remove obstructions from the gullet, has a spring forceps at one end in the
place of the cup-like arrangement at the end of the simple probang. The
forceps are closed while the probang is being introduced; their blades are
regulated by a screw in the handle of the instrument. This probang is used
to grasp and withdraw an article which may have lodged in the gullet and
can not be forced into the stomach by use of the simple probang.
Fig. 4. Wooden gag, used when the probang is to be passed. The gag is a
piece of wood which fits in the animal's mouth; a cord passes over the head
to hold it in place. The central opening in the wood is intended for the
passage of the probang.
Figs. 5_a_ and 5_b._ Trocar and cannula; 5_a_ shows the trocar covered by
the cannula; 5_b_, the cannula from which the trocar has been withdrawn.
This instrument is used when the rumen or first stomach becomes distended
with gas. The trocar covered by the cannula is forced into the rumen, the
trocar withdrawn, and the cannula allowed to remain until the gas has
escaped.
Fig. 6. Section at right angles through the abdominal wall, showing a
hernia or rupture. (Taken from D'Arboval. Dictionnaire de MÈdecine, de
Chirurgie de Hygiene): _a a_, The abdominal muscles cut across; _v_,
opening in the abdominal wall permitting the intestines _i i_ to pass
through and outward between the abdominal wall and the skin; _p p_,
peritoneum, or membrane lining the abdominal cavity, carried through the
opening _o_ by the loop of intestine and forming the sac S, the outer walls
of which are marked _b f b._
PLATE IV. Microscopic anatomy of the liver. The liver is composed of
innumerable small lobules, from 1/20 to 1/10 inch in diameter. The lobules
are held together by a small amount of fibrous tissue, in which the bile
ducts and larger blood vessels are lodged.
Fig. 1 Illustrates the structure of a lobule; _v v_, interlobular veins or
the veins between the lobules. These are branches of the portal vein, which
carries blood from the stomach and intestines to the liver; _c c_,
capillaries, or very fine blood vessels, extending as a very fine network
between the groups of liver cells from the interlobular vein to the center
of the lobule and emptying there into the intralobular vein to the center
of the lobule; _v c_, intralobular vein, or the vein within the lobule.
This vessel passes out of the lobule and there becomes the sublobular vein;
_v s_, sublobular vein. This joins other similar veins and helps to form
the hepatic vein, through which the blood leaves the liver; _d d_, the
position of the liver cells between the meshes of the capillaries; _A A_,
branches of the hepatic artery to the interlobular connective tissue and
the walls of the large veins and large bile ducts. These branches are seen
at _r r_ and form the vena vascularis; _v v_, vena vascularis; _i i_,
branches of the hepatic artery entering the substance of the lobule and
connecting with capillaries from the interlobular vein. The use of the
hepatic artery is to nourish the liver, while the other vessels carry blood
to be modified by the liver cells in certain important directions; _g_,
branches of the bile ducts, carrying bile from the various lobules into the
gall bladder and into the intestines; _x x_, intralobular bile capillaries
between the liver cells. These form a network of very minute tubes
surrounding each ultimate cell, which receives the bile as it is formed by
the liver cells and carried outward as described.
Fig. 2. Isolated liver cells: _c_, blood capillary; _a_, fine bile
capillary channel.
PLATE V. Ergot in hay: 1, bluegrass; 2, timothy; 3, wild rye; 4, redtop.
Ergot is a fungus which may affect any member of the grass family. The
spore of the fungus, by some means brought in contact with the undeveloped
seed of the grass, grows, obliterates the seed, and practically takes its
place. When hay affected with ergot is fed to animals it is productive of a
characteristic and serious affection or poisoning known as ergotism.
PLATE VI. Ergotism, or the effects of ergot. The lower part of the limb of
a cow, showing the loss of skin and flesh in a narrow ring around the
pastern bone and the exposure of the bone itself.
* * * * *
POISONS AND POISONING.
By V. T. ATKINSON, V. S.
[Revised by C. DWIGHT MARSH, Ph. D.]
DEFINITION OF A POISON.
To define clearly the meaning of the word "poison" is somewhat difficult.
