Racing Greyhounds Research Articles

Greyhound morbidity and mortality in Australia: A descriptive analysis of reported data from regulatory racing agencies.

Commercial greyhound racing is legal in Australia but controversial due to concerns around animal welfare. To make evidence-based recommendations of animal welfare standards, a comprehensive analysis of available data on race events, animal health, injuries and fatalities is required. We undertook a review of publicly available data and reports published by official greyhound racing bodies for the purpose of determining how morbidity and mortality events associated with dog training and racing could be benchmarked. 6 years of available data from stewards' reports, quarterly and annual reports were descriptively analyzed from New South Wales, Victoria and Queensland. Whole-of-life tracking for individual dogs was sparse. Although stewards' reports were published in all three states, the availability of aggregated quarterly and annual reports varied. When available these provided additional information such as injury incidents standardized per thousand starts. In Queensland, quarterly and annual reports provided an overview of greyhound mortality and morbidity rates. In contrast with Victoria, quarterly reports were unavailable and only annual reports were published, meaning quarterly trends could not be determined. Therefore, injuries categorized by severity that were routinely included in quarterly reports in Queensland and New South Wales were unavailable in Victoria. Our findings demonstrate that data recording and reporting practices must be standardized to accurately evaluate whether animal welfare standards are being met in the Australian greyhound racing industry. Our recommendation is to have national standardized reporting of injuries and deaths, and a publicly available database for whole-of-life tracking for individual racing greyhounds.

Vector-borne disease and its relationship to hematologic abnormalities and microalbuminuria in retired racing and show-bred greyhounds.

BackgroundReference intervals for platelets and white blood cell (WBCs) counts are lower in greyhounds than other breeds. Proteinuria is common. Vector‐borne diseases (VBD) cause thrombocytopenia, leukopenia, and proteinuria. Racing greyhounds are commonly exposed to vectors that carry multiple organisms capable of chronically infecting clinically healthy dogs.Hypothesis/ObjectivesVector‐borne disease prevalence is higher in retired racing greyhounds than in show‐bred greyhounds. Occult infection contributes to breed‐related laboratory abnormalities.AnimalsThirty National Greyhound Association (NGA) retired racing and 28 American Kennel Club (AKC) show‐bred greyhounds.MethodsPeripheral blood was tested for Anaplasma, Babesia, Bartonella, Ehrlichia, hemotropic Mycoplasma, and Rickettsia species using PCR. Antibodies to Anaplasma, Babesia, Bartonella, Ehrlichia, and Rickettsia species and Borrelia burgdorferi were detected using immunofluorescence and ELISA assays. Complete blood counts, semiquantitative platelet estimates, and microalbuminuria concentration were determined.ResultsSeven of 30 NGA and 1/28 AKC greyhounds tested positive for ≥1 VBD (P = .05). More positive tests were documented in NGA (10/630) than in AKC dogs (1/588; P = .02). Exposure to Bartonella species (3/30), Babesia vogeli (2/30), Ehrlichia canis (1/30), and infection with Mycoplasma hemocanis (3/30) occurred in NGA dogs. Platelet counts or estimates were >170 000/μL. White blood cell counts <4000/μL (4/28 AKC; 5/30 NGA, P > .99; 1/8 VBD positive; 8/51 VBD negative, P = .99) and microalbuminuria (10/21 AKC; 5/26 NGA, P = .06; 1/8 VBD positive; 14/25 VBD negative, P = .41) were not associated with VBD.Conclusions and Clinical ImportanceThe prevalence of thrombocytopenia and B. vogeli exposure was lower than previously documented. Larger studies investigating the health impact of multiple VBD organisms are warranted.

Effects of Norethisterone Acetate on the Performance of Female Racing Greyhounds

Effects of Norethisterone Acetate on the Performance of Female Racing Greyhounds

Patterns of Racing and Career Duration of Racing Greyhounds in New Zealand.

