death, especially in hot weather. One should carefully compare the time and date of death or destruction with that of autopsy, as it may aid in determining the cause of certain tissue changes.

Place. — Choose the cleanest place available in which to perform an autopsj^ The cadaver of a large animal should be placed upon a table 2I/2 feet high when convenient. In the field where this is impossible remove the cadaver from the stable in order to secure the best possible light and to prevent littering the premises. Carefully consider the place of death and that of autopsy, as it may assist in accounting for conditions of the hair, skin and extremities, induced by dragging or handling the animal after death. In rural places the carcass is sometimes moved on a stoneboat or dragged on its side to the place of burial or incineration before autopsy. In cities cadavers are removed to reduction plants soon after death. Secure floor space near a door or window where the most light is to be had, have the floor cleaned, and then work rapidly, when doing an autopsy at a reduction plant.

Clinical History. — Secure clinical history, diagnosis and treatment of the case and mode of termination of the animal. Know, if possible, whether death occurred quietly or if the animal struggled during the agonal stages, and finally the position of the patient at the time of death. Medicaments are sometimes responsible for alterations of tissues. Autopsy findings are sometimes absolutely valueless in establishing a diagnosis without the history. Body fluids gravitate to the side upon which the animal lies soon after death.

GE>^ERAL CONSIDERATIONS 7

Destruction of Animajl. — When an animal is to be destroyed, especially for autopsy purposes, it should be so dispatched as to least harm those parts which are of most probable interest for post-mortem examination. When inflammatory processes are anticipated, the animal should not be bled to death. It should not be shot or struck in the head if the brain is likely to be of especial interest. It should not be shot, or injected intrathoracically with strychnine if the heart or limgs are thought to be affected. Large animals usually may be most conveniently pithed or given strychnine intravenously. Small animals may be destroyed with chloroform, ether, illuminating gas, or strychnine subcutaneously. One should secure the name and address of persons who authorized, effectuated, and witnessed the destruction of the animal.

DescriptiOjST of Cadaver. — Take an accurate detailed description of the cadaver before the autopsy is begun, as the information may be needed in court proceedings. One should consider species, breed, sex, age, color, markings, size, weight, tag number, and clinic number.

Witnesses. — Secure witnesses to the autopsy, when convenient, for use in cases of probable forensic involvement. Witnesses of an autopsy should be ready to render any assistance possible. They should refrain from handling specimens until after the autopsist has finished his examination, and then only with his permission. To keep up a rapid fire of questions or to audibly volunteer one's opinion concerning the pathology^ of each lesion, cause of death and the final diagnosis is a decided breach of courtesy. One's opinion should be given only when asked and then guardedly, unless one has had special training in pathology.

Dress. — Dress properly. During regular autopsy work for students in a post-mortem room a complete change of clothes should be made when possible. Lockers should be provided for student use adjacent to the autopsy room.

FiQ. 1. — At left, white coat, rubber sleeves, apron and boots. At right, rubber gown and boots.

This prevents the street clothes from acquiring an odor which is most uncomfortable, both to the wearer and those with whom he may come in contact. One may wear a long white coat or a suit of overalls, and a rubber apron which covers the front from a few inches below the chin to a few inches above the shoe tops, and rubber half sleeves. Better still is a rubber gown which slips on over the head, reaches nearly to the ankles, buttons at the collar, and has a drawstring at the neck (Fig. 1). Rubber boots complete this outfit, which is ideal for an instructor and students working with the cadaver on a table. When the cadaver is on the floor or ground, overalls and a rubber apron which has a loop around the neck and strings that tie around the waist are preferable, as the skirt of a white coat or rubber gown gets in the way when one leans forward to work. For small animals, a white coat and rubber apron are sufficient.

Care of Instruments. — Keep instruments sharp. Always place an instrument upon a table, box, board or towel close to the cadaver when not in use durinii' an autopsy, so that it may be readily found when again needed. Do not stick a knife into the cadaver's flesh or place it in a body cavity, as it may later cause injury to the autopsist. After completing an autopsy upon an animal dead of any contagious or infectious disease, the instruments must be sterilized before being put away, and under no circumstances should an autopsy be conducted upon another animal with the same instruments until after they have been sterilized. If this were not done they might be a source of infection to the technician, and would possibly contaminate tissues of the second cadaver which, when examined bacteriologically, might lead to confusing results.