Even in law the word has never been defined, and when a definition is
attempted we are apt to include either too much or too little. The
following definition given by Husemann is perhaps the best: "Poisons are
those substances, inorganic or organic, existing in the organism or
introduced from the outside, produced artificially or formed as natural
products, which, through their chemical nature, under definite conditions,
so affect some organ of a living organism that the health or well-being of
the organism is temporarily or chronically injured." The common conception
of a poison is any substance which, in small quantity, will destroy life,
except such as act by purely mechanical means, as, for example, powdered
glass.
Some substances that are not usually looked upon as poisons may destroy
life if given in large doses, such as common salt. Other substances which
are perfectly harmless when taken into the body in the usual way are
poisons if injected into the circulation, such as distilled water, milk, or
glycerin. Living organisms are not "chemical substances," and are not
considered in this connection.
SOURCES OF POISONING.
Poisoning may come from many causes, among the chief of which are the
following:
(1) _Errors in medication._--By using the wrong substance or too large dose
an animal may be poisoned.
(2) _The exposure of poisons used for horticultural, technical, or other
legitimate purposes._--Poisons used for spraying plants, disinfecting,
poisoning vermin, dipping cattle or sheep, painting, smelting, dyeing, or
other purposes may be so handled as to come within the reach of animals.
(3) _Damaged food._--Food that has undergone putrefaction or certain kinds
of fermentation or heating, may have become poisonous, producing forage
poisoning, meat poisoning, cheese poisoning, etc.
(4) _Poisonous plants in the pasture or forage._
(5) _The bite or sting of a poisonous insect or the bite of an animal._
(6) _Malicious poisoning._
THE ACTION OF POISONS.
The action of poisons may be either local, and exerted directly on the
tissues with which they come in contact, or remote, acting through the
circulation or the nervous system; or both local and remote action may be
exerted by the same drug. Poisons which act locally generally either
destroy by corrosion the tissues with which they come in contact or by
inhalation set up acute inflammation. When any corrosive agent is taken
into the stomach in poisonous quantities, a group of symptoms is developed
which is common to all. The tissues with which the agent comes in contact
are destroyed, sloughing and acute inflammation of the surrounding
structures take place; intense pain in the abdomen and death ensue. In a
like manner, but with less rapidity, the same result is reached if the
agent used be not of a sufficiently corrosive nature to destroy the
tissues, but sufficiently irritating to set up acute inflammation of the
mucous membrane of the digestive tract. If the poison exerts a remote
influence alone, the action is quite different, little or no local effect
being produced upon the digestive organs.
To produce an effect on some part of the body distant from the channel of
entrance, a poison must have been absorbed and carried in the blood to the
central nervous system or other region involved. The poisonous effect of
any substance is modified by the quantity used; by its chemical
combinations; by the part of the animal structure with which it comes in
contact; by the physical condition of the subject; and also by the rapidity
with which the poison is excreted. As an illustration, opium may be given
with safety in much larger doses to an animal suffering from acute pain
than to one free from pain, and to an adult animal with greater safety than
to a young one. The rapidity with which the poison is absorbed, owing to
the part of the body with which it is brought in contact, is also an
important factor. So marked is this quality that some agents which have the
power of destroying life with almost absolute certainty when introduced
beneath the skin, may be taken into the stomach without causing
inconvenience, as curara, the arrow poisons, or the venomous secretion of
snakes. Other agents in chemical combination may tend to intensify, lessen,
or wholly neutralize the poisonous effect. For example, arsenic in itself
has well-marked poisonous properties, but when brought in contact with
dialyzed iron it forms an insoluble compound and becomes innocuous.
Idiosyncrasies are not so noticeable in cattle practice as in practice
among human beings, but the uncertainty with which some drugs exert their
influence would lead us to believe that well-marked differences in
susceptibility exist. Even in some cases a tolerance for poison is
engendered, so that in a herd of animals equally exposed injurious or fatal
effects do not appear with uniformity. For example, among cattle that are
compelled to drink water holding in solution a salt of lead the effects of
the poisoning will be found varying all the way from fatality to
imperceptibility.
GENERAL SYMPTOMS OF POISONING.
It is not always easy to differentiate between poisoning and some disease.
