Toxicity of Kalanchoe in dogs and cats
As the scientific community shows greater interest in research, the medicinal uses of cannabis are becoming more popular in veterinary practice. This has resulted in the diversification of treatment alternatives for the welfare of dogs and cats.
However, specialists have made several calls to warn about the problems that could occur in animal patients. Poisoning is one of the most talked about issues. Among the most common cases is Kalanchoe.
According to the American Society for the Prevention of Cruelty to Animals (ASPCA), this plant can be toxic to dogs and cats. While in humans it is used as a complementary treatment, in these companion animals, its administration can range from intoxication to death.
Let's get to know silver: characteristics and chemicals that make it up
Kalanchoe is a genus of plants belonging to the Crassulaceae family. It comprises 100 species native to tropical areas. [2,4,7] It is characterized by its bright and vivid flowers ranging from white to golden orange and red. [2]
Its extracts have diverse biological activities and are composed of different substances. Among them are: polysaccharides, flavonoids, sterols, ascorbic acid, trace elements, organic acids, hydrocarbons, triterpenoids, phenolic compounds and bufadenolides. The latter are responsible for intoxication in animals. [1,2,6] That is to say: those that cause frequent and irregular depolarization of the cell, which in patients manifests itself through arrhythmias. The risk is that the dog or cat suffers cardiac arrest.
How to detect Kalanchoe poisoning?
The absorption of toxic substances is rapid. The first signs appear 30 to 45 minutes to a few hours after ingestion. [2,5]
Since all parts of the plant are considered toxic, consumption of a few seeds or one to two leaves may be sufficient to cause serious clinical signs. Therefore, great caution should be exercised when in the vicinity of dogs and cats. Dogs are reported to be particularly sensitive to the cardiotoxic effects of the plant. [5,7]
Signs that appear in the early stages of toxicosis: [1-3,5,6].
depression,
vomiting,
excessive salivation
diarrhea with or without blood.
They are also considered as symptoms:
weakness
dyspnea
anorexia
mydriasis
tachycardia
tremors
vocalizations
comma.
As toxicosis progresses, severe arrhythmias with atrioventricular block may occur. Animals may develop severe weakness and cold extremities, collapse and eventually die.
The course is usually rapid (12 to 24 hours), but in some cases, signs may persist for four to five days and in severe cases death by asystole may occur. [5,6]
In the United States, neurological signs, including nystagmus, delirium, mild convulsions and tetany, have been reported in dogs consuming these plants. [2]
Other species that can be intoxicated with this plant
In cattle, the most common clinical sign is sudden death due to the profound cardiac effects of the toxin. Other signs observed are collapse, cyanosis, arrhythmias, dyspnea, and persistent diarrhea. [1,4,5]
In South Africa a neurological syndrome, called "krimpsiekte", has been well described in sheep and goats, which is associated with long-term ingestion of Kalanchoe species, involving progressive paresis of the limbs and neck. Animals eventually become paralyzed and usually have to be euthanized. The condition has also been reported in dogs in South Africa. [1,6]
Animals at greatest risk
Dogs of certain breeds such as collies, Australian and German Shepherds and Dobermans are more sensitive to the effects of central nervous system toxicity. Cases of poisoning in males tend to be more frequent than in females. In animals with a history of renal or cardiac disease (especially those receiving digoxin or other medications) the risk is higher. [1,5]
The prognosis for intoxicated patients is good if they present moderate gastrointestinal signs and are taken promptly to the veterinarian. On the other hand, patients with severe gastrointestinal signs will be more prone to cardiovascular problems and together with patients with arrhythmias, their prognosis will be reserved. In some cases the patient will require hospitalization for several days. [2,5]
It is worth mentioning that if active ingredients such as Kalanchoe are added to full spectrum products -which contain unknown or high amounts of THC-, the prognosis tends to be reserved. This is due to the risk of suffering a double intoxication affecting the cardiac and central nervous system.
Conclusions
As the medical cannabis industry advances and develops, it is vitally important for veterinarians and dog and cat guardians to be aware of the ingredients in the products they give to their patients and/or pets. They should verify that they are not toxic.
Likewise, it is essential to be cautious and not to use products that are intended for humans. Although in many cases the active principles implemented in human medicine are used in veterinary medicine, there are compounds that can be toxic and in some cases even lethal.
References
Diseases of the cardiovascular system (2017). In Veterinary Medicine (pp. 657-715). Elsevier.
Gwaltney-Brant, S. M. (2013). Christmastime Plants. In Small Animal Toxicology (pp. 499-511). Elsevier.
Kalanchoe. (s.f.). ASPCA. Recuperado de <Sitio web>, última consulta 5 de agosto de 2022.
Milad, R. (2014). Genus Kalanchoe (crassulaceae): A review of its ethnomedicinal, botanical, chemical and pharmacological properties. European Journal of Medicinal Plants, 4(1), 86–104. https://doi.org/10.9734/ejmp/2014/5901
Osweiler, G. D., Hovda, L., Brutlag, A., & Lee, J. A. (Eds.). (2011). Blackwell's five-minute veterinary consult clinical companion: Small animal toxicology (1st ed.). John Wiley & Sons.
Smith, G. (2004, November 1). Toxicology Brief: Kalanchoe species poisoning in pets. DVM 360. Recuperado de <Sitio web>, última consulta 5 de agosto de 2022.
Smith, G. F., Figueiredo, E., & van Wyk, A. E. (2019). Biocultural Significance and Toxicity. In Kalanchoe (Crassulaceae) in Southern Africa (pp. 105-110). Elsevier.
