Is Mothballs (Naphthalene / Paradichlorobenzene) Safe for Dogs?
Why it’s a problem
Dogs chew mothballs like toys or treats, and naphthalene is converted in the body into compounds that damage red blood cells, the liver and the nervous system. Paradichlorobenzene balls are somewhat less toxic but still harmful. Signs may be delayed for 24–72 hours, so owners often miss the exposure window.
How to keep your pet safe
Store mothballs in sealed containers well above nose height, and never scatter them loose in closets, attics, garages or gardens. Count them so you know if some disappear. Avoid moth-repellent products outdoors entirely, since garden mothballs poison curious dogs.
Warning signs to watch for
Often delayed 24–72 hours: vomiting, drooling, lethargy, weakness, pale or brownish gums, rapid breathing, tremors, seizures, jaundice, dark or discolored urine.
When to call the vet
Call your vet or a pet poison hotline immediately with the product type if known — the two chemical types carry different urgency. Bring the box or a mothball with you. Do not induce vomiting unless instructed, and monitor for a full 72 hours even if your dog seems fine at first.
Common questions
My dog ate one mothball — how bad is that?
A single naphthalene mothball can sicken a small dog, and larger dogs usually tolerate one better, but you cannot judge by size alone. Call a pet poison hotline now with the brand name and watch for vomiting or pale gums for 72 hours.
Are modern mothballs safer for pets?
Paradichlorobenzene balls are less toxic than old naphthalene ones but still cause vomiting and neurological signs. Check the ingredient list — either type means a call to your vet if eaten.
I use mothballs in my garden to repel animals — is that safe?
No — garden mothballs are a well-known poisoning source and are not an approved animal repellent. Remove them and choose humane, non-toxic deterrents.
More household hazards for dogs
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate or touched something concerning, contact your veterinarian or a pet poison hotline right away. In the US: Pet Poison Helpline (855) 764-7661, ASPCA Animal Poison Control (888) 426-4435 (fees may apply).