R. G. DHAYAGUDE 173
Helminths. After a thorough post-mortem, the
skin of every animal was flayed with a view to
getting the adult worms of the repens type, of
which the habitat is the subcutaneous tissue. The
worms are found as coiled knots of dead white
material which can be seen sometimes with diffi-
culty on the whitish yellow subcutaneous tissue.
When a little time is allowed to pass some more
come into view. They wriggle out very slowly
and can be observed to change their position if
watched for a little time. In the case of three
dogs in which, although the blood contained micro¬
filaria, adults could not be obtained. The negative
result for the adult worms could only be account-
ed for by supposing that the worms were already
calcified and could not be seen or that they were
so few that, in spite of a careful examination,
they were missed. The largest number recovered
out of two positive dogs was 1. 0 in each (Plate
XIV, Fig. 2).
Adult male and female worms.—In most of
them both males and females were found. They
can be easily distinguished by the fact that male
(Plate XIII, Fig. 2) is finer and has a curved
posterior extremity. A camera lucida drawing
(Plate XIII, Fig. 3) of the tail end of the male
worm shows two to four adanal or preanal papillae
on one side and five to six on the other. The
average dimensions of the specimens collected is
6.2 mm. × 0.357 mm. The male possesses two
spicules, one broad and short and the other fine
and long. The spicules measure from the surface,
of the cuticle broad 57.1µ while the fine 137.1µ.
The average length of the female (Plate XIV,
Fig. 1) measures 13.3 mm., while its breadth is
0.536 mm. The vulval opening is situated about
1.5 mm. from its anterior end.
DISCUSSION
From the foregoing description, there can be
no doubt that the commonest variety of filaria
infesting dogs in Bombay is Dirofilaria repens,
although there is a possibility that some other
variety may also be present, as evidenced by the
finding in one dog of microfilariœ different from
those of Dirofilaria type. The dog heartworm,
Dirofilariaimmits, infestation has been a subject
of intensive study by Hinman et al. [ 1935 ]
with reference to the filarial periodicity. No
such work appears to have been done on the repens
type and the only solitary reference that could be
traced in connection with it was the work of
Panda who mentions that there is no periodicity
in the microfilaria of the repens type. We cannot
confirm his statement. Our observations show
that there is a periodicity and that between 6 to
10 P.M. larger numbers of microfilaria are regu-
larly found in the peripheral blood of the dog,
while their count is low in the mornings. It is
of interest to note here that a case of Dirofilaria
repens infestation in a. human being has been
described by Skrjabin, Althausen and Schulman
[ 1930]
It appears that the infestation is not as common
here as in Bihar where 10 per cent of animals are
infested. In Bombay, the percentage works out
to be half as much. Panda [1932] mentions that
most of the animals harbouring the helminths
suffered from skin lesions of the cczematous type,
particularly on the back, because it is in the sub-
cutaneous tissues of the dorsum that a large
number of the worms are to be found. Our
experience does not corroborate his observation.
Most of the dogs studied did not show any lesion.
It is quite possible that these lesions might make
their appearance in the later stages when the
infestation has become chronic and that the dogs
studied in this series were probably not chronic
sufferers. So far as the general appearance and
vitality of the animal was concerned, there was
apparently no difference between the positive
and negative dogs. Autopsies held on the bodies
of dogs with and without filarial worms did not
reveal any abnormality in the naked eye and
histological characters of the viscera studied.
The impression gained as a result of this study
is that Dirofilaria repens infestation of the degree
found in dogs in Bombay does not materially
inconvenience them.
SUMMARY AND CONCLUSIONS
(1) The common variety of filarial worm in-
festing dogs in Bombay is Dirofilaria repens.
(2) About 5 per cent of the street dogs are
infested with this worm.
(3) Apparently the dogs do not suffer from any
inconvenience due to the presence of this worm.
(4) The microfilaria of Dirofilaria repens shows
a periodicity similar to that of D. immitis.
ACKNOWLEDGEMENTS
My warm thanks are due to Mr S. M. Nadkarni,
Assistant in my department for the zealous manner
in which he assisted me in this work and to
Dr D. K. R. S. Aiyar, G.B.V.C. of the Veterinary
College, Bombay, for the interest he took in this
investigation.
REFERENCES
Bhalerao, G. D. (1935). Scientific Monograph No. 6 of
the Imp. Coun. Agri. Res., Delhi
Hinman, E. H. et al. (1935). Amer. J. Trop. Med. 15, 371
Korke V. T. (1924) Indian J. Med. Res. 11, 1231-7
Neumann. L. G. (1905). (Original not seen)
Panda, P. (1932). Indian Vet. J. 8, 241
Skrjabin, K. I., Althausen A. J. & Schuhnan, E. S. (1930).
Trop. Med. & Veterin, Moscow 8, 9, 11. Abstracted in
Tropical Diseases Bulletin 28, 683