Care of Hands. — Remove rings from the fingers before beginning an autopsy, as they may become a source of infection and are sometimes difficult to clean and sterilize. One may smear the hands with carbolized petrolatum to close the pores of the skin before starting an autopsy when

10 VETERINARY TOST-MORTEM TECHNIC

rubber gloves are not worn. Wear rubber gloves when diseases communicable to man are suspected.

During an autopsy wash the hands frequently enough to prevent the accumulation of blood and filth. It should be remembered, however, that one should not hesitate to touch any tissue the consistency of which should be known simply because it has a repulsive appearance. Neither should one waste time cleaning and manicuring his nails diu'ing an autopsy period. The nails, except that of the right thumb, should be trimmed before an autopsy is begun. The thumb nail is used in stripping the capsule from an organ, except when rubber gloves are worn, when the sharp edge of a knife is emjjloyed. One should not be foolhardy and carelessly expose himself to danger by handling suspicious material without rubber gloves ( glanders, etc. ) .

In case of an abrasion or cut contracted during the performance of an autopsy, one should stop immediately and wash the wound with warm water and soap, and then apply an antiseptic such as concentrated iodine, 5 per cent, lysol, or 1-1000 mercury bichloride solution, then apply collodion or celloidin dissolved in equal parts of ether and alcohol, bandage, and put on a rubber finger stall or rubber glove and continue the autopsy. If this is not convenient one should wash and antisepticize the wound and direct another person in the performance of the autopsy until it is completed, thus taking no further chances of becoming infected.

Notes. — One must make notes of the post-mortem findings immediately after the completion of the autopsy or dictate them to another person (amanuensis) while conducting the autopsy. One should not depend upon his memory for the post-mortem protocol.

Specimens for Laboratory Examination. — For preservation of tissues for microscopical examination small bottles containing fixatives, such as formalin 8 per cent., concentrated sublimate of mercury, Muller's fluid, or 95 per cent, alcohol, should be taken to the place of autopsy and the tissue placed in the fixative immediately. The bottle should be packed in a wooden box with absorbent cotton ( tumors, actinomycosis, etc. ) .

Material for bacteriological examination may be used at the autopsy. Tubes of sterile bouillon may be taken to the cadaver and small pieces of diseased tissue dropped into the fluid with very little danger of contamination if the scissors have been sterilized and kept in paper wrapping or the scalpels sterilized and kept in test-tubes. If this is not convenient, place the tissue in a sterile, liquid-tight rubberstoppered, wide-mouthed bottle or fruit jar and then pack in ice and sawdust. The same holds true for specimens to be examined histologically when fixatives cannot be secured.

When packing specimens for shipment to a laboratory for examination keep the following points in mind : "

1. That the specimen should reach the laboratory in tlie shortest possible time.

2. That it should reach the laboratory, as nearly as possible, in the same condition as when removed from the cadaver or animal.

3. That it should be so packed as to incur the least possibility of contamination or decomposition.

4. That it should be so packed as to render the least chance of breakage of glass container, leakage of infectious fluid, or escape of unpleasant odor.

5. That ice should not come in direct contact with specimens that are to be examined bacteriologically.

6. Specimens should not be wrapped in cloths wet w4th antiseptics then 23acked in paper or pasteboard boxes and shipped, as the covering macerates and facilitates contamination of both the tissues and the surroundings.

7. Large specimens and those packed in ice should be sent by express, others by parcel post or mail.

8. The package should be plainly marked, " For bacteriological, serological or pathological examination," together with the name and address of the laboratory and the sender.

9. Separate containers should be so plainly marked as to insure identification of the animal from which the specimen w as taken.

10. When no particular disease is suspected, parts of heart, liver, spleen, kidneys, lungs and lymph-glands should be submitted to the laboratory. When possible the whole unopened heart should be sent.

11. A letter should be directed to the laboratory stating the specific tests desired, the disease suspected, time of the animal's death and that of the autopsy, complete history, and post-mortem report.

