STEPHANOFILARIASIS AMONG BUFFALOES IN ASSAM*
BY V. R. GOPALAKRISHNAN, Veterinary Investigation Officer, Assam, Gauhati
(Received for publication on 21 April 1948)
T HIS article is based on an investigation into an outbreak of Stephanofilariasis among buffaloes
in Nowgong district, Assam, and it also records the observations on its occurrence in other parts
of the province. Fairly large number of buffaloes are maintained in certain localities in Assam and
the climatic and geograhpical conditions seem to suit them well. Stephanofilariasis or ear-sore as
it is popularly called, was investigated in buffalo herds of several localities in five districts.
The
incidence of the disease has also been reported from other parts of India, particularly from Bihar,
Orissa and Madras. The clinical lesion observed in the ear of buffaloes is known by various names,
such as, ear-sore, Enzootic Otorrhoea, Otitis, Otacariasis, Contagious otorrhoea, etc. It seems
probable that the condition is likely to be caused by other factors or agents than Stepkanofilaria Sp.,
depending upon the locality, climate and enviornment. However, in this paper, the specific nature
of the parasite occurring in the ear-sore of buffaloes in Assam, is recorded and so it is considered
appropriate to designate the condition as Stephanofilariasis.
Microfilariae or the larval forms of certain adult nematode worms, are found free in circulating
blood as well as in skin lesions of demestic animals in India. It is not uncommon to demonstrate the
presence of microfilaria in the peripheral circulation, causing no apparent inconvenience to the
animal. However, the occurrence of microfilaria as a morbid entity of importance affecting the
health of some species of domestic animals in this country, has been recorded by some workers during
the past few years.
In a resume on the subject Sen [1931] stated that only two species of microfilaria were definitely
recorded in equines and pointed out that the occurrence of microfilariasis in the horse as a condition
concomitant with other forms of blood infection had been the general observation of workers. In
dogs microfilariasis is commonly noticed with variable symptoms—from being devoid of noteworthy
symptoms to being fatal. Datta [1935] indicated that his studies on the histopathology of hump-
sore in cattle, had led him to conclude that this disease of Indian cattle was similar to ' Cascado ' of
cattle in Dutch East Indies, caused by Stephanofilaria dedoesi. Pande [1935, 1936] detected the
occurrence of and recovered microfilaria and live adult worms from the lesions of hump-sore among
cattle in Assam. After pointing out certain anatomical differences between S. dedoesi and the new
parasite, he designated it as Stephanofilaria assamensis, a new species, and attributed its constant
presence in or association with the morbid skin lesions, to be the cause of hump-sore in cattle. While
elucidating the cause of subcutaneous haemorrhagic nodules in cattle, a disease of economic impor-
tance in this country, Bhalerao [1939] pointed out that the worm affecting cattle was Parafilaria
bovicola. Srivastava [1939] reported the occurrence of cutaneous microfilariasis in a bullock with a
description of the clinical features of the disease as it occurred among cattle in Bombay province.
Nathani and Sankaranarayanan [1940] have demonstrated the presence of microfilaria in a chronic
indolent sore in the sheath of a breeding bull that ultimately responded to treatment with antimosan.
Recently, in an interesting survey on applied helminthology in India, Bhalerao [1947] has dealt with
the occurrence and also new findings of some important parasites including filariid worms of man and
animals. He also refers to the attempts made to discover the insect vector of S. assamensis causing
hump-sore of cattle. It is evident that much attention is being paid, in recent years, to disease
conditions among livestock caused by helminths. In this paper the occurrence of Stephanofilariasis
as a specific disease entity in buffaloes causing ear-sore, is described.
* Paper read at the Indian Science Congress (Section of Medical and Veterinary Sciences), held at Patna in January
1948.
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