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CLINICAL OBSERVATION AND SURGICAL MANAGEMENT OF
EXTERNAL HERNIAS IN RUMINANTS IN DOHUK
GOVERNORATE
M.I.YASIN
Department of clinical sciences,Faculty of Veterinary Medicine,University of Dohuk
Kurdistan Region, Iraq.
(Received 22 October 2015, Accepted 8 December 2015)
Keywords: External hernias, Ruminants, Dohuk.
ABSTRACT
This study was conducted to determine the prevalence of external hernias in ruminants
in Dohuk governorate in relation to the species, age, and sex of the animals. During a
period of seven years, fifty eight cases of external hernias were presented for surgical
correction. Eighty one percent of the hernia cases were in ovine species, 15.6% were in
caprine; bovine constituted only 3.4% of the cases. High incidence of hernias was
recorded in females; the sex distribution was 72.4% females and 27.6% males.
Umbilical hernias constituted 44.8% of all hernias, followed, in reducing frequency, by
ventral (31%), scrotal (13.8%) and inguinal hernias (10.4%).
Clinical and surgical findings which include the size of the hernial rings, reducibility of
the contents, the condition of the peritoneum, suture patterns and materials used and
surgical outcome were described.
INTRODUCTION
External hernia is a displacement of an organ, part of an organ, or a tissue outside the
abdominal cavity through an abnormal opening in the abdominal wall which can be noted
from the outside of animal’s body and can be detected with external examination.
External hernias are classified according to their anatomical locations into umbilical,
inguinal, scrotal, femoral, perineal, and ventral (or abdominal) hernias. Ventral hernias
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occur in the abdominal wall other than through a natural orifice, they may occur high or
low in the flank, along the costal arch, on the midline, and in the area of the prepubic
tendon 1.
Herniorrhaphy is among the most commonly performed operations in animal and
human surgical practices. Most hernias enlarge over time and, if not repaired surgically,
they may cause pain, anorexia, weight loss, or it may cause dystocia when a gravid horn
is found in the hernial sac 2. Incarceration and strangulation of the bowel are the most
dangerous life threatening sequela of herniation 3.
Hernias were either reported in ruminants as individual cases 4, 5. 6, 7, 8, 9, 10 or in
studies involving different types of hernias 11, 12. 13, 14.
Because there is a dearth of informations concerning the prevalence of different types of
hernias in ruminants in relation to species, age, and sex of the animals in Dohuk
governorate/Kurdistan region/Iraq, this study was performed. Clinical signs of these
hernias, their surgical management and outcome were described in details
MATERIALS AND METHODS
Animals:
This study was conducted on animals having external hernias referred from different
parts of Dohuk governorate to the department of Medical Sciences/ Faculty of Veterinary
Medicine/Duhok University/ Kurdistan region/ Iraq and to Summel veterinary teaching
hospital during the period from October 2008 to July 2015.
Informations concerning the species, age, and gender of the animals, the history of the
cases and the locations of the hernias were recorded on medical cards. A thorough body
examination was carried out to identify the physical status of the animals and to detect
any defect in other parts of the body. The hernias were palpated to detect pain, heat,
presence of hernial rings, reducibility of the contents, and the presence of infection. Some
of these cases were documented by photographs.
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Preoperative preparations:
Food was withheld for 36 hours and water for 6-12 hours only from adult animals
especially those having large hernias. Hernias of immature animals (up to 6 months old)
were repaired at the day of arrival without withholding food and water.
Procaine penicillin (24mg/kg) and dihydrostreptomycin sulphate (30mg/kg) (Pen &
Strep® Norbrook G.B.) was given intramuscularly one hour before the operation and
repeated for five days thereafter. Hernia repairs were performed aseptically (clipping,
shaving of the site of the operation, skin scrubbing with povidone iodine and ethyl
alcohol and using sterile surgical instruments and drapes).
Anesthesia:
Field block anesthesia by making walls of infiltration of 2% lidocaine hydrochloride (pil,
India) enclosing the hernial borders was used for umbilical, small ventral hernias, and,
inguinal and scrotal hernias of immature animals. For large ventral hernias, in addition to
the local anesthesia, intravenous injection of 0.05mg/kg xylazine (Xyla, interchemie,
Holland) was used. Epidural (lumbosacral) anesthesia was used for inguinal and scrotal
hernias in adult animals using 10 ml of 2% lidocaine.
