Hibiscus Poisoning in Dogs

The hibiscus plant has 679 different species of many sizes, colors, and even shapes. Most of these are perennials, but a few are annuals. The most commonly grown is hibiscus syriacus, or rose of Sharon, which is a perennial that is grown as a bush or tree that can get up to 12 feet tall. Due to the variety of hibiscus, among other plants, you should always know what is growing in your yard (and inside your home) if you have a dog that spends time out there. If your pet decides to snack on these pretty plants, it can cause gastric irritation, burning and blistering of the mouth and tongue, and eye pain. In some cases, the burning and blistering can impede your dog’s ability to swallow, which can be dangerous.

Hibiscus poisoning is a condition caused by eating part of a hibiscus plant, including the root. The plant itself contains asparagine, which is an amino acid that can produce vomiting, diarrhea, loss of appetite, and a dermal burn and blistering that can interfere with eating and drinking. There are several other toxic properties in the roots and foliage of the hibiscus that have not been identified yet. These substances cause diarrhea and nausea similar to asparagine.

Since there are several different properties in the hibiscus plant and so many different species, the symptoms may vary and can be either mild or severe. In addition, if your dog somehow gets ahold of hibiscus root, the side effects are almost always severe. Here are some symptoms that have been reported:

• Burning of mouth or throat (scratching at mouth and face)
• Eye pain and damage to cornea (if eye contact occurs)
• Nausea and vomiting
• Diarrhea
• Coughing and gagging
• Swelling and blistering in the mouth or tongue (can affect swallowing)
• Inability to eat or drink

 Types

The hibiscus genus is part of the Malvaceae family and has over 650 types in various shapes, colors, and sizes. Some of the most common hibiscus plants are:

• Hibiscus syriacus
• Marsh mallow
• Rose mallow
• Rose of China
• Rose of Sharon
• St. Joseph’s rod
• Syrian ketmia

There are several substances in the hibiscus plant, including the foliage, flower, and roots.  

• Asparagine
• Other unknown chemicals

To accurately diagnose your dog with hibiscus poisoning, the veterinarian will usually want to rule out any other illnesses and diseases. If you know for sure that your dog ate a hibiscus, bring a sample or photograph of the plant so she will know exactly which type of hibiscus your dog consumed. Let her know how much you think was eaten and any signs of poisoning you have noticed, if any. If you do not have your pet’s medical records, be sure to let the veterinarian know if your dog is on any kind of medicine or has been ill lately. Any changes in diet or strange behavior should be noted as well.

Your veterinarian will do an extensive physical examination of your pet, which usually includes body weight, temperature, blood pressure, skin and coat condition, pulse, and breath sounds. In addition, a urine and stool sample may be taken for microscopic examination to rule out infection or parasites. The stool sample may also contain portions of the plant so your veterinarian will know it is at least partially digested.

Laboratory tests needed for diagnosis include complete blood count (CBC), blood urea nitrogen (BUN), chemistry profile, liver panel, and a packed cell volume (PCV) to check for dehydration due to diarrhea and vomiting. The veterinarian may also want to do an endoscopy to get a look at your dog’s throat, esophagus, and upper airway. This is especially important if your dog is having swallowing or eating difficulty because of blistering or inflammation. Abdominal radiographs (x-rays) are useful in determining if there are any plant particles or obstructions. An ultrasound may also be used to get a more detailed view.

Treating hibiscus poisoning is usually treated just like many other plant poisonings. The usual treatment consists of evacuation by emesis, detoxification with fluids, and observation.

Evacuation

To precipitate evacuation, the veterinarian will give your dog ipecac or a peroxide solution to induce vomiting. This may be followed by activated charcoal given by mouth to absorb any remaining toxins.

Detoxification

Detoxification includes intravenous (IV) fluids to flush the kidneys thoroughly. This also prevents dehydration from vomiting and diarrhea.

Medication

If your pet has any blisters or burns, the veterinarian will apply a topical ointment or lotion and will send you home with some to apply three times a day. If the blisters are on the inside of your dog’s mouth and throat, your veterinarian will administer a cortisone injection and may send you home with some spray to apply as necessary.

Observation

Your veterinarian will decide whether your dog needs to stay for observation or if you can observe your pet from home. It usually depends on how well your dog is responding to the treatment.

If you received treatment right away, your pet should be back to normal within a few days. Continue to observe your pet and be sure to apply the medication as directed. Make sure your dog does not have access to the hibiscus plant in the future to prevent another episode.