From: pfloyd@octel.com (Michael Barnett)
Subject: Vomiting -- a good article (long) (and a big hello)
Summary: how a vet should diagnose a vomiting animal
Organization: Octel Communications Inc., Milpitas Ca.
Date: Thu, 19 Nov 1992 22:16:13 GMT


    Well, it's time I came out of the rec.pets.cats closet and actually
make a post.  I've been an avid reader of this group for the past year
or so and I feel a little guilty about not giving anything back.
    My wife and I lost our 12 year old cat (Max) earlier this year to
cancer and have since been adopted by two new kitties (Koshka [russian
for cat] and Hendrix [pure-bred abysinnian]).  Max died at the vet.
We didn't have any clue that he was that sick.  Max was the first cat I'd
ever lived with so I really didn't know how to look for the subtle signs
that something was wrong.  I've since vowed to take the best possible care
of our new family members.  Working with my local vet, I'm managing to
get quite an education in cat medicine.
    Anyway, here's my gift back to all you incredibly nice people out
there.   Vomit. :-)  I know it does't sound like a nice gift, but we've all
had to deal with vomiting kitties at some time; and it really sucks when
you can't figure out what's wrong with them.  So get out those medical
dictionaries and start reading.  (or better yet, file it away so you
can take it to your vet next time you have a vomiting problem.)


The following article was shamelessly stolen from:
    Veterinary medicine magazine
    August 1992

(I thought the article was so good that I subscribed, so they got something
for it)

                                - Michael


                    Vomiting in dogs and cats:
            Investigating and treating a common problem

Vomiting is a common clinical sign in animals presented to small-animal
clinicians.  The causes, consequences, and treatment of vomiting are,
variable, emphasizing the need for a logical and systematic approach of
this problem.  In addition to anorexia, dehydration, and nausea, other
associated problems such as electrolyte and acid-based derangements
further complicate the evaluation and treatment of the vomiting patient.
Recent advances in the evaluation of a dog or cat with vomiting include
endoscopy and new techniques in radiography.  Knowledge of pathologic
features of the vomiting patient allows the clinician to more accurately
interpret these tests.
    In the first article in this symposium, Dr. Tams reviews the clinical
evaluation of vomiting patients.  He also describes the diagnostic workup
and lists the differential diagnoses.  In the second, article, Dr. Moore
discusses the laboratory test abnormalities and gross and microscopic
pathologic findings associated with vomiting dogs and cats.  Dr. Kantrowitz
then discusses the use of survey and contrast radiography in diagnosing
the cause of vomiting.  And in the final two articles, Dr. Richter
outlines a general approach to the symptomatic treatment of vomiting
pets and, in particular, therapy for vomiting animals with gastric
ulceration.  This series of articles should aid you in managing this
common problem.
                        -- Dr. Keith Richter


There are scores of reasons why a dog or cat could be vomiting.
Following the diagnostic plan outlined here will help you quickly
narrow the list of differential diagnoses down to the most likely
causes of this common clinical sign.

Todd R. Tams, DVM, Dipl. ACVIM
West Lost Angeles Hospital
Veterinary Centers of America
1818 Shouth Sepulveda Boulevard
Los Angeles, California 90025


    Most small-animal practitioners agree that vomiting is one of
the most common reasons for dogs and cats to be presented for
diagnosis and treatment.  Vomiting refers to the forceful ejection
of gastric and occasionally proximal small intestinal contents
through the mouth.  The vomiting act involves three stages: nausea,
retching, and vomiting.  It must be emphasized that vomiting is
simply a clinical sign of a number of disorders that can involve
any organ system in the body.  Vomiting itself does not constitute
a diagnosis in itself.
    The purpose of this paper is to outline a diagnostic approach
to the problem of vomiting in dogs and cats, with the emphasis on
chronic vomiting.  Because we are all busy practitioners, I will
present short lists that highlight the most commonly encountered
disorders.


