Erythrocyte losses from pigs with experimental Trichuris suis infections measured with a whole-body counter

The losses of 59 Fe labelled erythrocytes from pigs infected with 15 000, 40 000 or 100 000 T. suis ova have been measured using a whole-body counting technique. The average rate of loss of erythrocytes was approximately proportional to the infective dose of ova, ranging from 7 to 35 ml./d., but in none of the animals was anaemia observed. A transitory macrocytosis occurred in the animals infected with 40 000 ova, and a decrease in serum iron concentration in those infected with 100 000 ova. The clinical signs in the pigs infected with 15 000 ova were negligible, but infection with 100 000 was fatal. The losses of erythrocytes were not a major cause of the clinical disease.