Chapter 20

“Common things happen commonly” is a good adage for veterinary toxicology. Knowing which toxicoses happen most frequently can help when formulating a list of differential diagnoses. The Animal Poison Control Center (APCC) of the American Society for Prevention of Cruelty to Animals (ASPCA) began as the Illinois Animal Poison Information Center (IAPIC) in November 1978 at the University of Illinois. When it first started the center averaged one call per day and dealt mostly with large animal–related inquiries (48% ruminants, swine, horses, and poultry). By 1981 it received up to six calls a day, with 63% being small animal–related inquiries (dogs 49%, cats 14%).

During 2010 there were approximately 167,000 cases opened concerning possible animal poisoning. It should be noted that these data reflect exposure and not confirmed toxicosis. Domestic dogs made up the majority of exposures with 84.9%, followed by cats with 13.2%, birds and small mammals (ferrets, lagomorphs, and rodents) with 0.7%, and livestock (horses and cows) with only 0.5%. These changing demographics may reflect the fact that animals living in a house have more opportunities for exposure to various substances than livestock, which live in a more controlled environment. It also reflects the urbanization of North America, with more pets living inside as family members. Most calls are initiated by the owner (75.9%), but 18.5% stem from veterinary personnel.

The majority of dog and cat poisonings are accidental, with ingestion of dropped pills the most common scenario. Oral exposures to toxins make up 85.6% of all inquiries. Dermal exposures are next with 6.2%, followed by a combination of dermal/oral with 3.6%. Although exposures are steady throughout the year, the summer months always show an increase in calls (Figure 20-1). This may be due to pets having increased access to the outdoors and its associated toxins (plants, herbicides, insecticides), pets having increased exposure to flea and tick treatments, or children being at home on vacation and possibly not being as vigilant with keeping substances out of a pet’s reach. The 2 weeks around Christmas have a 10% increased call volume, mostly related to chocolate, a popular gift given during a hectic season in which pets may not be as carefully monitored. October, with Halloween, also has an increased call volume related to pets ingesting candy and chocolate.