SURGICAL AFFECTIONS OF SHEEP AND
GOATS
By
Dr. Mohamed karam Elsayed zabady
1- Retention of urine
It means that the animal can not empty its bladder. This may be partial or
complete retention as a result of acute or chronic obstruction of the urine
outflow.
Retention may be due to:
A) Mechanical causes: as calculi, neoplasms, strictures, prostatic diseases
and pressure due to constipation.
B) Functional obstruction: This is neurogenic as in cases of atonic bladder,
spasms of the bladder neck as in tetanus, colic and painful lesions of the
abdomen and pelvis.
Urolithiasis
It means the formation of calculi from less soluble crystalloids of urine
as a result of multiple congenital or acquired physiological or pathological
processes.
Etiology:
Many factors have been implicated in the etiology of the urinary calculi
formation but there are few clinical data supporting any one of them so that
urolithiasis is a multifactorial syndrome. In this respect we will discuss some of
these factors:
I. Dietary errors:
1. Diet of high phosphorus content.
2. Diet rich in silicon.
3. Diet rich in oxalate.
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4. Diet rich in calcium.
5. Diet rich in carbohydrates.
II. Metabolic disorders:
III. Water intake:
1. Amount of water:
2. Type of water:
IV. Urine characters:
1) Urine colloids.
2) Urine volume.
3) Urine pH.
V. Infection:
VI. Vitamin "A" deficiency:
VII. Breeds and hereditary factors:
VIII. Sex:
IX. Castration:
X. Anatomical considerations.
XI. Hormones.
XII. Stress factors:
Diagnosis:
- Uroliths are usually suspected on the basis of typical findings obtained by
history and physical examination. When calculi lodge in the urethra, the
pressure developed in the bladder will produce mild colic symptoms such as
stretching, treading with rear limbs and kicking. The most characteristic sign is
an up-and-down pumping of an elevated tail. With trials to urinate, few drops
of urine may drip from the perpetual hair.
- In large animals, rectal palpation reveals distended bladder and the calculi
may be palpated.
- In small animals, urethral pulsation will be easily felt and calculi may be
palpated in the urethra.
- Other signs include: anuria, haematuria and distended or turgid abdomen.
Signs of uremia may develop if there are complete obstructive urinary calculi
causing symptoms in the following manner, obstruction, irritation, base and
injury of tissues.
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- If the blockage persists, either the urethra or the bladder will rupture thus all
colic pains and tail pumping will cease. In addition urethral pulsation will
disappear. After bladder rupture, the abdomen will take a pear-like form due
to the accumulation of urine and inflammatory fluids in the abdominal cavity.
- However, rupture urethra is more common in steers, when urine escapes
leads to edematous swelling of the abdominal floor. Tissues saturated with
urine will be increased due to the necrotizing process as a result of the
breakdown of urine into urea and ammonia. Paracentesis of the edematous
area may produce a few drops of fluid with urine odour.
- Radiographic examination is of great value in pet animals. Since most
canine and feline uroliths have varying degree of radio density. However the
use of contrast substance will be helpful. Oxalate, phosphate and silica calculi
are more radio dense than the cystine and ureate calculi.
Treatment of obstructive urolithiasis:
Therapy of urolithiasis encompasses the relief of obstruction to urine
outflow and elimination of the existing calculi if possible and prevention of
recurrence of uroliths.
Medicinal treatment:
* The use of specific plain muscle relaxants as aminopromazine Hcl.
* Administration of atropine sulphate sub. /cut. (1 mg for sheep, goat).
* The use of antispasmodics, sympatholytic drugs (Tranquilizer).
Usually such drugs fail even with manual pressure over the urethra.
Surgical treatment:
1) Snip off the urethral process in rams and bucks. To remove calculi
lodging in and obstructing the urethra:
- Animal must be mechanically restrained on its back.
- By gentle manipulation, the penis is pulled from the prepuce.
- Snip off the urethral process from its base containing the obstructive
calculus.
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2) Perineal urothrotomy.
Definition:
It is the induction of a fistula in the urethra to allow meat of animal fit for
human consumption.
