Primary Splenic Torsion in Dogs

A study recently published in the Journal of the American Veterinary Medical Association provides details of prognosis, complications, and mortality risk factors in dogs undergoing laparotomy for primary splenic torsion.

Primary splenic torsion (not associated with gastric volvulus) is rare in dogs. This retrospective review included records of 102 dogs at 7 referral hospitals from August 1992 through May 2014. Nearly three-fourths of the dogs with primary splenic torsion were male (half of all dogs were neutered males). Half of the dogs belonged to 1 of 3 breeds: German Shepherd, Great Dane, and English Bulldog. According to the authors, this is the first study to identify the English Bulldog as a breed predisposed to primary splenic torsion.

“Chronic PST [primary splenic torsion] can be a diagnostic challenge in some cases,” write the authors. The most common clinical signs reported were lethargy, anorexia, depression, and vomiting. Initial physical examination results included palpable splenomegaly (69.4% of the dogs), hemoperitoneum (30.6%), and hypovolemic shock (22.5%). Splenomegaly was also evident on abdominal ultrasonography and radiology in most dogs. An abnormal spleen position was detected by ultrasonography in 31.7% of the dogs but by radiology in only 7.4%.

Splenectomy was performed in all but 1 of the dogs included in the review. In the remaining dog, the spleen was derotated and left in place. About two-thirds of the dogs received a prophylactic gastropexy during the operation (4 of the dogs had a preexisting gastropexy). The most common postoperative complications were anemia and ventricular arrhythmias. Results of splenic histopathology were consistent with vascular occlusion in all 79 dogs for whom findings were reported. Splenic neoplasia was not reported in any dog.

Two of the dogs died under general anesthesia; another 7 were euthanized before they were discharged from the hospital. Statistically significant risk factors for death prior to hospital discharge were septic peritonitis, intraoperative hemorrhage, and postoperative respiratory distress.

The researchers were unable to report overall survival time for the study population because dates of death were not available for most dogs. Of the 65 dogs with follow-up data, 49 had received gastropexy (47 during the surgery for primary splenic torsion and 2 preexisting). Subsequent gastric dilatation-volvulus was reported in 1 dog with and 1 dog without gastropexy.

The authors conclude that “the prognosis for dogs undergoing splenectomy for PST [is] favorable” and that monitoring coagulation status may reduce mortality. They suggest that dogs suspected of having primary splenic torsion be evaluated for septic peritonitis prior to laparotomy because it is associated with a higher risk of death, which could influence dog owners’ decisions to proceed with surgery.

Dr. Laurie Anne Walden received her doctorate in veterinary medicine from North Carolina State University in 1994. After an internship at Auburn University College of Veterinary Medicine, she returned to North Carolina, where she has been in companion animal general practice for over 20 years. Dr. Walden is also a board-certified Editor in the Life Sciences and owner of Walden Medical Writing.