Iron-Containing Molluscicide Exposure in Dogs

In the Literature

Lauinger CA, Wright L, Smart L. Characteristics and outcome of 73 dogs with iron EDTA molluscicide ingestion in Melbourne, Australia (2013-2019). Aust Vet J. 2025;103(1-2):13-21. doi:10.1111/avj.13388

The Research …

Iron-containing molluscicides are marketed as a safer alternative to metaldehyde-based snail and slug baits; however, ingestion can result in iron toxicosis in dogs. These products are available in pelleted and powdered forms, although they are uncommonly used in the United States.

This study reviewed medical records of 73 dogs with known or suspected ingestion of iron EDTA baits in Australia. The amount of iron ingested was unknown in most cases; however, an estimate of 24 to 600 mg/kg was obtained in 28 dogs. Clinical signs were consistent with iron toxicosis and most frequently included diarrhea, discolored stool, hemorrhagic diarrhea, and vomiting.¹ The most common clinicopathologic findings were a variety of acid-base disturbances.

Sixty dogs were hospitalized, 54 of which were chelated with deferoxamine. Three dogs had adverse reactions thought to be related to deferoxamine treatment, with hypotension (1 dog), syncope (1 dog), and cardiac arrest (1 dog) reported. Outcomes were generally good; 59 dogs were discharged home, 10 dogs were transferred to their primary clinician, and 4 dogs were euthanized.

Results of this study indicate more research is warranted to evaluate ideal duration and total dosage of deferoxamine in dogs after iron exposure.

… The Takeaways

Key pearls to put into practice:

• The active ingredient in the ingested bait must be identified and not assumed based on brand. Metaldehyde-containing molluscicides are more common than iron-based products in the United States and have a lower margin of safety. Metaldehyde causes significant CNS signs.

• In the United States, iron-containing snail and slug baits contain iron phosphate or sodium feredetate (sodium iron EDTA) as the active ingredient in pelleted or powdered forms. Estimated dosage of iron can be made by converting the concentration of the active ingredient in the product; iron phosphate is 37% elemental iron and iron EDTA is 13% elemental iron.

  • For example, ingestion of 100 g of 6% iron EDTA in a 44.1-lb (20-kg) dog results in a 39 mg/kg dose (100 g bait × [60 mg iron EDTA/g bait] = 6,000 mg [6 g] iron EDTA ingested; 6 g iron EDTA × [130 mg elemental iron/g iron EDTA] = 780 mg elemental iron ingested; 780 mg elemental iron/20 kg dog = 39 mg/kg).

• Minor exposure to iron-containing molluscicides typically only causes mild GI upset in dogs.

• In patients exposed to pellet(vs powder)bait, emesis 6 to 12 hours postexposure should be considered if the patient has not already vomited. Gastric lavage is unlikely to be rewarding, and pellets are unlikely to pass through a lavage tube. In this study, pellets were present in the vomitus of 7 of 14 dogs induced 6 to 12 hours postexposure.

• Adverse effects of deferoxamine include hypotension and, rarely, anaphylactic reactions or cardiac arrhythmias. Support and monitoring should be provided, and the risks and benefits of deferoxamine should be considered for each patient. Generally, deferoxamine administration can be considered if the serum iron level is >500 micrograms/dL or the patient has significant GI signs.³

• This study found that changes in urine color and decreases in serum iron after deferoxamine administration were variable and may not be useful for monitoring treatment efficacy. These findings should not be the only consideration when determining whether to discontinue deferoxamine.