Over-the-counter (nonprescription) nasal sprays and eye drops can pose a serious risk to animals that ingest them. The problem ingredients—imidazoline decongestants, phenylephrine, and xylitol—are common in products to treat allergies, colds, flu, and red eyes.
 
If your pet chews a nasal spray or eye drop bottle, call your veterinarian or an animal poison control hotline immediately. This type of poisoning is a medical emergency. Even small amounts of ingested product can be dangerous.
 
Pet poison hotlines (consultation fees apply):

• ASPCA Animal Poison Control: 888-426-4435, https://www.aspca.org/pet-care/animal-poison-control
• Pet Poison Helpline: 855-764-7661, https://www.petpoisonhelpline.com

 
Imidazoline Decongestants
Decongestants in the imidazoline class are found in many nasal sprays and eye drops that reduce nasal congestion and eye redness. Some of the drugs in this group are oxymetazoline, naphazoline, tetrahydrozoline, tolazoline, and xylometazoline. A few of the many brands that contain imidazolines are Afrin, Clear Eyes, Mucinex, Opcon, Privine, Sinex, Visine, and Zicam.
 
Imidazolines affect the heart, circulation, digestive system, and nervous system. They decrease nasal congestion and eye redness by narrowing small blood vessels in the nose and eyes.
 
Symptoms of imidazoline poisoning appear as soon as 15 minutes after ingestion of a large amount or a few hours after ingestion of a small amount. The symptoms last from about 12 to 36 hours and include the following:

• Vomiting
• Slow heart rate
• Abnormal heart rhythm
• Weakness
• Depression/drowsiness
• Tremors
• Coma[1]

 
Animals with imidazoline poisoning need to be hospitalized for treatment and monitoring. Reversal agents for imidazolines are available.
 
Phenylephrine
Imidazolines and phenylephrine have similar effects on the body. Like imidazolines, phenylephrine acts as a decongestant by shrinking small blood vessels in the nose.
 
Phenylephrine is available in oral forms, nasal sprays, eye drops, and hemorrhoid creams. Two brands of nasal spray that contain phenylephrine are Little Remedies and Neo-Synephrine. Ingestion can cause vomiting, agitation, hyperactivity, and increased blood pressure.[2]
 
Xylitol
Some nasal sprays, including some with labels reading “natural saline,” contain xylitol. One example is Xlear nasal spray. Xylitol is harmless in humans, but in dogs it causes a dangerous, rapid drop in blood sugar and can also cause liver damage. The best approach is to keep all remedies (prescription, nonprescription, and “natural”) out of reach of pets and never assume that a product that’s safe for children is also safe for animals.
 
References
1. Almgren C. Clear eyes, dry nose, no problem? Wrong! Intoxications due to eye drops and nasal sprays. Pet Poison Helpline webinar. November 14, 2017. Accessed March 21, 2021. https://www.petpoisonhelpline.com/webinar/november-2017-intoxications-due-eye-drops-nasal-sprays/
2. Khan SA. Decongestants (toxicity). Merck Veterinary Manual. Updated August 2014. Accessed March 21, 2021. https://www.merckvetmanual.com/toxicology/toxicities-from-human-drugs/decongestants-toxicity
 
Photo by Diana Polekhina

Some bugs carry dangerous diseases or have venomous stings. But what about insects that our pets catch and swallow? Most are harmless, but a few are unsafe for pets. As warm weather arrives, keep an eye out for insects that can cause trouble if they’re eaten.
 
Pesticides and insecticides can also be toxic to pets. Keep these products out of your pets’ reach and use them only according to the manufacturer’s instructions. Dogs and cats are most likely to get a toxic dose if they’re sprayed with the product or eat a significant amount. A pet that eats a single pesticide-covered insect would ingest a little bit of the product, but the amount would probably be too small to cause a problem (call your veterinarian if you’re unsure or if your pet shows any symptoms).
 
