NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
ON SOME NEMATODE PARASITES OF GOATS AND SHEEP AT
MUKTESAR
BY
G. D. BHALERAO, M.Sc.,
Helminthologist, Imperial Institute of Veterinary Research, Muktesar-Kumaon, U. P.
(Received for publication on 27th April 1932.)
(With Plates XVII—XX.)
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CONTENTS
Varestrongylus pneumonicus n.g., n. sp.
Dictyocaulus unequalis n. sp.
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Œsophagostomum venulosum (Rud., 1807)
Ostertagia orientalis n. sp.
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Ostertagia occidentalis (Ransom, 1907)
Ostertagia circumcincta (Stadelmann, 1894)
Hœmonchus contortus (Rud., 1803)
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Page
. 242
. 248
. 249
. 249
. 251
. 251
. 252
The goats and the sheep which are used for experimental work at Muktesar
appear to be very rich in their parasitic fauna and many interesting features have
been observed. An investigation into these has now been in progress for over a
year and some of the results of this are given in this communication. The parasites
were collected from four kinds of animals :—Hill and Tibetan goats (Capra sibirica
Meyer), hill sheep (Ovis nahura Gray) and Tibetan sheep (Ovis hodgsoni Blyth).
The systematic names of these animals were supplied by Dr. B. Prashad, the Super-
intendent, Zoological Survey of India, Calcutta, to whom I wish to express my
indebtedness. The animals from which the parasites were collected were, in all
cases, used for maintaining the Rinderpest virus at this Institute.
Varestrongylus pneumonicus n.g., n.sp.
(Plate XVII, Figs. 1-5.)
The specimens were obtained from the large as well as smaller bronchi of both
sheep and goats. The number of worms found each time was not many, but the
lung tissue presented many greyish patches, smears of which showed an incredibly
large number of ova of these worms. It appears therefore that the worms possess
a very great capacity for egg-laying. It is a matter of little surprise that these
animals, which are already debilitated owing to Rinderpest, should develop an
attack of broncho-pneumonia and in many cases succumb to it. Experiments
( 242 )
PLATE XVII.
FIG.1.
FIG.2.
FIG.3.
FIG.4.
FIG.5.
C 2
NEMATODE PARASITES OF GOATS AND SHEEP
243
to eradicate this infection have been undertaken at this Institute, and these, to-
gether with the effects of the parasite produced in the lung tissue, will form the
subject of a separate report.
The worms are very slender, delicate and of moderate size. The cuticle is
smooth without any kind of markings. The anterior portion of the body is some-
what tapering. The buccal cavity is very feebly developed and in the majority of
cases appears to be even absent. The mouth is surrounded by four lips ; two
lateral measuring 0.018*-0.022 in width and a smaller dorso-ventral pair measuring
0.012-0.014 in width.
Male.—The males measure 17.6-24 in length and 0.165-0.185 in thickness,
the maximum thickness being attained somewhat nearer the posterior end. The
œsophagus is club-shaped, measuring 0.34-0.39 in length. The nerve ring is
situated at a distance of 0.17-0.18 from the anterior end of the œsophagus. The
excretory pore is situated either at the level of the nerve ring or in some cases
somewhat posterior to it.
The spicules are long, fairly stout, with a blunt head and their inner side has
an ala which is transversely striated throughout its length. The alæ of the spicules
overlap each other in the middle portion. The spicules measure 0.29-0.57 in length
and are bifid at their ends. The bursa measures 0.14×0.22-0.165×0.165 and
consists of two large lateral lobes and a small dorsal lobe. The bursal formula is as
follows :—The dorsal ray is very thick and stout and ends in five digitations. The
externo-dorsal ray is very thin and does not reach the margin of the lateral lobe of
the bursa. The postero-lateral ray is very small and arises as a branch of the
lateral lobe. The antero-lateral ray arises independently of the other two laterals
and is stouter than them. It reaches the border of the lateral lobe. The ventral
ray is the stoutest of all at the beginning and divides at its extremity into two
branches, the latero-ventral and ventro-ventral.