Simple SummaryThere is limited information on the career length and patterns of racing for greyhounds. Performance outcomes, including number of racing starts, career length and the age at which greyhounds finish racing, provide insight into causes of attrition in the greyhound racing industry. To investigate trends in greyhound racing careers a baseline is required. This paper presents results from a retrospective cohort study exploring career duration and patterns of racing of greyhounds in New Zealand. The welfare and wastage of racing greyhounds is a topic of public concern. Little is published about the racing patterns of these dogs in New Zealand. The aim of this study is to describe the pattern of greyhound racing in New Zealand. Data on all race starts between 1 August 2011 and 25 March 2018 were supplied by Greyhound Racing New Zealand. A cohort was created containing dogs that had a racing career between 1 August 2013 and 31 July 2017. Data were collated within a customized Microsoft Access database from electronic records of all racing starts for every dog within the 2013–2016 racing seasons. For this cohort of racing dogs, there were 97,973 race starts across 22,277 races involving 2393 individual greyhounds. The median number of days between racing starts was 7 days (inter-quartile range (IQR): 4–10 days). The median career length was 424 days (IQR: 206–647 days) and the median number of racing starts throughout a racing career was 35 (IQR: 16–59 starts). Dogs of similar ability finished their career at a similar age.

Exercise-induced Acute Abdominal Haemorrhage due to Iliopsoas Trauma in Racing Greyhounds

Post-mortem examination of 74 racing greyhounds with sudden, unexpected death was undertaken at the Veterinary School, University of Nottingham, UK, from 2015 to 2019. These investigations revealed severe, acute haemoabdomen with extensive retroperitoneal haemorrhage and an underlying severe, unilateral iliopsoas tear in four cases (5.4%). In all four cases, unilateral trauma and haemorrhage affecting the right iliopsoas muscle was common near the caudal insertion. Despite the acute clinical event, three cases demonstrated histological evidence of previous muscle damage with muscular regeneration, fibrosis and evidence of chronic haemorrhage. To our knowledge, this is the first detailed description of exercise-induced trauma to the iliopsoas muscle leading to extensive haemoretroperitoneum and haemoabdomen with subsequent hypovolaemic shock and death in racing greyhounds.

A survey of undesirable behaviors expressed by ex-racing greyhounds adopted in Italy

Abstract Previous research showed that behavior problems are a major reason for relinquishing adopted dogs to animal shelters, and it is possible that undesirable behaviors also affect the success of adoptions of retired racing greyhounds. The present study aimed to measure behaviors of ex-racing greyhounds adopted through the Greyhound Adoption Center Italy, as reported by 176 owners. Desirable behaviors were reported by a large percentage of participants as occurring always or almost always, such as being easy to manage (90.9%), being clean in the home (89.2%), and being good with children (89.2%). The only desirable behavior that was reported as occurring always or almost always by less than half of participants was being good with other animals (48.9%). A few undesirable behaviors were expressed by more than 40% of dogs at least sometimes. These were predatory behavior toward cats (79.6%), aggression toward unfamiliar animals (61.9%), fear of thunderstorms (46.6%), and following the owner around the house (69.3%). Several participants indicated that the problematic behavior had improved over time, and very few reported that it appeared or worsened long after adoption. A principal components analysis revealed 6 factors for undesirable behaviors. Few, and generally weak, significant correlations were found between factors and owner features or dog management practices, and only social fear ( r = −0.180, P = 0.017) and nonsocial fear ( r = −0.208, P = 0.006) correlated with overall satisfaction with the dog. In comparison with similar data previously collected in Australia and New Zealand (ANZ), 8 undesirable behaviors were reported to occur more frequently by ANZ owners, and 2 by Italian owners. Predatory behavior toward cats was the only behavior reported as occurring by more than half of the sample at least sometimes among both ANZ and Italian owners. These findings are relevant for associations involved in the rehoming of ex-racing greyhounds and for perspective owners. In addition, the findings should be used to increase awareness about problematic behaviors among people who breed and/or train racing greyhounds.

