VPT 421: Veterinary Toxicology (2+0)

CLINICAL SYMPTOMS

The poisoning can be acute or chronic. But there is no clear demarcation between these. Both are cumulative poisonings.

• Acute poisoning
  • Acute poisoning is common in cattle.
  • Symptoms are not usually seen until 2-3 days after a fatal dose.
  • Calves show signs by starting to bellow and to stagger about with rolling eyes and frothing mouth.
  • Animal appears blind, is greatly excited and tries to climb the walls of its stall, during quiet phases remains with the head pushed against a wall and is inert to any external stimuli.
  • Muscular spasm, tetany and death will result.
  • In less severe cases, dullness and inappetance occur over a period of several days together with evidence of abdominal pain and constipation, sometimes followed by diarrhoea.
• Chronic poisoning
  • Chronic poisoning in cattle is characterized by anorexia, constipation, recumbency and death.
  • In sheep the clinical signs are similar to those in cattle but tetany is not observed. Pregnant ewes may abort.
  • In horses the symptoms rare not well marked.
  • Paralysis of the limbs, anorexia, a tucked up appearance, nasal discharge and jaundice have been reported.
  • Laryngeal muscle paralysis gives rise to roaring.
  • Pigs are considerably resistant to lead poisoning.
  • In dogs two sets of clinical signs namely gastrointestinal and nervous symptoms.
  • Gastrointestinal symptoms include anorexia, vomiting, colic and diarrhea with general loss of condition.
  • Nervous symptoms include anxiety, hysterical barking, salivation and epileptiform convulsions.
  • Lead poisoning in cats is not very common because they do not chew foreign objects, lick painted surfaces or eat material other than foodstuff.
  • In birds the symptoms are anorexia, ataxia, followed by excitement and loss of condition. Egg production fertility and hatchability decrease. Mortality is high.

  In human the important symptoms are blue line in the gums (Burton's line), wrist drop, growth arrest and lead lines in the bones. There is opacity of the extremities of long bones as evidenced by x-rays. Basophilic stippling of red cells is also seen in humans.