Hernia repair:
The animals were placed on dorsal position for umbilical and ventral midline hernias or
lateral position for inguinal, scrotal (with upward elevation of the uppermost hind limb of
the affected side), ventrolateral and paracostal hernias.
For umbilical, all ventral and inguinal hernias, a single linear skin incision was made
through the center of the hernial sac, starting 2 cm beyond the anterior border of the
hernia and extended for 2 cm posterior to it (Fig.1).
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Figure1. A single linear skin incision is made over the center of the hernial sac.
For umbilical hernias in males, the posterior part of the skin incision was made lateral
to the prepuce. For scrotal hernias a circular incision was made around the scrotal neck
and extended up to the inguinal region of the affected side.
The skin was bluntly dissected from the underlying tissues to expose and open the
hernial sacs. The condition of the peritoneum (intact or teared) was recorded. All the
adhesions between the hernial contents and the hernial sacs and/or the rings, if present,
were freed gently. The herniated contents were examined and pushed into the abdominal
cavity and the length of the rings was measured.
The technique and the suture materials used to close the hernial rings depended on the
size of the rings, the amount of tension on the suture line, and the type of suture material
available at the time of the repair. Ford interlocking No.2 catgut or No.1 polyglycolic
acid suture was used to close small (4-6 cm long) umbilical rings. The rings of larger
umbilical hernias, inguinal hernias of mature animals, and all the ventral hernias were
closed by modified Mayo closure (vest-over-pants) (Fig.2) using nonabsorbable suture
materials like No.2 silk, No.1 nylon or No.1 polypropylene. The free overlapping upper
edges were sutured to the adjacent tissue by simple continuous No.1 polyglycolic acid.
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Figure 2. Preplacing modified Mayo sutures before tying the knots.
Bilateral castration with scrotal ablation was performed for scrotal hernias. The rings
of inguinal hernias of immature females and all those of scrotal hernias were closed with
simple interrupted No.1 nylon, polypropylene or polyglycolic acid.
The tissues overlying all the repaired rings, including the subcutaneous tissue, were
sutured in a single or multiple layers (depending on the thickness of the abdominal wall
at the surgical area) with simple continuous No1 polyglycolic acid or No.1 chromic
catgut.
Excess skin was removed and skin wounds were closed using simple interrupted
No.1 silk or polypropylene. Drains were placed in the lower parts of the repaired
ventrolateral and inguinal hernias of adult animals to prevent seroma formation and
accumulation of blood in the dead spaces. The owners were asked to remove the drains
when no swelling is seen in the surgical area and no fluids or blood is coming out from
the drains.
Because most of these cases were brought from remote and rural areas, postoperative
care (daily wound dressing, antibiotic injection and removal of skin stitches 10 days after
the operation) was done in local veterinary hospitals. Postoperative complications and
follow up information were obtained from the owners through phone calls.
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RESULTS
Fifty eight cases of hernias were recorded over a period of seven years, 47(81%) cases
were in sheep, 9 (15.6%) in goats and 2 (3.4%) in calves. Forty two cases (72.4%) were
Females (35 sheep, 6 goats and 1 calf) and 16 (27.6%) were males (12 sheep, 3 goats and
1 calf). Anatomically, twenty six cases (44.8%) were umbilical, eighteen (31%) were
ventral, eight (13.8%) were scrotal and six (10.4%) were inguinal (table1).
Table 1. Distribution of the different types of hernias in relation to the species and sex of
the animals.
Type of
hernia
Species
Total
Ovine Caprin
e
Bovine
♀ ♂ ♀ ♂ ♀ ♂
Umbilical 18 2 2 2 1 1 26 (44.8%)
Ventral
Ventrolateral
Paracostal
Ventral mid
line
8
1
2
3
-
-
1
2
1
-
-
-
-
-
-
-
-
-
12
3
3
18 (31%)
Scrotal - 7 - 1 - - 8 (13.8%)
Inguinal 6 - - - - - 6 (10.4%)
Total 35 12 6 3 1 1 58
♀= female, ♂= male
Most animals had a normal physical condition and appetite even those having very
large hernial sacs. Diagnosis was mainly based on clinical signs, presence of hernial rings
with retraction of the hernial content back into the abdominal cavity in reducible hernias.
For irreducible hernias with impalpable rings, aseptic needle aspiration was used to
exclude other conditions and palpation of movable loops of intestine in the hernial sacs
confirmed the diagnosis.
