Toxicology

1.     Toxicities from Human Drugs

Human drugs or nutritional supplements available without a prescription are known as over-the-counter (OTC)
medications. Exposures to OTC drugs in pets can be accidental or intentional. Safety of most OTC drugs has not been determined in animals, as most are not approved for veterinary use by the FDA. For more information click here or call your veterinarian. 

A.     Ibuprofen , a non-steroidal anti-inflammatory drug (NSAID) and the active ingredient in products such as Advil¢ç is available over the counter in a number of strengths. It has a narrow margin of safety in dogs, which can develop gastrointestinal, renal, or central nervous system effects.

B.       Acetaminophen is available alone (i.e., in products such as Tylenol) or in combination with other drugs such as caffeine or antihistamines. With large ingestions dogs can develop liver failure and potentially methemoglobinemia, a condition affecting the oxygen carrying capacity of the blood. In some cases, dogs will develop a transient keratoconjuctivitis sicca (dry eye).

C.     Many cold and flu medications contain the decongestant pseudoephedrine, a stimulant drug structurally similar to amphetamine. Ingestion of pseudoephedrine can result in potentially lethal cardiovascular and central nervous system excitation.

2.     Insecticide and Acaricide (organic) Toxicity

A.     Carbamate Insecticides 

The carbamate insecticides act similarly to the organophosphates in that they inhibit cholinesterase at nerve junctions. Signs include hypersalivation , GI hypermotility, abdominal cramping, vomiting, diarrhea, sweating, dyspnea, cyanosis, miosis, muscle fasciculations (in extreme cases, tetany followed by weakness and paralysis), and convulsions. For more information click here or call your veterinarian.

B.      Insecticides Derived from Plants  

a.      Nicotine

Most insecticides derived from plants ( eg, derris [rotenone] and pyrethrum) have traditionally been considered safe for use on animals. Nicotine in the form of nicotine sulfate is an exception. Unless it is carefully used, poisoning may result. For more information click here or call your veterinarian.

b.      Pyrethrins

This is a closely related group of naturally occurring compounds that are the active insecticidal ingredients of pyrethrum. Pyrethrum is extracted from the flowers of Chrysanthemum cinerariaefolium. Synergists are added to increase stability and effectiveness; unfortunately, this also potentiates mammalian toxicity. For more information click here or call your veterinarian.

C.     Organophosphates

Organophosphates (OP) have replaced the banned organochlorine compounds and are a major cause of animal poisoning. They vary greatly in toxicity, residue levels, and excretion. Many of the OP now used as pesticides are generally less toxic, and intoxication occurs more slowly, but the toxic properties are still present. For more information click here or call your veterinarian.

D.     Pesticide Potentiating Agents

Piperonyl butoxide is used as a potentiator in many pesticide formulations including pyrethrins, pyrethroids, and d-limonene. It decreases breakdown of the chemical in the animal or insect's body and makes the pesticide more toxic to the insect¡ªand the host. For more information click here or call your veterinarian.

E.      Solvents and Emulsifiers

Solvents and emulsifiers are required in most liquid insecticide preparations. Usually they have low toxicity, but like the petroleum products (which many are) , they must be considered as possible causes of poisoning. In direct treatment with pesticides, emulsification must be thorough with an average droplet size of 5 microns (preferably smaller), or excessive amounts may stick to treated animals. Treatment should be as for petroleum product poisoning. For more information click here or call your veterinarian.

3.     Rodenticide Poisoning

A.     Anticoagulant Rodenticides (Warfarin and Congeners)

Potentially dangerous to all mammals and birds, anticoagulant rodenticides are the most frequent cause of poisoning in pets. Pets may be poisoned directly from baits or indirectly by consumption of poisoned rodents. For more information click here or call your veterinarian.

B.      ANTU (¥á- Naphthylthiourea)

ANTU causes local gastric irritation; when absorbed, it increases permeability of the lung capillaries in all animals, although species variability in dose response is marked. Properties of ANTU, when compared with those of warfarin, have led to near abandonment of its use. Dogs and pigs are occasionally poisoned. For more information click here or call your veterinarian.

C.     Bromethalin

This nonanticoagulant, single-dose rodenticide is a neurotoxin that appears to uncouple oxidative phosphorylation in the CNS. CSF pressure increases, which places pressure on nerve axons and results in decreased conduction of nerve impulses, paralysis, and death. In dogs, a dose of 1.67 mg/kg is toxic, and 2.5 mg/kg (25 g of bait/kg body wt) is lethal. For more information click here or call your veterinarian.