The gubernaculum is a large body measuring 0.138-0.165 in length. It is
almost spindle-shaped with a tapering anterior end and a somewhat blunt posterior
end. It has two pairs of lateral processes, one situated at the extreme posterior
end is very short and the other, which is about three times as long as the first, is
situated at a distance of about 0.02 in front of the former. Besides the guberna-
culum there are two chitinoid structures with a swelling at their base which form
the telamon. It measures 0.026-0.027 in length.
Female.—The females measure 19.6-28 in length and 0.175-0.19 in thickness.
The body is almost of uniform thickness. The œsophagus is club-shaped and
* All measurements in millimeters.
244 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
measures 0.36-0.4 in length. The nerve ring is situated at a distance 0.19-0.25
from the anterior end. The excretory pore is about 0.05-0.7 posterior to the
nerve ring. The tail tapers rapidly to a point. The anus is situated at a distance
of 0.04-0.045 from the tip of the tail. The vulva is 0.04-0.06 anterior to the anus.
It is guarded by two prominent lips, each being approximately 0.023 in breadth.
Inserted immediately anterior to the vulva and disposed posteriorly is a cuticular
valve measuring 0.065-0.08 in length. It covers the vulva and the anus ventrally.
The vagina is approximately 1.41 long. The two uteri run parallel to each other
anteriorly. The eggs measure 0.057-0.08×0.03-0.043. They are covered with
a very thin shell and are oviparous.
The worm described above being a parasite of the respiratory system with a
filiform body and possessing a well developed bursa with more or less typical rays
is evidently a member of the family Metastrongylidæ Leiper, 1908. Yorke and
Maplestone [1926] have included in this family the genera Metastrongylus Molin, 1861,
Dictyocaulus Railliet and Henry, 1907, Synthetocaulus Railliet and Henry, 1907
which is a synonym of Protostrongylus Kamensky, 1905, Hœmostrongylus Railliet
and Henry, 1907, Troglostrongylus Vevers, 1927 and Crenosoma Molin, 1861. To
this list Baylis [1928] added Parastrongylus. These genera are compared with the
specimens described here in Table I.
NEMATODE PARASITES OF GOATS AND SHEEP
245
TABLE I.
Cuticle . .
Lips . .
Dorsal ray .
Externo-lateral
ray.
Spicules . .
Posterior extre-
mity of male.
Gubernaculum
Telamon
Posterior extre-
mity of female.
Vulva
Metastrongylus
Molin, 1861
1
Not armed
Two lateral tri-
lobed.
Doubled,
small,
thin.
Separate from the
other laterals.
Long, delicate with
transversely
striated wing.
Simple
Present or absent
Absent
Straight, bent upon
itself.
At the posterior
end.
Dictyocaulus
Railliet and Henry,
1907
2
Not armed
Four : two lateral
smaller
than
dorso-ventral
pair.
Doubled bi or tri-
lobed at extremi-
ty.
Separate from the
other laterals.
Equal, short, stout
Simple
Present
Absent
Simple
Near mid-body
Protostrongylus
Kamensky, 1905
3
Not armed
Three
Single trunk ending
in few short digi-
tations.
Arises from a com-
mon trunk with
other laterals.
Equal, fairly stout,
striate or pecti-
nate.
Reinforced by chi-
tinous arc.
Present
Present
Simple
A little in front of
anus.
Hœmostrongylus
Railliet and Henry,
1905
4
Not armed
Six small
Single, large, thick
ending in a few
digitations.
Separate from the
other laterals.
Equal, long, deli-
cate.
Simple
Absent
Absent
Simple
Behind mid-body
246 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
TABLE I—contd.
Cuticle . .
Lips . .
Dorsal ray .
Externo-lateral
ray.
Spicules . .
Posterior extre-
mity of male.
Gubernaculum .
Telamon .
Posterior extre-
mity of female.
Vulva . .
