Though cattle do not eat Parthenium, its effects were observed on them when they walk by or graze through patches of this weed. Such cattle had inflamed udder and subsequently suffered from fever and rashes. It is reported that feeding the weed to buffalo and bull calves at different levels causes both acute and chronic forms of toxicity. Ulcerations were caused both in the mouth and digestive tract. Autopsy of the dead animals showed punched cut ulcers on the oesophageus and the obosomal folds. Histopathology of the kidney and liver revealed degenerative changes and necrosis. Consumption of milk from the livestock grazing around Parthenium invaded grazing land could be hazardous to man. Parthenium pollens wereobserved in the atmosphere throughout the year and that the pollen of Parthenium showed marked positive skin reactions and are in abundance in the month of June and August. Parthenium causes asthma and dermatitis. The pollen of this weed has been observed to cause allergic rhinitis. Parthenium to produce an average of 624 million pollens per plant and these were carried to distant places.