Indications
1- Obstructive urine retention.
2-- In connection with cases of ruptured bladder
Anesthesia and control:
Posterior epidural anesthesia or local infiltration of the sub cut. of the median
raphe 3-5 cm down the anus the animal is kept in dorsal recumbency.
Procedures.
- Prepare the perineum as usual.
- 3-5 cm long mid-line cutaneous incision is made below the anus.
- Break down bluntly the fascia around the penis. Care should be taken not to
mistake the retractor penis muscles for the penis itself.
- Isolate the penis and pull it outward through the incision.
- Incise the penis till reaching the urethra, incise it longitudinally for 3-5 cm.
- Introduce a catheter to the bladder.
- Suture the urethral mucosa to the wound of the skin using simple interrupted
sutures of silk.
- Remove sutures after 7-10 days.
Post-operative Care:
- Daily inspection and cleaning of the wound.
- Be sure of free urination from the induced fistula.
- Fluid therapy.
- Water should be given freely.
- Skin under the fistula should be smeared with ointment to avoid
urine irritation.
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Operations for ruptured bladder
(Laparotomy)
Indication:
Bladder rupture is a sequel of obstructive urine retention; it requires
immediate surgical interference so as to avoid uremia and peritonitis.
Anesthesia and control.
Anterior epidural anesthesia or local infiltration of intended line of incision.
Procedure:
- prepare the site of operation as usual (paramedian anterior to scrotum).
- Make an incision of about 15 cm. long just anterior to the prepubic tendon.
- Puncture of the abdominal muscles.
- Gradual evacuation of urine from the abdominal cavity.
- By gentle gradual manual traction of the bladder draw it forward toward the
abdominal wound.
- Explore the bladder for presence of any calculi, wash it with saline, and
introduce a catheter through the bladder to the urethra.
- Suture the bladder rent with double raw of Lembert sutures using 2/0 catgut.
- Flushing the peritoneal cavity with saline solution and put intra-abdominal
antibiotics.
- Close the abdominal wound as usual.
- Perform perineal
urethrotomy.
Post-operative care:
- Intensive administration of fluid therapy.
- Systemic antibiotics.
- Estimation of blood urea nitrogen if possible.
- Daily inspection of the urethrotomy wound.
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Hernias
Definition:
The protrusion of the viscera from its normal cavity through congenital or an
acquired aperture.
Classification:
Hernia can be classified into:
(1) External hernia: Abdominal protrusion of abdominal content through a
physiological opening (umbilical or ingunial) or a defect in the abdominal wall.
e.g. umbilical, abdominal, inguinal and scrotal hernias.
(2) Internal hernia: Is a protrusion of organ through a normal or pathological
opening within the abdominal cavity where there is no hernial sac.
E.g. mesenteric defects in the greater, lesser or gastrosplenic omenta,
epiploic foramen, omental defect and diaphragmatic defects.
3) Incisional hernia: represent a breakdown or loss of continuity of a fascial
closure consequent to abdominal surgical procedures.
Structure of hernia:
1- Hernial opening:
- It may be accidentally formed in abdominal wall, persistent prenatal orifice
(umbilicus) or normal passage (inguinal).
- Its size varies from small (one finger) to large (hand size).
- Its shape may be round, oval or irregular.
2- Hernial swelling (the protruded part)
- Its size may be small (as grape size) or large (man's hand)
- Its shape may be hemispherical, cylindrical, conical, and irregular.
- Its composed of:
a. Covering tissue (hernial sac); skin and subcutaneous tissues, fewer
muscle fibers, parietal peritoneum (if not ruptured). The sac has a neck
where it emerges from the abdomen, body (intervening region) and the
fundus (the lowest part).
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b. The hernial content: usually comprises: small intestine (enterocel,
urinary
bladder
(vesicocele),
omentum
(epiplocele)
stomach
(gastrocele).....ect.