Troglostrongylus
Vevers, 1907
5
Not armed
Two conspicuous
Single, large
Fused with medio-
lateral.
Long, equal, pecti-
nate, ending in
palmate expan-
sions.
Simple
Present
Absent
Simple
Just behind mid-
body.
Crenosoma Molin,
1861
6
Armed
....
Undivided ending
in a number of
minute
digita-
tions.
Separate from the
other laterals.
Equal, fairly long.
Simple
Present
Absent
Tapers rapidly to
a blunt point.
Near mid-body .
Parastrongylus
Baylis, 1928
7
Not armed
....
Short and broad
Arises from com-
mon trunk with
other laterals.
Equal, with striat-
ed alæ.
Simple
Absent
Absent
Slightly curved
Near posterior end
Varestrongylus
Bhalerao, 1932
8
Not armed
Four: two lateral
larger than dorso-
ventral pair.
Short, thick, ending
in five digitations.
Arises
separately
from other late-
rals.
Fairly stout, equal,
with striated alæ.
Simple
Present
Present
Tapers rapidly to a
point.
Near posterior end.
A valve covering
vulva and anus
present.
NEMATODE PARASITES OF GOATS AND SHEEP
247
From the above table it is clear that the position of the vulva at the posterior end
of the body and the presence of a telamon separates the present specimens from
Dictyocaulus, Hœmostrongylus, Troglostrongylus and Crenosoma. Metastrongylus
can be separated from it on account of the dorsal ray being double, the telamon
being absent and the posterior end of the female being bent upon itself. The
genera Protostrongylus and Parastrongylus can be separated from it on account of
the externo-lateral ray arising from a common trunk with other laterals ; the
former, moreover, has the posterior end of the male reinforced by a chitinous are
and the latter lacks both the gubernaculum and telamon. Apart from the
differences pointed out above the parasites in question possess some unique features
which are :—
(1) Four lips, the two lateral being larger than the dorso-ventral pair.
(2) The spicules are bifid at their ends.
(3) The female has a valve covering the vulva and the anus.
The species Metastrongylus (Chrostrongylus) pudendotectus described by
Gedoelst (1923) has a swelling at the posterior end of the female and may, to a cer-
tain extent, be linked to the valve of the present worms but it can easily be
separated from this by the nature of the spicules and the dorsal ray of the bursa of
the male.
From the discussion given above it is apparent that the present worms can not
be ascribed to any of the existing genera of Metastrongylidæ it is, therefore, propos-
ed to create a new genus for its reception for which I propose the name Vare-
strongylus, in honour of Mr. F. Ware, the Director of the Imperial Institute of
Veterinary Research, Muktesar, for his keen interest in Helminthology and constant
encouragement to the writer. The species is designated V. pneumonicus.
Varestrongylus Bhalerao, 1932.
Diagnosis.—Metastrogylidæ : Body filiform. Cuticle unarmed. Lips four :
two laterals being larger than dorso-ventral pair. Male.—Bursal formula : Dorsal
ray thick, short, ending in a few digitations, externo-dorsal thin ; postero-lateral
being a branch of medio-lateral ; externo-lateral arising separately from other
laterals ; ventral ray stout and divided at its extremity into ventro-ventral and
latero-ventral. Spicules equal, fairly stout, with striated alæ and divided at the
extremity. Gubernaculum and telamon present. Female.—Vulva situated slightly
in front of anus. Posterior end rapidly tapering to a point. A valve covering
vulva and anus ventrally. Eggs with thin shell. Ovisparous.
Type-species.—V. pneumonicus Bhalerao, 1932.
248 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
Specific
diagnosis.—Varestrongylus : Male.—Length 17.6-24, thickness
0.165-0.185. Œsophagus 0.34-0.39 long. Spicules 0.29-0.57 long. Female.—
Length 19.6-28, thickness 0.175-0.19. Œsophagus 0.36-0.4 long. Anus 0.04-0.045
and vulva 0.04-0.06 from tip of tail. Eggs measure 0.057-0.08×0.03-0.043.