Arterial Blood Pressure, Proteinuria, and Renal Histopathology in Clinically Healthy Retired Racing Greyhounds

Physiologic peculiarities of Greyhounds as compared to other dogs make interpretation of laboratory results in this breed challenging for veterinarians. Hypertension in retired racing Greyhounds (RRG) can contribute to microalbuminuria (MA), overt proteinuria, and renal histologic lesions. To evaluate clinicopathologic findings, hemodynamic status, and renal histology in a population of healthy RRG. RRG presented to Ohio State University College of Veterinary Medicine for inclusion in a spay and neuter program. Cross-sectional study. RRG were classified as normotensive (<160 mmHg) or hypertensive (>160 mmHg) based on blood pressure (BP) determinations using Doppler and oscillometric methods. Of the dogs evaluated, 62% (n = 29) were hypertensive and 38% (n = 18) were normotensive. Health status was evaluated using routine clinicopathologic tests (CBC, serum biochemistry, urinalysis) as well as evaluation of fractional excretion of electrolytes and MA determinations. Adequate renal biopsy specimens (n = 15) were evaluated using light, immunofluoresence, and electron microscopy. All serum biochemistry results were normal in 45/49 dogs, but MA was more common in hypertensive (84% positive for MA) as compared with normotensive (18% positive for MA) RRG. Observed renal lesions were mild and renal biopsy scores were low in this sample of RRG. Hypertension is common in RRG and might be breed-related. It is associated with MA, but observed renal lesions are mild. Whether or not hypertension and MA in RRG leads to progressive renal damage requires longitudinal study.

Epsilon Aminocaproic Acid for the Prevention of Delayed Postoperative Bleeding in Retired Racing Greyhounds Undergoing Gonadectomy

To evaluate the effects of epsilon aminocaproic acid (EACA) on the prevalence of postoperative bleeding in retired racing Greyhounds (RRG), and to assess its effects on selected thrombelastography (TEG) and fibrinolysis variables. Double-blinded, prospective, randomized study. 100 RRG had elective ovariohysterectomy or orchiectomy and were administered EACA or placebo for 3 days after surgery. TEG variables were analyzed preoperatively and 24, 48, and 72 hours after surgery. Thirty percent (15/50) of RRG in the placebo group had delayed postoperative bleeding starting 36-48 hours after surgery compared with 10% (5/50) in the EACA group (P = .012). On the TEG variables, the slopes for R and K time were significantly different between treatment groups (P <.05); the R and K time decreased over time in the EACA group after surgery whereas they increased in the placebo group. The angle, maximal amplitude (MA), and G slopes were also significantly different between treatment groups (P = .001, .001, and .006, respectively). The angle, MA, and G increased postoperatively over time in the EACA group and decreased in the placebo group. All these changes are supportive of hypercoagulability associated with EACA administration. Postoperative administration of EACA significantly decreased the prevalence of postoperative bleeding in RRG undergoing surgery by increasing the clot strength.

Bone volume and regional density of the central tarsal bone detected using computed tomography in a cross-sectional study of adult racing greyhounds

AIMS: To determine whether left-to-right asymmetry of the central tarsal bone (CTB) of racing greyhounds was detectable using computed tomography (CT) in live dogs; to quantify the asymmetry in terms of average bone volume, volumetric bone mineral density (vBMD), and dorsal cortical shape, and to determine if age, gender, bodyweight, number of starts or history of tarsal injury were significant covariates. METHODS: One trainer supplied 11 male and seven female, unrelated, skeletally mature, actively racing greyhounds, including dogs with a history of tarsal injury diagnosed by the trainer and/or track veterinarian (n=8), and dogs without a history of tarsal injury (n=10). Using CT, standardised parameters of the CTB were measured including volume and average vBMD of the left and right CTB, vBMD of regions within the CTB, and bone shape. RESULTS: There was no difference in the volumes of the left and right CTB and no association with number of racing starts. Volume of CTB in dogs with a history of tarsal injury was greater than in dogs with no history of injury (p<0.001). Mean vBMD of the right was greater than the left CTB (p=0.004), and was independent of history of injury, gender, bodyweight, and number of starts. Males with a history of injury weighed more than those with no history of injury (p=0.004). The region of greatest difference in vBMD between right and left limbs was the centrodorsomedial aspect of the CTB. Middle plantar ligament enthesiopathies and fractures of tarsal bones other than the central tarsal bone were identified in dogs with and without a history of tarsal injury. CONCLUSIONS: Significant left-to-right asymmetry of the CTB in racing greyhounds was detected using CT. Contrary to previous suggestions, the asymmetry was not associated with the number of racing starts. We propose that the majority of the adaptive modelling of the CTB occurred rapidly following the onset of counter-clockwise training, with little further modelling throughout the racing career of the dog, however further investigation is warranted. CLINICAL RELEVANCE: This study described a technique using CT for imaging the CTB in live dogs, which opens the way for a longitudinal study of bone modelling of the CTB in response to training and racing in a counter-clockwise direction.