Express Compa:nies Regulations. — Various State boards of health have decided that the custom of shipping bodies (especially dogs) to State laboratories or other public or private laboratories is unnecessary, and a menace to the health of the people, and regulations have been established that whenever analyses of dead animal tissue become necessary, the brain, spinal cord, stomach, liver, or other part must be removed from the body of the animal and placed in a tin, zinc, or other metal-lined box tightly closed before delivering to the express company or other public carrier.

Mailing and Parcel Post Regulations. — Section

36 of the Parcel Post Regulations: Specimens of dried blood or of diseased tissues or communicable diseases, cultures and tubercular sputum may be mailed in accordance with instructions of the Treasury Department (Bureau of Public Health and Marine Hospital Service), as promulgated by the Post Office Department under Order No. 3064 of April 22, 1910.

Diseased Tissues in the Mails. — Order No. 3064, Section 495, Postal Laws and Regulations, is hereby amended to read as follows: Specimens of diseased tissues may be admitted to the mail for transmission to the United States, State, Municipal or other laboratories in possession of permits referred to in paragraph 3 of this section only when enclosed in mailing cases constructed in accordance with this regidation:

Provided, that bacteriologic and pathologic specimens of plague and cholera (not hog cholera) shall under no circmiistances be admitted to the mails.

2. Liquid cultures or cultures of micro-organisms in media that are fluid at the ordinary temperatures (below 45° C. or 113° F.) are unmailable. Such specimens may be sent in media that remain solid at ordinary temperatures.

3. No package containing diseased tissues shall be delivered to any representative of any of said laboratories until a permit shall have been first issued by the Postmaster General certifying that said institution has been found entitled, in accordance with the requirements of this regulation, to receive such specimen.

4fl. Specimens of tubercular sputum (whether disinfected with carbolic acid or not disinfected) shall be transmitted in a solid glass vial with a mouth not less than one inch in diameter and capacity of not more than two ounces, closed by a metallic screw top protected by a rubber or felt washer. Specimens of diphtheria, typhoid or other infectious or communicable diseases or diseased tissue shall be placed in a test-tube of tough glass, not over one-half inch in diameter and not over three and a half inches in length, closed with a stopper of rubber or cotton and sealed with paraffin or covered with a tightly-litting rubber cap.

h. The glass vial or test-tube shall then be placed in a cylindrical tin box made of 1. C. bright tin plate, with soldered joints, closed by a metal screw cover with a rubber or felt washer. The vial or test-tube in this box shall be completely and evenly surrounded by absorbent cotton closely packed.

c. The tin box with its contents must then be inclosed in a closely fitting metal, wooden, or papier-mache block or tube at least three-sixteenths of an inch thick in its thinnest part, of sufficient strength to resist rough handling and support the weight of the mails piled in bags. This last tube to be tightly closed with a metal screw top.

5. Specimens of blood dried on glass microscopic slides for diagnosis of malaria or typhoid fever by the Widal test may be sent in any strong mailing case which is not liable to breakage or loss of the specimen in transit.

6. Upon the outside of every package of diseased tissues admitted to the mails shall be written or printed the words " Specimen for bacteriological examination." This package to be pouched with letter mail. See section 49, P. L. and R.

Milk or Urine. — The liquid should be placed in a tightly closed sterile container and packed in ice and sawdust.

Pus. — Pus should be collected on a sterile cotton swab that has been sterilized in a test-tube or placed in a sterile, tightly stoppered bottle.

Fceces. — Fecal matter should be collected in a clean, tightly stoppered bottle.

Blood. — For serological diagnosis of contagious abortion and glanders 20 to 30 c.c. of blood should be asceptically drawn from the j ugular vein of the living animal into sterile test-tubes or bottles and closed with rubber stoppers. Blood should not be smeared on glass slides or paper.

Ea'tenial Parasites. — Flies, fleas, ticks, and other easily seen external parasites may be collected readily, and mange and scab mites included in deep scrapings from the skin should be mailed in a tightly stoppered glass bottle.

Internal Parasites. — Tapeworms, flukes, and roundworms should be placed in a rubber- stoppered bottle containing 8 per cent, formalin, 60 per cent, alcohol or 1-1000 bichloride of mercury.

