Effects of the Screw-Worm on Guinea Pigs

Abstract

Guinea pigs with heavy sublethal infestations of screw-worms (Callitroga hominivorax) manifest a marked loss in weight, a rise in temperature, leucopenia and anemia, all of which reach maximum degrees, or experience the greatest change from normal, during the 3rd or 4th to the 6th or 7th days of the infestation, the period during which the third instar larvae undergo their maximum phase of growth. By the time the maggots have left the host (7th to 8th day) symptoms begin to subside, with the exception of the anemia, which lasts about 2 days longer. In general, animals with lighter infestations exhibit milder symptoms, and in lethal cases the clinical effects were the most severe, but in all criteria of injury investigated there was a remarkable variation in response in different animals.