Clinical pathology ofGreyhounds and other sighthounds

Owing to the development of Greyhounds as racing sighthounds, these dogs have acquired unique physiologic adaptations that distinguish them from other breeds. Reference intervals for many analytes in retired racing Greyhounds (RRGs) differ from those of other breeds; most of the hematologic differences have also been described in other sighthounds. In this review, we provide a survey of the literature on clinical pathology of Greyhounds and other sighthounds and results of laboratory testing, including analysis of CBCs, biochemical profiles, coagulation tests, and blood gases, in RRGs at The Ohio State University. Major clinicopathologic differences in this breed include higher RBC mass, creatinine concentration, glomerular filtration rate, activities of hepatic enzymes, and concentration of cardiac troponin, as well as lower WBC, neutrophil, and platelet counts, thromboelastographic values, and concentrations of serum haptoglobin, total globulins, and T4.

Thromboelastographic changes after gonadectomy in retired racing greyhounds

Twenty-one healthy greyhounds with no history or clinical signs of bleeding disorders, and no abnormalities on physical examination, complete blood count, serum biochemistry profiles (in dogs more than five years...

White‐Coat Effect on Systemic Blood Pressure in Retired Racing Greyhounds

Greyhounds are known to have a higher systemic arterial blood pressure (BP) than non-Greyhound dogs. The purpose of this study was to determine whether the high systemic BP was because of the white-coat effect. Twenty-two healthy retired racing Greyhounds (RRG) enrolled in a blood donation program. We prospectively measured systemic BP in 3 environments: in the hospital by the investigator (Hosp), in the home by the investigator (H/I), and in the home by the owner (H/O). Five serial measurements of systolic, diastolic, and mean arterial pressures (SAP, DAP, MAP) as well as heart rate (HR) were measured by an oscillometric method on the distal forelimb and distal hind limb in all 3 environments. There was a significant difference for SAP, MAP, and HR between the Hosp and both H/I and H/O (P < .001); there were no significant differences for any of the parameters between the H/I and H/O environments. HR, but not SAP, MAP, or DAP (P < .05) decreased in RRG with multiple hospital visits for blood donation before this study. The hind limb SAP was significantly higher than the forelimb SAP (P < .05). We conclude that the high SAP, MAP, and HR seen in the hospital setting are likely because of a white-coat effect. Furthermore, consideration should be given to defining the parameters of normal BP in RRG according to the environment in which they are obtained.

Serum Cardiac Troponin I Concentration in Retired Racing Greyhounds

Cardiac troponin I (cTnI) is a polypeptide found specifically in cardiac muscle tissue that has been used as a diagnostic and prognostic indicator of cardiomyopathy. Increases in cTnI are associated with myocardial pathologic processes. However, high serum cTnI concentrations have been observed in normal Greyhounds. We hypothesized that Greyhounds have cTnI concentrations higher than non-Greyhound dogs, and that a separate reference range should be established for Greyhounds. Blood samples were collected from the jugular vein from a group of 20 healthy Greyhound blood donors. Analysis of serum cTnI was performed with an immunoassay system with a detection level of 0.01 ng/mL, as described previously. The Greyhound values were compared with 2 groups of Boxers with and without arrhythmogenic right ventricular cardiomyopathy (ARVC), and to a group of non-Boxer control dogs from a previous study. The mean cTnI concentration in Greyhounds was significantly higher (P < .0001) than that in non-Greyhound control dogs, although not significantly different from normal Boxers (P= .50), or Boxers with ARVC (P= .58). Greyhound serum cTnI concentrations were in the range found in Boxers with ARVC. The proposed reference range for cTnI in Greyhounds is 0.05-0.16 ng/mL. Greyhounds have a reference range for serum cTnI concentrations that differs from that of other previously published reference ranges for dogs of other breeds. Until a broader database and more precise reference range can be established, caution should be exercised in interpreting serum cTnI concentrations in Greyhounds with suspected cardiac disease.