Host.—Goat, sheep (Hill as well as Tibetan).
Location.—Bronchi.
Locality.—Muktesar-Kumaun (U. P.).
Dictyocaulus unequalis n. sp.
(Plate XVIII, Figs. 1 and 2.)
Only three females and one male were obtained from the large bronchi of a
Tibetan sheep suffering from pneumonia.
The worms are filiform with a thin, smooth cuticle.
Male.—This measures 28 in length and 0.3 in thickness, the maximum thickness
being attained at the level of the spicules. The buccal capsule is 0.023 wide and
0.017 deep. The lips are 0.003 thick, each having a papilla. The œsophagus is
1.1 long. The nerve ring is situated 0.23 from the anterior extremity. The
spicules are reticulate, slightly wavy and measure 0.28-0.29. The gubernaculum
is 0.1 long. The bursa is 0.28 wide. The bursal formula.—The ventral ray
is cleft and its two branches are unequal, measuring 0.09 and 0.14 respectively ;
the externo-lateral arises separately from the other laterals and measure 0.16 ; the
medio- and postero-laterals are fused throughout their length excepting a distance
of 0.015 from their extremities ; the externo-dorsal arises separately from the dorsal
and measures 0.17 in length ; the dorsals are 0.215 in length and are trilobed at their
extremities.
Female.—The length is 64 and the maximum thickness attained at some
distance anterior to the caudal extremity is 0.43. The buccal capsule measures
0.032×0.018. The œsophagus is 1.23-0.37 long. The tail measures 0.57. The
vulva is situated at a distance of 29 from the anterior extremity and is covered
with prominent lips. The eggs measure 0.10-0.123 × 0.061-0.073.
Among the existing species of Dictyocaulus the present species is very allied to
D. filaria (Rud. 1809), but differs from it in having much smaller spicules and the
branches of the ventral ray being unequal instead of equal. It is, therefore,
considered that the species is a new one for which I propose the name Dictyocaulus
unequalis.
Specific diagnosis.—Male :—Length 28, thickness 0.3. Œsophagus 1.1 long.
Spicules reticulate slightly wavy, 0.28-0.29 long. Branches of ventral ray
unequal.
PLATE XVIII.
0.1 mm.
FIG. 2.
FIG. 3.
0.1 mm.
FIG. 4.
PLATE XIX.
FIG. 1.
FIG. 2.
FIG. 3.
FIG. 4.
NEMATODE PARASITES OF GOATS AND SHEEP
249
Female.—Length 64, thickness 0.43. Œsophagus 1.23-0.37 long. Anus
0.57 and vulva 35 from the tip of tail. Eggs measure 0.10-0.123 × 0.061-0.073.
Host.—Tibetan sheep.
Location.—Bronchi.
Locality.—Muktesar-Kumaun (U. P.).
Œsophagostomum venulosum (Rud. 1807).
This parasite has not so far been recorded from goats in India, although its
occurrence in sheep in this country was noted by Gaiger [1915, 70]. One collection
from a goat consists of only one male and about half a dozen females. These
specimens agree in all respects with the material described by Ransom [1911]
excepting the gubernaculum which is slightly smaller, 0.058 long, whereas Ransom
described it to vary from 0.09-0.1. A few measurements of the material at my
disposal are given below :—
Male: Length 12.1; œsophagus 1.72 long, cervical papillae 1.18 behind the
posterior end of the œsophagus ; spicules 1.45 long, gubernaculum 0.058×0.03.
Female :—Length 14.8 ; anus 0.19 and vulva 0.36 from the tip of the tail.
Host.—Hill goat.
Location.—Cæcum.
Locality.—Muktesar-Kumaun (U. P.).
Ostertagia orientalis n. sp.
(Plate XVIII, Figs. 3 and 4 and Plate XIX, Figs. 1-4).
