Objective—To evaluate platelet surface-associated
P-selectin, mean platelet component concentration
(MPC), mean platelet component distribution width
(MPCDW), mean platelet volume (MPV), and platelet
distribution width (PDW) for detection of activated
platelets in dogs with septic and nonseptic inflammatory
Animals—20 healthy dogs and 20 dogs with septic
and nonseptic inflammatory disease.
Procedures—Platelet surface-associated P-selectin
(expressed as the median fluorescence intensity
[MFI] of the platelet population), MPC, MPCDW,
MPV, and PDW were determined in 20 healthy adult
dogs, and reference ranges were calculated. These
parameters were also determined in 11 dogs with
nonseptic and 9 dogs with septic inflammatory disease
and evaluated to determine which parameters
were useful for detection of activated platelets.
Results—12 dogs with inflammatory disease had Pselectin
greater than the upper limit of the reference
range, whereas 16 dogs with inflammatory disease
had MPC lower than the lower limit of the reference
range. All dogs in which P-selectin was greater than
the upper limit of the reference range had MPC lower
than the lower limit of the reference range. The correlation
coefficient for P-selectin and MPC was 0.62.
Differences in the MPCDW, MPV, and PDW in most
dogs with inflammatory disease (compared with
healthy dogs) were found; however, the correlation
coefficients for P-selectin and MPCDW, MPV, and
PDW were low.
Conclusions and Clinical Relevance—Platelet surface-
associated P-selectin and MPC appeared to be
useful to detect activated platelets in most dogs with
septic and nonseptic inflammatory disease. (Am J
Vet Res 2005;66:325–329)
Objective—To determine whether platelets and neutrophils
become activated in dogs during short-distance
Animals—18 physically fit adult Siberian Huskies.
Procedure—Dogs were allocated into 2 teams (9
dogs/team). Each team ran a course of approximately
6.4 km while pulling a sled that contained 2 people.
Blood samples were collected immediately before
and within 10 minutes after completion of sled-pulling
activity. Blood was aspirated into sterile syringes and
immediately transferred to evacuated tubes containing
EDTA solution. Platelet activation status was evaluated
by determining cell-surface P-selection expression,
number of platelet aggregates and platelet
microparticles, mean platelet-component (MPC) concentration,
and mean platelet-component distribution
width (MPCDW) concentration. Neutrophil activation
status was evaluated by determining cell-surface
CD11/CD18 expression, neutrophil size, and neutrophil
Results—Short-duration strenuous sled-pulling activity
was associated with lower MPC concentration,
higher MPCDW concentration, and higher cell-surface
P-selectin expression after activation with phorbol
myristate acetate. An increase in neutrophil
CD11/CD18 expression and a decrease in neutrophil
granularity were also observed after exercise.
Conclusions and Clinical Relevance—Results of
this study provide evidence of priming and activation
of platelets and activation of neutrophils after strenuous
short-duration sled-pulling activity. Additional
studies will be needed to determine whether these
changes have adverse effects on animal performance
or induce tissue injury. (Am J Vet Res 2003;64:855–859)
Objective—To investigate the influence of diameter of the catheter and blood collection technique on platelet function and variables reflecting secondary hemostasis, physiologic anticoagulation, and fibrinolysis in dogs.
Animals—6 healthy Beagles.
Procedures—Blood samples were collected with 20- and 18-gauge venous catheters immediately after catheters were inserted in a peripheral vein, through a 14-gauge central venous catheter that had been placed via the Seldinger technique in a jugular vein < 30 minutes before sample collection, and through a 13-gauge central venous catheter placed via a catheter-through-the-needle technique < 30 minutes before sample collection (techniques 1 to 4, respectively). Platelet function was assessed in hirudin-anticoagulated whole blood via an impedance-based aggregometer with collagen (0.8, 0.4, 0.2, 0.1, and 0.05 μg/mL) as an inductor. Kaolin-activated thromboelastography variables were determined in citrated whole blood. Prothrombin time, activated partial thromboplastin time, fibrinogen and fibrin D-dimer concentrations, and activity of factor VIII, antithrombin, protein C, and protein S were assessed automatically in citrated plasma.
