Trichobezoar in a 3-week-old calf
- Jenna Donaldson
Abstract
A three week old, Hereford crossbred heifer calf was presented for abdominal distension and
decreased feed intake. Intestinal obstruction was suspected. Exploratory laparotomy revealed
distension of the proximal small intestine. An enterotomy was performed and a trichobezoar
removed from the proximal jejunum. The calf was euthanized two weeks following surgery after
showing signs of peritonitis.
-------------------------A 3 week old, Hereford crossbred heifer calf was presented to a large animal mobile service in
southern Ontario for depression, abdominal distention and inappetance. The owner first noted
significant depression and inappetance 36 hours prior to calling the veterinarian and treated the
calf with dioctyl sodium sulfosuccinate (Bloat-Eze; Dominion, Winnipeg, Manitoba), ketoprofen
(Anafen; Merial Canada, Baie d’Urfé, Quebec), and tulathromycin (Draxxin; Pfizer Animal
Health, Kirkland, Quebec).
Case Description
On presentation, the calf was depressed with a body condition score of 3/5 accompanied by
marked abdominal distension on the left side. Physical exam noted a temperature of 38.5◦C,
heart rate of 88 beats per min, and respiratory rate of 44 breaths per min with normal lung
sounds. The calf was approximately 7% dehydrated, assessed by skin tent and sunken eyes. A
gas-distended viscous was noted by the presence of a ‘ping’ in the right upper quadrant.
Succusion of fluid on both sides of the abdomen was possible.
An intestinal obstruction was suspected based on clinical exam findings. Differential
diagnoses for inappetance, reduced fecal output, and abdominal distension in calves include
intestinal intussusception, peritonitis, abomasal ulceration, and ileus. An ultrasound examination
and further laboratory diagnostics were not available so an exploratory laparotomy was elected
upon discussion with the owners. One L of isotonic intravenous fluids (Uni-lyte; Univet
Pharmaceuticals, Milton, Ontario) was administered to begin to correct dehydration and provide
cardiovascular support before sedation and anesthesia. The calf was premedicated with 0.03
mg/kg bodyweight (BW) of xylazine (Rompun; Bayer Healthcare, Toronto, Ontario) and 0.1
mg/kg BW of diazepam (Sandoz Canada; Quebec City, Quebec), IV before being placed in left
lateral recumbency. After aseptically preparing the right flank, an inverted ‘L’ block was
performed using 0.2 mL/kg BW of lidocaine (Lidocaine Neat; Pfizer Animal Health, Kirkland,
Quebec). Anesthesia was induced with 2.5 mg/kg BW of ketamine (Vetalar; Bioniche Animal
Health, Belleville, Ontario) IV. An additional dose of 0.03 mg/kg BW xylazine, IV and 1 mg/kg
BW ketamine, IV was administered ten minutes into surgery in response to surgical stimulation.
Pulse and respiratory rate/pattern were utilized to monitor cardiorespiratory function and
remained within normal limits throughout the procedure. Depth of anesthesia was assessed with
palpebral reflexes and ocular signs.
A 15 cm incision was made in the right paralumbar fossa. A 3 cm x 4 cm firm obstruction
was noted mid-jejunum with marked gas distension of the duodenum and proximal jejunum.
The abomasum, distal small intestine, and large intestine were not noted to have any ingesta.
The intestinal tissue appeared well-perfused and viable at the location of the obstruction, so a 4-
cm enterotomy incision was made on the anti-mesenteric surface of the jejunum. The
obstruction was exteriorized and identified as a trichobezoar. The jejunum was closed using
Polysorb (Covidien; Mansfield, Massachusetts), in a two-layer, simple continuous pattern. The
small intestine was lavaged with sterile saline, and normal peristalsis was noted in the proximal
jejunum. The abdomen was closed in 2 layers: peritoneum and transversus abdominalis muscle,
and internal and external rectus abdominus muscles, each using a simple continuous pattern with
Surgigut (Covidien). Skin was closed in a Ford interlocking pattern with Vetafil (S. Jackson;
Washington, DC, USA). Anesthetic recovery was smooth, with the calf being placed in sternal
recumbency following surgery, and standing smoothly 30 minutes later. Ketoprofen, 3 mg/kg
IV, and procaine penicillin (Depocillin; Merck Animal Health, Kirkland, Quebec), 20,000 iu/kg
IM, were administered after surgery. Antimicrobial therapy was continued for 4 days postoperatively. The remaining deficit (approximately 4.5 L) was corrected orally with electrolyte
supplementation over the 48 hours following surgery.
