Calamondin Orange Poisoning in Dogs

The calamondin orange plant is a small citrus tree that is mainly used as an ornamental plant. It is an attractive plant, with fragrant white flowers that develop into small orange fruits, and is sometimes favored as a bonsai plant. The fruit is edible and has been used in place of limes in iced tea or as a garnish to seafood, and it makes an excellent marmalade. Unfortunately, calamondin orange has the same pet-toxic components as other citrus fruits and can cause serious health problems when ingested by our pets.

The calamondin orange plant, like other citrus plants, produces limonene and linalool, as well as phototoxic compounds called psoralens. Although safe for humans, these substances are toxic to canines.

Symptoms of poisoning from citrus fruits like the calamondin orange plant are caused by a combination of the essential oils limonene and linalool, and the phototoxic compounds known as psoralens.

• Cold limbs
• Collapse
• Depression
• Diarrhea
• Excessive drooling
• Lethargy
• Loss of coordination
• Low blood pressure
• Photosensitivity 
• Skin irritation
• Sudden death
• Tremors
• Vomiting
• Weakness

Types

While the essential oil limonene is generally restricted to all sorts of citrus plants, both linalool and psoralens are found in other plants as well. Other plants with high concentrations of psoralens:

• Anise seeds
• Caraway seeds
• Carrots
• Celeriac
• Celery
• Chervil
• Cilantro
• Coriander seeds
• Cumin seeds
• Dill
• Fennel seeds
• Figs
• Grapefruit
• Lemons
• Limes
• Lovage
• Mustard seeds
• Parsley
• Parsnips
• Root parsley

Some of the plants that contain Linalool

• Beech trees 
• Cinnamon
• Laurels
• Mint plants
• Rosewood

The toxicity of the calamondin orange plant lies in the essential oils Limonene and Linalool, as well as in the phototoxic compound psoralen.

• Limonene - A terpene produced in all citrus fruits and is the main component in the aroma of the different citrus fruits, often used in cosmetic products, flavoring compounds, and cleaning products; D-limonene is often safely employed in dog shampoos and fragrances; it is important to note that the amount of d-limonene in these shampoos, although safe for most canines, can be deadly to use on cats 
• Linalool - A terpene that contributes a floral scent to the citrus aroma, linalool is often utilized in soaps and lotions as a fragrance as well as being employed as an insecticide
• Psoralen - A compound found in many plants, including citrus plants like the calamondin orange, it is used as a treatment for skin disorders but can induce phototoxicity

If you catch your pet consuming any part of the calamondin orange plant, identification of the plant combined with the signs and symptoms may be enough to posit an initial diagnosis. Your veterinarian will question you regarding the amount of plant material ingested, what part of the plant was eaten, and how long ago this occurred, as these factors can help to determine the most effective treatment plan. If consumption of the plant was not witnessed, a blood chemistry profile, complete blood count, and urinalysis will be required in order to determine what toxin is causing the distress, and any skin interaction will be noted. Vomit or stools will be analyzed as well, and plant material may be found and tested. Neurological testing to measure your pet’s reflexes and coordination may also occur during the diagnostic appointment. These evaluations are done in an attempt to pinpoint the specific areas of the nervous system that have been affected.

Any areas of the skin that have been exposed to the oil of the citrus plant should be immediately washed with a mild soap and water. Many dog shampoos include limonene and linalool as a fragrance, and these should not be used if you are attempting to remove citrus oil. Inducing vomiting is not generally recommended to avoid breathing any of the oils into the lungs.

Gastric irrigation, usually under general anesthesia, will be performed on the patient to physically remove as much of the toxin from the digestive system as possible. Activated charcoal will then be administered to prevent any further absorption of the toxic compound into the bloodstream. There is no specific antidote for either the essential oils or for the psoralens, so treatment beyond decontamination is generally supportive. This can include IV fluids for dehydration as well as mixtures of electrolytes and sugars to adjust for any imbalances that develop. Oxygen will be provided to your dog if breathing is becoming more difficult and antiseizure medications may be administered if tremors become acute.

A calm, quiet setting to return home to will help speed recovery for the patient. Although symptoms of the poisoning usually last only a few hours, dogs that are recovering from anesthesia, as would be required for gastric lavage, may have coordination difficulties and confusion until both the toxic components and the sedatives have fully cleared the patient’s system. In the case of citrus poisoning, cases of phototoxicity have developed, and your pet should be sheltered from sunlight for around 48 hours after treatment to prevent skin reactions. Your veterinarian may also recommend regular monitoring of blood chemistry levels for your pet after any type of poisoning, particularly in relation to liver and kidney functionality or impairment.