Page 73 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

40 SECTION | I General

VetBooks.ir Cats to naturally occurring toxicants, exposures to man-made
hazards (e.g., oil spills, industrial effluents) can result in
Due, perhaps, to their more discriminating habits and
significant wildlife morbidity and mortality.
appetites, cats account for only 11% 20% of reported
animal exposures to potential toxicants, which is three
times less frequent than dogs (Hornfeldt and Murphy, AGENTS INVOLVED
1992, 1998; Xavier et al., 2002; Forrester and Stanley,
There is an unlimited number of agents by which exposed
2004; Berny et al., 2009; McLean and Hansen, 2010). In
animals may become poisoned, and for the most part the
2010, 71% of cats exposed to potential toxicants were
specific agents involved in animal poisonings will be
identified as domestic (or American) shorthairs, 8% as
dependent upon what is available in the animals’ environ-
domestic longhairs and 6% as domestic medium hairs
ment, the potential or inclination for the animal to be
(ASPCA Animal Poison Control Center, unpublished
exposed to the agent, the amount of agent to which the
data, 2010). Excluding these types of cats due to the
animal is exposed, and the individual sensitivity of the
generic nature of their classification, the top 10 purebred
animal to the effects of the agent. The potential for expo-
cats were Siamese (24%), Main Coon (15%), Persian
sure to specific agents may be uniform throughout the
(10%), Himalayan (8%), Ragdoll (6%), Bengal (6%),
year or may be seasonal, depending on the agent and the
Russian Blue (3%), Abyssinian (3%), Manx (2%), and
species involved. For instance, exposures to lawn care
Siberian (2%). Of these, the Persian, Maine Coon,
products, such as herbicides and insecticides, would be
Siamese, Abyssinian, and Ragdoll are listed in the 10
expected to be more common during the seasons when
most popular breeds registered by the Cat Fancier’s
these products are most in use (i.e., spring and summer).
Association in 2010 (CFA, 2010). As with dogs, no gen-
Table 2.2 summarizes the most common agents
der differences in incidence of exposure have been noted,
involved in animal exposures reported to veterinary emer-
and cats 1 year and under comprise the largest age group
gency referral centers (VEC) and human or animal PCC
(McLean and Hansen, 2010). Cats may, due to their
in the United States. These exposures predominantly
grooming habits, be more susceptible to toxicants that
involve companion animals, particularly dogs and cats,
come into contact with their fur; this is especially prob-
and are consistent with the types of animal exposures
lematic with agents to which cats are extremely sensitive,
reported by PCC in other countries (Xavier et al., 2002;
such as ethylene glycol.
Giuliano Albo and Nebbia, 2004; McFarland et al., 2017).
Rodenticides, pharmaceuticals, and chocolate make
up the majority of agents involving canine poisonings
Other Species
presenting to VEC (Fig. 2.2)(Cope et al., 2006).
Demographic information on potential poisonings in ani- Rodenticides and chocolate each accounted for approxi-
mal species other than dogs and cats in North America is mately one quarter of all presentations to VEC, yet these
largely lacking. Production animals are generally kept in agents comprised ,10% of calls to PCC. This discrep-
large groups, meaning that when a toxicosis occurs, there ancy may largely be because PCC receive calls regarding
is potential for multiple animals of varying age and gen- a large range of agents, many of which would not pose a
ders to be exposed. Most production animals are kept in toxic hazard, while VEC are most likely to see only those
some form of confinement, which limits the potential for exposures that have potential to cause clinical problems.
exposure to toxic agents. However, mistakes in manage- Pharmaceutical agents, because they are designed to have
ment, such as feed mixing errors or improper ventilation, a pharmacologic effect and thereby can cause clinical
may result in acute or chronic toxicosis in large numbers effects if veterinary patients are exposed, appear to be
of animals. A study of livestock poisonings in Greece more closely represented between VEC and PCC cases.
indicated that sheep were the commonly poisoned species, Pharmaceuticals exposures have increased since first
attributed primarily to their ingestion of potentially con- reports in 1983 (Beasley and Trammel, 1994), likely due
taminated soil (Guitart et al., 2010a). to the increased use of these agents in veterinary and
Wildlife is almost continuously exposed to potentially human medicine over the past 30 years. The most common
toxic agents in the environment, but specific demographic pharmaceutical agents associated with animal exposures
information is not available in most cases. In France, are analgesics, primarily nonsteroidal antiinflammatory
birds are reported to be more commonly poisoned than drugs (Hornfeldt and Murphy, 1992, 1998; McLean and
mammals (Guitart et al., 2010b). Seasonality of poisoning Hansen, 2010). Pesticides have historically been respon-
incidences in wildlife would vary with the agent involved. sible for large numbers of exposures and toxicoses in
For instance, avian botulism in waterfowl tends to be sea- domestic animals (Beasley and Trammel, 1994), but the
sonal, with most cases occurring between the months of incidence is declining (Fig. 2.3). This may be due in part
July and September (Locke and Friend, 1989). In addition to the development of newer herbicides and insecticides