VPT 421: Veterinary Toxicology (2+0)

DIAGNOSIS AND TREATMENT

Diagnosis

• Dark chocolate coloured blood or coffee coloured blood indicates poisoning due to nitrites.
• Analysis of stomach and intestinal contents for nitrites gives a conclusive diagnosis.

Treatment

• Methylene blue intravenously at the rate of 4-8 mg/kg in cattle and sheep as a 1% solution.
• Methylene blue is an oxidising agent which is reduced to leucomethylene blue by the action of NADPH₂ - reductase.
• This leucomethylene blue converts methaemoglobin to haemoglobin.

• A second dose of methylene blue is recommended after 6-8 hours. Ascorbic acid is also found to be useful.
• Large doses of antibiotics can be administered orally to reduce conversion of nitrate to nitrite by the microflora of the rumen.