Sir James Dunn
Animal Welfare Center
TOXICOLOGICAL INFORMATION SOURCES FOR CANADIAN VETERINARIANS
A vast number of substances potentially toxic to animals exist, including pesticides, household cleaning products, agricultural chemicals, automotive products, human prescription and non-prescription drugs, herbal remedies, and poisonous plants and animals. With such huge numbers of potential toxins, it is impossible for veterinarians to be knowledgeable about all of them. But because some poisonings can cause illness or even death within only minutes to hours after exposure, immediate access to reliable information on diagnosis and treatment is essential. Often intoxications involve new drugs or chemical products for which very little or no published veterinary toxicity data is available. Standard veterinary medical textbooks usually include information on only the more common toxins. Even texts devoted specifically to toxicology cannot provide information on all toxins in all species. Information gained from product manufacturers or human poison control centers often pertains to human exposures only. Because of wide metabolic and physiological differences between species, it is rarely appropriate to extrapolate toxicity data from humans to other species. Veterinary toxicologists at veterinary colleges can provide valuable information on many toxicants, but as with many manufacturers, are often available only during routine office hours. Therefore, it is important that veterinarians be aware of the variety of additional toxicological information sources available.
Internet websites can be
convenient, useful, and accurate sources of information for
veterinary practitioners. Internet searches are most useful for
intoxications involving new or unusual drugs, chemicals, or products
that are not addressed in standard veterinary medical or toxicology
texts. The Internet can provide manufacturer phone numbers, product
ingredient documents, abstracts from research and medical papers, and
toxicity data documents for many species, 24 hours a day. However, some
important problems do exist when using the internet: (1) Internet
service provider problems can occur, making websites unavailable for
variable periods of time. In such case, use of alternative source of
information (such as phone consultations discussed later in this
newsletter) will be necessary. (2) Numerous unofficial,
unscientific, and unmonitored websites exist. Anyone, anywhere, with
absolutely no credentials whatsoever can set up a website and provide
any kind of "information" they want. Many times anecdotal information
is passed along from person to person, or personal opinions are stated
as if they are fact. Clients can easily be fooled by reading these
unofficial websites – be sure you don’t fall into the same trap. Be
sure to use only official or scientific websites, such as those backed
by government, universities, or veterinary or human medical
organizations. (3) Website addresses do change occasionally, and useful
new sites become available, so you will
need to periodically search for new addresses. Canadian government
sites are particularly notorious for changing web addresses frequently.
However, despite these problems, the Internet remains one of the most
useful information tools available to practitioners. Following are a
few of the more useful websites for obtaining toxicological information
for veterinarians practising in Canada.
Very useful for searching for
product manufacturers, governmental and news bulletins, and other
general or background information. Google "Images" is useful for
Information Service. Need to sign up, but is free to veterinarians. The
site has a variety of veterinary information (confernece proceedings,
on-line books, etc). A useful toxicology book on this sit is Val
Beasley's Veterinary Toxicology text. The text is being updated over
Called "PubMed", this site is one
of the most useful sites for any medical search. Articles published in
the major medical and veterinary journals are indexed, with abstracts
available for most articles. Often you can derive valuable information
from the abstract. Some articles can also be viewed in full for free.
You may need to narrow the search considerably in order for it to be
useful. See the examples at the end of the newsletter for more details.
Contains additional databases of veterinary literature that may not be indexed by PubMed.
Toxnet: this site is one of the
most useful sites for toxicity information. The most helpful sections
are generally the HSDB (Hazardous Substances Databank) and Toxline
(abstracts from various documents) sections. You will generally need to
use the specific chemical or Latin name rather than product name or
common name. See examples at end of the newsletter for more details.
The Households Products Database link on the homepage is also very
useful for US products. Many differences can exist between US and
Canadian products of the same name so do not assume that the
information on a US product can necessarily be extrapolated to its
ANIMAL POISON CONTROL CENTER
ASPCA Animal Poison Control Center
website. This site gives information on how to call the center, how to
join their information program, and a compilation of literature and
news briefs. The site also has a good interactive link for clients that
shows them how to make their homes safe for pets.
