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Cutaneous Microfilariasis in Indian Cattle
sharply pointed and slightly curved posterior extremity. The number of the
larvae in the skin is subject to seasonal variations. With the approach of
winter the number of microfilariae in the skin rapidly decreased and finally
the larvae almost disappeared and the skin presented almost a normal
appearance ; but with the return of the hot season the larvae and the
associated clinical manifestation reappeared.
At first sight the animal appeared to be an advanced case of ' cutaneous
bleeding ' or ' blood boils ' due to a very heavy infestation with Parafilaria
multipapillosa. These parasites live as adults in the subcutaneous and inter-
muscular connective tissue and produce subcutaneous nodules which appear
suddenly, break open, blead and then heal up. The condition is seen during
summer and disappears in winter. The microfilariae of P. multipapillosa
measure 0.22 to 0.23 mm. in length and 0.009 to 0.01 mm. in breadth and are
never found in the blood of the host. Apart from the absence of the
microfilaria in the general circulation and their seasonal incidence, the
disease described in this paper and the one caused by P. multipapillosa have
no points of similarity between them.
There is only one reference in literature to a somewhat similar disease
occurring in Japanese cattle described by Oguni in 1927, as ' Wahi' or ' Kose '
or an elephantiasis-like disease. This disease has been known among Japanese
cattle for a long time and was considered to be merely a kind of scabies, or
referred to as intoxication or some other condition till Oguni [1927] succeeded
in demonstrating a type of microfilariae which is believed to be the cause of
this disease. The cases usually occur in summer in large numbers and are rare
in winter, three to seven years old animals being mostly affected. Symptoms
differ according to the stage of the disease. The lesions are usually found on the
skin of the head, neck and back. At first several small nodules, which may
be felt with stroking, appear here and there on the skin. In some cases
many parts of the skin are peeled off, leaving bright red, sensitive, moist and
bleeding surfaces. As the disease progresses the number of nodules increases,
hairs fall off and thick folds due to the thickening of the skin are gradually
formed on the neck and throat, which ultimately present the appearance of
elephantiasis. Severe itching is a constant symptom of the disease and conti-
nuous rubbing, biting and scratching due to irritation result in loss of condition.
The symptoms are less severe in winter and the animal appears to be normal
but with the return of warm season the lesions reappear, assuming larger propor-
tions. The microfilariae, which are found in the blood, measure 130µ
in
length, the breadth being equal to the diameter of the red blood corpuscle. The
larvae appear to be without sheath. The microfilariae and eosinophiles are
abundant in the initial stages of the disease but practically disappear in ad-
vanced cases.
The points of similarity between the Japanese and Indian disease are the
seasonal incidence, both flaring up in summer, peeling of pieces of skin at the
slightest injury, casting of the coat in patches and the causative agents of both