Is String, Yarn, and Thread (Linear Foreign Body) Toxic to Cats?
String, yarn, dental floss, sewing thread, and similar linear materials can cause a life-threatening condition called a linear foreign body obstruction in cats. The string can slice through the intestines as they attempt to move it along, causing peritonitis and sepsis. If you suspect your cats has ingested string, yarn, and thread (linear foreign body), contact your veterinarian or nearest emergency vet clinic immediately.
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This is one of the most commonly reported cats poisoning events — thousands of other cats owners check this same substance every year.
If Your Pet May Have Ingested Something Toxic
Contact your veterinarian or nearest emergency vet clinic immediately. Do not wait for symptoms to appear — early intervention significantly improves outcomes.
| Toxic? | Severity | Time to Onset | Commonness | Urgency |
|---|---|---|---|---|
| Yes | Potentially Fatal | Hours to 2 days | Very common | Immediate |
The Toxic Principle
The dangerous compound in String, Yarn, and Thread (Linear Foreign Body) is Physical obstruction and intestinal slicing.
When a cat swallows a linear object (string, yarn, thread, ribbon, tinsel, dental floss), it can become anchored at one end — typically under the tongue, around the base of the stomach, or at the pylorus. As the intestines attempt to propel the string through peristalsis, the string acts like a cheese cutter, bunching up the intestines and eventually slicing through the intestinal wall. This causes intestinal perforation, peritonitis (abdominal infection), and sepsis. Needle-thread combinations are especially dangerous.
How Much Is Dangerous?
The risk depends on your cats's weight and the amount ingested.
| Pet Weight | Dangerous Amount | Expected Severity |
|---|---|---|
| Any size cat | Any length of string, yarn, or thread | Potentially Fatal |
| Any size cat | Thread with attached needle | Potentially Fatal |
| Any size cat | Dental floss | Severe |
| Any size cat | Rubber band or hair tie | Severe |
Symptoms to Watch For
Symptoms of string, yarn, and thread (linear foreign body) poisoning in catss typically progress through these stages:
Early Signs
2-12 hours- Vomiting
- Loss of appetite
- Lethargy
- Abdominal pain
- Straining to defecate
Progressive
12-48 hours- Persistent vomiting
- Dehydration
- Hunched posture
- Fever
- Swollen abdomen
Severe (Perforation)
1-3 days- Peritonitis
- Sepsis
- Shock
- Collapse
- Death without emergency surgery
You just learned the symptoms. Now be ready for them.
The #1 regret pet owners have after an emergency? "I wish I'd been prepared."
You care enough to research this — that puts you ahead of most pet owners. But research without preparation is just worry. This guide covers exactly what to do in the first 15 minutes after poisoning — the window that determines whether your cats lives or dies.
Get the First Aid Guide — Protect Your Cats →
Be Ready If This Happens to Your Cats
You just read what string, yarn, and thread (linear foreign body) does to catss. The symptoms. The suffering. The $800–$6,000 vet bill. The question is: are you prepared if it happens again?
Get the Emergency Kit — Be Ready →What to Do Right Now
- 1 If you see string hanging from your cats mouth or rear, do NOT pull it — cutting it can cause further damage.
- 2 Call your veterinarian or emergency clinic immediately.
- 3 Call your vet immediately for guidance — do not attempt any treatment at home.
- 4 Get your cat to the vet for X-rays and possible endoscopy or surgery.
- 5 Remove all string, yarn, thread, dental floss, rubber bands, and hair ties from your cats environment.
- 6 Keep sewing kits, craft supplies, and trash cans in closed cabinets.
Treatment and Recovery
Diagnosis is via X-rays (which may show plicated or bunched intestines) and sometimes ultrasound. If the string is visible under the tongue, it may be cut under sedation. If it has passed into the stomach or intestines, endoscopic removal may be attempted. Most cases require exploratory abdominal surgery to remove the linear foreign body and repair any intestinal damage. If perforation has occurred, the damaged section is resected. Post-operative care includes antibiotics, pain management, and IV fluids. Prognosis is good with early surgery but poor if peritonitis has developed.
