Poisons
Some Common Substances Toxic To Dogs
Since toxic chemicals are found in all areas of the animal's environment, exposure may occur through a
variety of routes. Most commonly, exposure occurs by inhalation of contaminated air, by application to or through
the skin, or by oral ingestion.
The major groups and specific agents commonly observed to cause poisoning in dogs are:
- Rodenticides: Strychnine, Sodium flouroacetate (1080), Thallium,
Warfarin, Metaldehyde.
- Insecticides: Chlorineted hydrocarbons, Organophosphorus
compounds, Carbamates.
- Heavy Metals: Lead, Arsenic.
- Herbicides And Fungicides
- Poisonous Plants: Mycotoxins, Algae, Ivy, Mushrooms.
- Environmental Contaminants: Ethylene glycol,
Garbage, Phenols.
Most rodenticide poisonings are the result of careless placement of baits, overuse of baits, failure to discard
poisoned rodents, and malicious poisonings.
Anticoa Gulant Rodenticides
- The most commonly used rodenticides - used by the lay person, professional exterminators and for agricultural
rodent control.
- Clinical Signs: There is a latent period of two to five days before clinical effects are observed. The
poisoned animal may be found dead with no history of illness as a result of haemorrhage in vital areas. Less acute
cases exhibit depression, lethargy, pallor, anaemia, and weakness. Haemorrhaging is often noticed through a bloody
nose.
Strychnine
- It is the primary toxicant in malicious poisonings. Strychnine is used as a pesticide. Commercial formulated
baits are often pelleted and dyed green or purple.
- Clinical Signs: The onset of strychnine effects occur within ten minutes to two hours after ingestion.
Affected animals appear nervous and apprehensive, developing a tense abdomen and saw-horse stance. This progresses
to violent, intermittent seizures. Death occurs in one to two hours after onset if not treated.
Sodium Fluoroacetate (1080)
- Dogs are very susceptible to poisoning by 1080. 1080 is used to control rodents such as rabbits. Dogs are
usually poisoned by eating contaminated rodents.
- Clinical Signs: There may be an initial period of restlessness, followed by hyperesthesia and vocalization.
Repeated defecation and urination are characteristic. Dogs die of convulsions or subsequent respiratory paralysis
within one to four hours of eating a lethal dose.
Warfarin
- Commonly found in rat and mouse baits. Generally a slow acting poison.
- Clinical Signs: Causes internal bleeding, leading to anaemia, depression, difficult breathing, convulsions and
death in severe cases.
Cyanide
- Extremely poisonous chemical compound. Used in New Zealand in the form of a paste to kill possums, and is
usually used in conjunction with a lure of flour or jam. Dogs are usually poisoned by eating a contaminated possum
carcass.
- Clinical Signs: The poisoned dog may be found dead for no apparent reason. Cyanide is very fast acting and in
most cases, without an immediate emetic. the dog will die before veterinary attention can be sought.
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- Intoxication has occurred from a variety of compounds. Exposure is usually the result of improperly stored or
disposed of preparations, spilled mixtures or containers left open where dogs may have access to them. Dogs have
been poisoned by applying preparations intended for another species, an overly aggressive control program for
internal/external parasites, and by oral ingestion of insecticides such as snail bait. Other common insecticides
include sheep dips, flea powders and flea washes.
- Clinical Signs: Each animal may not exhibit all possible effects. Early in the poisoning symptoms are
uneasiness and apprehension, progressing to licking, chewing or swallowing motions (associated with increased
salivation) and muscular twitching around the face and eyes. As the poisoning progresses abdominal pain, cramping,
vomiting, defecation, end frequent urination commonly occur. Wetness around the lips, froth and slobbering are
noticed. Muscular twitching progresses to whole body muscle fasciculations that become evident over the back of
the animal. Death occurs within minutes to hours after onset of clinical signs and results from respiratory
failure.
Arsenics
- Inorganic arsenicals are used in insecticides, herbicides, pesticides, insulation, paint pigments, wood
preservatives and detergents.
- Clinical Signs: Arsenic is a severe gastrointestinal irritant and commonly produces initial signs of vomiting,
restlessness. and abdominal pain evidenced by whining and a defensive abdominal wall. A profuse, often bloody
diarrhoea results. This leads rapidly to weakness, dehydration and anaemia. Signs occur within 30 minutes of
ingestion and death occurs in a few hours.
Lead
- Lead is commonly found in old paints, toys, lubricants, gasoline, batteries, galvanizing, improperly glazed
dishes, and many other sources. Lead accumulates in the body as do other heavy metals.