        THE CLINICAL FEATURES OF VOMITING

Because there are a wide variety of disorders and numerous
stimuli that can cause vomiting (Table 1), a vomiting animal can
be a major diagnostic challenge.  Although vomiting does not always
signify a serious disorder, it can be the first indication of,
among other things, intestinal obstruction, renal failure,
pancreatitis, addisonian crisis, drug toxicity, or neoplasia.
    A complete historical review, with an emphasis on all body
systems, is essential to formulating a realistic and effective
diagnostic plan and treatment protocol.  All too often,
concentrating on only the gastrointestinal tract leads to mis-
diagnosis and inappropriate treatment for the cause of the vomiting.
    It is essential to clearly distinguish between regurgitation and
vomiting at the outset.  Regurgitation is the passive, retrograde
movement of ingested material, usually before it has reached the
stomach.  Failure to recognize the difference between regurgitation
and vomiting often leads to misdiagnosis.  This occurs most
commonly in dogs with adult-onset idiopathic megaesophagus, when
both the client and vererinarian mistakenly assume that the
observed signs represent vomiting rather than regurgitation.
If uncertainty remains after reviewing the patient's history,
survey radiographs of the thorax should be taken to rule out
esophageal dilatation.  Contrast studies are occasionally
necessary to identify esophageal dilatation.
    It is useful to consider the following factors when assessing
a patient with a vomiting problem:
        o The duration of the clinical signs
        o The current condition of each organ system
        o The time vomiting occurs in relation to eating
        o The content of the vomitus
        o The nature of the vomiting acts (i.e. type [projectile
            vs. nonprojectile], frequency)

    To begin with, you should ask the owner questions to determine
whether the vomiting is a recent acute problem or a chronic problem.
You should also review the signalment, immediate clinical signs,
pertinent history, and beneficial or deleterious effects of any
drugs that have been adminsistered (either for the immediate
clinical signs or as a treatment for another disorder).  In particular,
you should determine whether any nonsteroidal anti-inflammatory drugs
(e.g. aspirin, flunixin meglumine [Banamin -- Schering-Plough],
phenylbutazone, ibuprofen [Motrin -- Upjohn; Nuprin -- Bristol-Myers],
piroxicam [Felden -- Pfizer]) have been used.  Gastric and intestinal
erosions and potentially serious ulceration may develop in conjunction
with their use.  Nephrotixicity may also occur.  Inhibition of renal
prostaglandins (e.g. PGI) can be associated with renal ischemia and
acute renal failure.  Fortunately, this syndrome is uncommon.  However,
animals with hypovolemia, congestive heart failure, or pre-existing renal
insufficiency may be at increased risk.
    Sometimes the first clinical sign of a chronic, previously
asymptomatic disorder is the acute onset of vomiting.  The vomiting may
then persist as either a frequent or sporadic problem until the patient
receives definitive treatment for the underlying problem.  Inflammatory
bowel disease is an example of a common disorder that may present in
this way.
    In all cases, you should gather specific information regarding the
patient's:
        o   Diet (What type of food is the animal fed?  When, how
            often, and how much per meal is the animal fed each day?
            Have there been any recent changes in the diet?)
        o   Vaccination history (Has the dog or cat been vaccinated
            against systemic disorders such as distemper, parvovirus,
            and feline infectious peritonitis?)
        o   Travel history (Has the dog or cat been to any areas where
            fungal disorders, such as histoplasmosis, or parasitic
            disorders are common?)
        o   Environment (Has the animal been exposed to toxins or ingested
            garbage or foreign bodies?  Is a cat from a heartworm endemic
            area?)