Useful site for Canadian poisonous
plants. Not all poisonous plants are included, but many of the more
common ones are. The site provides human and animal information, as
well as plant images.
Nova Scotia museum of natural
history "poison plant patch", with pictures and information on a few of
the poisonous plants found in Nova Scotia
Another very useful site for plant poisonings in animals.
This site contains a web version of the book Guide to Plant Poisoning of Animals of North America by Anthony P. Knight and Richard G. Walter (Teton New Media), 2001 (see Textbook section). This text is aimed at food animal and equine species, but information on small animal exposures is occasionally included.
Contains a poisonous plants
database provided by the ASPCA Animal Poison Control Center
This is an extremely useful site (called ELSE label search) for determining the active ingredients of particular pesticide products and for obtaining specific pesticide information. All pesticides licensed in Canada should be included in this site, including insecticides, fungicides, herbicides, rodenticides, molluscicides, etc. You will need Adobe Acrobat to view some of the information, but this can be downloaded free from the Internet if necessary. The easiest way to search this site is scroll down to "Search Full Contents Of E-labels" and type in the product name or the chemical name. Be sure to spell the name correctly.
If you have trouble accessing the site with the address above, use the following address instead:
Go to the black toolbar at the top
of this homepage and click on "search". When the search page
click on option 2 (ELSE) and then click on the '"search ELSE" blue
ExToxNet -- Provides pesticide information (U.S.) for the lay person. Useful for obtaining general background information on pesticides.
Contains information on human and veterinary drugs approved for use in Canada. The site can be very useful for finding out generic drug names (see example at end of newsletter).
This site provides information on drugs approved for human use in the U.S., and is aimed at the general public. However, the site can beuseful for obtaining basic drug information, and may be particularly useful for human drug exposures in animals belonging to U.S. tourists.
Contains product labels/monographs for drugs approved for veterinary use in Canada.
Veterinary Drugs Directorate --
Many searches are available for finding MSDS (Materials Safety Data Sheet) information on the Internet. However, there are no free governmental or national repositories for MSDS documents, and no sites contain all MSDS documents. Additionally, MSDS documents posted on various websites are NOT necessarily provided by the product manufacturer, and many MSDS documents provided by these sites are incomplete, out-dated, or incorrect. All of the MSDS search sites on the Internet post disclaimers such as, "All Public Access Databases come with a disclaimer due to the fact that the MSDSs are not provided by the manufacturer. You should use these resources at your own risk with the understanding that they may be out of date, contain errors, and do not qualify as being from the manufacturer". Also be aware that product MSDS information, availability of products, and product ingredients can differ between the United States and Canada. I have found on several occasions that MSDS information I obtained from the Internet were incomplete and incorrect. The best place to obtain a valid MSDS document is from the product manufacturer. MSDS search sites can be used to obtain contact information for the manufacturer who can then fax you the valid MSDS information. Above is one MSDS search site that contains links to numerous MSDS databases. I have not yet found any good free Canadian MSDS search site.
Purdue Animal Disease Diagnostic
lab -- contains links to veterinary diagnostic labs the US and Canada.
I use this site just for these links. Go to "State or University sites"
or "international links".
"Urban legend" site. Check this
site for information on rumors (ie, the swiffer wet jet rumor) that
circulate via e-mail and other media sources.
Theobromine concentrations in
various Hershey's products
The list above contains just a handful of Internet websites containing toxicological information useful for veterinarians. New sites periodically become available, and old ones can be discontinued. However, these addresses should give you a good place to start. If you are new to the Internet and are unfamiliar with web searches, please contact Dr. Gaskill at the numbers provided at the end of this newsletter for instruction on how to best use these websites. Examples of how to use some of these sites are also provided at the end of the newsletter.
