The peak in enquiries about slug baits occurs in May and June. There are 3 main ingredients in slug baits: metaldehyde, ferric phosphate and methiocarb.
Metaldehyde causes rapid onset tremors, muscle fasciculation and prolonged seziures. There is no antidote and treatment is supportive with the focus on controlling seizures and preventing complications from prolonged seizure-activity (e.g .pyrexia, rhabdomyolysis). Gastric lavage should be considered. As mentioned last month, outdoor use of metaldehyde slug bait is banned from spring 2020 to protect birds and mammals. Hopefully this will reduce the number of cases reported in dogs.
Ferric phosphate is a relatively insoluble iron salt and is available in slug baits in 1% (amateur products) and 3% (professional products). The remainder comprises filler such as bran and wheat. As a result iron poisoning is not common from ingestion of ferric phosphate slug baits but gastrointestinal signs occur. Treatment is supportive.
Methiocarb, is a carbamate and causes rapid onset signs with diarrhoea, bronchial hypersecretion, constricted pupils, vomiting, twitching, tremors and in severe cases, bradycardia, seizures, respiratory depression and coma. Treatment is supportive with the use of atropine to reverse cholinergic effects