    You should also conduct a thorough systems review, asking questions
about any significant signs not necessarily referable to the
gastrointestinal tract (e.g. polyuria/polydipsia, coughing or sneezing,
sysuria, or hematuria).  This routine systematic approach will help you
avoid diagnostic "tunnel vision."
    A description of the vomiting episodes, including any association
with eating or drinking, yields important information in some cases.  All
food is normally evacuated from the stomach within eight to 10 hours after
ingestion.  Vomiting shortly after eating usually suggests dietary
indiscretion or food intolerance, overeating, stress or excitement,
gastritis, or a hiatal disorder.  Vomiting of undigested or partially
digested food more than eight to 10 hours after eating is an important
clinical sign.  It usually indicates a gastric motility disorder or
gastric outlet obstruction.
    Dogs with gastric hypomotility may vomit undigested food 10 to 18
hours or more after eating and often exhibit a cyclic pattern of clinical
signs.  This disorder has been recognized much more frequently in recent
years.  Misconceptions about gastric retention commonly lead to
misdiagnosis and mismanagement of such patients.  It is often incorrectly
assumed that gastric retention means gastric outlet obstruction, and
unnecessary surgery (such as pyloromyotomy) may be performed.  It is now
well recognized that pyloromyotomy procedures are NOT usually indicated
for dogs or cats with chronic vomiting.
    Causes of gastric outlet obstruction include foreign bodies, antral
mucosal hyperplasia, pyloric muscal hypertrtophy, gastric and duodenal
ulcers, and antral or pyloric neoplasia or polyps.  All are characterized
by vomiting that occurs shortly or a number of hours after eating.  Foreign
bodies are identified much more frequently than the other disorders listed.
    Significant information can often be obtained from a complete
description of the color and consistency of the vomitus.  If food is
present, the degree of digestion and time since the most recent meal should
be determined.  If either undigested food or clear fluid is present,
determining the pH may be useful in differentiating vomiting of gastric
contents (acid pH).  Bile is often found in the vomitus when the vomiting
is due to inflammatory bowel disease, bile reflux syndromes, idiopathic or
secondary hypomotility (bile alone or with food), intestinal foreign
bodies, and pancreatitis.  The presence of bile helps rule out a complete
pyloric obstruction.
    The vomitus may contain small amounts of fresh blood in any case of
grastic mucosal compromise with gastric erosions (e.g. hypovolemia,
drug-incuded chronic gastritis, gastric ulceration, or neoplasia).  Large
clots of blood or "coffee grounds" (blood altered by and mixed with
gastric juice) usually indicate a more significant degree of erosions or
ulceration.  A fecal odor suggests intestinal obstruction, peritonitis
with ileus, ischemic injury to the intestine, or stasis with bacterial
overgrowth.
    Projectile vomiting is an imprecise term used to describe vomitus
that is ejected forcefully from the mouth and expelled a considerable
distance.  Its occurrence suggests a significant degree of gastric or
proximal small bowel obstruction (due to a foreign body, antral or pyloric
polyps or neoplasia, or pyloric hypertrophy).  In my experience, this sign
occurs infrequently.
    Chronic intermittent vomiting is a common presenting complaint in
veterinary medicine.  Often there is no specific time relation to eating,
the content of the vomitus varies, and the occurrence of vomiting is very
cyclic.  Depending on the disorder, other signs such as diarrhea, lethargy,
inappetence, and saliviation (nausea) may occur.  When a patient presents
with this pattern of clinical signs, you should strongly chronic gastritis,
inflammatory bowel disease, irritable bowel syndrome, and gastric motility
disorders as the leading differential diagnoses.  A detailed workup
including gastric and small intestinal biopsies is often required to make a
definitive diagnosis in these cases.  It is important to note that chronic
intermittent vomiting is a common clinical sign of inflammatory bowel
disease in both dogs and cats.  Diarrhea may or may not be a concurrent
problem in these cases.
    Vomiting from systemic or metabolic causes may be an acute or chronic
sign.  In these cases there is generally no direct correlation with eating
and the content of the vomitus is unpredictable.