Classification of hernias:
It can be classified according to
1- Type:
a. Congenital (those present at birth) e.g. umbilical.
b. Acquired: These came in later life (perineal)
2- Content: gastrocele, enterocele,
3- Site: ventral abdominal, umbilical, perineal,
4- Nature: (whether or not the content can be pushed back into the abdomen:
A. Reducible: the content returns to the abdomen spontaneously or
with manual pressure when the patient is recumbent.
B. Irreducible: when the content cannot be returned to the abdomen,
usually because of the following:
- Incarceration: the content has become too large to pass through the hernial
ring.
- Strangulation: where compression obstruction of the blood supply to the
incarcerated loop of the bowel, later on gangrene of the strangulated part may
happen.
- Adhesions: as a result of local inflammation of the hernial part fibrinous
adhesions and later become fibrous tissue present between the hernial sac
and hernial content.
Causes:
May be:
1) Congenital: due to:
a- Inherited weakness of the muscle.
b- Congenital aperture in the linea Alba.
c- Imperfect developed umbilicus.
2) Acquired cause which may be:
a- Predisposing factors as:
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- Affections that cause muscular weakness which is liable to
breakdown easily (abscess, wound).
- Affections which increase intra-abdominal pressure (e.g. chronic
cough, diarrhea, constipation, last stage of pregnancy) lead to
weakness of the muscle that may rupture.
b- Exciting cause:
- Postoperative imperfect repair of abdominal wall
- Trauma inflicted by violent blunt force e.g. kicks, blows, horn thrust,
and falling object.
Symptoms:
Local:
- Presence of a mass in the abdomen by palpation, the hernial ring was
detected.
- The hernial swelling was soft homogenous (if omentum), tympanic (if
intestine).
- It may be reducible (on palpation) or irreducible.
General:
- In non complicated cases, slight colic and indigestion.
- In complicated cases (obstruction or strangulation) sever abdominal pain,
colic, vomiting, and depression).
Diagnosis:
1- History.
2- Local examination.
3- Laboratory investigation.
4- Exploratory laparatomy.
5- Ultrasonography.
Differential diagnosis:
Diagnosis from other swelling (abscess, hematoma, cyst, tumour)
General treatment of hernia
Many small hernias (< 5 cm) may be spontaneously closed by time. If
not resolve in 6 months of age or in case of large hernia (> 10 cm) or in case
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of irreducible or appearance of signs of strangulation surgical interference
must be done.
Conservative treatment:
- Trass: a pad on a belt (for supporting hernia)
- Hernial clamp: used to manage reducible hernia less than 5 cm. Two parts
of wooden or plastic bars is placed externally to the skin and hernial sac after
reducing the hernial content it causes strangulation, necrosis, sloughing of the
hernial wall within 10 - 21 days. The scar is subsequently heals by contraction
and epithelization.
Surgical treatment:
Indication:
1- When the hernia has not disappear spontaneously.
2- In irreducible hernia
Principle line of treatment:
A- Reducing the hernial content
B- Closure of the hernial ring (defect):
a- with sutures
b- Occasionally in large hernia, metalic or synthetic fiber mesh
prosthesis is used to cover the defect in the abdominal wall.
Technique adopted for abdominal and umbilical hernias:
- Positioning of the animal: casting (dorsal recumbency)
- Anaesthesia:
General anesthesia
- Preparation of the animal and site of operation (as usual for abdominal
operation).
- Procedures:
1- Opening of the hernial swelling: by elliptical incision through the skin,
fibrous covering of the sac at its center (parallel to the long axis of the body).
Isolate the delicate peritoneal covering of the sac.
2- Reduce the hernial content intra-abdominally in case of reducible hernia.
On the other hand if incarceration due to dissension of the intestinal loop with
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gas or liquid, may be tapped to diminish the volume or opening the
peritoneum and widening the hernial opening.
In case of strangulation more care is required in manipulation of the bowel on
account of its more or less damaged, but in advanced cases, excision of the
part is indicated.
In case of adhesion, the peritoneum must be incised to permit of their
separation. If not possible to separate, cut the adhesive part round the hernial
organ and then reduced together. In case of adhesion, the peritoneum must
be incised to permit of their separation. If not possible to separate, cut the
adhesive part round the hernial organ and then reduced together. In case of
adhesion with omentum, the part may be excised.