Estimated Cost
$800 – $6,000
💰 Vet bills like this can bankrupt a family. Pet insurance covers poisoning emergencies.
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A basic first aid kit costs a fraction of an emergency vet visit
Having basic first aid supplies and an emergency reference on hand is something most veterinary professionals recommend.
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Why String, Yarn, and Thread (Linear Foreign Body) Is Dangerous for Cats
Cats are especially vulnerable to string, yarn, and thread (linear foreign body) because they have a significantly smaller body mass and a liver that metabolizes certain compounds differently than humans or dogs. The toxic principle — Physical obstruction and intestinal slicing — can overwhelm a cat's detoxification pathways rapidly, making even small ingestions a medical emergency. Symptoms typically begin within Hours to 2 days of ingestion.
When a cat swallows a linear object (string, yarn, thread, ribbon, tinsel, dental floss), it can become anchored at one end — typically under the tongue, around the base of the stomach, or at the pylorus. As the intestines attempt to propel the string through peristalsis, the string acts like a cheese cutter, bunching up the intestines and eventually slicing through the intestinal wall. This causes intestinal perforation, peritonitis (abdominal infection), and sepsis. Needle-thread combinations are especially dangerous.
Other Substances to Watch For
If your cats got into string, yarn, and thread (linear foreign body), be aware of these related hazards that often appear in the same contexts:
Expected Veterinary Costs
Based on typical emergency treatment for string, yarn, and thread (linear foreign body) toxicity in cats, including:
- •Emergency exam and stabilization
- •Induction of vomiting and activated charcoal
- •IV fluid therapy and monitoring
- •Possible overnight hospitalization
Actual costs vary by location, clinic, and severity of the case. Emergency clinics typically charge more than daytime veterinary offices.
Frequently Asked Questions
What if I see string hanging from my cats rear end?
Do NOT pull it. Gently cut the visible portion with scissors and get to a vet. Pulling can slice through the intestines. The remaining string must be removed professionally.
My cat ate dental floss — is it dangerous?
Yes. Dental floss is one of the most dangerous linear foreign bodies because it is thin, strong, and can easily cut through intestinal tissue. Call your vet immediately.
Can a cat pass string naturally?
Sometimes short pieces pass without issue, but there is no way to know if the string is anchored and causing damage. Any known string ingestion should be evaluated by a vet.
People Also Ask
One more thing to check
Many cats owners who worry about string, yarn, and thread (linear foreign body) also need to know about Are Lilies Toxic to Cats?. If your cats had access to string, yarn, and thread (linear foreign body), they may have been exposed to other hazards too.
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Sources & Citations
Toxicity data is based on published veterinary toxicology references. In an emergency, contact your veterinarian or nearest emergency vet clinic immediately.
📚 Sources & Methodology
Toxicity data compiled from the following veterinary toxicology databases:
- • ASPCA Animal Poison Control Center — case data and species-specific toxicity ratings
- • Pet Poison Helpline — dosage threshold data and symptom timelines
- • Merck Veterinary Manual — clinical treatment protocols
Weight-based severity thresholds are calculated using established veterinary toxicology formulas. All "toxic" and "non-toxic" classifications are based on peer-reviewed veterinary literature. Last reviewed: May 2026.
Medical Disclaimer: The information on this page is for educational purposes only and is not a substitute for professional veterinary advice. If you suspect your pet has been poisoned, contact your veterinarian or nearest emergency vet clinic immediately. This page was last reviewed on 2026-05-22.
Sable T. Thornwood
Pet Toxicity Researcher
Sable T. Thornwood has spent over a decade researching pet toxicity and companion animal safety, with a focus on common household substances, plants, and foods. Her research draws on veterinary toxicology databases, ASPCA case records, and peer-reviewed clinical literature to help pet owners make informed, timely decisions during potential poisoning events.
About Sable & PetToxCheck