- Clinical Signs: Often vague and non-specific. Occasional vomiting, depression. constipation, anorexia, colic,
a wasting syndrome, dehydration, diarrhoea and thirst. Nervous effects observed later include chomping of the
jaws, hysteria, epileptic form of convulsions, partial paralysis end blindness. The overriding prominence of
nervous signs has often lead clinicians to diagnose distemper in young dogs suffering from lead intoxication. If
untreated, death may occur several weeks after clinical signs begin, due to respiratory arrest.
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Herbicides
- In addition to toxicity from arsenic herbicides, dog toxicity is also occasionally observed from the phenol
containing herbicides and from the chlorate salts. The low cost of both these materials makes them popular with
local agencies for weed control. Only rarely are toxicities observed from 2,4,5-T and paraquat. No specific
antidotes are available for these chemicals.
- Clinical Signs: With few exceptions, clinical signs associated with herbicides are non-specific and include
loss of appetite, vomiting and diarrhoea. progressive muscular weakness and possible death.
Fungicides
- Although the various solvents used for currently employed fungicides may be toxic, by and large the chemical
fungicides themselves are of limited hazard. Methyl bromide, captan, dinitroorthocresol, carbamate fungicides and
organotin materials are potentially toxic.
- Clinical Signs: Usually similar to those observed in herbicide intoxication, but may include greater
involvement of the nervous system.
The accessibility of a numerous variety of plants around households, coupled with the tendency for dogs to play
with and chew on foreign objects. presents the constant hazard of pet poisoning due to the existence of poisonous
plant materials. Since the dog has a physiology basic anatomy similar to mans, plants that are toxic for human
beings should also be considered toxic for dogs.
The specific plant, amount eaten and the part of the plant consumed are vital in evaluating the potential toxic
effect.
Numerous toxic principles and syndromes are associated with contact or ingestion of a wide variety of
plants.
Some of the most commonly observed plant poisonings in dogs are those producing mechanical injury, digestive
tract irritation, and specific toxicity resulting from consumption of algae, mushrooms and fungi.
Commonly found poisonous plants include:
- Daphne
- English Ivy
- Flax
- Iris
- Lantana
- Larkspur
- Lily of the Valley
- Lobelia
- Oleander
- Poinciana
- Rhubarb
- Wisteraie
- Yew
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Household Products
The potential for household products to cause toxicity in dogs is significant because dogs are often confined
to the home. Among cleaners disinfectants, strong acids and alkalis are often used.
A variety of household compounds are potentially toxic:
- Dry cleaning fluid
- Fertilizers
- Furniture polish
- Matches
- Mothballs
- Laundry bleach
- Perfumes
- Shampoos
- Window cleaner
To name just a few!!
Clinical Signs: These can range from vomiting and diarrhoea to pneumonia.
Antifreeze
- Ethylene Glycol is found in antifreeze (up to 95%). It is odourless, colourless, and sweet tasting water-soluble
liquid.
- Clinical Signs: The first clinical stage occurs 30 minutes to 12 hours after ingestion and is characterised by
vomiting, depression, abnormal righting reflexes, generalized or focal seizures and coma.
Fuels
- Fuels consist of a variety of hydrocarbon compounds. They are widely used in household and commercial products,
such as charcoal lighters, cooking fuels, lighter fluid and fire kindlers. Kerosene, diesel oils and house heating
oils are included.
- Clinical Signs: Depending on the fuel, level of exposure and time since exposure. Exposure is an emergency.
Signs may include: Irritation to skin and mouth, diarrhoea, coughing, tremors, depression, seizures and coma.
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Prevention Of Poisoning
Dog Owner Education Is The Most Effective Method To Prevent Toxicosis In Dogs. Remember - Prevention Is Better Than Cure.
- If A Dog Has Access To A Poison, So May A Child
- Always Keep Poisons Out Of Reach Of Both Children And Animals, Either On A High Shelf Or Locked Away
In A cupboard.
If You Suspect Your Dog Has Been Poisoned
- Transport the dog to a Veterinarian as soon as possible.
If you are able, take with you the poison container, or a sample of the suspected source of poisoning and/or
vomitus in a clean plastic container or jar.
- Try to induce your dog to vomit by:
(Note: Do not induce vomiting if it appears the animal has ingested corrosive material e.g. Kerosene,
Acids or Alkalis)
- Crystal of washing soda on the back of the tongue.
- Mix 1 teaspoon Mustard and 1 teaspoon Salt in 1 tablespoon of water - this mixture will sometimes induce
vomiting.
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