Results—At 0.05 μg of collagen/mL, the highest median rate of aggregation was observed for collection techniques 2 and 3 with 4.3 (range, 2.5 to 6.5) and 3.7 (range, 2.8 to 8.3) aggregation units/min; however, these values were not significantly different from values for the other collection techniques. Generally, sample collection technique did not have a significant impact on results of coagulation variables investigated.
Conclusions and Clinical Relevance—Various blood collection techniques can be used to obtain samples for coagulation testing.
Objective—To investigate whether submaximal aerobic exercise in dogs is followed by activation of all phases of coagulation as has been reported for humans.
Animals—9 healthy Beagles.
Procedures—30 minutes before dogs were exercised, a 16-gauge central venous catheter was placed in a jugular vein of each dog by use of the catheter-through-the-needle technique. Samples were collected before exercise, after running on a treadmill (6 km/h for 13 minutes), and at 60 minutes. Platelet activation was evaluated with platelet morphology indices (mean platelet component, mean platelet volume, and number of large platelets) provided by a laser-based hematology system. Platelet function was assessed in hirudin-anticoagulated whole blood with an impedance-based aggregometer with collagen as the agonist (final concentrations, 0, 1.6, 3.2, 5, and 10 μg/mL). Prothrombin time, activated partial thromboplastin time, and concentrations of fibrinogen, factor VIII, antithrombin, protein C, protein S, and fibrin D-dimer were determined automatically. Kaolin-activated thromboelastography variables R (reaction time), K (clot formation time), angle α, maximal amplitude, and G (clot stability) were measured in recalcified citrated whole blood.
Results—Exercise resulted in a significant decrease in mean platelet volume and the number of large platelets but did not change the mean platelet component, which reflected platelet activation as well as platelet function. Secondary and tertiary coagulation did not change significantly, nor did thromboelastography variables.
Conclusions and Clinical Relevance—Aerobic exercise resulted in a decrease in the number of large and thus most likely activated platelets but otherwise had no major impact on coagulation in dogs.
Objective—To determine the prevalence of seizures in cats after head trauma.
Design—Retrospective cross-sectional study.
Animals—52 cats with head trauma.
Procedures—Information was obtained from medical records of cats with head trauma and via telephone interviews of owners at least 2 years after cats had head trauma. Severity of head trauma in cats was classified with the modified Glasgow coma scale (mGCS), and the association between scores and development of seizures was determined.
Results—9 cats had moderate head trauma (mGCS score, 9 to 14), and 43 cats had mild head trauma (mGCS score, 15 to 18). None of the cats developed seizures during the follow-up period (≥ 2 years after head injury). The calculated 95% confidence interval for prevalence of seizures in cats after head injury was 0% to 5.6%. There was no significant relationship between severity of head trauma and the risk of seizures in cats.
Conclusions and Clinical Relevance—Results indicated the probability that cats with mild to moderate head trauma would develop posttraumatic seizures was low. However, clinicians should monitor cats with a history of head trauma for development of secondary epilepsy.
Objective—To compare response rates and remission and survival times in dogs with lymphoma treated with a continuous, multiagent, doxorubicin-based chemotherapeutic protocol or with a short-term single-agent protocol incorporating doxorubicin.
Design—Nonrandomized controlled clinical trial.
Animals—114 dogs with lymphoma.
Procedures—Dogs were treated with a chemotherapeutic protocol consisting of L-asparaginase, vincristine, cyclophosphamide, doxorubicin, methotrexate, and prednisolone (n = 87) or doxorubicin alone (27).
Results—63 of 86 (73%) dogs treated with the multiagent protocol (data on response was unavailable for 1 dog) and 14 of 27 (52%) dogs treated with the single-agent protocol had a complete remission. Dogs with lymphoma classified as substage ≤ and dogs with a high BUN concentration at the time of initial diagnosis were significantly less likely to have a complete remission. No significant difference in remission or survival time could be demonstrated between treatment groups. Incidence of hematologic and gastrointestinal tract toxicoses did not differ between treatment groups, with the exception that vomiting was more common among dogs treated with the multiagent protocol.
Conclusions and Clinical Relevance—In this population of dogs, we were not able to identify any significant difference in remission or survival times between dogs with lymphoma treated with a continuous, multiagent chemotherapeutic protocol and dogs treated with a short-term single-agent protocol involving doxorubicin.