Mothball Poisoning in Cats

The severity of symptoms depends on the dosage, time elapsed since exposure, and route of exposure. It is unknown exactly what dosage of each insecticide is toxic to cats. Cats are more sensitive to mothball toxicity than dogs, so even low doses require urgent veterinary care.

Cases of cats ingesting mothballs are rare. Ingestion of mothballs produces more severe symptoms than skin exposure or fume inhalation, but symptoms take up to several days to develop. Mothballs in the gastrointestinal tract dissolve over several days and symptoms don’t arise until a toxic dose is absorbed into the bloodstream. The absence of symptoms immediately after ingestion does not mean exposure was below toxic levels. Delaying treatment negatively impacts the outcome and increases the risk for permanent kidney and liver damage due to prolonged exposure.

Mothball toxicosis in cats is rare with only 158 cases reported to the APCC between 2002 and 2004. Mothball toxicosis has the potential to be fatal for a cat, even with ingestion of only one mothball. Emergency medical attention for decontamination is vital to a good outcome. There is no safe or effective way to attempt to induce vomiting for cats at home. First aid for inhalation and contact exposure involves providing fresh air and bathing. Product packaging, labels, and samples of the mothballs are helpful for identifying the active ingredient in the clinic after exposure has occurred.

Mothballs contain pesticides which are toxic to cats. Mothball toxicosis occurs after exposure to a toxic dose via ingestion, skin contact, or inhalation. The three main types of pesticides found in mothballs are p-dichlorobenzene, naphthalene, and camphor. P-dichlorobenzene is the most commonly sold type of mothball in North America, as it is safer than its precursor naphthalene.

This condition results regardless of the form of the moth repellent: mothballs, cakes, flakes, or powders.

Symptoms of mothball toxicosis vary in each case and depending on which of the three pesticides is the active ingredient is present in the moth repellent.

If exposure is known, the diagnosis is self-evident. Whether exposure is confirmed or not, cats displaying symptoms of toxicosis typically undergo routine diagnostic testing:

• Physical examination
• Blood work
• Diagnostic imaging
• Urinalysis

Treatment varies depending on the dose and route of exposure. Strategies include:

• Decontamination (induction of vomiting, bathing, etc.)
• Supplemental oxygen
• IV fluids
• Medication administration to control vomiting
• Anti-seizure medication

As a specific antidote to these pesticides doesn’t exist, treatment is supportive with the goal of preventing further damage and reducing the impact of the compound throughout the body.

Outcome of treatment depends on the pet’s overall health, dosage, type of exposure, and time between exposure and treatment. Both naphthalene and p-dichlorobenzene cause kidney and liver damage. The risk is lower with exposure to p-dichlorobenzene. Kidney and liver damage can be permanent. Liver damage, also known as cirrhosis, warrants follow-up monitoring and possible surgery to remove scar tissue.

Naphthalene can cause cataracts. While permanent, treatment is not commonly recommended for cataracts resulting from exposure to toxic compounds.

Mothball toxicity is not contagious, it is caused by exposure to mothballs. Mothball poisoning can be prevented completely by using non-toxic alternatives for pest management. If moth balls must be used, ensuring manufacturer directions are followed and use is restricted to fully sealed containers stored out of reach of pets are the best strategies to prevent feline exposure.

Mothball poisoning is rare in cats.

Early treatment is the most critical factor for a good outcome with respect to mothball poisoning. No antidote exists, therefore treatment varies greatly. Decontamination efforts immediately after exposure and supportive care based on symptoms are the general approach to treatment.