These worms were obtained from the caecum of goats and rarely from the
abomasum. The males measure 9.5-14.3 in length and the maximum thickness
which is attained slightly in front of the bursa is 0.17-0.19. The cervical papillæ
are situated at a distance of 0.42-0.47 from the anterior extremity. The
œsophagus is somewhat club-shaped measuring 0.83-0.965 in length. The nerve
ring is situated at a distance of 0.29-0.305 from the anterior end. The excretory
pore is situated slightly posterior to the nerve ring.
The spicules are 0.27-0.31 long, light yellowish-brown in colour and rather
delicate in structure. At about five-eighths of the distance from their anterior
end, they divide into three branches; two ventral and one dorsal. The
latter is shorter than the other two and ends in a small knob. The outer ventral
branch is the longest and terminates into an acute point. It gives out a small,
slender process at a short distance from its tip. The inner ventral branch is
slightly swollen at its tip, which gives it an appearance of a small knob. The
bursa, when both the lateral lobes are spread out, measures approximately 0.742
250 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
wide. The pre-bursal papillæ are approximately 0.95 anterior to the bursa. The
accessory bursal membrane is about 0.2 wide and is supported by the rays about
1 mm. long. The gubernaculum is absent. The dorsal ray is about 3.3 long
and divides, at a distance of 2 from its anterior end, into two branches. Each of
these branches gives out a short lateral branch on its outer side. The externo-
lateral ray is stouter than the dorsal and ends at some distance from the margin of
the bursa. The postero-lateral ray is the longest of all and reaches almost the margin
of the bursa. The medio- and the antero-lateral rays are increasingly stouter than
the postero-lateral. The ventral ray divides into two, the ventro-ventral and the
latero-ventral, the former being the smallest and the latter the stoutest of all the
rays. Both these almost reach the margin of the bursa.
The females measure 15.4-21.7 in length and the maximum thickness which
is reached in the region of the vulva is 0.19-0.24. The cervical papillæ are
situated at a distance of 0.43-0.48 from the anterior extremity. The œsophagus
is somewhat club-shaped and measures 0.74-0.97 in length. The nerve ring is
situated at a distance of nearly 0.365 from the anterior end. The excretory pore
is slightly posterior to the nerve ring. The tail is slender, gradually attenuated
and rounded at the tip. The anus is 0.22-0.225 in front of the tip of the tail.
The vulva is a transverse slit, about 0.12 wide, situated at a distance of 3.5-5
from the posterior extremity. In the majority of cases it is not covered with any
kind of flap, but occasionally an anterior or a posterior flap may be present. The
vagina is very short, measuring about 0.06 in length. It leads into the muscular
portion of the ovijector. The sphincters are very well developed. The muscular
portion of the ovijector together with the sphincters measure 0.64 in length and
about 0.135 in breadth. The sphincters on either side are followed by a non-
muscular portion of the ovijector measuring 0.4 in length. This latter is followed
by an uterus which does not contain a large number of ova. The ova are. large,
elliptical, with a thick shell and measure 0.168-0.23 × 0.09-0.116.
Among the species of the genus Ostertagia that have been recorded up to the
present time, the specimens described here resembles the species O. marshalli
Ransom, 1907, but it differs from it in the following respects :—
(1) The spicules branch at the posterior three-eighths.
(2) The nature of the three branches of the spicule is different.
(3) The larger size of the bursal membrane and its supporting rays.
(4) The eggs are comparatively larger.
For these reasons it appears justifiable to regard it as a new species for which
the name Ostertagia orientalis is proposed.
NEMATODE PARASITES OF GOATS AND SHEEP
251
Specific diagnosis.—Ostertagia: Male: Length 9.5-14.3, thickness 0.17-0.19.
Cervical alæ 0.42-0.47 from anterior end. (Esophagus 0.83-0.965 long.
Spicules 0.27-0.31 long, dividing into three branches at the posterior three-
eighths, the dorsal branch being the shortest and terminating in a knob. The
outer ventral branch terminates in a point and gives out a short, slender process,
a short distance from its extremity. The inner ventral branch has a small knob
at the tip. The accessory bursal membrane is about 0.2 wide and its supporting
rays 1 mm. long. Gubernaculum absent. The dorsal ray divides at about its
posterior two-thirds.
