Introduction

• Practitioners may be called upon to investigate cases of suspected poisoning. 
• Poisoning may be due to ingestion, inhalation or dermal exposure to a toxic substance. 
• Presenting signs may be variable, depending on the agent involved. Possible poisoning should be investigated in cases of sudden onset illness or sudden death.
• Diagnosis will be based on history, clinical signs and toxicological investigations. 
• Treatment is generally supportive, few antidotes are available. 
• Prognosis is variable, depending on the severity of clinical signs and the causal agent.
• This article summarizes the approach to a suspected case of poisoning in cattle.

Public Health considerations

• There will be a risk that contaminated milk, offal and meat may enter the human food chain.
• Food safety authorities should be contacted early in the investigation to prevent contaminated material entering the human food chain.

Etiology

• Poisoning may occur in various circumstances including:
  • Lack of access to fodder, eg due to adverse weather conditions.
  • Lack of fresh water.
  • Ingestion of contaminated feed or water source. 
  • Incorrect storage of feed.
  • Access to poisonous plants.
  • Miscalculation of doses for feed supplements or medicines. 
  • Inadequate storage of hazardous substances, eg lead batteries, pesticide products.
  • Poor state of repair of structures with lead paint.
  • Cattle are inquisitive and will eat materials they find, particularly if it is palatable, or because of boredom. 
  • Pica as a result of nutritional deficiency or imbalance may increase the risk of poisoning.

Timecourse (incubation, duration)

• Very variable. 
• Some poisons act quickly (eg blue green algae, nerium oleander) but others have delayed onset of signs require (eg anticoagulant Rodenticides Rodenticides) or require repeated exposure (eg Bracken Bracken). 
• In many cases there may be sudden death with few or no apparent clinical signs.

Diagnosis

Treatment

Prevention

Sequelae

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• Bates N & Payne J (2017) Risk assessment and risk management of poisoning in farm animals. Livestock 22 (3), 146-149.
• Payne J & Murphy A (2014) Plant poisoning in farm animals. In Practice 36, 455-465.
• Varga A & Puschner B (2012) Retrospective study of cattle poisonings in California: recognition, diagnosis and treatment. Vet Med Res Rep 3, 111-127.
• Osweiler G D (2011) Diagnostic guidelines for ruminant toxicoses. Vet Clin North Am Food Anim Pract 27 (2), 247-254 PubMed.
• Poppenga R H (2011) Commercial and industrial chemical hazards for ruminants. Vet Clin North Am Food Anim Pract 27 (2), 373-387 PubMed.
• McGuirk S M & Semrad S D (2005) Toxicologic emergencies in cattle. Vet Clin North Am Food Anim Pract 21 (3), 729-49 PubMed.

Other sources of information

• Waine K, Busin V & Strugnell B (2019) Getting the Most out of On-Farm Post-Mortems: A Guide for Veterinary Surgeons. AHDB, UK. Website: https://ahdb.org.uk.
• Payne J, Livesey C & Murphy A (2015) Cattle Poisoning: Principles of Toxicological Investigations. In: Bovine Medicine. 3rd edn. Ed: Cockcroft P D. John Wiley and Sons Ltd. 
• Plumlee K H (2004) Clinical Veterinary Toxicology. Ed: Plumlee K H. Mosby, USA.
• Burrows G E & Tyrl R J (2013) Toxic Plants of North America. 2nd edn. Wiley Blackwell, USA.

Organisation(s)

• ASPCA Animal Poison Control Center: www.aspca.org, telephone number (888) 426-4435.
• Veterinary Poisons Information Service (VPIS); www.vpisglobal.com. + 44 (0) 2073 055 055.