Galoncus perniciosus is a nematode parasite seen rarely in tigers and leopards. The worms are seen in fibrous nodules or tumours on the wall of the intestine and lead to death from septicaemia. In Thiruvananthapuram Zoo, Galoncus perniciosus infection was identified in a male tiger aged 17 years on post mortem examination and subsequent histopathologic and parasitic studies.

This tiger, which is also known to have parented white (albino) tigers, showed signs of colic followed by anorexia, absence of defaecation and toxaemia. The animal did not respond successfully to treatment and succumbed five days following the onset of the initial symptoms.

On post mortem examination the intestine was bloated, tense and diffusely congested. There were more than twenty whitish nodules of varying sizes in the intestinal wall. In one area the nodule was large enough to have blocked the intestine completely. On incision the nodules had an inner cavity, which opened to the intestinal lumen and contained thick sanguineous pus that came out to the lumen on expression.

Histopathology of these nodules revealed cross sections of adult nematode parasites in the muscular layer of the intestine,surrounded by an inflammatory reaction comprising of numerous plasma cells and neutrophils, and a few eosinophils.Proliferation of granulation tissue was seen around this reaction. Some stained ova could also be detected along the necrotic tract, which opened to the lumen of the intestine.

Cross section of the nodule. Note the parasite inside.The parasites both male and female were collected from the nodules by microscopic dissection.The morphological features of the head, tail, bursa,cuticle and ova revealed the species to be Galoncus perniciosus of the family Ancylostomatidae

Traceable reports on the incidence of Galoncus perniciosus are comparatively rare. Pthyal and Madhavan Pillai et al had reported in 1993, the death of a wild Indian Leopard Panthera pardus fusca (Meyer) due to parasitism with the lung fluke Paragonimus westermani (Kerbert, 1878) and the hookworm Galoncus pernicious (Linstow, 1885). Cohrs has reported Galoncus perniciosus infestation in tigers in 1928.

The observations discussed in this paper warrant a detailed investigation to screen the tiger and leopard populations, both captive and wild, and to elucidate the pathogenesis and life cycle of the parasite.Research in developing better methods to diagnose the infestation is highly warranted, as the ova may not be observed during
faecal sample examination due to its low number.Efficacy of conventional treatment should also be assessed as the adult worm is seen embedded in nodules.

The authors are thankful to Mr.C.S. Yalakki,Former Director ofDepartment of Museums & Zoos,Thiruvananthapuram for the encouragement and facilities provided to undertake this study.