Female :—Length 15.4-21.7, maximum thickness 0.19-0.24. Cervical papillæ
0.43-0.48 from anterior extremity. Œsophagus 0.74-0.97 long. The tail 0.22-0.225
long. Vulva 3.5-5 from the posterior extremity. Eggs large, elliptical,
measuring 0.168-0.23 × 0.09-0.116.
Host.—Hill goats.
Location.—Cæcum, abomasum.
Locality.—Muktesar-Kumaun (U. P.).
Ostertagia occidentalis Ransom, 1907.
Amongst about two dozen specimens of O. orientalis n. sp. which were
classified for the above description a single male worm identical with 0. occidentalis
was found. Ransom [1907] who described this species has also recorded only the
male. With the object of getting a female of O. occidentalis, several females from
the collection were examined, but they showed no essential deviations from the
species 0. orientalis. It appears therefore likely that the males of 0. orientalis
undergo some variations, while the females remain unaffected. This question,
however, has to be left undecided at the present moment, and opportunities will
be taken to examine this problem more thoroughly at some future date.
The male specimen at my disposal measures 11.5 in length. The spicules are
0.26 and gubernaculum 0.11 long.
Ostertagia circumcincta (Stadelmann, 1894).
About 50 per cent. of the goats at Muktesar appear to be affected with the
parasite. In spite of its frequency it appears rather surprising that a record of
this parasite has not yet been made from India. On examination the parasite
did not reveal any essential points of difference from the description of Ransom
[1911].
252 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
Hæmonchus contortus (Rud. 1803.)
(Plate XX, Figs. 1-6.)
This is a very common parasite of goats and much less so of cattle at
Muktesar. A large collection of this worm both from goats and cattle was exa-
mined. The male specimens are very constant in regard to their structure and
do not reveal any fluctuations. The females, however, exhibit very interesting
variations in regard to the structure or structures developed in the vicinity of the
vulva. Veglia [1915] remarks that some variations occur in H. contortus and
Le Roux [1929, 1, 2] describes some of them in the species H. michelli, H. Vegliai,
H. bedfordi and H. longistipes, but in spite of this variable nature of the lingui-
form flap covering the vulva and the occurrence of some structure or structures
in its vicinity in so many species of the genus Hæmonchus, it appears that the
knowledge in regard to these is far from being well-known. The present oppor-
tunity is therefore taken to describe these variations with the help of illustrations
in the type species of the genus, Hæmonchus contortus, obtained from both goats
and cattle :—
(1) In some cases the flap covering the vulva is altogether absent and
there is no development of any cuticular structure near it. In this
case the vulva opens on the cuticle and its lips are represented by
slight prominences of the cuticle. (Plate XX, Fig 1.)
(2) Overhanging the vulva there may be a flap which is merely a small
protuberence of the cuticle (Plate XX, Fig. 2). In this case the degree
of its development varies to some extent.
(3) The flap may be quite well developed and linguiform as represented by
Ransom [1911, Fig. 36] and by Veglia [1915, Fig. 52].
(4) The flap may be bilobed, one of the lobes being rounded and the other
conical. The bilobed flap together with the opening of the vulva
presenting an appearance of the head of bird. (Plate XX, Fig. 3.)
(5) In addition to a well developed linguiform flap there may be near it a
cuticular swelling or boss. (Plate XX, Fig. 4.)
In the two cases mentioned below the linguiform process is altogether
absent:—
(6) A single cuticular boss is developed immediately anterior to the vulva.
(Plate XX, Fig. 5.)
(7) There may be a boss laterally on each side of the vulva. (Plate XX, Fig.
6.)
PLATE XX.
FIG. 1.
FIG. 2.
FIG. 3.
FIG. 4.
FIG. 5.
FIG. 6.
D