Effects of Time of Collection and Sample Processing on von Willebrand Factor Concentration in Retired Racing Greyhounds

Concentrations of von Willebrand factor (vWF) are less than 30% in approximately 10% of Greyhounds. That sample collection, processing, and storage can affect the concentration of vWF in plasma of Greyhounds. Nineteen healthy former racing Greyhounds. Prospective study: Blood samples were obtained from the jugular vein of dogs at 4 times during the day. Samples were divided and processed in each of 3 ways. The 1st tube was centrifuged immediately, the 2nd tube was kept in a household refrigerator, and the 3rd tube was kept at room temperature for 3 hours before centrifugation and processing. There were no significant differences in the vWF concentration between different sample storage and processing (P = 5.31). There was no statistically significant diurnal variation in vWF concentration in the samples evaluated (P = .37). Time of sample collection and short-term storage temperature do not influence the vWF concentration in retired racing Greyhounds.

Postoperative Bleeding in Retired Racing Greyhounds

Some retired racing Greyhounds (RRG) that undergo surgery bleed excessively. Greyhounds that bleed excessively will have one or more preoperative hemostatic abnormalities that can be used to predict the risk and severity of postoperative bleeding. Eighty-eight RRG undergoing ovariohysterectomy or castration. All dogs were evaluated preoperatively with a physical exam, CBC, platelet count, OSPT, APTT, platelet function with PFA-100(a); fibrinogen, d-dimer, plasminogen (Plmg), antiplasmin (AP), antithrombin (AT), and vWF concentration (vWF:Ag); vWF collagen binding assay (vWF:CBA), and Factor XIII assay. Assays were repeated in the dogs that bled, and in an age- and sex-matched control group of RRG. Twenty-six percent of the dogs had bleeding 36-48 hours after surgery. AP (P <.0001) and AT concentration (P= .007) were significantly lower, and vWF:CBA (P= .0284) was higher preoperatively in the dogs with excessive hemorrhage. A lower platelet count (P= .001) and hematocrit (P= .002), shorter OSPT (P= .0002) and higher plasma fibrinogen (P <.0001), and AP (P= .001) concentration were detected at the time of bleeding compared with preoperative values in the dogs that bleed excessively. The same findings were observed postoperatively for the control group, except for the decrease in hematocrit. The results indicate that this excessive postoperative bleeding is not attributable to a primary or secondary hemostatic defect, but could result from altered fibrinolysis.

Thromboelastographic Tracings in Retired Racing Greyhounds and in Non‐Greyhound Dogs

Bleeding disorders in patients with normal coagulation test results are frequently reported in Greyhounds. The purpose of this study was to compare Greyhounds to non-Greyhounds by thromboelastography (TEG). TEG parameters in Greyhounds are different from those in non-Greyhounds. Forty-three healthy dogs (28 Greyhounds and 15 non-Greyhounds) based on the results of physical examination, CBC, activated partial thromboplastin time, prothrombin time, fibrinogen, and platelet count. Recalcified citrated native TEGs were performed in both groups; data were compared using Student's, Mann-Whitney, and Pearson's statistical tests. In Greyhounds, mean +/- SD were as follows: R-time 4.3 +/- 1.7 minutes, K-time 3.8 +/- 1.4 minutes, angle (alpha) 50.0 +/- 8.0 degrees , maximum amplitude (MA) 47.6 +/- 5.6 mm, clot strength (G) 4,647 +/- 1,097 dyn/cm2, and percent lysis at 60 minutes (LY60) 2.8 +/- 5.0%. In the non-Greyhounds they were R-time 3.7 +/- 1.6 minutes, K-time 2.5 +/- 0.9 minutes, angle 59.8 +/- 7.0 degrees , MA 53.1 +/- 5.6 mm, G 5,811 +/- 1,256 dyn/cm2, and LY60 3.1 +/- 2.5%. All parameters were significantly different between the groups, except for R-time and LY60. In Greyhounds, clotting kinetics are slower and clot strength are weaker than in non-Greyhounds, supporting the increased tendency to bleed observed after minor trauma or surgical procedures in the breed. The findings may also be attributed to blood viscosity or to the concentration of citrate in the sample (ie, Greyhounds have higher hematocrit and less plasma per unit volume).