        PHYSICAL EXAMINATION OF THE VOMITING ANIMAL

A complete history and thorough physical examination are enormously
important in the evaluation of a vomiting patient.  An all-too-frequent
error in clinical paractice is to make a diagnosis bases on incomplete
history and a cursory examination.  This may lead to unnecessary diagnostic
tests and inappropriate treatment.  Also, you may miss an essential early
diagnosis of a serious disorder.  A systematic approach to the vomiting
patient can ensure both a thorough and a time-efficient workup.
    The mucous membranes should be evaluated for evidence of blood loss,
dehydration, sepsis, shock, and jaundice.  Oral examination may reveal
a part of an oral or pharyngeal foreign body that may extend into the
stomach or intestine.  The best example of this is a string foreign body
in a cat which a portion of the foreign material lodges under the tongue
while the remainder causes intestinal plication and perhaps perforation.
It is extremely important to examine the oral cavity of all vomiting cats.
In some cases, mild tranquilization is required before performing this
examination.
    The cervical soft tissues of vomiting cats should be palpated for
thyroid nodules.  Hyperthyroidism commonly causes vomiting and should be
considered in any cat five years of age of older.  Cardiac auscultation may
reveal heart rate and rhythm abnormalities that can accompany metabolic
disturbances such as hypoadrenocorticism (bradycardia, weak femoral
pulses), infectious enteritis with septic shock (tachycardia, weak pulses),
or gastric dilation-volvulus (tachycardia, weak pulses, pulse deficits).
    The abdomen should be carefully assessed for pain, either generalized
(e.g. gastrointestinal ulceration, peritonitis, severe enteritis) or more
localized (e.g. pancreatitis, foreign body, pyelonephritis, hepatic
disease, regional inflammation in inflammatory bowel disease).  Other
abdominal factors to evaluate include abnormal organ size (hepatomegaly,
small or large kidneys), the presence of any masses (foreign body,
intussusception, lymphadenopathy, neoplasia), the degree of gastric
distention (increased with gastric dilatation, dilatation-volvulus, and
gastric retention due to hypomotility or out-flow obstruction), and altered
bowel sounds.  Bowel sounds are often absent in peritonitis and increased
in acute inflammatory disorders.  An increased pitch suggests distention
of intestinal loops.
    You should always perform a rectal examination to evaluate the feces
for fresh blood or mucus (about 30% or patients with colitis present with
vomiting), melena, or any foreign material.  During this examination, you
should obtain a fresh fecal sample for parasite and possibly cytologic
examination.  Serial rectal examinations, performed once to twice daily,
are most important when gastrointestinal bleeding is either suspected or
has been identified.


        THE DIAGNOSTIC PLAN

In some cases, vomiting patients require and extensive workup, but an
organized approach will minimize the tests needed to make an early
diagnosis.  The most important considerations for determining what tests
to perform are:
    1.  The signalment
    2.  The duration of the problem (acute [3 or 4 days] vs. chronic)
    3.  The frequency of vomiting
    4.  The severity of the clinical signs present (mild vs. moderate to
        severe illness)
    5.  The presence of other clinical signs (e.g. shock, melena, abdominal
        pain)
    6.  The finding of the physical examination

