Aortic body tumours, also called chemodectomas, are slow-growing neoplasms that arise from chemoreceptor cells located near the base of the heart, close to the aorta. In dogs they are typically locally expansive masses that cause trouble by compressing adjacent cardiovascular structures rather than by invading the heart chambers themselves. Intracavitary or intracardiac involvement is genuinely uncommon, and previous reports of intracardiac extension did not describe tumour debulking under cardiopulmonary bypass. Cardiopulmonary bypass, or CPB, has been used in dogs for selected intracardiac procedures, including removal of a left atrial paraganglioma and a tricuspid valve myxoma, but a partial-bypass palliative debulking of a heart-base tumour protruding into the right atrium had not previously been documented.

The patient was a seven-year-old, 15.2-kilogram castrated male French Bulldog referred for lethargy, poor appetite, exercise intolerance and abdominal distension of roughly two weeks’ duration. Ultrasound had revealed free fluid in the abdomen, and echocardiography showed severe right-sided cardiac enlargement together with a mass measuring 3.2 by 3.1 centimetres occupying most of the right atrial lumen. The mass was heterogeneously echogenic with an irregular surface, appeared to originate from the heart base adjacent to the aorta, and was associated with significant tricuspid regurgitation and paradoxical septal motion. Abdominal imaging showed hepatic venous congestion and a large volume of ascites, and roughly 600 millilitres of fluid was drained to relieve the distension. The fluid was classified as a modified transudate, consistent with back-pressure from an obstructed right atrium rather than primary abdominal disease.

The clinical picture was one of mechanical obstruction of venous return. Blood attempting to flow from the caudal vena cava into the right atrium was blocked by the intracavitary mass, raising right atrial pressure, congesting the hepatic veins and driving fluid out into the peritoneal cavity. Medical management with pimobendan, furosemide and low-molecular-weight heparin failed to resolve the ascites or improve the dog’s activity and appetite, which strengthened the suspicion that the problem was structural rather than functional. Differential diagnoses included neoplasia, thrombus and tumour-associated thrombus, but antithrombotic therapy produced no reduction in the mass. Preoperative biopsy was judged too hazardous because the mass sat within the right atrium adjacent to critical structures, so the team proceeded without a definitive tissue diagnosis, informing the owner that the operation would be palliative rather than curative.

The surgical plan was deliberately unconventional. After premedication with midazolam, fentanyl and cefazolin, anaesthesia was induced with propofol and maintained with sevoflurane. The right jugular vein and right carotid artery were exposed for cannulation: a 14-Fr venous drainage cannula was advanced through the cranial vena cava to near the right atrial junction, and an 8-Fr arterial cannula was placed in the carotid artery. A right fifth intercostal thoracotomy exposed the heart. Notably, the team attempted additional venous cannulation from the right atrium toward the caudal vena cava but could not advance the cannula because the mass was in the way. Partial CPB was therefore run on the cervical cannulas alone, with heparin achieving activated clotting times above 400 seconds and later around 1000 seconds. Pump flow was set at 60 to 80 millilitres per kilogram per minute, and the dog was cooled to a lowest recorded oesophageal temperature of 28 degrees Celsius.

The authors made two decisions that reveal the improvisational nature of the procedure. First, the azygos vein was deliberately left unoccluded. Although temporarily occluding it would have reduced venous return into the operative field, venous return from the caudal body was already compromised by the mass, so preserving collateral drainage through the azygos system was considered preferable even at the cost of some surgical visibility. Second, after debulking improved caudal vena caval return, the team chose not to pursue additional cannulation, instead managing venous blood with two suction lines whose contents were returned to the extracorporeal circuit. Perfusion was judged adequate on the basis of arterial pressure, serial blood gas analyses and lactate concentrations, which remained between 1.0 and 2.5 mmol/L throughout.

