This is a rare occurrence in well designed and maintained ships. However, bad weather, maintenance works and inexperienced crew may create situations where these poisoning accidents occur. In bad weather, rolling, pitching and flexing of the ship can cause containers to relocate and pipes to break. Feed and water in bulk storage tanks may become contaminated with chemicals leaked from broken drums or pipes.
Maintenance, especially modifications on cattle decks, may be performed by crew inexperienced in the ways of cattle. On ships penned cattle will lick and chew anything within reach and can turn on taps and move levers that seem out of reach. Hazards include unguarded or badly located pipes and valves, and containers of potentially poisonous chemicals (sealant, corrosion inhibitors) left laying around that might slide or roll into cattle pens. Cattle may be temporarily penned in unusual and poorly ventilated locations with access or exposure to chemicals, paint, lubricant and gas bottle storage areas or engine exhaust systems. Carbon monoxide and carbon dioxide poisoning may occur in poorly ventilated pen areas where portable combustion engines are being used for repairs or maintenance.
Multiple animals in a pen or group of pens may be affected. Clinical signs will depend on the poison. Respiratory distress may be expected with fumigants and exhaust gases. Nervous signs or diarrhoea may be expected with lubricants. Animals may simply be found dull, down, dying or dead.
At necropsy, some of the ingested poisons may be detectable in the reticulum or rumen by sight or smell.
Specimens which might be submitted to a diagnostic laboratory include 100 g of rumen content and 500g of suspect feed material submitted chilled for toxicology, and sections of liver, kidney and other organs showing lesions in buffered formalin for histology.
Treatment options are dictated by cause or signs. These may include immediate relocation to sick pens for monitoring and to provide improved air quality and ventilation if there is respiratory distress. Affected animals should be provided with clean water and fed with chaff or hay if there are concerns about digestive system function or reduced appetite.
Ships should be well designed and maintained and crews made aware of the potential for inadvertent poisoning from exposure to these hazards. Bad weather, maintenance works and inexperienced crew are predisposing factors.