3- Closure of the hernial ring (defect). (Herniorrhaphy)
Suture technique used:
1- Overlapping mattress.
2- Modified horizontal mattress.
3- Simple interrupted.
4- Purse string.
A- In small sized hernial ring: (where co-optation is easily without
unnecessary tension)
The apposition suture pattern:
- In small animal; simple continuous or interrupted. Its advantages; (lesser
tension on the suture line; minimal tissue damage and operative tone.
- In large animals; everting suture pattern (internal).
Horizontal mattress: Its advantages; avoid any possible breakdown of suture.
Overstitching of the everted edges of the ring by single or double raws of
simple continuous suture is done to strengthen the primary suture line.
Suture materials used:
- Catgut (chromic) especially in small ring but in presence of infection
dissolution of the suture was happened earlier.
- Synthetic absorbable suture of high tensile strength e.g. vicryl. (It has the
advantages; good tensile strength, easily handle, knot security, minimal
reactivity the absorption rate not altered in the presence of infection,
completely absorbed when the suture is no longer needed.
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- Synthetic non-absorbable e.g. mersilene, prolyene, nylon is used especially
in conditions required adequate tension (in large ring). (Must be of high tensile
strength, monofilament structure)
B) In large sized ring (> 10 cm)
- Prosthetic mesh is indicated
- Other cases indicated the use of mesh:
- When the tissue of the ring is attenuated.
- When the primary closure is done with strong tension.
- When hernia is located nearby bony attachment e.g. costal arch,
pubis.
- In long standing recurrent hernia.
Aim of use the mesh:
- Gives support to the granulation tissue and capillary to grow through it (in
about 2 - 3 weeks).
- To bridge tissue gaps that cannot be eliminated by suture alone.
Postoperative care:
- Abdominal bandage
- Reduce the amount of food for the first week post operation and gradually
returned to normal amount.
- Systemic broad spectrum antibiotic was given for 3 - 5 days.
- The skin suturing were removed 10 days post-operation.
Umbilical Hernia (Omphalocele)
- Common in foals, calves, and less in lambs, dogs and cats.
- More common in females than males
- More common in animals less than 6 months old and may exist at birth.
Causes: may be:
1- Congenital: due to
a. Developmental defects involving the umbilical opening.
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2- Acquired:
A) Predisposing factors:
- Chronic infection of the umbilical cord.
- Opening of the navel is relatively large giving a way to the pressure of the
bowel on the inherited weak abdominal muscle.
- Mechanical failure for natural closure of the umbilical opening.
B) Exciting factors: e.g. straining, excessive traction of the umbilicus during
birth, external trauma.
Structure of the hernial content: commonly omentum, May bowel (caecum or
colon).
Symptoms:
- Appeared either alone or accompanied with umbilical infection or thickening
of the naval cord.
- Locally, presence of a mass in the ventral abdomen where the umbilical scar
should be located.
- Generally abdominal pain and colic.
Diagnosis:
- History.
- Clinical signs.
- Local examination.
- Exploratory laparatomy.
- Ultrasonography.
Differential diagnosis:
From other umbilical affections e.g. infection (omphalitis, omphalophlebitis,
omphaloartritis, omphalourachitis), umbilical abscess and tumours.
Treatment:
As previously mentioned.
a- Conservative treatment: stall rest, abdominal bandage, anti-inflammatory
medication) clamps, counter irritant.
b- Surgical management
1- Reduction of the content.
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2- Closure of the ring with:
- Suture of the ring (suture herniorrhaphy)
- Prosthetic herniorrhaphy.
Inguinal or Scrotal Hernia
Definition:
The hernia content is descending through the inguinal ring into the inguinal
canal. If it descent into the scrotal sac, it is called scrotal hernial. It may be
unilateral or bilateral.
Common hernial content: (Distal jejunum, ileum, omentum, rarely small
colon).
The inguinal canal has 2 rings (external and internal ring).
Structure of hernia:
The inguinal ring forms the hernial orifice and the tunica vaginalis forms the
hernial sac. The content may be loop of intestine or omentum.