Indeed, examination during the life of the animal is sometimes wholly
inadequate to the formation of an opinion as to whether the case is one of
poisoning or, if it is, as to what the poison may be. A chemical and
physical examination after the death of the animal may be necessary to
clear up the doubt. On the other hand, the symptoms may be of such a nature
as to point unmistakably to poisoning with a certain agent. In general, the
following classes of symptoms may be regarded as indicative of poisoning:
Sudden onset of the disease without visible cause, a number of animals
being similarly affected at once, with severe gastrointestinal disorder or
derangement of the nervous system, or both; sudden alteration of heart
action in relation to frequency, force, or rhythm; local irritation,
dyspnea, or change in the urine or urination.
After death, lesions of the greatest variety may be found, and it is
necessary for one to be skilled in anatomy and pathology in order to
determine their significance. Oftentimes the stomach and intestines are
red, have thick walls, and contain blood. This signifies a severe irritant,
such as arsenic or corrosive sublimate. Other alterations sometimes found
are inflammation of the kidneys or bladder, points of hemorrhage in various
organs, changes in the blood, congestion of the lungs, and certain
microscopic changes.
GENERAL TREATMENT.
The treatment of animals suffering from poison must vary according to the
nature of the toxic agent. There are a few general plans of action,
however, which should be followed so far as possible. In man and in some of
the smaller animals it is possible to eliminate unabsorbed poison by the
use of the stomach pump or by causing vomiting. These proceedings are
impracticable in cattle. It is well, therefore, in many cases to endeavor
to expel the unabsorbed poison by emptying the digestive tract, so far as
may be, with a nonirritating purge. Castor oil in doses of 1 pint to 2
quarts is adapted to this purpose. If the poison is known to be
nonirritant--as a narcotic plant--from 10 to 20 drops of croton oil may be
given with a quart of castor oil. When poisons are somewhat prolonged in
their effect, Epsom salt in doses of 1 pound can be given advantageously.
To protect the mucous membrane from the action of strong irritants, one may
give flaxseed tea, barley water, the whites of eggs, milk, butter, olive
oil, or fresh lard. Chemical antidotes may sometimes be used for special
poisons, as advised below. In general, if an acid has been taken it may be
neutralized with an alkali, such as chalk, magnesia, bicarbonate of soda
(baking soda), ammonia (diluted), or soap. If the poison is an alkali, such
as caustic soda or potash (lye), or ammonia, an acid, such as diluted (1
per cent) sulphuric acid or vinegar, may be administered. Special
treatments and antidotes are considered below.
A poisonous agent may be so gradually introduced into the system as to
slowly develop the power of resistance against its own action. In other
cases where the poison is introduced slowly the poisonous action becomes
accumulative, and, although there is no increase in the quantity taken,
violent symptoms are suddenly developed, as if the whole amount, the
consumption of which may have extended over a considerable period, had been
given in one dose. Other agents, poisonous in their nature, tend to
deteriorate some of the important organs, and, interfering with their
natural functions, are productive of conditions of ill health which,
although not necessarily fatal, are important. Such might properly be
called chronic poisons. Poisons of themselves dangerous when administered
in large doses are used medicinally for curative purposes, and a very large
percentage of the pharmaceutical preparations used in the practice of
medicine if given in excessive quantities may produce serious results. In
the administration of medicines, therefore, care should be exercised not
only that the animal is not poisoned by the administration of an excessive
dose but that injury is not done by continued treatment with medicines the
administration of which is not called for.
MINERAL POISONS.
ARSENIC POISONING.
Of the common irritant and corrosive poisons, arsenic, especially one of
its compounds (Paris green), is likely to be the most dangerous to our
class of patients. The common practice of using Paris green and other
compounds of arsenic as insecticides for the destruction of potato beetle
and other insect enemies of the farmer and fruit grower has had the effect
of introducing it into almost all farming establishments. White arsenic is
also a principal ingredient in some popular dipping preparations, and
poisoning from this source occasionally takes place when, after dipping,
animals are allowed to run in a yard in which there is loose fodder. The
drippings from the animals falling on the fodder render it poisonous and
dangerous to animal life if eaten. Familiarity with its use has in many
instances tended to breed contempt for its potency as a poison. Rat poisons
often contain arsenic. The excessive use of arsenic as a tonic, or of
"condition powders" containing arsenic, has been the means of poisoning
many animals. This is the common poison used by malicious persons with
criminal intent. The poison may also be absorbed through wounds or through
the skin if used as a dip or bath.