Opening the right atrium revealed a mass firmly adherent to the septal aspect of the chamber, with marked induration suggesting neoplastic tissue. The surgeons used Babcock forceps to gently stabilise the intracavitary component and removed tumour primarily by blunt dissection with careful sharp dissection near the attachment site. No distinct dissection plane existed in the firmly adherent portion, so complete separation was not attempted. Residual tumour was intentionally left in place wherever further dissection risked perforation, uncontrollable haemorrhage or injury to critical structures such as the coronary sinus or atrioventricular junction. The atriotomy was closed in two layers with 6-0 polypropylene. Approximately ten minutes after atriotomy, ventricular fibrillation occurred; defibrillation after closure restored sinus rhythm. Total anaesthesia time was 410 minutes, surgical time 350 minutes, CPB time 140 minutes and intracardiac manipulation time just 40 minutes.

The haemodynamic payoff was immediate and measurable. Intermittently recorded central venous pressure fell from approximately 19 mmHg before debulking to approximately 5 mmHg afterwards, while systemic arterial pressure actually rose. Postoperatively, the mucous membrane pallor resolved, the ascites disappeared, and appetite and activity returned. Pimobendan and furosemide were discontinued, clopidogrel was prescribed for about a month, and follow-up echocardiography showed only minimal residual intracardiac tissue, reduced right-sided enlargement and no detectable tricuspid regurgitation. The dog was discharged on day 14. Histopathology of the resected tissue suggested a neuroendocrine neoplasm, and immunohistochemistry positive for synaptophysin and chromogranin A supported the diagnosis. Toceranib, a tyrosine kinase inhibitor with reported benefit in canine chemodectomas, was started on day 21.

The longer arc of the case tempers the enthusiasm. On day 360, a recurrent right atrial mass measuring 2.0 by 1.9 centimetres was documented, although without signs of right-sided heart failure. On day 390 the dog developed pancreatitis with biliary obstruction and died of multiple organ failure. Necropsy confirmed an aortic body tumour infiltrating from the endocardial surface into the right atrial myocardium, with pulmonary metastases and tumour emboli in the left caudal lung lobe. The authors are careful to note that they cannot determine whether the pulmonary spread represented spontaneous disease progression or was partly procedure-associated, because suctioned blood was returned to the circuit and standard filters cannot reliably remove individual tumour cells. They also acknowledge that the contribution of surgery, toceranib and the tumour’s naturally slow growth to the dog’s ten-month survival cannot be disentangled.

The team is equally clear that this should not be read as a new standard of care. Preoperative CT staging was not performed, central venous pressure was not monitored during bypass, and no strict numerical abort criterion was set, all acknowledged limitations. Total venous inflow occlusion was considered as a simpler alternative but rejected because the mass required careful stepwise debulking rather than rapid excision, and the 40-minute intracardiac manipulation exceeded the short window that technique allows. The authors frame the operation as an exceptional, high-risk rescue intervention justified only when severe intracardiac obstruction is the dominant life-limiting problem, medical and radiation options cannot provide rapid relief, and advanced cardiac surgical and perfusion support are available. Within those narrow boundaries, the case demonstrates that partial cardiopulmonary bypass can deliver real, if temporary, palliative benefit in veterinary patients facing obstruction that would otherwise be fatal.

Subject of Research: Palliative surgical debulking of a canine aortic body tumour with right atrial invasion under partial cardiopulmonary bypass

Article Title: Palliative Debulking of an Aortic Body Tumour With Right Atrial Invasion in a Dog Under Partial Cardiopulmonary Bypass

Article References: Suzuki, S., Tanaka, S., Kanno, N., Yogo, T., Harada, Y., Michishita, M., & Hara, Y. (2026). Palliative Debulking of an Aortic Body Tumour With Right Atrial Invasion in a Dog Under Partial Cardiopulmonary Bypass. Veterinary Medicine and Science, 12(5), Article e71244. https://doi.org/10.1002/vms3.71244

Image Credits: AI Generated

DOI: 10.1002/vms3.71244

Keywords: aortic body tumour, chemodectoma, cardiopulmonary bypass, right atrium, veterinary surgery, French Bulldog, cardiac tumour, ascites, toceranib, palliative care, echocardiography, neuroendocrine tumour

