SELENIUM TOXICITY IN DOMESTIC ANIMALS.

This research paper deals with the toxicity of Selenium (Se) in domestic animals, providing valuable information regarding its adverse effects in different situations, its severity based on different factors, as well as the clinical symptoms. The study shows that not only can the severity of Se poisoning be influenced by the type of Se compound consumed, but also by the method of administration and the species of domesticated animal affected.

Selenium Toxicity and Severity

• The study revealed that the extent of Se toxicity in animals can be quite varied and depends heavily on certain factors.
• These factors include the chemical forms of Se, the species of animals affected, and the method of administration.
• Chemically, Se salts like Na2SeO3 and Na2SeO4 are among the most toxic compounds, while selenoamino acids, such as selenomethionine and selenocystine, have a moderate toxicity level. Some forms of Se, especially the poorly soluble ones like elemental Se, Na2Se, SeS2, and diphenyl selenide, are among the least toxic.
• It was also observed that the compounds’ toxicity is significantly reduced when they are ingested orally rather than intravenously.

Types of Selenium Intoxication

• The researchers identify three clinical types of Se intoxication, including acute selenosis, subacute selenosis, and chronic selenosis.
• Acute poisoning usually occurs when animals consume Se-heavy plants in large quantities within a short period, or due to mistakes in the formulation of Se-enriched diets. Symptoms include breath that smells like garlic (due to the excretion of volatile Se metabolites), lethargy, excessive salivation, vomiting, and respiratory issues among others.
• Subacute poisoning, also known as blind staggers, occurs over a longer exposure period. Subacute poisoning mainly results in neurological symptoms like blindness and disorientation. Such poisoning mostly occurs in grazing animals that consume Se-enriched plants.
• Chronic selenosis, also known as alkali disease, sets in when animals consume moderate levels of Se for a prolonged period. Symptoms include hair loss, emaciation, hoof lesions, lameness, etc. In severe cases, liver cirrhosis, heart atrophy, and anemia also occur.
• Animals’ responses to Se poisoning also vary significantly by species.