If a large dose is given, at once acute poisoning is produced; if repeated
small doses are given, chronic poisoning may result. The poisonous dose for
an ox is from 3 drams to 1 ounce.
_Symptoms._--The symptoms of acute poisoning first appear as those of
colic; the animal is restless, stamping with the feet, lying down and
getting up. There is tenderness on pressure over the abdomen. The acute
symptoms increase; in a few hours violent diarrhea is developed; in many
cases blood and shreds of detached mucous membrane are mixed with the
evacuations. There is irregular and feeble pulse and respiration, and death
is likely to supervene between the eighteenth hour and the third day. If
the latter period is passed, there is a reasonable hope of recovery.
In chronic poisoning the symptoms are similar to those of chronic
gastrointestinal catarrh, with indigestion, diarrhea, and general weakness
and loss of condition.
_Treatment._--The antidote for arsenic is a solution of hydrated oxid of
iron in water. It should be prepared fresh by mixing a solution of sulphate
of iron, made by dissolving 4 ounces of sulphate of iron in one-half pint
water, with a suspension of 1 ounce of magnesia in one-half pint water.
This quantity is sufficient for one dose for a cow and may be repeated in
an hour, if much arsenic was taken. A solution of calcined magnesia or
powdered iron or iron filings or iron scale from a blacksmith's forge may
be given in the absence of other remedies. Powdered sulphur is of some
value as an antidote. One must also administer protectives, such as linseed
tea, barley water, whites of eggs, etc.
LEAD POISONING.
Lead poisoning of cattle sometimes comes from their having licked freshly
painted surfaces and thus swallowed compounds containing white lead. In
several instances cattle have been poisoned by silage from a silo painted
inside with lead paint shortly before filling. Sometimes cattle eat dried
paint scrapings with apparent relish and are poisoned. Cattle grazing on
rifle ranges have been poisoned by lead from the bullets. Sugar of lead has
been administered by mistake for Glauber's salt. Lead poisoning may be
acute or chronic. The fatal dose of sugar of lead is from 1 to 4 ounces.
Water drawn from lead pipes or held in a lead-lined tank may cause
poisoning.
_Symptoms._--The symptoms are generally dullness, lying down with the head
turned toward the flank, colic, rumbling in the abdomen, loss of control of
the limbs when walking, twitching, champing of the jaws, moving in a
circle, convulsions, delirium, violent bellowing, followed by stupor and
death. The symptoms generally extend over considerable time but may end in
death after 24 hours.
_Chronic lead poisoning_ occasionally occurs in districts where lead mining
is the principal industry. The waste products of the mine thrown into
streams contaminate the water supply, so that the mineral is taken into the
system gradually, and a very small per cent of any of the salts taken into
the system in this way is pernicious. Water which contains any salt of lead
to the extent of more than one-tenth of a grain to the gallon is unfit to
drink. Such water when used continually is likely to produce colic from the
resulting intestinal irritation, and in aggravated cases paralysis more or
less severe is likely to be developed. A blue line on the margin of the
gums, the last symptom, is regarded as diagnostic and its presence as
conclusive evidence of the nature of the disorder.
_Treatment._--The treatment should first be directed toward removing the
cause. A large dose of purgative medicine should be given, and the brain
symptoms be relieved by giving bromid of potassium in half-ounce doses
every 4 or 5 hours and by the application of cold water to the head. Dilute
sulphuric acid in half-ounce doses should be given with the purgative
medicine. In this case sulphate of magnesia (Epsom salt) is the best
purgative, and it may be given in doses of from 1 to 2 pounds dissolved in
warm water. After the acute symptoms have abated, iodid of potassium may be
given, in doses of 2 drams each, three times a day for a week.
No treatment is likely to be of avail until the cause is removed.
COPPER POISONING.
The soluble salts of copper, though used as a tonic in the medicinal
treatment of cattle, are poisonous when taken in large quantities. Like
lead and arsenic, they have an irritant effect upon the mucous membrane
with which they come in contact in a concentrated form. Cattle are not very
likely to be poisoned from this cause unless through carelessness. Sulphate
of copper, commonly called blue vitriol, is occasionally used for
disinfecting and cleansing stables, where it might inadvertently be mixed
with the feed. It is also used largely for making the Bordeaux mixture used
in spraying fruit trees. The general symptoms produced are those of
intestinal irritation, short breathing, stamping, and tender abdomen.
