What is Oregon Holly Poisoning?
The Oregon holly tree can grow up to 50 feet and has smooth gray bark, glossy green oval-shaped leaves with sharp spines, and the berries start out as small green flowers, changing to round, red berries when ripe. These contain many different toxic properties, such as methylxanthine, ilicin, theobromine, ilexanthin, ilex acid, and saponins. Even though dogs do not usually eat more than one or two leaves because of the pain from the spines, the berries are small and many can be consumed in just one bite. The methylxanthine in the berries is also found in chocolate and is thought to cause a reaction similar to chocolate poisoning; the signs may be rapid heart rate, tremors, fever, coma, and death.
Oregon holly trees are dangerous to dogs for more than one reason. The fruit (berries) contain poisonous substances, the pointed leaves can cause puncture wounds, and the foliage is so hard to digest it can cause a bowel obstruction or block the airway. The poisons in the fruit include saponins, caffeine, tannins, and several others. In fact, the fruit is so toxic that 10 or more berries can cause death in a large dog, and they are even poisonous to humans. Some of the side effects of Oregon holly poisoning are diarrhea, vomiting, gagging, and whining. However, the symptoms may be more severe and can include coma, seizures, and death.
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Symptoms of Oregon Holly Poisoning in Dogs
There are varying degrees of severity in the symptoms of Oregon holly poisoning. Some of the most common are:
- Smacking lips
- Excessive drooling
- Scratching at mouth and face
- Shaking head
- Not drinking or eating
- High body temperature
- Abdominal pain
- Appetite loss
- Loss of weight
- Rapid heartbeat
- Throat swelling and wheezing
- Difficulty breathing
- Convulsions (rare)
- Coma (rare)
- Death (rare)
The botanical name of Oregon holly is Ilex opaca of the Aquifoliaceae family. Some of the other common nicknames are:
- American holly
- Box-leaf holly
- Chinese holly
- Christmas holly
- Common holly
- English holly
- European holly
- Japanese holly
Causes of Oregon Holly Poisoning in Dogs
There are many ways that Oregon holly can be dangerous to your pet, such as:
- The foliage has sharp points that can injure your pet’s mouth, tongue, throat, and gastrointestinal tract
- There are saponins in the berries that irritate the stomach, damage red blood cells, and alter mucosal cells in the digestive system
- There are several other toxic substances that can cause side effects, which are ilex acid, ilexanthin, ilicin, theobromine, tannins, and methylxanthine
Diagnosis of Oregon Holly Poisoning in Dogs
Diagnosis of Oregon holly poisoning may be difficult unless you see your pet eating part of the tree because the symptoms can be similar to many other disorders, such as chocolate toxicity and intestinal upset. If you believe your dog has Oregon holly poisoning, bring a sample of the tree, such as a leaf, or even a photograph. This can help the veterinarian get the right diagnosis and treatment. Make sure you mention if your pet is on any kind of medication, over the counter and prescription, and bring medical and shot records with you if you can. You should also tell the veterinarian about any symptoms you have noticed and how long ago they started.
A complete physical examination will be done first, including height, weight, age, coat and skin condition, reflexes, oxygen level, blood pressure, heart rate, respiration rate, and breath sounds. The veterinarian may use an endoscope (long flexible tube with a lighted end) to view your pet’s throat and upper airway to see if there is any swelling or obstruction. If there are any plant particles or sap, the veterinarian can insert a tool to remove it. During this procedure, which is called an endoscopy, your dog will be sedated and have intravenous (IV) fluids and oxygen. Abdominal x-rays (digital radiographs) and an ultrasound can be used to check for intestinal obstructions, inflammation, and damage from the spiny leaves. If necessary, an MRI or CT scan can show more detailed images. Laboratory testing will include a biochemistry profile, urinalysis, CBC (complete blood count), liver enzyme panel, and possibly a packed cell volume (PCV) to check for dehydration.
Treatment of Oregon Holly Poisoning in Dogs
The treatment for Oregon holly poisoning can include several options depending on the test results, your dog’s overall health, and severity of the symptoms. The most common treatment includes:
Emetics, such as peroxide or ipecac, will be given to instigate vomiting. Afterward, gastric absorbing products, such as activated charcoal, can be given to absorb any undigested sap and poisons.
If your veterinarian has not already started an IV, one will be started now to administer fluids. This will flush out your pet’s kidneys and help with dehydration from vomiting and diarrhea.
Medications and Other Treatments
Oxygen therapy may be given if not already started during endoscopy, antibiotics to prevent infection, corticosteroids to reduce inflammation and pain, stomach protectants, and antiemetics if vomiting persists.
Recovery of Oregon Holly Poisoning in Dogs
The veterinarian will want you to observe your pet carefully for the next 24 - 72 hours for signs of complications. You should continue the prescriptions until complete and bring your pet back for a follow up examination as directed by your veterinarian. Be certain to keep all plants out of reach of your canine companion.