The indoor world is not an overwhelmingly dangerous place for cats. Most indoor cats lead long, low-risk lives. (The outdoor world, especially for free-roaming cats, is a different story.)

Many households, however, harbor little-known hazards that can be risky or even deadly for cats. If you live with a cat, I recommend that you make yourself aware of and protect your furry friend from these hazards.

1. Lilies and sago palms

Lilies are beautiful but extraordinarily dangerous for cats. Lilies contain an unknown toxin that can cause fulminant fatal kidney failure in exposed cats. Every part of the lily plant is toxic. Cats often chew or swallow the leaves, resulting in significant exposure. However, even the pollen is a major risk — cats that walk through the pollen and then groom their feet can suffer life-threatening toxicity.

While we’re on the subject of good looking but deadly ornamental plants, be aware that sago palms are extraordinarily toxic when eaten. Sago palms cause liver failure, and symptoms can include loss of appetite, bloody diarrhea, jaundice, vomiting, and uncontrollable hemorrhage. Death often occurs.

2. “Linear” items (including yarn)

Norman Rockwell loved to depict cats with balls of yarn, but he rarely showed scenes of the surgeries necessary to remove yarn from cats’ intestines after it was ingested.

So-called linear items, which include yarn, thread, dental floss, fishing line, and ribbon, are attractive to cats. They also are dangerous. When swallowed, they can cause the intestines to bunch up, leading to gastrointestinal obstruction. Laceration of the intestines is not uncommon. Surgery or endoscopy is necessary to address the matter, but if the intestines are severely damaged, even surgery might not be life-saving.

Sewing thread poses an especial risk if a needle is attached, and it is not uncommon for owners to watch in horror as a cat gradually swallows a segment of sewing thread, with the needle going down last.

3. Hair scrunchies and rubber bands

Hair scrunchies and rubber bands, for reasons that nobody understands, also are attractive to cats. Although these items (especially single rubber bands) might pass through the intestines without causing harm, they also have the potential to ball up and cause an intestinal obstruction. Surgery or endoscopy is then necessary to resolve the situation.

4. Ear plugs

I’m sure nobody reading this has ever sniffed their finger after digging around in their ear. It might come as a surprise that ear wax has a unique odor. That odor can be attractive to cats. Combine this with the fact that ear plugs are perfectly sized to lodge in the intestines, and you have a recipe for a gastrointestinal foreign body obstruction.

Ear plugs are one of the more common causes of intestinal obstruction in cats, so be sure to keep yours locked in a place that is out of reach for your feline family members.

5. The great outdoors

Cat doors are a bad idea in my opinion. They generally aren’t dangerous in and of themselves (there are exceptions — I have treated a few cats for lacerations after they got caught in their doors), but they lead to the big, dangerous outdoor world. Cats that use them are at risk of predation, vehicular injuries, altercations with other cats, falls from height, infectious disease, and all manner of other nastiness. Agile raccoons or feral cats also might use the doors to come inside and cause trouble. I have treated many innocent cats who were attacked by large neighborhood cats in their own houses after the intruders entered through cat doors.

Although free-roaming cats suffer the greatest number of casualties, be aware that even your own yard might harbor cat hazards. Foxtails can grow in any yard, and can lodge in eyes, the skin, the ears, and even the genitals of cats. Cats who chew on grass are at risk of gagging as they try to swallow — this can cause the grass to lodge in the back of the throat, leading to coughing, retching, and hard swallowing until the offending item is removed by means of a procedure that requires general anesthesia.

Grass that is eaten by cats might also contain pesticides. And although cats, unlike dogs, don’t generally chow down on containers of pesticide, you should be aware that cats’ fastidious grooming can lead to accidental oral exposure of powdered or liquid pesticides if they get the products on their feet or hair.

6. Household cleaners and automotive products

Household cleaning agents pose a similar risk of oral exposure after topical contamination. Cats that go into the garage might be exposed to antifreeze or other toxic automotive products in a similar fashion.

Although there are many potentially hazardous items for cats, it is not especially difficult to keep your cat safe. Keep him indoors, and limit his access to the items listed in this article.

Other stories by Dr. Eric Barchas:

• You Might Be Your Vet’s Worst Client and Not Know It
• Why Do Vets Take Cats “Into the Back?” What Happens There?
• A “Day” in the Life of an Emergency Vet Is Actually a Night Shift

Got a question for Dr. Barchas? Ask our vet in the comments below and your topic might be featured in an upcoming column. (Note that if you have an emergency situation, please see your own vet immediately!)