Caterpillars
Caterpillar hairs can be irritating to the touch, and some types of hairs release a toxin. Fur typically protects dogs’ and cats’ skin from the stings of caterpillar hairs. If a pet eats a caterpillar, though, the hairs can irritate the mouth and throat. Symptoms include drooling, pawing at the mouth, shaking the head, vomiting, and trouble swallowing. Processionary caterpillars (found in Europe, North Africa, and Asia) produce a toxin that causes an especially severe reaction.[1,2]
 
Fireflies
Fireflies are highly toxic to lizards, amphibians, and birds. Ingestion of a single firefly can kill a bearded dragon. Fireflies contain lucibufagins, which are chemicals that cause heart damage in susceptible species.[3]
 
Asian Lady Beetles
Asian lady beetles (Harmonia axyridis) look a lot like ladybugs, but unlike ladybugs they gather in large numbers and come inside houses in cold weather. As a defense mechanism, they secrete an irritating chemical compound. One published report describes a dog with oral trauma similar to chemical burns caused by 16 Asian lady beetles stuck to the roof of the mouth.[4]
 
Blister Beetles
Blister beetles (family Meloidae) produce a toxin called cantharidin, an irritant that causes blistering on contact with the skin, mouth, or digestive tract. Cantharidin poisoning is most common in horses that eat alfalfa hay contaminated with blister beetles. Exposure can be fatal to horses. Other species, including dogs, cats, rabbits, and people, are also susceptible to cantharidin poisoning.[5]
 
Walking Sticks
The insects known as walking sticks (order Phasmatodea) use camouflage as their main defense mechanism, but some of them also secrete a chemical that can burn the eyes or mouth. Anisomorpha buprestoides, a stick insect found in the southern United States, can aim this secretion directly at the face of a predator. Severe eye damage has been reported in humans and a dog.[6]
 
Bombardier Beetles
Brachinus beetles are called bombardier beetles because they secrete a toxic chemical that they aim at predators in what is usually described as “explosive discharge.” This chemical irritant is released at a boiling temperature.[7] Although I did not find any research reports of bombardier beetle poisoning in dogs or cats, I can’t imagine that eating one would be a comfortable experience.
 
References
1. Bad bugs, bad bugs: what you should do to keep your pets safe. ASPCA. August 1, 2018. Accessed March 5, 2021. https://www.aspca.org/news/bad-bugs-bad-bugs-what-you-should-do-keep-your-pets-safe
2. Fuzzy green poisoners: caterpillar toxicosis in pets. ASPCA Pro. Accessed March 5, 2021. https://www.aspcapro.org/resource/fuzzy-green-poisoners-caterpillar-toxicosis-pets
3. Treating firefly toxicosis in lizards. ASPCA Pro. Accessed March 5, 2021. https://www.aspcapro.org/resource/treating-firefly-toxicosis-lizards
4. Stocks IC, Lindsey DE. Acute corrosion of the oral mucosa in a dog due to ingestion of multicolored Asian lady beetles (Harmonia axyridis: Coccinellidae). Toxicon. 2008;52(2):389-391. doi:10.1016/j.toxicon.2008.05.010
5. Schmitz DG. Overview of cantharidin poisoning. Merck Veterinary Manual. Updated June 2013. Accessed March 5, 2021. https://www.merckvetmanual.com/toxicology/cantharidin-poisoning/overview-of-cantharidin-poisoning
6. Thomas MC. Featured creatures: twostriped walkingstick. University of Florida Entomology & Nematology. Publication No. EENY-314. November 2003. Accessed March 5, 2021. http://entnemdept.ufl.edu/creatures/misc/walkingstick.htm
7. Schaller JC, Davidowitz G, Papaj DR, Smith RL, Carrière Y, Moore W. Molecular phylogeny, ecology and multispecies aggregation behaviour of bombardier beetles in Arizona. PLoS One. 2018;13(10):e0205192. doi:10.1371/journal.pone.0205192
 
Photo by Kazuky Akayashi