|
ANTIFREEZE |
|
Why
do cats & dogs lick or drink antifreeze? |
| |
Because it tastes
sweet due to the "glycol" sugar base. |
| There are three common types of
antifreeze: ethylene glycol, propylene glycol and methanol. |
|
ETHYLENE GLYCOL |
|
Source |
| Ethylene glycol is found in various
compounds, and is the main component of many forms of automotive antifreeze
and other engine coolants. It can also be found in a number of industrial
solvents, rust removers and color film processing fluids. |
| Symptoms |
| First Phase (1-4 hours) |
- Incoordination (acting “drunk”), stumbling, swaying
- Increased respiratory rate / panting
- Increased thirst
|
| Second Phase (4-6 hours): |
- Anorexia (no interest in food)
- Depression
- Vomiting
- Decreased body temperature
- Coma
|
| Third Phase (after 6
hours): |
- Severe vomiting
- Severe anorexia and depression
- Coma
- Seizures
- Minimal to no urine production
|
| Toxicity |
| Ethylene glycol is metabolized to glycolic acid, which is
further metabolized to form very toxic compounds. The kidneys can become
severely and permanently damaged from ethylene glycol exposure. |
| Diagnosis |
| Although ethylene glycol poisoning is definitively
diagnosed by detecting the presence of ethylene glycol in the blood, other
blood tests and a urinalysis can help confirm the diagnosis. Animals
poisoned by ethylene glycol typically form a certain type of crystal in the
urine known as calcium oxalates. Blood work shows progressive elevation of
the kidney values as the toxicity manifests. |
| Treatment |
| Treatment is based on removing the ethylene glycol from the
animal’s body and/or preventing it from being broken down into toxic
metabolites. Detoxification may include the induction of vomiting (within
20-40 minutes), feeding an activated charcoal suspension, and administering
intravenous fluids. Inducing vomiting in animals that are already
symptomatic is not recommended since they are at increased risk of
aspirating their vomit. The drug 4-methylpyrrazole (4-MP) is the treatment
of choice in treating dogs with ethylene glycol intoxication. 4-MP has been
proven to be effective in dogs, but not in other veterinary species as of
yet. This drug, although expensive, can prevent the ethylene glycol from
being broken down into toxic compounds if administered within the first
several hours after exposure. Giving ethanol intravenously can have the same
effect as 4-MP, and is an alternative therapeutic choice when 4-MP is not
available. |
|
Prognosis |
| Prognosis is based on the amount of ethylene glycol
ingested as well as the length of time that elapses between exposure and
treatment. Animals that are not treated promptly have a poor to guarded
prognosis. If significant kidney damage has occurred from the toxic
metabolites of the ethylene glycol, the only option for treatment is to
attempt dialysis of the blood for multiple weeks in the hope that some
kidney function may return. |
| |
| Source |
| Like ethylene glycol, propylene glycol can be found in some
forms of automotive antifreeze as well as other engine coolants. It is also
present in a variety of food, pharmaceutical and cosmetic agents. |
| Symptoms |
- Ataxia / Incoordination (acting “drunk”)
- Increased respiratory rate / panting
- Anorexia
- Depression
- Vomiting
- Decreased body temperature
- Seizures
- Coma
|
| Toxicity |
| Although it is not as toxic as ethylene glycol, significant
ingestions of propylene glycol can lead to intoxication similar to that seen
with other alcohols. Propylene glycol toxicity does not cause kidney damage
the way ethylene glycol does. |
| Diagnosis |
| Although propylene glycol poisoning is definitively
diagnosed by detecting its presence in the blood, other blood tests can help
confirm the diagnosis. |
| Treatment |
| Treatment is based primarily on supportive medical care and
aggressive IV fluid diuresis. Decontamination by inducing emesis can be
attempted if the animal is asymptomatic and if the exposure was within 20-40
minutes. |
| Prognosis |
| The prognosis in cases of propylene glycol ingestion is
usually good provided the animal receives prompt medical attention. |
| METHANOL
(methyl alcohol, wood alcohol) |
| Source |
|
Windshield washer fluid is the most commonly
encountered form of methanol. |
| Symptoms |
- Incoordination (acting “drunk”)
- Increased respiratory rate / panting
- Anorexia
- Depression
- Vomiting
- Diarrhea
- Decreased body temperature
- Seizures
- Coma
|
| Toxicity |
| Methanol is metabolized to formic acid which causes
acidosis and damages the central nervous system. Cardiac arrhythmias can
also occur from methanol toxicity. |
| Diagnosis |
|
Detection of metabolic acidosis on blood work combined
with clinical signs and a history of exposure to windshield washer fluid
(and not to ethylene or propylene glycol) is usually enough to establish a
diagnosis. |
| Treatment |
| Treatment is based primarily on supportive medical care.
Decontamination by inducing emesis can be attempted if the animal is
asymptomatic and if the exposure was within 20-40 minutes. |
| Prognosis |
| The prognosis in cases of methanol ingestion is usually
good provided the animal receives prompt medical attention. |
|
