VPT 421: Veterinary Toxicology (2+0)

TREATMENT

• Di sodium calcium edentate can be used as an antidote for lead poisoning. This chelates lead to make it non-toxic and the complex lead EDTA so formed is rapidly excreted.
• This itself is nephrotoxic. This drug is administered in cattle and horses 110 mg/kg i/v or s/c two doses at 6 hours interval every other day for three treatments.
• In dogs 110 mg/kg subcutaneously as a 1% solution diluted with 0.9% saline or dextrose divided into four doses every other day for three treatments is recommended.
• Intestinal lavage or a cathartic can be administered to eliminate the unabsorbed lead.
• Thiamine 2 – 4 mg/kg subcutaneously in cattle with sodium calcium edentate is found to be useful.
• BAL increases lead excretion in urine and removes lead from the parenchymatous organs.
• It can also reach the brain tissue. Unithiol (DMPS) and succimer (DMSA) are also useful as chelating agents for lead. They can be given orally or rectally. They have excellent margin of safety and sparing effect on chelation of essential minerals like zinc.
• d- penicllamine can be used in dogs given in empty stomach at 110 mg/kg daily for two weeks. This drug may produce undesirable side effects. Hence the dog should be monitored closely during treatment.
• It should not be used in cattle, horses and sheep.
• Whenever chelating agents are used, close monitoring of water intake and urine output is required.
• Vitamin D and calcium borogluconate and sedatives may give additional support. Oral magnesium sulphate will also be useful.
• Magnesium sulphate will prevent further absorption of lead by reducing the solubility of lead.
• Seizures can be controlled with the use of barbiturates and diazepam.
• Cerebral oedema can be controlled using dexamethasone and mannitol. Since lead is an immunosuppressant, broad spectrum antibiotics are required to control secondary bacterial infection.