Postoperative bleeding in retired racing greyhounds

BACKGROUND: Some retired racing Greyhounds (RRG) that undergo surgery bleed excessively. Hypothesis: 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. ANIMALS: Eighty-eight RRG undergoing ovariohysterectomy or castration. METHODS: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL IMPORTANCE: The results indicate that this excessive postoperative bleeding is not attributable to a primary or secondary hemostatic defect, but could result from altered fibrinolysis.     

Dorsal tarsal instability in three racing greyhounds

Rupture of the dorsal ligaments of the tarsus in the greyhound is a rare racing injury. This case report describes dorsal tarsal instability in three greyhounds. A stumble and somersault were observed in two cases and were thought to have caused the injury. Previous reports advocate partial intertarsal arthrodesis as the preferred treatment for dorsal instability of the proximal intertarsal joint, but not all dogs returned to successful racing. In these three cases, stability was restored by the insertion of a wire tension band anchored to two bone screws, allowing the development of periarticular fibrosis. The dogs raced again with no loss of form.     

Rickets in a litter of racing greyhounds

Rickets was diagnosed in six 14-week-old racing greyhound littermates presented with musculoskeletal disease. Physical findings included listlessness, profound muscle weakness, lameness, lateral bowing of the antebrachll and focal hard swellings proximal to the tarsi and carpl. Radiological findings included generallsed osteopenia, axial and radial thickening of growth plates, and 'cupping' of the adjacent metaphyses; the distal ulnar growth plates were most severely and consistently affected. The diagnosis was confirmed by demonstrating subnormal concentrations of 2bhydroxycholecalciferol in serum samples collected at admission. The pups' diet consisted of an inexpensive generic kibble formulated for adult dogs, porridge, milk, pasta, minced beef, vegetables and a small quantity of calcium carbonate powder. The pups were successfully treated by feeding a nutritionally complete, vitamin D-containing ration formulated for growing pups. Bilateral growth retardation of distal ulnar physes occurred as a sequel In one pup.     

Factors affecting prerace dehydration and performance of racing greyhounds

Several factors, including age, sex, race number, post position, and race class, were evaluated for relationships to prerace percentage body weight loss and performance in all Greyhounds racing during August 1983 in Oregon. The incidence of percentage body weight loss greater than or equal to 2.5% was low (5%). Race number had a direct effect on weight loss; the later the dogs raced, the more weight loss they experienced. Female dogs were 3 times more likely to lose greater than 2.4% of body weight than males. All dogs experiencing greater than 2.4% body weight loss were 2 times more likely to finish in the first 3 places when racing in the first 5 races overall. In addition, males losing greater than 2.4% of body weight performed better than females when racing together in the final 6 races. Males appeared to be better performers than females, as they were twice as likely to be in class A races. However, once in the race, males and females performed equally.     

Genetic analysis of racing performance in Irish greyhounds

The aim of this study was to analyse racing performance data in Irish greyhounds with regard to genetic and environmental variation. Estimation of heritabilities for racing time (RT) and ranking, and the prediction of breeding values for all greyhounds in the investigated data were carried out. Data from 42,785 races in Ireland in the years 2000-2003 were available. These results were obtained from 42,880 greyhounds on 20 race tracks over a distance of 480 m. Three traits were analysed, RT, ranking and a scaled logarithmic function for RT (ART), which was used to adjust racing time to be normally distributed. The data were analysed with a bivariate animal model. The estimated heritabilities were moderate for RT (0.31) and ART (0.38), but very low for ranking (0.10). The repeatabilities were 0.56 (RT), 0.51 (ART) and 0.13 (ranking). The genetic correlations were very high, 0.99 (RT-ranking) and 0.96 (ART-ranking), while the phenotypic correlation was lower, 0.60 (RT-ranking) and 0.62 (ART-ranking). The genetic trend for the traits as well as the phenotypic change of the average RT was positive.     

Left basilar systolic murmur in retired racing greyhounds

Nineteen of 28 (67%) Greyhounds enrolled in the Blood Donor Program at The Veterinary Teaching Hospital, The Ohio State University (Columbus, OH), had a left basilar systolic murmur. Ten Greyhounds with murmurs and 9 without murmurs were evaluated to gain knowledge about the pathogenesis of this murmur. Echocardiograms were performed without sedation by means of a GE Vivid 7 Echocardiographic System with a continuous ECG; systolic arterial blood pressure (SABP) was measured with an Ultrasonic Doppler Flow detector model 811-B. The mean peak aortic velocity in the Greyhounds with murmurs (2.15 m/s; range, 1.8-2.2 m/s) was significantly higher than in the Greyhounds without murmurs (1.89 m/s; range, 1.6-2.0 m/s) (P < .001); there were no significant differences between groups for aortic valve or annulus diameter, fractional shortening, pulmonic velocity, SABP, hematocrit, serum protein concentration, or red blood cell counts. In this study, Greyhounds with soft, left basilar systolic murmurs had mildly (but significantly) higher mean peak aortic velocities than similar dogs without murmurs. In the dogs with murmurs (and higher velocities), we could not identify structural abnormalities, such as valvular lesions or other congenital defects. There was no inverse correlation between the systolic murmur and the higher hematocrit and red blood cell counts observed in this breed. This 1-2/6 basilar systolic murmur is common in Greyhounds, and it does not appear to be of any clinical consequence.     