D.     Cholecalciferol

Although this rodenticide was introduced with claims that it was less toxic to nontarget species than to rodents, clinical experience has shown that rodenticides containing cholecalciferol are a significant health threat to dogs and cats. For more information click here or call your veterinarian.

E.      Metaldehyde

This polymer of acetaldehyde is used as a snail or slug bait, to which dogs may be exposed. Signs range from salivation and vomiting to anxiety and incoordination with muscle tremors, fasciculations, and hyperesthesia leading to continuous muscle spasms, prostration, and death. For more information click here or call your veterinarian.

F.      Phosphorus

In its white (or yellow) form, phosphorus is hazardous to all domestic animals and is locally corrosive and hepatotoxic when absorbed. Phosphorus is infrequently used as a rodenticide today, but dogs occasionally become exposed through ingestion of fireworks that contain white phosphorus. For more information click here or call your veterinarian.

G.     Red Squill

This rodenticide is a cardiac glycoside derived from the plant Urginea maritima. It is of limited current use. Because rats are incapable of vomiting, red squill is more toxic to that species. It is unpalatable to domestic animals but, when eaten, usually induces vomiting in dogs and cats. It is considered relatively safe, but dogs, cats, and pigs have been poisoned. For more information click here or call your veterinarian.

H.     Sodium Monofluoroacetate (1080) and Sodium Fluoroacetamide (1081)

1080 and 1081 are colorless, odorless, tasteless, water-soluble chemicals that are highly toxic ( 0.1-8 mg/kg) to all animals, including humans. Its use is restricted to certain commercial applications. Fluoroacetate is metabolized to fluorocitrate, which blocks the tricarboxylic acid cycle¡ªa mechanism necessary for cellular energy production. For more information click here or call your veterinarian.

I.       Thallium Sulfate

This general cellular poison can affect all species of animals. It has been banned for use as a rodenticide. For more information click here or call your veterinarian.

J.       Zinc Phosphide and Aluminum Phosphide

Zinc phosphide has been used extensively around farms and barns because affected rats tend to die in the open. Toxicity is due to liberation of phosphine gas at the acid pH in the stomach. The gas results in direct GI tract irritation along with cardiovascular collapse. For more information click here or call your veterinarian.

3.      Natural and synthetic derivatives of thyroid hormones are used to treat hypothyroidism in animals and people. Dogs tend to tolerate accidental ingestions of thyroid hormones fairly well. Following large ingestions, however, hyperactivity and tachycardia are the most common signs. For more information click here or call your veterinarian.

4.      All animals are susceptible to ethylene glycol (EG) toxicity, but it is most common in dogs and cats. Most intoxications are associated with ingestion of radiator antifreeze, which is usually 95% EG. The widespread availability of antifreeze, its sweet taste and small minimum lethal dose, and the lack of public awareness of the toxicity ( ie, improper storage and disposal) contribute to the frequency of this intoxication. For more information click here or call your veterinarian. 

5.     Food Hazards

A.     Bread Dough 

Raw bread dough made with yeast poses mechanical and biochemical hazards when ingested, including gastric distention, metabolic acidosis, and CNS depression. Although any species is susceptible, dogs are most commonly involved due to their indiscriminate eating habits. For more information click here or call your veterinarian.

B.      Chocolate  

Chocolate toxicosis may result in potentially life-threatening cardiac arrhythmias and CNS dysfunction. Chocolate poisoning occurs most commonly in dogs, although many species are susceptible. Contributing factors include indiscriminate eating habits and readily available sources of chocolate. For more information click here or call your veterinarian.

C.     Macadamia Nuts  

Ingestion of macadamia nuts by dogs has been associated with a nonfatal syndrome characterized by vomiting, ataxia, weakness, hyperthermia, and depression. Dogs are the only species in which signs have been reported. For more information click here or call your veterinarian.

D.     Raisins/Grapes  

Ingestion of grapes or raisins has resulted in development of anuric renal failure in some dogs. Cases reported to date have been in dogs; an anecdotal report exists of a cat developing renal failure following ingestion of 1 cup of organic raisins. It is not known why many dogs can ingest grapes or raisins with impunity while others develop renal failure following ingestion. For more information click here or call your veterinarian.

6.     Household Hazards

A.     Alcohols 

Alcohol toxicosis results in metabolic acidosis, hypothermia, and CNS depression. All species are susceptible. Ethanol is present in a variety of alcoholic beverages, some rubbing alcohols, drug elixirs, and fermenting bread dough. Methanol is most commonly found in windshield washer fluids (windshield "antifreeze"). The lethal oral dose of methanol in dogs is 4-8 mL/kg, although significant clinical signs may be seen at lower doses. For more information click here or call your veterinarian.