Results of a Web‐Based Health Survey of Retired Racing Greyhounds

Background: Adoption of retired racing Greyhounds has become increasingly popular during the past decade. To date, research has focused on the physiologic and clinicopathologic peculiarities of Greyhounds but there is little published information on disease prevalence in the breed.Objective: The objective of this study is to determine the prevalence of disease in retired racing Greyhounds.Animals: In this study, 747 Greyhounds were used.Methods: A standardized survey method was used, and survey responses were collected by an Internet survey. Owners could answer a survey for every Greyhound that they had owned since January 1, 2005.Results: Of the 692 eligible participants, 441 (63.7% response rate) completed surveys for 747 Greyhounds. The mortality rate for Greyhounds within the 2‐year period was 15% (113 of 747 died). The most common cause of death reported was cancer (66 dogs, 58%), and the most common type of cancer listed as the cause of death was osteosarcoma (28 dogs, 25%). The most commonly reported groups of diseases or disorders were skeletal (232 dogs, 33%), skin (197 dogs, 28%), digestive (132 dogs, 18%), cancer (94 dogs, 13%), and endocrine (85 dogs, 11.9%). Forty‐five percent of Greyhounds diagnosed with cancer and 6% of the overall population had osteosarcoma.Conclusions and Clinical Importance: The results of this study can be used by veterinary researchers to continue to investigate the most common diseases in this population. As more retired racing Greyhounds enter the pet population, the results of this study will help educate veterinarians and owners about the most prevalent diseases in the breed.

Results of a Web-Based Health Survey of Retired Racing Greyhounds

Adoption of retired racing Greyhounds has become increasingly popular during the past decade. To date, research has focused on the physiologic and clinicopathologic peculiarities of Greyhounds but there is little published information on disease prevalence in the breed. The objective of this study is to determine the prevalence of disease in retired racing Greyhounds. In this study, 747 Greyhounds were used. A standardized survey method was used, and survey responses were collected by an Internet survey. Owners could answer a survey for every Greyhound that they had owned since January 1, 2005. Of the 692 eligible participants, 441 (63.7% response rate) completed surveys for 747 Greyhounds. The mortality rate for Greyhounds within the 2-year period was 15% (113 of 747 died). The most common cause of death reported was cancer (66 dogs, 58%), and the most common type of cancer listed as the cause of death was osteosarcoma (28 dogs, 25%). The most commonly reported groups of diseases or disorders were skeletal (232 dogs, 33%), skin (197 dogs, 28%), digestive (132 dogs, 18%), cancer (94 dogs, 13%), and endocrine (85 dogs, 11.9%). Forty-five percent of Greyhounds diagnosed with cancer and 6% of the overall population had osteosarcoma. The results of this study can be used by veterinary researchers to continue to investigate the most common diseases in this population. As more retired racing Greyhounds enter the pet population, the results of this study will help educate veterinarians and owners about the most prevalent diseases in the breed.