ADDITIONAL SOURCES OF TOXICOLOGICAL INFORMATION
Veterinary toxicology texts
provide information on a much larger number of poisons than do standard
textbooks. A very useful small animal toxicology text is "Small Animal
Toxicology", 2nd edition, editors Michael Peterson and Patricia Talcott
Co), 2006. I would recommend this text to any veterinarian who treats
small animals. It is one of the best small animal toxicology text
available at this time, written specifically for the practitioner, and
is relatively inexpensive. Another very good small animal
text is the 2004 second edition "Handbood of Small Animal Toxicology
and Poisonings" by Roger Gfeller and Shawn Messonier (Mosby Inc). This
book, combined with the Peterson book above, covers small animal
poisonings quite nicely. "Clinical Veterinary
Toxicology", editor Konnie Plumlee (Mosby Inc), 2004 contains
information on large and small animals and exotics.
A very useful poisonous plants
"Guide to Plant Poisoning of Animals of North America" by Anthony
and Richard Walter (Teton New Media), 2001. This is an inexpensive
handbook with good pictures, succinct descriptions, and a logical
systems organization, and is one of the more useful poisonous plants
books for the veterinarian. Maps usually cover only the U.S., but can
be readily extended northwards to estimate locals in Canada.This text is aimed at food animal and equine
species, but information
on small animal exposures is occasionally included. A web
version of the book is available at http://www.ivis.org/special_books/Knight/toc.asp
. A new book with information about toxic house and garden plants
should be available in the fall of 2006 from Teton New Media. The ASPCA
Animal Poison Control Center has poisonous
plants information on their website, as well as a booklet that can be
purchased for a small fee. A new handbook of Toxic Plants of North
America by Burrows and Tyrl should also be available summer of 2006.
The Veterinary Clinics of North American series has some recent issues that focus on toxicology -- Veterinary Clinics of North American Small Animal Practice March 2002; Equine Practice December 2001; and Food Animal Practice 2000. (WB Saunders Co). These issues are useful to supplement other toxicology texts.
Product package labels and inserts
If the animal owner knows or suspects a particular toxic substance is involved, the package label can be a very valuable source of information. Labels should provide the product name, active ingredient and concentration, total amount of product, manufacturer, and usually a contact phone number. Have the owner bring the label (and package insert if applicable) when they bring the animal to the hospital. If the package is small enough to transport, have the owner bring the package and its contents or any part remaining so that you can obtain label information and estimate the amount of product missing (for example, the amount ingested).
(1) The ASPCA Animal Poison Control Center (1-888-426-4435). This is the only animal-oriented poison control center in North America and is a very useful information source for practitioners. The Animal Poison Control Center (APCC) is a 24-hour emergency toxicology telephone hotline service that provides diagnostic and treatment recommendations to veterinarians and animal owners. The center is staffed by 25 veterinarians specially trained in toxicology, five of whom are board-certified in veterinary toxicology. These veterinarians have access to an large collection of scientific journals and texts as well as an extensive database consisting of over 500,000 intoxication consults involving hundreds of thousand of toxic substances. The center handles tens of thousands of calls each year from all over North America and elsewhere in the world. The APCC is located in Urbana, Illinois and is affiliated with the University of Illinois College of Veterinary Medicine. To cover operating costs, the center charges a $55 US fee for each consultation. The one-time fee covers the cost for the entire consultation, which may include several phone calls over many days, as well as follow-up phone calls. However, many chemical and pharmaceutical companies pay for any consultations involving their products. Therefore many consultation are free to you and the animal owner. The major benefits of the APCC are: (1) the center can often provide information on new or unusual toxicants for which no information can be found in standard medicine or toxicology texts; (2) the center is dedicated to poisonings in veterinary species and is staffed by veterinarians; (3) the service is available 24 hours a day; and (4) the service is often free if the product manufacturer is known.
