Page 469 - Clinical Small Animal Internal Medicine

437

VetBooks.ir

45

Acute Poisoning

Ben O’Kelley, DVM, DACVECC

BluePearl Veterinary Partners, Tampa, FL, USA

Veterinarians are frequently presented with patients who Physical Examination
may have been exposed to a toxin. Often the suspected
toxicity is based on known exposure to a toxin. In other A thorough physical examination of any patient suspected
situations, patients exhibit symptoms (such as muscle to have been poisoned is important. Ensuring a patent
tremors, central nervous system [CNS] dysfunction, airway, verifying respirations, and assessing circulation
spontaneous intracavitary hemorrhage, acute liver fail- (the basic “ABCs” of examination) should always be the
ure in the absence of an obvious cause, etc.) that lead the first part of the physical exam. Many toxins target the CNS
clinician to suspect toxicity. A basic understanding of or the gastrointestinal (GI) tract, and symptoms such as
common toxins, diagnostic testing for toxic compounds, mental obtundation or severe vomiting and diarrhea
general decontamination procedures, and available may be obvious. Stimulants and cardiotoxins may cause
antidotes is important for the practicing small animal tachyarrhythmias, bradyarrhythmias, or signs of poor
clinician. Prompt diagnosis and treatment of the intoxi- perfusion, including pale or gray mucous membranes,
cated patient can lead to good clinical outcomes while cool extremities, and poor pulse quality. Careful physical
failure to recognize toxicity may lead to death. examination may uncover subtle symptoms such as pain
on palpation of the kidneys of a patient who has ingested a
nephrotoxin. Cats who exhibit acute, severe muscle trem-
History ors often have recent exposure to topical parasiticides
such as pyrethrins or permethrins. Veterinary patients
Obtaining a detailed history is extremely important poisoned by a vitamin K1 antagonist frequently exhibit
whenever a patient may have been poisoned. Owners signs of hemorrhagic shock, including tachycardia, pale
often fail to recognize a substance as possibly toxic, gums, and tachypnea. Signs of hemorrhage may include
especially when the onset of clinical signs is delayed or muffled ventral lung sounds, a palpable abdominal fluid
the intoxicants are common items. Asking general ques- wave, hematemesis, hemoptysis, hyphema, hematuria or
tions such as “Has your pet been exposed to any toxins?” ecchymoses of the skin. If history or physical exam sug-
may lead to a quick response of “No” if clients do not gests poisoning as a possibility, treatment should proceed
identify medications (e.g., ibuprofen, phenazopyridine according to a plan designed around the suspected toxin.
[“AZO standard”], etc.) or plants (lilies in cats, sago palms
in dogs, etc.) as toxicants. Asking specific questions may
help to identify a possible exposure. It is often useful to Clinical Approach
ask if the patient has been given any medications or
ingested any plants. It is necessary to ask clients about Diagnostic Testing
toxic exposure over the past few weeks, as they may not
recognize the delay between ingestion and symptoms Every patient who is known or suspected of having been
that can be seen with toxins such as vitamin K antagonist exposed to a poison should have a minimum database
rodenticides. of complete blood count (CBC), blood chemistry profile,

Clinical Small Animal Internal Medicine Volume I, First Edition. Edited by David S. Bruyette.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/bruyette/clinical