Decontaminating poisoned pets (Proceedings)
Aug 01, 2008
CVC IN KANSAS CITY PROCEEDINGS
To Treat or Not to Treat, That is the Question
A number of factors should be considered in deciding the best approach to case management.
These factors include: Substance ingested, amount of substance ingested, co-ingestants, time post ingestion, prior intervention(s), species/age of animal, and concurrent health problems (particularly problems that might interfere with detoxification or elimination of the ingested substance, e.g., liver or kidney dysfunction)
*The 1/10th of an LD50 rule of thumb is only a General Guideline. Non-toxic doses are dependent on a number of factors including the nature of the dose-response curve for the exposed species. Extrapolations from available data are often required.
In many situations, even where there is a strong suspicion of intoxication, no specific toxicant can be identified and therefore, no exposure determined. Fortunately, with many toxicant exposures, appropriate symptomatic and supportive care will result in a positive case outcome. Sometimes a known toxicant may have been ingested, but there is no information available concerning its toxicity to the particular animal species exposed. In such situations, extrapolation of toxicity data from other species such as laboratory rodents may be all that is possible. Ultimately, the advice to "treat the patient and not the toxicant" is sound.
Prioritizing Your Priorities
Once a determination is made that an animal has been exposed to (or potentially exposed to) a toxicant or is intoxicated, a general approach to case management should adhere to the following principles: (1) stabilize vital signs (this may include administration of an antidote if sufficient information concerning a specific toxicant exposure is immediately available), (2) obtain a history and clinically evaluate the patient, (3) prevent continued systemic absorption of the toxicant, (4) administer an antidote if indicated and available, (5) enhance elimination of absorbed toxicant, (6) provide symptomatic and supportive care, and (7) closely monitor the patient. Obviously, each situation is unique and one or more of the steps may be eliminated or their priority changed depending on the circumstances of the case. For example, there may not be an antidote for a given toxicant or a way to significantly enhance its elimination once it has been systemically absorbed. In some situations with a known exposure, it may be critical to administer an antidote quickly. For example, in suspected cholinesterase-inhibiting insecticide intoxications, administration of atropine may be critical to control life-threatening signs before proceeding with subsequent management steps.