Causes:
1) Congenital: appeared within the first few days of birth, it may be due to:
- Hereditary (in lambs and foals).
- Normal anatomic variation (increased size of the inguinal ring)
2) Acquired:
a- Breeding
b- Abdominal trauma
c- Strenuous work
d- Any events that increase intra-abdominal pressure (during exercise or
breeding).
- As a sequel to increase cryptorchid castration.
- Hind leg slipping around and backward which may lead to dilatation of
inguinal canal.
Incidence:
More common in male
In female only in bitch is observed.
Symptoms:
- Sign of abdominal pain
- Local firm enlarged testicle.
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(Swelling at the antero-external aspect of the spermatic cord).
- In large one swelling may reach as far as the hock
- In chronic cases the testicle becomes atrophied from the pressure.
- Lameness, as hernias may interfere with gait (abducted lameness).
Diagnosis: from local examination and general symptoms.
Differential diagnosis: from hydrocele, tumour, cyst and scirrihous cord.
Treatment:
- Conservative: In congenital cases; daily manual reduction of hernia may
lead to reduction by time.
- Surgical treatment:
1- Reduction of the inguinal hernia.
2- Closure of the internal inguinal ring.
3- Removal of the testicle on the affected side (because it is frequently
edematous due to compromised blood supply).
Several methods have been described for immediate surgical reduction:
1) Inguinal approach:
- Skin incision was made over the superficial inguinal ring and extended
downward over the scrotum for a required distance according to the size of
the hernia.
- Release the parietal tunic from the scrotal fascia bluntly.
- The hernial contents were reduced into peritoneal cavity.
- The inguinal tunic was twisted on itself to obliterate the inguinal cavity and
force the hernial content out.
- The spermatic cord was ligated after trans-fixation at the level of superficial
inguinal ring using chromic catgut. The cord has then transected and the
stump was allowed to retract into the inguinal canal.
- The inguinal ring was closed by vicryl no. 0 with internal horizontal mattress.
- The excess of the scrotal sac was trimmed and then sutured with internal
mattress pattern using silk no.1.
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- In irreducible hernia incising the peritoneal inguinal tunic may be necessary
to breakdown the adhesion and continue as before.
2) Trans-abdominal approach:
Ventral midline skin incision was made extending from the cranial brim of the
pelvis os cranially as necessary to allow exposure of the hernial sac. The
incision extends down to the ventral rectal sheath. In female it extends under
the mammary tissue to expose the inguinal ring and the hernial sac.
- Dissect the sac from the subcutaneous tissue. Open the sac. The content
was inspected to breakdown any adhesions.
- Reduce the hernia intra-abdominally.
- The redundant sac was twisted and trimmed at the margin of the inguinal
ring.
- The ring is sutured with interrupted pattern using vicryl no.1.
- The skin and subcutaneous fascia was closed as usual.
RUMENOTOMY
- Weingart`s Technique:
Indications:
- Removal of ruminal foreign bodies.
- Persistent impaction of the rumen and traumatic reticulitis.
Control:
The operation is performed with the animal in a standing position, either in a
stanchion or box stall properly controlled. A kicking strap is applied above the
hocks, if considered necessary.
Pre-operative preparation:
If possible, the entire region of the left flank over the rumen is clipped, shaved
and washed with soap and water then dried with sterile towel. The skin is
disinfected with spirit, then tincture of iodine or Betadine is applied.
Anesthesia:
- Apply careful disinfection with 70% alcohol or tincture iodine/ Betadine.
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- Local anesthesia using inverted – L field block using Xylocaine 2%. The
horizontal line runs two fingers below the transverse lumbar processes and
the vertical line runs behind the last rib by 2 fingers breadth and 10 cm
downwards. The anaesthetic is injected under the skin, in the muscles and on
the peritoneum.
- The animal must be given Xylazine2% i/m at a dose of 0.15 mg/kg body
weight.