If reasonable concern is established, then it is essential to continue the
workup by collecting a minimum laboratory database.  (See the second
article in the symposium: The laboratory and pathologic assessment of
vomiting animals.)  The minimum database includes the results of a CBC,
a biochemical profile (or specific tests to evaluate the liver, kidneys,
pancreas, and electrolytes), a complete urinalysis (pretreatment urine
specific gravity is extremely important for diagnosing renal failure), and
a fecal examination.  Survey abdominal radiographs are also indicated if
thorough abdominal palpation is not possible or suggests an abnormality
(e.g. foreign body, pancreatitis or pyometra).  (See the third article in
this symposium: Using radiography to evaluate vomiting in dogs and cats).
In heartworm endemic areas, serologic tests for adult heartworm anitgen
should also be part of the minimum laboratory database for cats.
    Unfortunately, these tests often are not done early enough.  Even if
the baseline results are unremarkable, the tests are more than justified
because they help to rule out serious problems right away (e.g. vomiting
due to renal failure, diabetes mellitus, or liver disease).  Alternatively,
any abnormalities that are uncovered can help direct the initial treatment
and the next diagnostic tests to perform.
    The decision to perform even more in-depth diagnostic tests is based
on ongoing clinical signs, the response to initial therapy, and the
initial laboratory test results.  The more in-depth tests include an ACTH
stimulation test, a complete barium series, and serum bile acids assay.
The ACTH stimulation test is done to confirm hypoadrenocorticism in a 
patient with an abnormal Na:K ratio (less than 27:1) or to detect this
disorder if the electrolyte concentrations are normal but you still
suspect the problem.  Eight to 10% of patients with hypoadrenocorticism
have normal Na and K levels.  If an ACTH stimulation is not performed, the
diagnosis will be misses.  (Hypoadrenocorticism is most common in young
to middle-aged female dogs.)  A barium series is done to detect gastric
or intestinal foreign bodies, gastric hypomotility, gastric outflow
obstruction, and partial or complete intestinal obstruction.  The serum
bile acids assay is done to detect significant hepatic disease, including
portosystemic shunts.
    The results of liquid barium contrast studies may be normal in patients
with gastric hypomotility disorders.  A better way to test gastric
motility is to measure the emptying of barium mixed with food.  Solids are
emptied by a different mechanism than liquids are, and it is not uncommon
for animals with a known gastric emptying disorder to empty a liquid meal
in a timely manner.  Alternatively, small indigestible radiopaque markers
can be mixed with food for a radiographic series.  (For the markers, you
can use 2-mm segments of 1-mm diameter plyvinyl tubing or a product called
Sitzmarks, manufactured by Konsyl Pharmaceuticals, Ft. Worth, Texas.)  Air
contrast gastrograms are often useful in identifying gastric foreign
bodies when survey films alone are not diagnostic.  Barium swallow with
fluoroscopy is often necessary to diagnose hiatal hernias and
gastroesophageal reflux.  Endoscopy is also useful for identifying these
disorders.
    Because vomiting is a frequent sign in cats with heartworm disease,
serologic tests for adult heartworm antigen (i.e. ELISA) should be done to
investigate this possibilty.  Most cats with heartworm disease are
amicrofilaremic, so tests for microfilariae are usually negative.  Thoracic
radiographs may provide important clues in a cat with heartworm disease.
Suggestive findings include right ventricular enlargement, pulmonary
lobar artery enlargement, and pulmonary parenchymal disease.
    Since vomiting is a common clinical sign of hyperthyroidism in cats,
this disorder should be kept in mind when examining middle-aged to older
cats for vomiting.  A thyroid test should be performed on all vomiting
cats more than five years old to rule out this problem.
    Chronic vomiting in cats is occasionally due to infestation with the
gastric parasite Ollulanus tricuspis, and it has been reported in many
regions of the United States.  Young, free-roaming casts are most often
affected.  This infestation is diagnosed by evaluating the gastric
contents via the Baerman technique or by examining filtered vomitus for the
nematode using a magnification of 400X or a dissecting microscope.
Xylazine (Rompun --Haver) may be administered at a dosage of 2.2 mg/kg
intramuscularly to induce vomiting in order to collect gastric secretions
for these tests.
    Serum gastrin levels should be measured if you suspect a gastrinoma
(Zollinger-Ellison syndrome).  Gastrinomas, which are gastrin secreting
tumors usually found in the pancreas, are not common in clinical practice.
Clinical signs include chronic vomiting and perhaps diarrhea, weight loss,
and anorexia.  Middle-aged to older dogs are most often affected. 
Gastrinomas are quite rare in cats.  You should consider measuring the
serum gastrin level in animals with chronic vomiting and wasting disease
that is not readily explained by the results of more routine diagnostic
tests (i.e. blood tests, urinalysis, radiography, and endoscopy).
    One of the most reliable and cost-effective diagnostic tools currently
available for evaluating vomiting animals is endoscopy.  Endoscopy allows
for direct axamination of the stomach and duodenum, mucosal biopsy of
these areas, and, in many cases, retrieval of gastric foreign bodies.
Endoscopy is considerably more reliable than barium series for diagnosing
gastric erosions, ulcerations, chronic gastritis, gastric neoplacia, and
inflammatory bowel disease.  Vomiting due to the presence of the parasite
Physaloptera in the upper gastrointestinal tract is best diagnosed through
endoscopy.  These nematodes are easy to see on the surface of the gastric
mucosa and can be retrieved through the endoscope working channel for
definitive identification.
    Biopsy samples should always be collected from the stomach and,
whenever possible, the small intestine during endoscopic procedures,
regardless of the gross mucosal appearance.  Normal gastric biopsy results
may support a diagnosis of a gastric motility abnormality, psychogenic
vomiting, or irritable bowel syndrome, and such results may lead you to 
look elsewhere for a diagnosis.  Many dogs and cats with vomiting due to
inflammatory bowel disease have no abnormalities on gastric endoscope
examination or biopsy.  If only gastric biopsies are obtained, the
diagnosis may be missed.
    Ultrasonography can be useful in the diagnostic workup of a number
of disorders that can cause vomiting.  Amoung the problems that may be
detected with ultrasonography are certain liver disorders (inflammatory
diseases, abcessation, cirrhosis, neoplasia, vascular problems), gall
bladder disease (cholecystitis, choleliths), gastrointestinal foreign
bodies, intestinal and gastic wall thickening, intestinal masses,
intussusception, and kidney disorders.  Needle aspirations or biopsies
can be done at many sites under ultrasound guidance.
    Abdominal exploratory surgery is indicated for a variety of problems
including intussusception and gastric mucosal hypertrophy syndromes, as
well as for foreign body removal, procurement of biopsies, and resection
of neoplasia.  If the diagnosis is unclear on examination, biopsy specimens
of the stomach and small intestine must be collected (two or three samples
total).  In most dogs and cats with gastritis and inflammatory bowel
disease, no gross abnormalities are detected during exploratory surgery.
Samples should also be obtained from the liver and any enlarged lymph
nodes.