Umbilical hernias arise when abdominal contents protrude through the umbilical ring, the natural opening in the abdominal wall at the navel. In normal development, this opening closes within a few days after birth, but closure can fail for congenital or acquired reasons. Congenital hernias are present at birth and often carry a hereditary component, while acquired hernias appear weeks after birth and are associated with infection, trauma, or increased pressure inside the abdomen. Anatomically, every hernia consists of three components: the sac, which forms the visible swelling; the contents, which may include intestine, omentum, or other organs; and the ring, the opening through which the contents pass, which may be natural or acquired.

The clinical significance of these defects varies widely. Most umbilical hernias are small, reducible, and clinically silent, causing little more than a cosmetic bulge. Larger hernias, however, can become irreducible, creating a risk of incarceration in which the herniated tissue becomes trapped, followed by strangulation, in which the blood supply to the trapped tissue is cut off. Strangulation produces acute, severe clinical signs and can be life-threatening. In breeding animals, hernias also carry an economic dimension, since they can significantly reduce both reproductive and productive performance, making timely repair a matter of practical husbandry as well as animal welfare.

Diagnosis rests on history, physical examination, and, where necessary, diagnostic imaging. For umbilical hernias, a visible swelling at the umbilicus is the typical presenting sign, and the diagnosis is usually confirmed by manually reducing the herniated mass and palpating the hernial ring, a maneuver made easier by placing the animal on its back. The condition must be distinguished from other umbilical swellings, including abscesses, hematomas, cysts, and tumors. An abscess typically shows local inflammatory signs and may discharge pus; a hematoma feels like free fluid and may yield bloody content on aspiration; a cyst fluctuates uniformly without pain or tendency to point. The pathognomonic findings for hernia are a palpable umbilical ring, a hernial sac, and reducible contents, with ultrasonography, radiography, or abdominocentesis available as supplementary tools when adhesions or swelling obscure reducibility.

In the reported case, the ram, weighing 21 kilograms and managed semi-intensively within a flock, had carried a one-month history of an enlarging umbilical swelling, with no reported trauma or prior treatment. On examination the animal was alert, with a heart rate of 74 beats per minute, a respiratory rate of 24 breaths per minute, and a rectal temperature of 39.0 degrees Celsius, all within normal physiological ranges. Palpation of the spherical swelling confirmed a distinct hernial ring, a hernial sac, and soft, non-painful contents. When the ram was positioned in dorsal recumbency, the contents reduced fully and manually into the abdominal cavity under gentle pressure. Exploratory abdominocentesis at the swelling yielded no fluid or purulent discharge, ruling out abscess and hematoma, and a diagnosis of umbilical hernia was reached. Because the animal was a year old, the hernia was classified as acquired, of unknown etiology, a finding consistent with earlier reports of acquired umbilical hernias in sheep ranging from four months to four years of age.

Surgical repair was scheduled after an overnight fast of 12 hours. Preoperative preparation followed a rigorous aseptic protocol: the swelling and surrounding region were washed with soap and water, closely shaved, and scrubbed with an antiseptic solution containing cetrimide and chlorhexidine gluconate, alternated with 70 percent isopropyl alcohol. The field was then painted with 2 percent iodine tincture in a centrifugal fashion, with concentric circles moving outward from the intended incision site, and draped with a sterile fenestrated drape secured by towel clamps. Anesthesia was achieved by local infiltration alone, using 2 percent lidocaine hydrochloride injected circumferentially around the base of the hernia at a total dose of 4 milligrams per kilogram of body weight. The surgical team deliberately avoided systemic sedation or general anesthesia to eliminate the risks of bloat, regurgitation, aspiration pneumonia, and prolonged cardiopulmonary depression, hazards particularly relevant in ruminant patients.