B.      Chlorine Bleaches

Exposure to undiluted chlorine bleaches may result in alimentary, dermal, and ocular irritation or ulceration as well as significant respiratory irritation. For more information click here or call your veterinarian.

C.     Corrosives

a.      Alkaline Batteries

Ingestion of alkaline batteries poses a risk of both alimentary tract corrosive injury and foreign body obstruction. Dogs are most commonly involved. For more information click here or call your veterinarian.

b.      Cationic Detergents

Exposure to cationic detergents may result in local corrosive tissue injury as well as severe systemic effects. Cats are at increased risk of oral exposure due to grooming habits. For more information click here or call your veterinarian.

D.     Detergents, Soaps, and Shampoos 

Exposures to products containing anionic and nonionic detergents generally cause mild GI irritation that responds well to symptomatic care. For more information click here or call your veterinarian.

E.      Hydrocarbons are found in a number of household products including paints, varnishes, furniture polish, lighter fluids, and paint removers. Volatile hydrocarbons are of particular concern because of their risk of aspiration, and subsequent chemical pneumonitis. Ingestion can result in vomiting and diarrhea. Ocular exposure can produce mild to moderate ocular irritation. Dermal exposure can produce skin cracking, redness, and pruritis. Inducing vomiting is contra-indicated with any hydrocarbon exposure, and immediate veterinary advice should be sought. For more information click here or call your veterinarian.

F.      Fertilizers are available in a number of formulations including liquid, granular, and solid stakes. They are usually composed of varying concentrations of nitrogen, phosphoric acid, and potash (N-P-K), leading to gastrointestinal irritation. In some cases, fertilizer products may contain insecticides, fungicides, herbicides, or other compounds, that may pose more serious hazards to pets.

7.     Petroleum Product Poisoning

Ingestion or inhalation of¡ªor skin contact with¡ªpetroleum, petroleum condensate, gasoline, diesel fuel, kerosene, crude oil, or other hydrocarbon mixtures may cause illness and occasionally death in dogs and cats. For more information click here or call your veterinarian.

1.     Houseplants and Ornamentals  

Plants are an important part of the decor of homes; pets often chew on or ingest these plants, which can result in toxicoses (see Table:Poisonous Houseplants and Ornamentals). Inquiries to poison control centers on plants ingested by children <5 yr old are estimated at 5-10% of all inquiries. Similar estimates (though not documented) could be made for pets.   For more information click here or call your veterinarian.  

2.     Algal Poisoning

Algal poisoning is often an acute, fatal condition caused by high concentrations of toxic blue-green algae (more commonly known as cyanobacteria¡ªliterally blue-green bacteria) in the drinking water. For more information click here or call your veterinarian.

3.     Arsenic Poisoning

Arsenic poisoning in animals is caused by several different types of inorganic and organic arsenical compounds. Toxicity varies with factors such as oxidation state of the arsenic, solubility, species of animal involved, and duration of exposure. For more information click here or call your veterinarian.

4.     Cantharidin Poisoning

In nature, cantharidin is found in beetles belonging to the Meloidae family. The striped blister beetles are particularly troublesome in the southwestern USA. For more information click here or call your veterinarian.

5.     Coal-tar Poisoning

A variety of coal-tar derivatives induce acute to chronic disease in animals. Clinical effects are acute to chronic hepatic damage with signs of icterus, ascites, anemia, and death. For more information click here or call your veterinarian.

6.     Copper Poisoning

Acute or chronic copper poisoning is encountered in most parts of the world. In various breeds of dogs, especially Bedlington Terriers, an inherited sensitivity to copper toxicosis similar to Wilson's disease in humans has been identified. Acute poisoning is usually seen after accidental administration of excessive amounts of soluble copper salts, which may be present in anthelmintic drenches, mineral mixes, or improperly formulated rations. For more information click here or call your veterinarian.

7.     Cyanide Poisoning

Cyanide inhibits cytochrome oxidase and causes death from histotoxic anoxia. Cyanides are found in plants, fumigants, soil sterilizers, fertilizers, and rodenticides ( eg, calcium cyanomide). For more information click here or call your veterinarian.

8.     Fluoride Poisoning (Fluorosis)

Acute poisoning from inhalation of fluorine-containing gases or from ingestion of rodenticides or ascaricides containing fluoride is rare. Oral cleaning products present a danger to pets, especially dogs. The fatal dose of sodium fluoride is 5-10 mg/kg and toxic effects occur below 1 mg/kg. For more information click here or call your veterinarian.

