December, 1948]
V. R.
GOPALAKRISHNAN
229
animal. A large number of cases are usually seen in working animals, i.e., male buffaloes. They
are mainly used for field work such as ploughing and for carts. During the rest period of the day
they often remain in miry and marshy places near water-ways. This habit, to a certain extent,
seems to retard the improvement in treated cases. The condition usually becomes chronic and
often remains quiescent in the cold season. Generally active lesions reappear during rains, the
monsoon weather being most favourable.
Several cases were examined in various localities during the rainy and winter seasons, to study
the differential characters of the lessions in the active and quiescent stages. The symptoms described
above refer to the active stage in the rainy season. In winter, the lesions become inactive and
appear more or less dry. The surface presents a healthier appearance and there is less local irrita-
tion. In fact, the animal does not manifest any inconvenience or pain. Parasites have been re-
covered from all the cases though their number from these cases may be less. When the lesions are
active, more parasites are obtained from the scrapings.
The disease usually runs a slow course of two to three weeks or more. Generally one ear is
affected and sometimes both are involved. Recovery ordinarily takes place and there is rarely any
mortality.
Collection of scrapings
Scrapings are collected from the affected part after cleaning the surface with normal saline
solution. A blunt scalpel or a curette will serve the purpose. Certain observations regarding the
collection of adult worms from fresh scrapings are worthy of note. While scraping affected areas
or lesions, it is not uncommon that a portion of the parasite protrudes from the scraped surface.
Dropping a small quantity of saline over the area, removes the oozing blood, thus exposing more
distinctly the adherent parasite which can be gently removed with a pair of forceps or camel-hair
brush. Besides, when scrapings are collected in normal saline in a Petri-dish, the worm could be
found embedded in a piece of scraped tissue, sometimes with a portion of it protuding. A careful
teasing of the clumps of the scrapings dislodges the worm. While examining the worm under micro-
scope, it is not infrequent that the anterior extrimity is covered with fragments of tissue.
Laboratory findings
Scrapings and smear preparations were examined in all the cases that were investigated. From
the scrapings adult nematode worms, both male and female, have invariably been recovered for
examination. As usual in Filariidae, female parasites were found longer than the male ones. Smear
preparations have revealed numerous microfilariae. These preparations have been examined fresh
as well as stained with Leishman stain. In wet smears, the microfilaria is coiled up inside an egg-
like membrane. In stained smears, free forms are detected. The morphological characters of the
parasite have been found apparently identical with those of Stephanofilaria assamensis causing hump-
sore of cattle as recorded by Pande [1936].
Further, with the object of getting the findings confirmed, collection of worms from the ear
scrapings was sent to the Officer in-charge, Veterinary Zoology Section, Imperial Veterinary Research
Institute, Mukteswar, and it has been identified as belonging to Stephanofilaria (sp). Besides,
specimens of worms from further cases were sent to the Officer-in-charge, Helminthiasis Scheme,
Imperial Council of Agricultural Research, Lucknow University, Lucknow, and these too were
identified as Stephanofilaria (sp).
In the smear preparations, in addition to microfilaria, various organisms have been seen, such
as cocci, fungi, acari parasites, etc. These are considered saprophytic or secondary invaders in
view of the anatomical position of the parts affected ; nor is their presence constant in all cases.
Transmission of the disease
Experimental transmission or reproduction has not been successful so far. In view of the
seasonal occurrence of the disease, insects must be considered to be the probable vectors of the