_Treatment._--Give powdered iron, or iron reduced by hydrogen, or calcined
magnesia. Sulphur may be used. This should be followed by a liberal supply
of demulcents, linseed infusion, boiled starch, whites of eggs, etc.
ZINC POISONING.
Several of the soluble salts of zinc are irritant poisons. The chlorid and
sulphate are those in most common use. In animals which have power to vomit
they are emetic in their action. In others, when retained in the stomach,
they set up more or less irritation of the mucous membrane and abdominal
pain, producing symptoms already described in the action of other poisons
which produce the same result.
_Treatment._--The treatment should be the same as for copper poisoning.
PHOSPHORUS POISONING.
Only one of the forms of phosphorus in common use--the ordinary yellow--is
poisonous. Phosphorus in this form is used for the destruction of rats and
mice and other vermin, and has been largely used in the manufacture of
matches.
_Symptoms._--The symptoms are loss of appetite, colic, diarrhea, irritation
of the mouth and throat, and paralysis of the throat. There is also
weakness, difficult breathing, and rapid pulse. The course of the poisoning
is usually rapid, terminating in either recovery or death within three
days. The toxic dose for cattle is from 5 to 30 grains. If taken in large
quantities the excreta are occasionally noticed to be luminous when
examined in the dark.
_Treatment._--Turpentine is given in an emulsion with flaxseed tea in a
single dose of from 2 to 8 ounces. Permanganate of potassium may be given
in a one-fourth of 1 per cent solution. Stimulants, such as alcohol and
ether, should be administered. Oils and milk must not be given.
MERCURY POISONING.
Mercury poisoning is not rare in cattle from the fact that these animals
have a special susceptibility to the action of this substance. Antiseptic
washes or injections containing the bichlorid of mercury (corrosive
sublimate) must be used on cattle with great care. Mercurial disinfecting
solutions or salves must be used cautiously. Calomel can not be given
freely to cattle.
_Symptoms._--The symptoms are salivation, sore mouth, indigestion,
diarrhea, skin eruption, paralysis of local groups of muscles, and
nephritis.
_Treatment._--The treatment consists in administering sulphur in large
doses (2 to 4 ounces) or iron powder. Both make insoluble compounds with
mercury. Follow with the whites of eggs mixed with water and with linseed
tea. If the case does not terminate promptly, give iodid of potash in
1-dram doses twice daily.
POISONING BY ACIDS.
MINERAL ACIDS.--The mineral acids--nitric, sulphuric, hydrochloric, etc.--
when used in a concentrated form destroy the animal tissues with which they
come in contact, and in this respect differ from most of the poisons
previously described. When taken into the stomach the mucous membrane of
the mouth, pharynx, esophagus, and stomach is apt to be more or less
completely destroyed. If taken in large quantities death is likely to
result so speedily that nothing can be done to relieve the patient, and
even if time is allowed and the action of the acid can be arrested it can
not be done until considerable and, perhaps, irreparable damage has been
done. The mucous membrane with which the acid has come in contact in the
esophagus may be destroyed by its corrosive action and carried away,
leaving the muscular tissues exposed. The raw surface heals irregularly,
the cicatrice contracting causes stricture, and an animal so injured is
likely to die of starvation. In the stomach even greater damage is likely
to be done. The peristaltic action of the esophagus carries the irritant
along quickly, but here it remains quiet in contact with one surface,
destroying it. It is likely to perforate the organ and, coming in contact
with the abdominal lining or other organs of digestion, soon sets up a
condition that is beyond repair. In a less concentrated form, when this is
not sufficiently strong to be corrosive, it exerts an irritant effect. In
this form it may not do much harm unless taken in considerable quantity.
When thus the mucous membrane of the stomach and intestines becomes
inflamed pain and diarrhea are likely to result.
_Treatment._--Any of the alkalies may be used as an antidote. Most
convenient of these are chalk, baking soda, marble dust, magnesia, lime,
soap, or plaster from a wall. Mucilaginous drinks should be given in large
quantities.