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 of age), and SNAP-4DX test for vector borne diseases underwent routine gonadectomies at the Ohio State University Veterinary Teaching Hospital. Blood samples were collected 24 hours before and after surgery by jugular venepuncture for thromboelastography and haemostasis assays (prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen concentration). The magnitude of the bleeding in each patient was estimated using a bleeding scoring system recently validated in greyhounds. Eight dogs were classified as bleeders and 13 as non-bleeders. Thromboelastograph (TEG) tracings in bleeders were different to that of non-bleeders. Neither sex (odds ratio [OR]: 0.148, P=0.05), haematocrit (OR: 0.907, P=0.39), platelet count (OR: 0.996, P=0.65) or age (OR: 0.949, P=0.83) were predictors of the outcome. None of the variables that evaluated clot kinetics, and fibrinolysis (that is, aPTT OR: 0.781, P=0.51; PT OR: 1.337, P=0.63; TEG(R) OR: 1.269, P=0.06; TEG(K) OR: 1.696, P=0.05; TEG(LY60) OR: 1.028, P=0.81) were able to predict the bleeding episodes. Only the TEG variables that represent the fibrin cross-linking of the clot (TEG(angle) OR: 0.903, P=0.03); and the strength of the clot (TEG(MA) OR: 0.833, P=0.03) were considered predictors of the outcome.     

Thromboelastographic tracings in retired racing greyhounds and in non-greyhound dogs

BACKGROUND: 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). HYPOTHESIS: TEG parameters in Greyhounds are different from those in non-Greyhounds. ANIMALS: 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. MATERIALS AND METHODS: Recalcified citrated native TEGs were performed in both groups; data were compared using Student's, Mann-Whitney, and Pearson's statistical tests. RESULTS: 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. CONCLUSION: 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).     

Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

Fractures of the central tarsal bone in eight racing greyhounds

The case records of eight greyhounds that had undergone a surgical repair of either a type III or type IV fractured central tarsal bone were reviewed. In some cases difficulties were encountered which resulted in less than ideal fixation methods being used, but the fractures healed satisfactorily by intertarsal ankylosis and were radiographically complete after four to six months. For a successful outcome it was not necessary to preserve functional intertarsal joints by interfragmentary reconstruction and compression. The absence of dorsal slab fixation, poor dorsal screw positioning, or loss of the dorsal fragment, had no influence on the results. It took from six months to one year for the dogs to return to racing.     

Effects of racing on hematologic and serum biochemical values in greyhounds

Blood samples were collected on nonracing days from 57 racing Greyhounds at 2 weeks, 8 weeks, 13 weeks, and 16 weeks after the beginning of the racing season. Hematologic and biochemical tests were performed to detect marked changes induced by stress of racing. In general, these Greyhounds were healthy. Rhabdomyolysis was detected in one dog. In several other dogs, possible subclinical muscle injury was identified by increased serum creatine kinase activities. Mean serum Ca concentrations tended to decrease during the racing season. None of the tests was a good predictor of racing performance. Mean values for several hematologic and biochemical tests were different from those of other breeds of dogs.     

Helminth infections of British dogs: Prevalence in racing greyhounds

Examination of faeces from 572 dogs, blood samples from 270 animals, and post mortem material from 27 dogs, confirmed the view that racing greyhounds in the British Isles are heavily infected with a range of helminth parasites. Dipylidium caninum and Uncinaria stenocephala were most common. Also frequently encountered were: Toxocara canis, Toxascaris leonina and Trichuris vulpis. One dog harboured Angiostrongylus vasorum. Five of the 27 animals examined at post mortem were infected with Filaroides osleri and 5.6% of the blood samples contained unidentified microfilariae, possibly of an unknown Dipetalonema species.The infections were not evenly distributed throughout the population; variations were associated with the sex and age of the host, and the season of the year. The prevalence of ascarid and hookworm infections declined with the increasing age of the host, and more male dogs harboured patent T. canis infections than females. Seasonal variations during the 13 months of the study were noted for T. leonina and U. stenocephala; the faecal egg output peaked during the winter months, with lower values recorded in the spring and early summer.