Nineteen umbilical, 5 scrotal and 2 inguinal hernias were observed in 10 days to 3 month
old animals, they were detected by the owners shortly after birth (table 2).
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Table 2. The distribution of the hernias in relation to the age of the animals.
Type of
hernia
The age of the animals
Total
da
ys
Months Years
10 1 2 3 5 8 2 3 4 5 6 7
Umbilical - 3 9 7 1 1 - 1 3 1 - - 26
Ventral - - - - - 1 2 2 6 5 1 1 18
Scrotal - 3 1 1 - - - - 1 1 1 - 8
Inguinal 1 1 - - - - - - 2 1 1 - 6
Total 1 7 10
8 1 2 2 3 12
8 3 1 58
All the remaining hernias were observed in older animals. They were found by the
owners accidently with an unobvious cause. Most ventrolateral and inguinal hernias were
detected during pregnancy or after parturition in 4-5 years old females with no history of
trauma.
Twenty one hernias (ten ventrolateral, two paracostal, 5 scrotal, and 4 inguinal) were leftsided.
Eight hernias (2 ventrolateral, one paracostal, 3 scrotal, and 2 inguinal) were rightsided,
and three were at the ventral midline (fig. 3, 4, 5, and table 3).
Figure 3. Left sided hernias: Scrotal (1); Inguinal (2); Ventrolateral (3); Paracostal (4)
Inguinal (5 and 6)
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Figure 4. Right sided hernias: Scrotal (1, 2); ventrolateral (3); Inguinal (4, 5)
and Paracostal (6).
Figure 5. Ventral midline hernia located anterior to the udder in a goat.
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Table 3. The distribution of the hernias in relation to the side.
The incidence of umbilical hernias was higher in females than in males. The sizes of
the umbilical hernias and rings were related to age. They were larger in mature animals
(fig.6).
Figure 6. Umbilical hernias in mature animals (upper pictures) and in immature animals
(lower pictures)
Type of hernia
The side of the hernia
Left sided Right sided Ventral midline
Ventral 12 3 3
Scrotal 5 3 -
Inguinal 4 2 -
Total 21 8 3
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All umbilical hernias were reducible with palpable rings except in one, 2 months old,
male lamb with irreducible umbilical hernia, showed signs of pain and anorexia suddenly
one day before admission for repair. On palpation, the hernia was firm, hot and painful
with impalpable ring (fig.7). Part of the abomasum was seen incarcerated by a 6 cm long
ring.
Figure 7. Irreducible umbilical hernia in a lamb containing part of the abomasum.
The peritoneum was teared in 5 umbilical hernias, and was intact but tightly adhered
to the skin and the ring in the remainders.
The midline ventral, paracostal and most of the ventrolateral hernias were reducible with
palpable rings. Five ventrolateral hernias were irreducible with impalpable rings which
were due to severe adhesions of the contents with the hernial rings and hernial sacs
(Table 4).
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Table 4. The conditions of the peritoneum and the hernial contents.
Type of
hernia
The condition of the
peritoneum
The condition of the herniated
contents
intact teared Reducible Irreducible
Umbilical 21 5 25 1
Ventral - 18 13 5
Scrotal 8 - - 8
Inguinal 2 4 4 2
Total 31 27 42 16
For scrotal hernias and inguinal hernias of 2 female lambs, the sizes of the rings were
small with large hernial sacs. They were irreducible with impalpable rings due to stacked
hernial contents (intestine) with relatively small rings compared to the voluminous
contents, the peritoneum was intact with no adhesion between the contents and the
peritoneum (fig.8 and 9) which facilitated easy reduction of the contents into the
abdomen after enlarging the hernial rings. The inguinal hernias in the remaining 4 ewes
were reducible with large palpable rings.
Figure 8. Intact peritoneum in two female lambs with inguinal hernias.
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Figure 9 . Intact peritoneum (tunica vaginalis) in scrotal hernias.
The peritoneum in all ventral and inguinal hernias of the 4 mature females was teared
and the herniated organs (mainly intestine and omentum, and with the rumen in one case)
(fig.10) were found under the skin forming large dead spaces particularly in mature
females with ventrolateral and inguinal hernias which extend ventrally above the udder
and, in some cases, to the level of the milk vein. Severe adhesions of the contents to the
rings and the inner surface of the sacs were detected (fig.11).
Figure 10. Hernias with ruptured peritoneum with the presence of the herniated contents
(intestine in the left and middle pictures and rumen in the right one) under the skin.
