Oregano Poisoning in Dogs

The oregano plant is a common perennial herb that is sometimes grown as an indoor potted plant. It can grow up to three feet tall and two feet wide with unmistakable scented leaves, tiny white, pink, or purple flowers. It is a woody and bushy plant native to Asia and Europe, but is now grown in the United States and Canada as well. Oregano plants are grown commercially to be cultivated for culinary uses, such as spices and herbal properties. The spice is recognized all over the world and most commonly known to be used in pizza and Italian dishes, like spaghetti. There are over forty species and several subspecies and varieties such as marjoram, thyme, sage, and basil.

Oregano poisoning is usually a mild condition caused by the consumption or ingestion of an oregano plant or the oregano herb. Although this spice is not very toxic, it may still cause intense digestive disturbances in your pet, including vomiting and diarrhea. It has also been known to cause more serious side effects in some rare cases, such as decreased heart rate, low blood pressure, and ulcers in the gastrointestinal tract. It is best to take your dog to see a veterinary professional if you suspect oregano poisoning.

The most common side effects of oregano poisoning in dogs are usually mild stomach irritation. However, it is possible for your pet to consume enough of this tasty herb to cause more dangerous symptoms like blood clotting disorders and low glucose levels. The most commonly reported signs of oregano toxicity are:

• Abdominal pain
• Vomiting
• Diarrhea
• Decreased blood glucose
• Slow heart rate
• Gastrointestinal ulcers
• Bruising and bleeding disorders (slow clotting time)

Types

The botanical name for the oregano plant is Origanum vulgare hirtum from the Lamiaceae family. There are some other names that the oregano plant is known by, such as:

• Common oregano
• Cuban oregano
• Greek oregano
• Mexican oregano
• Potted oregano
• Wild oregano
• Thymus vulgaris

Although it is not completely understood how oregano plants can affect your dog’s health, some of the reported irritants and toxic properties are:

• Flavones
• Monoterpenes
• Monoterpenoids
• Polyphenols
• Other unknown gastric irritants

Your dog should be thoroughly checked by a veterinary professional if you suspect oregano plant poisoning even if there are no symptoms. Try to bring a picture or part of the plant you believe your pet was eating to help with the diagnosis and treatment planning. Let the veterinarian know how much of the oregano you think was eaten and when it happened. Also, explain in detail any side effects that you have seen so far and if your dog is on any medication, whether they are prescriptions or over the counter drugs. If you have your dog’s immunization records it is a good idea to bring that with you as well as any medical records you have.

The veterinarian will then complete an examination of your dog, which commonly includes your pet’s weight, height, reflexes, temperature, blood pressure, breath sounds, pulse and respiratory rates, oxygen level, skin and coat condition. Additionally, a urine and stool sample will be taken for microscopic examination at this time. Some of the other laboratory tests that may need to be done include a CBC (complete blood count), BUN (blood urea nitrogen), liver enzyme panel, chemical profile to check glucose, protein, bilirubin, potassium, sodium, and creatinine, and a PCV (packed cell volume) to determine the level of dehydration from diarrhea and vomiting.

Another common procedure is an endoscopy in which the veterinarian uses an endoscope (flexible lighted tube) to look for inflammation, plant particles, and obstructions in the esophagus, throat, and upper airway. The veterinarian will be able to remove any foreign material at this time with tools that can be placed in the endoscope to get rid of plant residue and small blockages. Abdominal x-rays (radiographs) will also be necessary to look for intestinal blockages and inflammation. If more detailed views are needed, CT scans, an MRI, or an ultrasound may be suggested.

Oregano poisoning is usually treated like other plant toxicity cases, which commonly include removing the toxins with evacuation techniques, detoxification, medications as needed, and possible hospitalization (rare) for observation.

Evacuation

An emetic drug (ipecac) will be given to encourage vomiting for easy evacuation. If this is unsuccessful after 30 minutes the veterinarian may repeat the process. Activated charcoal will also be given by mouth to absorb any toxins still in your pet’s system.

Detoxification

To detoxify your dog, a gastric lavage may be necessary, but usually only if a large amount of oregano was consumed. Afterward, intravenous (IV) fluids will be administered to decrease chances of dehydration.

Medication

No medication is necessary in cases of oregano poisoning unless your dog is still having uncontrolled vomiting. In that case they will administer antiemetics and omeprazole.

Observation

There is no need for hospitalization to observe your dog because you can do this from home.

Your dog’s prognosis in the case of oregano poisoning is excellent. Even if your dog consumed a great deal of oregano leaves, with treatment your dog should recover within 24 - 48 hours. If you have concerns, contact the clinic; a member of the veterinary team will be able to answer questions and offer advice about your companion’s recovery.