Many plants or their seeds contain substances that are metabolized in the animal’s organism to form hydrocyanic acid. This can lead to hydrocyanic acid poisoning.
Ornamental plants such as the cherry laurel, but also many types of fruit (plums, peaches, apricots, etc.) contain so-called “cyanogenic glycosides” in some parts of the plant. These are plant substances that are processed by plant enzymes, which produce hydrocyanic acid (cyanide). In the case of plums or peaches, it is the stone, in the case of cherry laurel, a very popular ornamental plant in German gardens, all parts of the plant. Fruit stones are especially a problem when they are bitten. If they remain whole, they pose a greater risk of intestinal obstruction.
Other sources of prussic acid poisoning include illegal industrial effluents, but this is rare in animals. Cyanide disrupts respiration at the cellular level. This means that the inhaled oxygen cannot be used and no more energy is made available to the cells.
Symptoms of prussic acid poisoning in animals
Symptoms of hydrogen cyanide poisoning vary depending on the amount ingested. If large amounts of hydrocyanic acid are directly ingested, the animal can die within a short time (seconds to minutes). However, since the hydrogen cyanide has yet to be formed in the case of vegetable glycosides, the process tends to be slower and can last for several hours. The amount absorbed is also important for cyanogenic glycosides. Depending on the animal species, small amounts lead to symptoms of illness, but are not fatal.
Possible signs of prussic acid poisoning are:
- heavy salivation
- Difficulty breathing with increased respiratory rate
- falling blood pressure, very low or very high heart rate
- dilated pupils
- convulsions, tremors
- strong excitability
- rigid head position with the head tilted back
- bright red mucous membranes
- Breathing air smells of bitter almond oil
If large amounts of hydrocyanic acid are consumed and left untreated, the animals eventually fall into a coma and die.
When should you go to the vet?
Does your pet have trouble breathing, is it salivating heavily, or is it having seizures? In any case, go to the veterinarian so that the cause of this can be clarified. Breathing problems, for example, can of course have much more harmless reasons than hydrogen cyanide poisoning. However, if you notice the smell of bitter almonds in the air you breathe, you should definitely react quickly, because this is a characteristic sign of prussic acid poisoning.
Diagnosis and therapy of prussic acid poisoning
Based on the symptoms of the disease, the veterinarian will have a suspicion if you cannot tell him what your animal has eaten anyway. A blood sample can be used to determine the content of a metabolic product that gives an indication of the extent of the poisoning.
If the animal has eaten plants containing hydrocyanic acid but has not yet shown any symptoms, it is given an emetic so that it can be vomited up again. With the administration of activated charcoal, toxins can be bound and eliminated harmlessly, so this is done in parallel.
If there is already visible poisoning, there are several drugs that can be used to try therapy. They bind the hydrocyanic acid and make it harmless. Depending on the condition of the animal, the veterinarian may decide that hospitalization is necessary. Hydrocyanic acid is only slowly broken down by the organism and symptoms could reappear after some time.
Prognosis and prophylaxis
In the case of hydrogen cyanide poisoning, a rather cautious prognosis for healing can always be assumed.
To avoid prussic acid poisoning, check your ornamental plants in the home and garden for toxicity to your pets. Don’t leave stone fruit pits unnoticed, e.g. in the kitchen for your dog to play with and chew on.