Hematologic abnormalities do not correlate with survival in dogs with multiple acquired portosystemic shunts

To determine whether anemia, thrombocytopenia, and RBC morphologic changes are identified in canine patients with multiple acquired portosystemic shunts (MAPSS), and to determine whether hematologic abnormalities in dogs with MAPSS correlate with survival.

In a retrospective study from January 2014 to December 2023, CBC, RBC morphology, biochemistry results, diagnostic imaging findings, diagnosis, and survival times were recorded. Dogs were categorized on the basis of suspected MAPSS etiology.

Thirty-seven client-owned dogs diagnosed with MAPSS were included. Thirty-five percent of dogs with MAPSS were anemic, with a median RBC concentration of 5.79 X 106/µL (range, 2.48 X 106 to 9.11 X 106/µL; reference interval, 5.4 X 106 to 8.4 X 106/µL). Poikilocytosis was identified in 43% of dogs with MAPSS. Thrombocytopenia was reported in 65% of dogs with MAPSS with a median platelet concentration of 177 X 103/µL (range, 10 X 103 to 635 X 103/µL; reference interval, 220 X 103 to 600 X 103/µL). Hematologic abnormalities did not correlate with survival. Median survival of dogs with MAPSS was 100 days (range, 0 to 2,217 days; n = 35, with survival data unavailable for 2 dogs). Thirty-five percent of dogs with MAPSS survived for > 1 year after diagnosis.

Long-term survival is possible in dogs with MAPSS regardless of hematologic abnormalities. The reduction in platelets in dogs with MAPSS may be caused by splenic sequestration, consumption secondary to vascular shear stress, or coagulation derangements related to the underlying disease.

Anemia, poikilocytosis, and thrombocytopenia are not prognostic indicators of survival in dogs with MAPSS.