        SUMMARY

The cause of chronic vomiting can be determined in most dogs and cats and
early diagnosis is facilitated when a systematic diagnostic approach is
followed.  In my experience, the most common causes of chronic vomiting
encountered in practice are dietary hypersensitivity, inflammatory
disorders (gastritis, inflammatory bowel disease), gastric hypomotility,
obstructive disorders (foreign bodies, hypertrophy syndromes), and
neoplasia.  The most clinically useful diagnostic procedures (i.e. the
ones that yield the most important information and thus are cost-effective)
are the hemogram, biochemical profile, urinalysis, fecal examination,
survey radiography of the abdomen, and endoscopy.




                            TABLE 1
                        Causes of Vomiting

--------------------------------------------------------------------------
                        DIETARY PROBLEMS
Sudden change in diet
Ingestion of foreign material (grabage, grass, plant leaves, etc)
Eating too rapidly
Intolerance to specific foods
Food allergy

--------------------------------------------------------------------------
                        DRUGS
Intolerance (antineoplastic drugs, cardiac glycosides, arsenical compounds)
Blockage of prostoglandin biosynthesis (nonsteroidal anti-inflammatory
        drugs)
Injudicious use of anticholinergics
Accidental overdosage
--------------------------------------------------------------------------
                        TOXINS
Lead
Ethylene glycol
Others (e.g. cleaning agents, herbicides, fertilizers, heavy metals)
--------------------------------------------------------------------------
                        METABOLIC DISORDERS
Diabetes mellitus                   Hyperkalemia
Hypoadrenocorticism                 Hypokalemia
Renal disease                       Hypercalcemia
Hepatic disease                     Hypocalcemia
Sepsis                              Hypomagnesemia
Acidosis                            Heat stroke
--------------------------------------------------------------------------
                        DISORDERS OF THE STOMACH
Obstruction (foreign body, pyloric mucosal hypertrophy,
             external compression)
Chronic gastritis (superficial, atrophic, hypertrophic)
Parasites (Physaloptera spp [dog and cat], Ollulanus tricuspis [cat])
Gastric hypomotility
Bolious vomiting syndrome
Gastric ulcers
Gastric polyps
Gastric neoplasia
Gastric dilation
Gastric dilation-volvulus
--------------------------------------------------------------------------
                        DISORDERS OF THE GASTROESOPHAGEAL JUNCTION
Hiatal hernia (axial, paraesophageal, or diaphragmatic herniation;
               gastroesophageal intussusception)
--------------------------------------------------------------------------
                        DISORDERS OF THE SMALL INTESTINE
Parasites
Enteritis
Intraluminal obstruction (foreign body, intussusception, neoplasia)
Inflammatory bowel disease -- idiopathic
Diffuse intramural neoplasia (lymphosarcoma)
Fungal disease
Intestinal volvulus
Paralytic ileus
--------------------------------------------------------------------------
                        DISORDERS OF THE LARGE INTESTINE
Colitis
Obstipation
Irratable bowel syndrome
--------------------------------------------------------------------------
                        ABDOMINAL DISORDERS
Pancreatitis
Zollinger-Ellison syndrome (gastrinoma of the pancreas)
Peritonitis (any cause incluing FIP)
Inflammatory liver disease
Bile duct obstruction
Steatitis
Prostatitis
Pyelonephritis
Pyometra
Urinary obstruction
Diaphragmatic hernia
Neoplasia
--------------------------------------------------------------------------
                        NEUROLOGIC DISORDERS
Psychogenic factors (e.g. pain, fear, excitement)
Motion sickness
Inflammatory lesions (e.g. vestibular lesions)
Edema (e.g. head trauma)
Autonomic or visceral epilepsy
Neoplasia
--------------------------------------------------------------------------
                        MISCELLANEOUS CAUSES
Heartworm disease in cats
Hyperthyroidism in cats

-- 
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pfloyd@octel.com