Discussion
Trichobezoars are compacted spherical or ovoid masses of hair that provide a rare but reported
source of gastrointestinal obstruction in bovine medicine (1). Initial formation in the rumen or
abomasum is attributed to excessive ingestion of hair and is most commonly an incidental
finding at slaughter. Trichobezoars may obstruct the pylorus, small intestine, or spiral colon if
passed distally (2). Cases of esophageal obstruction (3) and caecal dilation/torsion (4) have also
been documented. Incidence of trichobezoar-related pathology is higher in the late winter to
early spring, correlated with increased ingestion of hair during shedding (1). Lack of dietary
forage may trigger ‘grazing’ on penmates. Infection with sarcoptic mange or pediculosis
promotes grooming and licking, predisposing animals to trichobezoar formation. The higher
incidence of trichobezoars in young animals is likely related to suckling behaviours and curiosity
(2).
Trichobezoars cause a luminal blockage or physical obstruction of the intestinal lumen
without interrupting blood supply to the area (1). Progression of clinical signs is slower than
expected with an infarct-causing lesion, developing over one to two days versus the per-acute
presentation of volvulus or intussuception (2, 6). Most common reasons for presentation are
inappetance, reduced fecal output, and slowly developing abdominal distension. Signs of acute
abdominal discomfort may or may not be noted (1). Physical exam findings include depression,
dehydration, poor rumen motility, ‘pinging’ and fluid on abdominal auscultation and succusion.
Diagnostic modalities helpful in the localization of an intestinal lesion include ultrasound
evaluation and complete blood count, clinical chemistry, and blood gas analysis. Ultrasound
examination revealing non-motile distended loops of small intestine alternating with empty loops
indicate a surgical lesion, often a physical obstruction (6). Blood gas analysis may demonstrate a
hypochloremic, hypokalemic metabolic alkalosis due to hydrochloric acid sequestration in the
obstructed small intestine. A mixed disturbance involving a lactic acidosis may be seen if
intestinal perfusion is compromised (4). Fluid therapy requirements can be inferred through the
physical exam and ideally are administered IV pre-operatively. An inflammatory leukogram
often accompanies a trichobezoar, even in cases where abdominocentesis does not indicate the
presence of peritonitis (2).
When an ultrasound examination is not available, exploratory laparotomy is warranted in the
presence of progressing abdominal distension and lack of fecal production. Surgical removal via
enterotomy offers the best prognosis (1, 2, 7). A right paralumbar fossa surgical approach
provides optimal access to abdominal organs in young calves (6). Sedation and/or intravenous
anesthesia, with regional anesthesia of the flank, should provide adequate analgesia and allow
easy restraint of the calf in left lateral recumbency for a short procedure (8). Mucous membrane
colour and respiratory rate/rhythm should be closely monitored throughout, especially in cases
with significant abdominal distension (6). Risks with surgery include secondary peritonitis (6, 9)
and complications associated with concurrent disease, such as pneumonia or abomasal
ulceration, or death from sedation or general anesthesia (5). Postoperative antimicrobial therapy
is warranted as the gastrointestinal tract has been entered with possible contamination of the
abdomen. Systemic beta-lactam antimicrobials such as penicillin or the third-generation
cephalosporin, ceftiofur sodium, are good options with reasonable meat withdrawal periods in
cattle (9). Assuming adequate hydration and renal function, non-steroidal anti-inflammatory
drugs such as flunixin meglumine or ketoprofen can reduce inflammatory effects, endotoxemia,
and discomfort postoperatively (6). Prognosis after surgical removal of a trichobezoar is good
(2, 7).
Conservative management with oral or intravenous fluids, anti-inflammatories, and
antimicrobials are reasonable in the short term when the diagnosis is uncertain or financial
considerations preclude surgical treatment. Exploratory laparotomy should be recommended
when fecal production is absent for an extended period and medical management fails to resolve
clinical signs. Outcomes in medically-treated cases are typically unfavourable as prolonged
obstruction leads to hemodynamic deterioration and respiratory compromise due to progressive
abdominal distension (1, 2).
In summary, trichobezoars are a rare but documented cause of small intestinal obstruction.
Exploratory laparotomy should be considered as a diagnostic and therapeutic option in calves
presenting with progressive abdominal distention and absence of feces. This calf did well for
two weeks following surgery, but was euthanized due to poor prognosis after showing signs of
peritonitis and sepsis, likely as a result of bacterial contamination secondary to enterotomy.
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