9.     Gossypol Poisoning

Gossypol poisoning, which is usually subacute to chronic, cumulative, and sometimes insidious, follows consumption of cottonseed or cottonseed products that contain excess free gossypol. It has been reported in dogs fed cottonseed meal in diets. For more information click here or call your veterinarian.

10. Halogenated Aromatic Poisoning (PCB, PBB, Dioxins, and others)

Common persistent halogenated aromatics (PHA) include polychlorinated and polybrominated biphenyls (PCB, PBB), naphthalenes, benzenes, and diphenyl ethers (PCDE, PBDE), as well as a number of pesticides such as DDT. Unwanted byproducts formed during manufacture and heating or burning of chlorophenoxy herbicides, chlorophenols, or PCB include polychlorinated dibenzofurans (PCDF) and dibenzo-p -dioxins (PCDD). For more information click here or call your veterinarian.

11. Herbicide Poisoning

Herbicides are used routinely to control noxious plants. Most of these chemicals, particularly the more recently developed synthetic organic herbicides, are quite selective for specific plants and have low toxicity for mammals; other less selective compounds ( eg, arsenicals, chlorates, dinitrophenols) are more toxic to animals. When used properly, problems are rare. For more information click here or call your veterinarian.

12. Lead Poisoning

In veterinary medicine, lead poisoning is most common in dogs and cattle. Sources of lead include paint, linoleum, grease, lead weights, lead shot, and contaminated foliage growing near smelters or along roadsides. Lead poisoning is also encountered in urban environments, and renovation of old houses that have been painted with lead-based paint has been associated with lead poisoning in small animals and children. For more information click here or call your veterinarian.

13. Mercury Poisoning

Mercury exists in a variety of organic and inorganic forms. The replacement of commercial mercurial compounds, including antiseptics ( eg, mercurochrome), diuretics, and fungicides by other agents has decreased the likelihood of mercurial toxicosis; however, the possibility of exposure to environmental sources of organic methylmercury exists. For more information click here or call your veterinarian.

14. Metaldehyde Poisoning

Metaldehyde is the active ingredient in molluscicides used especially during the wet season for slug and snail control in domestic gardens. In certain locations, it is also used for rat control. Metaldehyde comes as a liquid or bait (3.5%) combined with bran, either as flakes or pellets, and is palatable to pets and farm animals. For more information click here or call your veterinarian.

15. Mycotoxicoses: aflatoxicosis

Aflatoxins are produced by toxigenic strains of Aspergillus flavus and A parasiticus on peanuts, soybeans, corn (maize), and other cereals either in the field or during storage when moisture content and temperatures are sufficiently high for mold growth. Aflatoxicosis occurs in many parts of the world and affects dogs. For more information click here or call your veterinarian.

16. Selenium Toxicosis

Selenium is an essential element that has a narrow margin of safety. Parenteral selenium products are also quite toxic, especially to young animals, and have caused deaths in baby pigs, calves, and dogs at doses as low as 1.0 mg/kg. For more information click here or call your veterinarian.

17. Snakebite

Fatal snakebites are more common in dogs than in any other domestic animal. Due to the relatively small size of some dogs in proportion to the amount of venom injected, the bite of even a small snake may be fatal. Snakebite, with envenomation, is a true emergency. Rapid examination and appropriate treatment are paramount. Owners should not spend time on first aid other than to keep the animal quiet and limit its activity. For more information click here or call your veterinarian.  

18. Spider Bites

Envenomation of animals by spiders is relatively uncommon and difficult to recognize. It may be suspected on clinical signs, but confirmatory evidence is rare. Spiders of medical importance in the USA do not inflict particularly painful bites, so it is unusual for a spider bite to be suspected until clinical signs appear. For more information click here or call your veterinarian. 

19. Toad Poisoning

Dogs and, less frequently, cats may be poisoned by oral exposure to many types of toads. Severity varies greatly, depending on extent of contact and type of toad. Venom is produced by all toads, but its potency varies with species and apparently between geographic locations within individual species. For more information click here or call your veterinarian. 

20. Zinc Toxicosis

It is seen commonly in pet dogs, possibly because of a higher degree of dietary indiscretion and greater levels of exposure to zinc-containing substances. Common sources of zinc include batteries, automotive parts, paints, zinc-oxide creams, herbal supplements, zippers, board-game pieces, screws and nuts on pet carriers, and the coating on galvanized metals such as pipes and cookware. One of the most well known sources of zinc that causes toxicity following ingestion is the USA Lincoln penny. For more information click here or call your veterinarian.