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Figure11. Adhesions of the contents (omentum) to the hernial sacs.
Table 5 shows the length of the hernial rings. Hernias with different ring lengths are
shown in fig. 12.
Table 5. The length of the rings of recorded hernias
Type of hernia
Length of the rings (cm)
4 6 10 15 20
Umbilical 2 17 5 2 -
Ventral - - 7 8 3
Scrotal 3 4 1 -
Inguinal 2 - - 3 1
Total 7 21 13 13 4
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Figure 12. Hernial rings with different sizes.
All umbilical, scrotal, paracostal, midline ventral hernias, and, inguinal hernias of
female lambs were successfully repaired, even in those with large rings, and no
postoperative complications and hernial recurrence was recorded. Withdrawal of food for
36 hours was very helpful in reducing the volume of the digestive tract and facilitated
ring closure and administration of large dose of prophylactic antibiotic prevented
infection.
Difficulties were encountered in repairing some large ventrolateral and inguinal hernias
of mature females, the normal anatomy of these region was deformed, leaving large
(≥15cm long), irregular, weak, and thin edged rings which were approximated using
excessive tension particularly the middle portions of the rings, and with difficulties in
obliterating large dead spaces after resecting the large hernial sacs. Hernia recurrence was
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recorded in four ewes (one with inguinal and three with ventrolateral hernias) which were
eventually slaughtered.
DISCUSSION
This study showed that hernias were more frequently encountered in sheep followed
by goats; this is because sheep is the major livestock type raised in Dohuk governorate,
goats rank the second. Cattle are raised in few numbers with small ruminants in some
farms.
Higher incidence of these hernias were observed in females (42 cases) than in males
(16 cases) this is because of the fact that males in Dohuk governorate are slaughtered
regularly at a lifespan of 6 months to 1 year; few are kept solely for breeding, moreover,
the owners are apathetic about treating hernias in males as males will eventually be
slaughtered.
Umbilical hernia was the commonest type recorded especially in sheep, and was much
more common in females than males, followed, in order of decreasing frequency, by
ventral, scrotal, and inguinal hernias.
Many studies performed in developing countries showed that prevalence of different
types of hernias in animals is nearly similar and does not differ to the results in the
present study.
Umbilical hernias were the most common type observed in goats by 11 followed by
abdominal hernias, the incidence of hernias were more in females than in males.
The researcher 12 found that hernias were more common in sheep than in goats with
high incidence of abdominal hernias followed by umbilical hernias.
In Egypt, a study by 13 showed that hernias were recorded more in buffaloes followed, in
reducing frequency, by cattle, sheep, donkeys, goats and horses. They found that the most
common type was diaphragmatic hernia in buffalo, umbilical hernia in cattle, and ventral
hernia in sheep and goats.
In Nigeria, ovine species had the highest percentage of hernias followed by caprine and
bovine species, ventral abdominal hernias were the most common type recorded 14.
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Inguinal, scrotal, and perineal hernias were the least frequent types recorded in literatures
11, 12, 14.
In this study, most umbilical, scrotal and two inguinal hernias were congenital seen
upon birth in the early postpartum period.
Umbilical hernia occurs due to failure of closure of the umbilical ring at birth, it may
have a genetic component and considered to be inherited in sheep 15 and in many cattle
breeds 16, 17, 18, 19, animals with these hernias should not be used for breeding
purposes 1. Some umbilical hernias are not inherited, they may develop due to infection
and abscess formation in the umbilical vessels 1.
Congenital inguinal and scrotal hernias are inherited and considered as a genetic
autosomal recessive disorder in sheep as in other animal species 5 particularly in Merino
sheep 20 and Swiss sheep 21.
The researcher 22 recorded that inguinal and scrotal hernias were found in lambs
rather than in older sheep as a result of raised intra-abdominal pressure in lambs fed on
artificial or highly fermentable diets and this pressure is believed to force intestinal loops
through the inguinal ring.
The researcher 4 stated that scrotal hernia is thought to be of traumatic causes that
weakens the inguinal area especially in group-housed rams.
Ventral hernias are considered to be traumatic [2] due to violent impact with blunt objects
like horn thrust separating the abdominal muscles 1.
In this study ventral hernias were seen in adult animals, especially multiparae
females. Of the 18 ventral abdominal recorded hernias, 12 were ventrolateral with leftsided
predominance without a clear cause, this result is in contrast to Roberts [2] who
mentioned that these hernias in ruminants is commonly seen on the right side of the
abdominal floor.