(2) Product manufacturers. If an animal is exposed to a known product, the manufacturer can often be a very useful source of information. Frequently a toll-free phone number can be found on the product package. If the package has been destroyed or is otherwise unavailable, a general internet web search (see Internet section in this newsletter) can often locate a manufacturer web page with contact information. Some manufacturers are available 24 hours a day, but others are only available during regular business hours. Manufacturers can provide full ingredient and MSDS information about the product, as well as additional information that may not be available on the MSDS. Remember, most technical information regarding poisoning and treatment obtained from manufacturers will be aimed at human intoxications. However, by knowing the ingredients contained in the product, you can then do your own search for information pertaining to the species involved (see Internet section).
(3) Human Poison Control Centers. These centers can generally provide basic product ingredient information. However, as with manufacturers, information on treatment, clinical signs, and risk will generally pertain to humans only. Personnel at human poison control centers are rarely trained to be cognizant of species differences.
(4) Veterinary toxicologists at veterinary colleges and diagnostic laboratories. Veterinary toxicologists can provide valuable information on many toxicants, but are generally only available during routine office hours.
EXAMPLES of using Internet sites to obtain toxicological information
Example #1. A pet owner calls you because his cat ate one of his Ritalin tablets. The tablet contained 20 mg of the drug. The owner wants to know what to do. You are uncertain what Ritalin is, and what effects it might have on a cat. You can check your veterinary internal medicine, toxicology, and pharmacology text books, but it is unlikely that you will find anything about Ritalin exposure in cats. A quick Internet web search would be indicated.
(1). Search the Canadian drug website (http://www.hc-sc.gc.ca/hpb/drugs-dpd/) to learn more about Ritalin. Click on the "active products" search button, and when the search page comes up, mark "Product Name" under Search Sources. Be sure to spell ritalin correctly, or the search may not find the drug. The results page will include the manufacturer or company and the active ingredient (methylphenidate hydrochloride).
(2). Search a basic human drug information site to find out more about this drug. (http://medlineplus.gov/ , click on Ddrugs and Supplements. The site will give you information on the drug, what it is used for, dosing, and side effects in humans. This will give you some idea of the type of drug you are dealing with. Now you need to see if any toxicity data is available for cats.
(3). Search PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) to see if any papers have been published on the effects of methylphenidate in cats. If you search "methylphenidate", you will get over 4,000 papers. If you search "methylphenidate and cats", you will get lots of papers looking at various research aspects of methylphenidate using cats as models for human diseases. You can limit your search even more by searching "methylphenidate and cats and poisoning". This will take you straight to what you are most interested in. When searching for papers on specific toxins, you may need to play around with the limiting terms – ie, try different terms for "poisoning" (ie, poisoning, intoxication, toxicity, adverse effects, etc); try different species names (ie, cat vs feline, singular vs plural), and try different names for the toxin (chemical name vs brand name, Latin name vs common name, etc). For the present example, your search should bring up two papers, one entitled "Methylphenidate toxicosis in a cat". You can double-click on the title to bring up the abstract, or you can click on the button next to the "Display" button on the tool panel to show a list of selections. Chose "abstract" and hit the Display button and this should bring up the abstract. The abstract of this paper summarizes a case report of a cat who ingested methyphenidate – clinical signs, toxic dose, treatment used, outcome, etc. Although this is just one case report, it will give you some idea of what might happen with Ritalin exposure in cats.
(4). Do a search of Toxnet (http://toxnet.nlm.nih.gov/) to see if any additional information is available. You will find 14 records under HSDB. Click on the highlighted number 14 and the records will be brought up. Click on "methylphenidate" and then browse through the various sections listed on the left-hand side of the screen. Note: the emergency medical treatment recommendations in Toxnet are for humans, and extrapolation to other species is often inappropriate. However, the information can still be useful to give you some basic impressions.
(5). You should now how enough information to determine that treatment of this cat is indicated, and to be able to provide basic information to the client. For additional information on how best to treat this cat, consider phone consultation with either a small animal clinician or a veterinary clinical toxicologist or with the Animal Poison Control Center (see phone consultation section above).
