OBJECTIVE To compare platelet function and viscoelastic test results between healthy dogs and dogs with chronic kidney disease (CKD) to assess whether dogs with CKD have platelet dysfunction and altered blood coagulation.
ANIMALS 10 healthy control dogs and 11 dogs with naturally occurring CKD.
PROCEDURES Blood and urine were collected once from each dog for a CBC, serum biochemical analysis, urinalysis, and determination of the urine protein-to-creatinine ratio, prothrombin time, activated partial thromboplastin time, plasma fibrinogen concentration, and antithrombin activity. Closure time was determined by use of a platelet function analyzer and a collagen-ADP platelet agonist. Thromboelastography (TEG) variables (reaction time, clotting time, α angle, maximum amplitude, and global clot strength [G value]) were determined by use of recalcified nonactivated TEG. Platelet expression of glycoprotein Ib (GPIb; receptor for von Willebrand factor), integrin αIIbβ3 (αIIbβ3; receptor for fibrinogen), and P-selectin (marker for platelet activation) was assessed by flow cytometry.
RESULTS Compared with healthy control dogs, the median closure time was prolonged, the median maximum amplitude and G value were increased, and the median clotting time was decreased for dogs with CKD. Platelet expression of both αIIbβ3 and P-selectin was also significantly increased for dogs with CKD, compared with that for control dogs. Platelet expression of GPIb, αIIbβ3, and P-selectin was not correlated with closure time or any TEG variable.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dogs with CKD frequently had evidence of platelet dysfunction and hypercoagulability that were not totally attributable to alterations in platelet surface expression of GPIb, αIIbβ3, and P-selectin.
Objective—To determine the effect of a commercial
bioflavonoid antioxidant on acetaminophen-induced
oxidative injury to feline erythrocytes.
Design—Randomized controlled study.
Animals—45 healthy age-matched cats.
Procedure—Cats were assigned to 3 experimental
groups. Groups 1 and 3 received a bioflavonoid antioxidant
(10 mg/d) orally for 2 weeks. Groups 2 and 3
received an oxidative challenge with acetaminophen
(90 mg/kg [41 mg/lb] of body weight, PO) on day 7.
Packed cell volume, percentage of erythrocytes with
Heinz bodies, blood methemoglobin concentration,
and blood reduced and oxidized glutathione concentrations
were determined at various times during the
2-week study period.
Results—Adverse effects were not associated with
bioflavonoid antioxidant administration alone.
Acetaminophen administration resulted in a significant
increase in methemoglobin concentration in groups 2
and 3; differences were not detected between these
groups. Heinz body concentrations in groups 2 and 3
increased after acetaminophen administration; however,
the increase in cats that received the antioxidant
was significantly less than in group-2 cats. Total blood
glutathione concentrations did not change significantly
in groups 2 and 3 after acetaminophen administration;
however, ratio of reduced to oxidized glutathione
concentration increased significantly after administration
in group-2 cats, compared with group-3 cats.
Conclusions and Clinical Relevance—Oral administration
of bioflavonoid antioxidants to cats at risk for
oxidative stress may have a beneficial effect on their
ability to resist oxidative injury to erythrocytes. (J Am
Vet Med Assoc 2000;217:1157–1161)