Anthrajc. — The specimen should consist of an ear or hoof. These should be used for two reasons : In the first place they are extremities, distantly situated from the intestinal tract from which point in the process of post-mortem decomposition various organisms simulating the anthrax bacillus pass toward the periphery following the bloodand lymph-vessels and later pass directly through the tissues. Thus they reach the ear or hoof later than most parts of the anatomy and lessen the possibility of contaminating the blood at those points, which is an advantage to the pathologist when examining for anthrax bacilli. Secondly, by using the ear, little or no blood escapes from the cadaver which prevents contaminating the premises or infection of the technician, a condition which might obtain if an autopsy were performed to secure specimens of spleen or other organs. When more than one tissue is sent to a laboratory for bacteriological examination, each should be packed in a separate container to prevent contamination of the others. The ear is placed in a glass jar, preferably a Mason fruit jar with rubber ring to prevent escape of fluid. This is then packed with ice and sawdust in a strong box. A portion of ear or other tissue may be placed in a hollowed-out potato and shipped. Cut a large potato in halves ; hollow out part of it; place specimen in the vacant space, place halves together and tie with a string, wrap in paper, pack in a box and mail.

Blackleg. — Pieces of affected muscle should be put in a wide-mouthed bottle and tightly corked or sealed in a fruit jar. " Blackleg muscle should be covered with salt because the decaying process is arrested by salt and the blackleg bacilli are stimulated to the rapid formation of clostrydian forms and spores " (Muller).

Malignant CEdema and Tetanus. — Locally affected parts should be excised, packed in fruit jars, and then in ice and sawdust in a box.

Hemorrhagic SejJticceinia. — Portions of pneumonic lung and portions of liver showing infarcts and focal necrosis should be selected. From these the causative agent can often be isolated in pure culture directly on agar slants. These may be packed as above described.

Tubercidosis. — Small specimens may be sent in bottles or glass jars which can be tightly closed. Large specimens should be wrapped in cheese-cloth and oil-cloth, placed in tin container, tightly closed, and then packed in sawdust and ice in a closed wooden box.

Hog Cholera, Swine Plagve, Swine Erysipelas. — Portions of skin, kidneys, lungs, lymph-glands, and intestines are preferable. The intestines should include the ileoc^ecal valve. These may be packed as other specimens.

Bacterial Dysentery, or Para-tubej'culosis. — About a foot of the ileum should be ligated in two places so that an unopened portion may reach the laboratory. This is placed in a glass jar and packed as above described.

Infectious Abortion. — A foetus, unopened, and placenta should be wrapped in cloth, placed in a tightly closed can, then packed as other specimens.

Rabies. — The head of a small animal suspected of rabies should be severed from the body as closely to the trunk as possible. This facilitates the location of the ganglia to be examined. The head of a large animal should be severed in such manner as to leave six inches of the neck with the head. To lessen the weight the lower jaw may be removed and the head may be cut in two parts transversely at a point just anterior to the eyes, and the nasal portion discarded. The head should be packed securely in a tin receptacle and this packed in sawdust and ice in a wooden pail or box and tightly closed.

Glanders. — Pieces of skin, nasal septum, lung or lymph-gland showing nodules or ulcers should be carefully excised, tightly sealed in a fruit jar or other container that can be made liquid tight, then packed as other specimens.

Poultry and Small Animals. — The entire cadaver should be wi-apped in cloth, packed, and shipped as other specimens.

Chapter II Autopsy Room

RooM.^ — An ideal autopsy room for teaching purposes is one 20' X 28', with high ceihng, plenty of skylight and ventilation. The Hoor should be cement, graded slightly toward a central drain. The walls should be cement or enamel upward five feet from the floor so that they may be readily cleaned and antisepticized ( Fig. 2 ) .

Large Table. — A convenient autopsy table for large animals is one built somewhat like a truck except that a handle is not necessary. It is 8' long, 3' wide, and 32" high. The top is more durable when made of hard wood approximately 3" thick, covered with zinc or other metal and sloped toward a drain in the centre. Side leaves are of no particular advantage, and when a table is built to revolve it is seldom used for that purpose. Wheels under the table are necessary for convenience in moving it about while cleaning the room. The wheels at one end may be arranged as large castors which facilitates directing the table in case it should be necessary to demonstrate a sub j ect in an adjacent class-room. The main points necessary are that the table be simple, strong, convenient and easily cleaned. It should be placed in the centre of the room, as it is necessary to work on all sides of it.