Example #2. A pet owner sees her dog eating a package containing rat poison. She immediately brings the dog in to your clinic, along with what is left of the package and its ingredients (as you have instructed her to do). She is not sure what kind of rat poison it is, but you can just make out the name "Quintox" on the tattered remains of the package. The portion of the package with the active ingredient list has been destroyed by the dog. You are uncertain which type of rodenticide is contained in Quintox.
(1). Search the Canadian
Pesticides website (http://www.eddenet.ca/4.0/4.0.asp
to find out the active ingredient in this product. Scroll down to the
window labelled "Search Full Contents Of E-labels" and type in
"Quintox". Your search will bring up two records on Quintox Rat and
Mouse Bait. Click on "more information" highlighted in blue, and you
will find that the product contains cholecalciferol 0.075%. The label
also includes the manufacturer name and phone number. If you click on
the highlighted registration number, you can also get additional
information on the product (requires Adobe Acrobat, which you can
download free from the Internet). You can use Google to find the
manufacturer's phone number. (NOTE: be very careful to use the approved
pesticide website for the country where the product was sold, and if
possible find out when the product was purchased. There can be
important differences in product active ingredients between the US and
Canada, even in products with the same name. Also, product ingredients
can be changed by the company without changing the product name. The
can make a big difference in treatment and progosis.
(2). If you are unfamiliar with cholecalciferol toxicity, you can easily find information and treatment recommendation on this toxin in standard veterinary medicine and toxicology texts. If desired, searches of additional websites or phone consultations as described for Example #1 can be done, but are probably unnecessary as information on this toxin is readily available from standard sources.
Example #3. A pet owner calls because he just saw his dog chewing on Lily of the Valley plants in the yard. He wonders if this is a problem or not. You are uncertain about the toxicity of this plant and how much would be a risk to this dog.
(1). Search the Canadian Poisonous Plants website (http://sis.agr.gc.ca/pls/pp/poison?p_x=px). Click on "all poisonous plants by common name" and scroll down to Lily of the Valley. You find information on the plant, images of the plant, the Latin name (Convallaria majalis), and information on other animal exposures, but not much information concerning dogs.
(2). Search PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi).
You find one report of possible Convallaria poisoning in dogs (search
"convallaria and dogs and poisoning) but you can not determine from the
abstract what a minimum toxin dose might be in dogs. Toxnet (http://toxnet.nlm.nih.gov/) has
some additional information on Convallaria in the HSDB section, but
still not much specific information in dogs. However, you should at
this point have enough information to determine that Lily of the Valley
exposure could be a risk to the dog, that decontamination measures are
indicated, and that additional treatment may be needed. For more
information, phone consultations as described for Example #1 would be
appropriate. You can also find more information in current veterinary
Example #4. A pet owner calls you because she found her puppy chewing on a can of Easy Off Oven Cleaner and wants to know what to do. Ingredients cannot be discerned from the label.
(1). To find the product
manufacturer, search Google (http://www.google.ca/)
or an MSDS database (http://www.msdssearch.com/DBLinksN.htm).
I would recommend if you use the MSDS search that you use it ONLY to
the name and phone number of the manufacturer, and call the
manufacturer directly for product and MSDS information. The MSDS
provided by the database search may be
incomplete or inaccurate. Many large manufacturers have 24 hour phone
lines for emergency purposes. The manufacturer can provide the correct
and complete MSDS information, and additional information on human
emergency treatment. Remember, extrapolation to other species may be
inappropriate, but at least you will have more information than when
you started. You can now do more in-depth searches on each of the
specific ingredients contained in this product using the toxicology
information websites (Toxnet, etc.), or consider additional phone
consultations as described in Example #1 or with the manufacturer.
For additional information or assistance with toxicological information sources, please contact:
Dr. Cynthia Gaskill, DVM PhD,