In addition to trauma, increased intra-abdominal pressure during pregnancy, loss of
abdominal wall strength with age, and under nutrition weakens the muscles and tendinous
support of the abdominal wall and contributes in causing ventral hernias 22.
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The flank and ventrolateral abdominal region in ruminants lacks a continuous muscle
covering, it has a rather narrow fleshy portion with holly tendinous nature and an
extensive aponeurosis 23, 24.
The researcher 25 described a region on lateral abdominal wall of the ox which lacks a
muscle covering. In this region, the transverse and the oblique muscles form a purely
aponeurotic zone of the abdominal wall, it begins medial to stifle and extend forward for
a variable distances along the lateral border of the rectus, hernias sometimes result from
injury to this area.
In ewes, intestinal herniation through a rupture of the weakened abdominal muscles
has been observed 1-3 weeks before lambing in multiple pregnancies 3.
In different studies, for closing the hernial rings, different suture materials and patterns
have been used. A study by 26 showed that hernial recurrence was minimal when
polypropylene was used to close umbilical hernial rings in calves compared to silk and
catgut using Mayo overlapping mattress or horizontal mattress suture.
Absorbable suture materials like polyglactine 910, polydioxanone, or polyglycolic acid is
recommended to close umbilical ring by simple interrupted, simple continuous or
interrupted cruciate patterns; tension relieving sutures such as near-far-far-near is used to
close large abdominal wall defects 27, 28.
No.2 chromic catgut was used to close umbilical hernial rings of calves 29. In goats, No.5
Dexon or polyester with mattress or Mayo-mattress was used to close umbilical and
ventral hernial rings and figure-of-eight-suture pattern for closing inguinal rings 11.
The researchers 12 used catgut or polydioxanone to close small hernial rings in young
animals, and used silk for larger hernial rings in older animals. They stated that the types
of suture material used had no effect on the surgical outcome.
In the present study, absorbable suture materials were not used to close large hernial
rings because they may lose their tensile strength or become absorbed before the healing
process is completed, causing reherniation.
Modified Mayo closure (vest-over-pants) was a suitable suture pattern for large
hernias to support and reinforce the thin and weak parts of the abdominal wall
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particularly the ventrolateral region. In scrotal hernias and inguinal hernias of immature
females, simple interrupted pattern was used to close the external inguinal rings to
preserve the blood vessels and nerves passing through the ring and prevent their
compression and blockage by the suture materials which may occur if a continuous
pattern is used.
Reherniation occurred only in some cases with very large hernial rings which may be
due to tissue ischemia or cutting of the ring edges by the suture materials caused by
excessive tension applied on the suture line. Hernioplasty is the best option for repairing
such rings using prosthetic materials 28, 30.
Polypropylene mesh is the only prosthetic material available in Dohuk local market
but, due to financial constraints, the owners cannot afford the coasts and prefer to
slaughter the animals rather than paying for these relatively expensive meshes ($ 80 for
30 cm x 30 cm mesh).
الملاحظات السریریھ ونتائج التداخل الجراحي للفتوق الخارجیھ للمجترات في محافظة دھوك
مریم أبراھیم یاسین
فرع العلوم السریریھ، كلیة الطب البیطري، جامعة دھوك، دھوك، أقلیم كرردستان، العراق
الخلاصة
أجریت ھذه الدراسة لمعرفة نسبة أنتشار الفتوق الخارجیة للمجترات في محافظة دھوك وعلاقتھا بنوع وعمر
وجنس الحیوانات. تم أجراء التدخل الجراحي لثمان وخمسون حالة فتق خلال فترة سبعة سنوات (من تشرین الأول
.( 2008 الى تموز 2015
15.6 % في الماعز و 3.4 % في الأبقار. نسبة حدوث الفتوق في ، % نسبة الفتوق في الأغنام كانت 81
الأناث كانت أعلى من الذكور و خاصة في الأغنام.
شكلت الفتوق السریة نسبة 44.8 % تلتھا، تنازلیا، الفتوق البطنیة ( 31 %)، فتوق الخصیة ( 13.8 %)، ثم الفتوق
الأربیة ( 10.4 %). تم وصف العلامات السریریة والجراحیھ المتعلقھ بحجم حلقة الفتق، رجوعیة محتویات الفتق الى
البطن، حالة البریتون، نوع الخیاطھ والخیوط الجراحیھ المستعملة، و نتائج التدخل الجراحي.
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