Operative technique:
- An incision of about 7 - 10 cm in length is made through the skin (a few
inches posterior to and parallel with the last rib at a distance of 2 fingers
below the transverse processes of the lumbar vertebrae). The incision is
continued through the external and internal oblique as well as transversalis
muscles thus exposing the peritoneum.
- Hemorrhage is controlled.
- The peritoneum is then carefully incised exposing the rumen, a portion of the
rumen is pulled through the incision and maintained in position to the bow by
means of two special forceps.
- The ruminal wall is then incised between the two forceps and an incision of
about 15 - 18 cm in length continued upwards and downwards.
- The margins of the rumenal incision are then stretched to the bow by means
of a series of special hooks, 3 or 4 on each side.
- The hand is introduced to the rumen, then the reticulum and search for the
foreign bodies is made.
- The reticulum should now be explored thoroughly for foreign bodies and for
adhesions to the diaphragm or floor of the abdomen.
- In palpating or removing penetrating objects one should carefully avoid
breaking down any existing adhesions which might be successfully preventing
the spread of infection.
- The ruminal incision is then closed with two rows of continuous Lembert
sutures, using catgut no. 0.
- The first stitch of the row is made in a transverse direction at the lowest point
of incision, 1/2 inch of the rumen wall is turned in, tied and the two serious
surfaces brought together.
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- The needle is then inserted close to the knot and advanced up. As the top is
reached, the stitching is made downwards in a diagonal way and this confirms
the first row of sutures.
- The exposed portion of the rumen is then swabbed and is powered with
penicillin streptomycin, then the bow and forceps are removed and the rumen
is replaced into the abdomen.
- The peritoneum and transversalis muscle are taken together in the first line
of continuous abdominal sutures. Care is always taken to make sure of an air
tight closure. A dose of aqueous penicillin streptomycin is injected into the
abdominal cavity before the complete closure of the peritoneum.
- The internal and external oblique muscles and the fascial layers are included
in the next row of sutures. The skin wound is closed with silk. Usually the
stitches are removed 10 days later.
Udder Amputation
Indications:
1- Udder tumors.
2- Udder gangrene.
3- Chronic septic mastitis.
4- When there is a break down of the supporting ligaments of a large
pendulous udder.
Anesthesia:
- Epidural anesthesia, in sheep and goat (4 to 6 ml of 2% solution of a local
anaesthetic between the last lumbar and first sacrum vertebrae (lumbo-sacral
anesthesia).
Operation:
In sheep and goats:
- The animal should be controlled in dorsal recumbency. In unilateral
amputation, the animal is laid on its healthy side with forequarter and head
elevated. The fore limbs and the lower hind extremity are fixed to the
operation table. The free upper hind limb is held in a fixed and raised position
by an assistant.
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- The surgical field and surrounding areas are thoroughly cleansed, shaved,
disinfected and covered with sterile cloths.
- Make elliptical incisions at the base of the teats. The incisions are extended
in a straight line in both cranial and caudal directions. Gangrenous and
otherwise pathologically altered skin is circumvented. Sufficient skin should be
retained to permit the covering of the skin defect excess skin can be trimmed
later when sutures are inserted.
- With careful homeostasis, the skin is separated from the udder tissue
dorsally with blunt dissection where possible; the first defective is to secure
the pudendal vessels in the inguinal region by locating the pulsating A.
pudenda externa. Incise the udder fascia, expose the vessels and ligate. Then
ligate the perineal vessels and the V. subcutanea abdominis at the exit
from the udder. Dissect the skin from the udder upward to the sulcus
intramammaricus and from there dorsally to isolate the diseased half of the
udder along the ligamentum suspensorium mamae (medial division) and
finally along the abdominal fascia.
- After the isolated udder has been shelled out hemostasis must be checked
and completed. Close the wound by means of recurrent single sutures
(mattress) of synthetic material.
- Trim away excess skin about 1.5 cm. above the comb of the suture. Infuse
the wound cavity with antibiotics or sulfonamides via a teat canula.
- In case of unilateral amputation, affect prophylaxis of the remaining udder
half by the intracisternal administration of antibiotics.
- Remove the sutures after eight to 10 day.
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