The operation itself illustrates the technical decisions that determine outcomes in herniorrhaphy. A single longitudinal skin incision was made over the apex of the swelling in the midline, anterior to the prepuce, and curved laterally to the right as needed, an approach chosen to avoid inadvertent injury to the preputial sheath and penile structures in this male animal. Hemostasis was maintained with direct gauze pressure and hemostatic artery forceps. Blunt dissection with closed Mayo scissors separated the hernial sac completely from the surrounding subcutaneous tissues and fascia. The sac was grasped with tissue forceps and tented upward away from the viscera, a small stab incision was made with a number 11 scalpel blade, and the surgeon’s index finger was inserted to palpate and clear any adhesions before the incision was extended. Opening the sac revealed herniated omentum and intestine, which were carefully returned to the abdominal cavity, exposing a circular hernial ring approximately 2 to 3 centimeters in diameter.

Closure began with refreshing the fibrotic edge of the ring with a scalpel blade to create a clean, viable surface for healing. To achieve a tension-free closure, the ring was enlarged with two small relief incisions, each roughly 1 centimeter long, made in opposite directions cranially and caudally. The ring was then closed with a cruciate suture pattern using size 2 silk, with all sutures placed first and tightened sequentially from the center of the defect toward its lateral margins in a centrifugal fashion. Procaine penicillin powder was applied topically over the sutured fascial site for local antimicrobial prophylaxis. Excess sac, redundant skin, and subcutaneous tissue were trimmed away, the subcutaneous layer was closed with a simple continuous pattern of size 2 polyglactin 910 to obliterate dead space and withstand abdominal wall tension, and the skin was apposed with a horizontal mattress pattern of size 2 silk for mechanical security against animal movement. The site was dressed with 2 percent iodine solution and the ram was discharged.

Postoperative management combined wound care with a three-day regimen of antimicrobials and analgesics. A combination of procaine penicillin G and dihydrostreptomycin sulfate was administered intramuscularly at 0.1 milliliters per kilogram once daily, while meloxicam was given at 0.3 milligrams per kilogram once daily for pain control. The wound was cleansed and re-dressed with iodine tincture every other day until healing was complete, and skin sutures were removed on the fifteenth day after surgery. Follow-up examinations at 30 and 60 days postoperatively found the ram in good health, gaining weight, and showing no signs of recurrence.

The choice of suture pattern is the case’s most instructive element. Commonly reported techniques for umbilical hernia repair in veterinary practice rely on interrupted and overlapping horizontal mattress patterns with non-absorbable suture material, in some studies supplemented by an additional row of simple interrupted nylon sutures. The successful use of a cruciate pattern with size 2 silk in this ram suggests that this configuration, which distributes tension across the closure while requiring less suture material and less time than layered mattress techniques, is a viable alternative for reducible hernias of similar size. The authors note that anesthetic protocol selection ultimately depends on patient temperament, hernia complexity, animal stability, and resource availability, and that local infiltration of lidocaine combined with xylazine sedation has also been reported for this procedure in sheep. The case’s principal limitation is its nature as a single report: larger prospective clinical studies with broader case series will be needed to validate long-term outcomes and compare the cruciate technique’s efficacy directly against the established mattress patterns. Until then, the case stands as a clear demonstration that timely diagnosis, careful surgical execution, and diligent postoperative care can restore a hernia-affected ram to full health with equipment and techniques accessible to field practitioners.

Subject of Research: Surgical repair of an acquired umbilical hernia in a ram using herniorrhaphy under local anesthesia

Article Title: Umbilical Hernia in a Ram and Its Successful Surgical Repair

Article References: Siyoum, G. T. (2026). Umbilical Hernia in a Ram and Its Successful Surgical Repair. Clinical Case Reports, 14(10), Article e73621. https://doi.org/10.1002/ccr3.73621

Image Credits: AI Generated

DOI: 10.1002/ccr3.73621

Keywords: umbilical hernia, ram, herniorrhaphy, veterinary surgery, sheep, cruciate suture pattern, local anesthesia, lidocaine, silk suture, small ruminants, case report, Addis Ababa University