A fourth-year veterinary student on a large animal rotation was assisting Dr. G with the pregnancy evaluation of five Dexter beef cows. The examinations were conducted at the clinic using an ultrasound with an introducer wand. The student assisted in the initial palpation and ultrasonography of the cows but Dr. G took over when pregnancy status could not be confirmed. Dr. G also experienced difficulty locating the uterus in most of the cattle but ultimately diagnosed three as pregnant and two as open.
Two days later, the owner reported that two of the evaluated cows had been
found deceased in the pen. Upon examination, Dr. G noted that the deceased
animals did not appear obviously bloated. The remaining three cows were alert,
although one exhibited a fever of 102.9°F and abnormal lung sounds (crackles)
on the left side of the thorax. Dr. G administered treatment to all three cows with
an antibiotic, Draxxin (Tulathromycin) and an anti-inflammatory, Banamine
(Flunixin meglumine). No postmortem examination was performed on the two
deceased cows at that time. Dr. G discussed the possibility of nitrate
poisoning and submitted a sample for testing.
A few days later, the owner reported that a third cow—previously noted as slightly “off” on the date of examination—had also died. This animal was transported to the state Veterinary Diagnostic Laboratory (VDL) for postmortem examination. Later that day, the VDL informed Dr. G that the cause of death was peritonitis secondary to a full-thickness rectal tear near the uterus. Dr. G and an associate veterinarian visited the owner’s farm and performed gross necropsies on the two initially deceased cows. Both were found to have peritonitis and rectal tears, and pregnancy was confirmed in both cows via necropsy.
The owner filed a lawsuit naming Dr. G and the veterinary
student, demanding $15,800 for the replacement cost of three Dexter cows and
two Dexter calves, as well as necropsy and lab fees, burial expenses, lost wages, and transportation, mileage, and shipping costs for the animals. Dr. G reported
the incident to their professional liability insurance carrier.
A review of the claim raised concerns regarding colon perforation leading to peritonitis and death in one cow, and colon trauma in the other two. Although a perforation was not identified in the latter two cases, the gross necropsies—performed by an associate veterinarian and not a boarded pathologist—revealed signs of peritonitis. Given the presence of bacteria, clinical signs, and timing, the veterinarian (who is this? Dr. G? The carrier?) opined that iatrogenic rectal tears had occurred in all three animals with peritonitis secondary to rectal trauma. The claim was settled by the insurance carrier for $15,200 pre-litigation.
Understanding the Case
Rectal tears may be an inherent risk of rectal palpation even when examinations are conducted appropriately. If a tear occurs during rectal
palpation, the veterinarian or veterinary student may feel a sudden release in
pressure, cessation of straining, an improved ability to palpate the abdominal
structures, and possibly the presence of blood on the rectal sleeve. When using
an introducer wand for trans-rectal ultrasound, it's important to examine the
wand for evidence of blood. Introducer wands have been developed as a way to
reduce recurrent stress injuries to bovine practitioners associated with
repetitive rectal examinations.
Cattle are less likely to sustain rectal tears than horses
or camelids. Most rectal tears are iatrogenic and caused by rectal palpation
during examination for breeding management, and occur most commonly when the
examiner is palpating during a peristaltic wave, the animal is straining or the
animal moves abruptly during rectal examination.
Rectal tears are classified according to the layers damaged; this directly relates to prognosis
- Grade I: mucosa and submucosa torn
- Grade II: only muscular layer is disrupted; mucosa and submucosa prolapse through defect
- Grade IIIa: involves all layers except serosa
- Grade IIIb: involves all layers except mesorectum
- Grade IV: full thickness
Full-thickness tears are generally accompanied by a poor prognosis. As a student, should you be concerned about rectal tears due to palpation or ultrasonography? A 2019 retrospective study by Bond, et al. Demonstrated that palpation of the reproductive tract for pregnancy diagnosis by inexperienced students did not increase the risk of bovine pregnancy wastage compared with diagnosis by an experienced clinician using transrectal ultrasonography.
References:
Rectal
Palpation Procedure (University of Wisconsin-Madison)
https://www.ansci.wisc.edu/jjp1/ansci_repro/lab/lab4_09/palpation_proc.html
Management
of Rectal Tears Based on Grade/Classification (Vetlexicon)
https://www.vetlexicon.com/bovis/alimentary/articles/rectal-tear-surgery/
Large
Animal Surgery, Supplemental Notes - University of Minnesota CVM