The Case: “Routine” Dog Neuter That Has Gone Awry
Clinical History
9-year-old intact male German shepherd dog with 2-month history of stranguria
Up-to-date vaccinations/monthly heartworm medication
No other medical history
Physical Examination Findings
Firm, large bladder on abdominal palpation
Lobular enlarged prostate (5–6 cm diameter) on rectal palpation
Remainder of findings unremarkable
Diagnostic Procedures
Thoracic radiographs: within normal limits
Laboratory abnormalities: - ALP 325 U/L (N 20–150 U/L) - Globulins 5.0 g/dL (3.0–4.7 g/dL) - BUN 32 mg/dL (10–25 mg/dL)
Urinalysis within normal limits
Abdominal ultrasonography: homogenous, enlarged prostate
Abdominal radiographs: within normal limits
Pelvic radiographs: moderate osteoarthritis in bilateral coxofemoral joints
Master problem list: stranguria, prostatomegaly (rule out benign prostatic hyperplasia/prostatic neoplasia), and moderate hip dysplasia
Therapeutic Procedures
Owner chose conservative treatment: castration, medical management of prostatic disease, and close monitoring of clinical response. Owner refused ultrasound-directed prostatic biopsy.
Surgery: routine prescrotal castration - Anesthetic Premedication - Hydromorphone (0.05 mg/kg IM) - Atropine (3 mg total IM) - Acepromazine (0.05 mg/kg IM) - Cefazolin (10 mg/kg IV) - Induction/Maintenance - Propofol to effect (70 mg IV) - Lactated Ringer’s solution (200-mL bolus IV) - Isoflurane inhalant to effect - Intraoperative Treatment - Lactated Ringer’s solution (10 mL/kg/hr IV) - Isoflurane inhalant to effect
Postoperative Treatment - Hydromorphone (0.1 mg/kg IM) - Polysulfated glycosaminoglycan (5 mg/kg IM) - Meloxicam (0.2 mg/kg SC)
Routine procedure and anesthetic recovery
Discharge medications - Tramadol (2 mg/kg PO Q 12 H × 7 days) - Meloxicam (0.1 mg/kg PO Q 24 H × 7 days)
Follow-up - Patient returned the following morning wih ecchymosis around surgical site, swollen scrotum, and petechiae of the gingiva and penile mucous membranes. - Ecchymoses spread across body by afternoon - Blood collected for CBC, serum biochemical profile, PT/PTT, d-dimers - Vitamin K1 (2.5 mg/kg SC, divided over several sites) - Normosol R solution (100 mL/hr IV) - Patient prepared for fresh frozen plasma transfusion
Clinical Outcome- Patient died prior to initiation of transfusion- CPR attempts unsuccessful
The Specialist’s OpinionThere are several possible explanations for this dog’s clinical signs of coagulopathy. First, this dog received a dose of polysulfated glycosaminoglycan (PSGAG) immediately postoperatively, with simultaneous administration of a nonsteroidal antiinflammatory drug (NSAID). The likelihood of significant adverse events from PSGAG is low; however, there is a dose-related inhibition of coagulation and hemostasis that has previously been reported. Safety studies evaluating PSGAG administration have detected that it has a wide margin of safety; in one study, there were no signs of coagulopathy detected with chronic administration at 5 mg/kg. However, as PSGAG is a heparin analog, its use is not recommended with concurrent NSAID or anticoagulant (eg, heparin) therapy, so it should be used judiciously.
Secondly, the dog had no previous surgery (based on preliminary history). Whether it had a preexisting primary clotting disorder, such as von Willebrand’s disease, is unknown. While von Willebrand’s disease has been reported in the German shepherd, it is not a breed highly associated with such inherited coagulopathies. Finally, although the dog was geriatric, rule-outs including coagulopathy or DIC secondary to hemangiosarcoma were lower on the list of causes based on ultrasound evaluation.
There are some points that are important in regard to this possibility:
In a patient that has never had previous surgery or in a breed predisposed to inherited coagulopathies additional diagnostic testing (eg, buccal mucosal bleeding time) may be warranted. At the very least, such testing should be discussed with the pet owner.
The clinical use of concurrent PSGAG and NSAIDs should be judiciously considered.
JUSTINE A. LEE, DVM, DACVECC, DABT, is the CEO and founder of VetGirl, a subscription-based podcast service offering RACE-approved continuing education (CE). Dr. Lee graduated from Cornell University and completed her internship at Angell. She also completed an emergency fellowship and residency at University of Pennsylvania. Dr. Lee is double-boarded in both emergency critical care and toxicology. In 2011, she was named the NAVC Conference Small Animal Speaker of the Year, and she is passionate about delivering clinically relevant CE.
The Generalist’s OpinionThis dog had a thorough workup prior to surgery, and the decision to neuter it without tissue analysis was based on appropriate informed consent by the client. Some options for obtaining a tissue sample of a prostatic lesion include ultrasound-guided biopsy, fine-needle aspiration, catheter-suction biopsy, or prostatic wash. Considering the client’s refusal of further diagnostics, neutering the dog was the next best option.
The postsurgical administration of polysulfated glycosaminoglycan (PSGAG) along with meloxicam was appropriate use of multimodal pain control. However, PSGAGs can have heparin-like effects and, although side effects are extremely rare, prolonged coagulation times have been reported.1 Some concern has also been voiced about using PSGAGs concurrently with nonsteroidal antiinflammatories. The dog in this case had an elevated BUN, which should prompt caution with NSAID use. Although the use of NSAIDs and PSGAGs together is commonplace, veterinarians need to be aware of the potential for an increased risk for side effects with such use. The outcome of this case was an extremely unfortunate and unlikely occurrence. It demonstrates the risks we take even when practicing good, solid medicine.
1. Antithrombotic and bleeding effects of glycosaminoglycans with different degrees of sulphation. Van Ryn-McKenna J, Ofosu FA, Hirsh J, Buchanan MR. Br J Haematol 71:265-269, 1989.Barak Benaryeh, DVM, DABVP, is the owner of Spicewood Springs Animal Hospital. He graduated from the University of California-Davis School of Veterinary Medicine in 1997 and completed an internship in Small Animal Medicine, Surgery and Emergency at the University of Pennsylvania. Dr. Benaryeh has also taught practical coursework to first-year veterinary students and was a primary veterinary surgeon for the Helping Hands Program, which trains assistance monkeys for quadriplegic people. Dr. Benaryeh is board certified by the American Board of Veterinary Practitioners in Canine and Feline Practice.