Evaluation of Platelet Aggregation Using a Point‐Of‐Care Instrument in Retired Racing Greyhounds

Veterinarians involved in Greyhound rescue have anecdotally observed that 10–15% of Greyhounds bleed profusely after simple surgical procedures. In most patients, platelet counts and hemostasis profiles are normal; therefore, it is possible that these dogs have platelet dysfunction. The PFA‐100a is a novel point‐of‐care platelet function analyzer that has recently been evaluated as a rapid method to assess platelet function in dogs. The objectives of this study were to characterize platelet function in a group of healthy Greyhounds by means of the PFA‐100. Blood samples were collected from the jugular vein from 30 healthy Greyhounds. CBC, biochemical profile, PFA‐100 assay with collagen/epinephrine (COL‐EPI) and collagen/ adenosindiphosphate (COL‐ADP), plasma von Willebrand factor antigen concentration (vWF: Ag), and vWF collagen‐binding assay (vWF:CBA) were performed. PFA‐100 closure times (CTs) with COL/ADP ranged from 63 to 92 seconds (mean ± SD, 74.7 ± 7.9 seconds) and with COL/EPI from 87 to 238 seconds (138 ± 41 seconds); vWF:Ag ranged from 22 to 120% (87.52 ± 25.5%) and vWF:CBA ranged from 36 to 102% (77.4 ± 17.3%); and platelet counts ranged from 147 to 265 ± 109/L (194.6 ± 31.64 ± 109/L). Greyhound CTs were significantly shorter than CTs in a mixed population of 50 healthy non‐Greyhound dogs, in which the COL/ADP CTs ranged from 61 to 172 seconds (mean ± SD, 87 ± 21.6 seconds), and the COL/ EPI CTs ranged from 81 to 300 seconds (mean ± SD, 183 ± 67.6 seconds; P= 0.005 for COL/ADP CT; P= 0.001 for COL/ EPI CT). Also, platelet counts were significantly lower (P= 0.001) and packed cell volume was significantly higher (P= 0.001) in the Greyhound than in the non‐Greyhound group. The PFA‐100 is a reproducible method that can be used in the clinical setting to assess platelet function in Greyhounds; however, normal CTs in healthy Greyhounds are shorter than in other breeds. The results obtained in this study will be used to screen for abnormal platelet function in Greyhounds with postoperative bleeding.

Evaluation of Platelet Aggregation Using a Point-Of-Care Instrument in Retired Racing Greyhounds

Veterinarians involved in Greyhound rescue have anecdotally observed that 10-15% of Greyhounds bleed profusely after simple surgical procedures. In most patients, platelet counts and hemostasis profiles are normal; therefore, it is possible that these dogs have platelet dysfunction. The PFA-100 is a novel point-of-care platelet function analyzer that has recently been evaluated as a rapid method to assess platelet function in dogs. The objectives of this study were to characterize platelet function in a group of healthy Greyhounds by means of the PFA-100. Blood samples were collected from the jugular vein from 30 healthy Greyhounds. CBC, biochemical profile, PFA-100 assay with collagen/epinephrine (COL-EPI) and collagen/ adenosindiphosphate (COL-ADP), plasma von Willebrand factor antigen concentration (vWF:Ag), and vWF collagen-binding assay (vWF:CBA) were performed. PFA-100 closure times (CTs) with COL/ADP ranged from 63 to 92 seconds (mean +/- SD, 74.7 +/- 7.9 seconds) and with COL/EPI from 87 to 238 seconds (138 +/- 41 seconds); vWF: Ag ranged from 22 to 120% (87.52 +/- 25.5%) and vWF: CBA ranged from 36 to 102% (77.4 +/- 17.3%); and platelet counts ranged from 147 to 265 x 10(9)/L (194.6 +/- 31.64 x 10(9)/L). Greyhound CTs were significantly shorter than CTs in a mixed population of 50 healthy non-Greyhound dogs, in which the COL/ADP CTs ranged from 61 to 172 seconds (mean +/- SD, 87 +/- 21.6 seconds), and the COL/ EPI CTs ranged from 81 to 300 seconds (mean +/- SD, 183 +/- 67.6 seconds; P = 0.005 for COL/ADP CT; P = 0.001 for COL/ EPI CT). Also, platelet counts were significantly lower (P = 0.001) and packed cell volume was significantly higher (P = 0.001) in the Greyhound than in the non-Greyhound group. The PFA-100 is a reproducible method that can be used in the clinical setting to assess platelet function in Greyhounds; however, normal CTs in healthy Greyhounds are shorter than in other breeds. The results obtained in this study will be used to screen for abnormal platelet function in Greyhounds with postoperative bleeding.