Use of colouring agents in wet faecal mounts for diagnosis of parasite eggs

Different colouring agents like malachite green, carbol fuchsin, writing blue ink and lacto phenol cotton blue were used for diagnosis of parasite eggs in faecal examination. Eggs of Toxocara canis and Ancylostomum caninum of dogs did not get stained by any stains. Malachite Green stained the back ground in greenish and produced a better contrast and was able to highlight the ova even in mild infection. Carbol Fuchsin gave a reddish tint to embryo of T. canis ova. Eggs of A. caninum from fresh faeces stained with lacto phenol cotton blue stain. Eggs of Trichuris, paramphistomes and strongyles remained unstained. However, blue writing ink gave better back ground than Malachite Green for ova of paramphistomes of cattle.