Metaldehyde toxicosis in ducklings

Contact toxicity and biochemical impact of metaldehyde against the white garden snail Theba pisana (Müller, 1774)

BACKGROUND

Terrestrial snails are one of the most damaging threats to sustainable agriculture. Chemical control using molluscicides is the main approach used to combat these agricultural pests. Metaldehyde is the active ingredient in most snail control products in use. However, its toxicity indices and mode of action have scarcely been investigated. For the first time, we characterized the metaldehyde contact toxicity indices against the white garden snail Theba pisana. The biochemical impact of metaldehyde on acetylcholinesterase (AChE), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), alkaline phosphatase (ALP) and glutathione S-transferase (GST) activities and the lipid peroxidation (LPO) level was investigated.

RESULTS

The median lethal dose (LD₅₀ ) values at 24, 48 and 72 h of treatment were 11.33, 8.53, and 6.87 μg g^-1 body weight (BW), respectively; while, the median lethal time (LT₅₀ ) values were 88.16, 55.85, and 25.67 h when doses of 6, 8, and 12 μg g^-1 BW were applied, respectively. In the snails treated with 2.83 and 5.67 μg g^-1 BW (¼ and ½ LD₅₀ at 24 h of treatment) and 2.13 and 4.27 μg g^-1 BW (¼ and ½ LD₅₀ at 48 h of treatment), higher AChE, GST, AST, ALT, and ALP activities as well as higher levels of LPO were observed compared with that of untreated snails.

CONCLUSION

Metaldehyde displayed dose- and time-dependent contact toxicity. The biochemical results suggest that metaldehyde may have neurotoxic and cytotoxic actions in terrestrial snails. Application of metaldehyde in ways that could control pest snails and slugs and reduce its negative impact on the environment are discussed. © 2021 Society of Chemical Industry.

Arsenic and Metaldehyde Toxicosis in a Beef Herd

Over a 12-day period, 13 animals in a herd of 110 beef cattle developed ataxia with profound muscle fasciculations progressing to recumbency. Twelve animals (5 adults and 7 calves from 8–10 months of age) died, and 1 cow was euthanized. Hemorrhagic diarrhea occurred in some, but not all, animals. The onset of clinical signs was at least 12 hours after the cattle had gained access to contents of old buildings used for storage, and the majority of deaths occurred within 24 to 48 hours after the onset of clinical signs. Approximately 9 kg of unidentified pellets were found strewn in the barn area where the cattle had been. Autolysis considered more severe than expected for the postmortem interval, suggestive of high body temperature before death, and congestion of body tissues were the only significant findings detected in the cow that was euthanized and submitted for necropsy examination. The clinical history and lack of postmortem lesions were most consistent with toxicity. A toxic level of arsenic (6.18 ppm) was detected in the kidney, and metaldehyde was detected in the liver. The pellets were analyzed and found to contain both arsenic and metaldehyde, consistent with a discontinued molluscicidal product.