Journal of the American Veterinary Medical Association
A breeding colony was established to investigate the inheritance of associated ocular and skeleta... more A breeding colony was established to investigate the inheritance of associated ocular and skeletal dysplasia in Labrador Retrievers; 124 pups were produced. These pups were evaluated for the presence of ocular lesions, including cataracts, vitreous strands, persistent hyaloid remnants, retinal folds, retinal dysplasia, peripapillary hyperreflectivity, and rhegmatogenous retinal detachments, and skeletal abnormality, which was recognized by shorter than normal forelimbs and an abnormal morphologic appearance of the radius and ulna. Analysis of the distribution of lesions in pups indicated that the syndrome is caused by one abnormal gene, which has recessive effects on the skeleton and incompletely dominant effects on the eye. This would suggest that suspect carrier dogs could be identified by test matings with a known homozygote.
Journal of the American Veterinary Medical Association
A young female Labrador Retriever-type dog had a 4 1/2-month history of respiratory distress, whi... more A young female Labrador Retriever-type dog had a 4 1/2-month history of respiratory distress, which eventually became severe, leading to cyanosis. Physical examination suggested an upper airway obstructive lesion, which was confirmed by bronchoscopy and radiography to be a mass in the thoracic portion of the trachea. The mass was removed surgically and, on histologic examination, was found to be an osteochondroma. Six months after surgical extirpation, there was no indication of recurrence of tumor.
Journal of the American Veterinary Medical Association
Osteochondritis dissecans of the tarsocrural joint was diagnosed in three canine siblings. The le... more Osteochondritis dissecans of the tarsocrural joint was diagnosed in three canine siblings. The lesion, unilateral in one dog and bilateral in two dogs, was on the caudomedial aspect of the trochlea of the talus. Surgical treatment resulted in marked improvement of hindlimb gait.
Journal of the American Veterinary Medical Association
The efficacy of clindamycin in the treatment of experimentally induced, posttraumatic Staphylococ... more The efficacy of clindamycin in the treatment of experimentally induced, posttraumatic Staphylococcus aureus osteomyelitis was studied in dogs. At the end of the experiment, bacteria could not be isolated from bone marrow of 15 of 16 (93.7%) dogs treated with clindamycin, whereas bacteria could not be isolated from similar specimens obtained from 6 of 13 (46.1%) untreated dogs. None of the 16 dogs treated with clindamycin had histopathologic evidence of osteomyelitis at the end of the experiment. Five of the 13 untreated control dogs had histopathologic evidence of osteomyelitis. The recovery rate was 31% in untreated dogs, whereas 94% of dogs treated with clindamycin recovered from osteomyelitis. Clindamycin, 11 mg/kg of body weight, given orally, q 12 h, for 28 days, was efficacious in the treatment of experimentally induced, posttraumatic S aureus osteomyelitis in dogs.
To determine the effect of platelet count on the accurate assessment of serum electrolyte concent... more To determine the effect of platelet count on the accurate assessment of serum electrolyte concentrations, simultaneous platelet counts and electrolyte determinations were performed on serum and plasma from 40 dogs. Dogs were grouped according to platelet count as follows: thrombocytopenic (less than 150,000/microliters), normal (150,000 to 600,000/microliters), or thrombocytotic (greater than 600,000/microliters). Serum potassium concentration was significantly higher than plasma potassium concentration in normal dogs (mean difference, 0.63 +/- 0.17 mEq/l) and in dogs with thrombocytosis (mean difference, 1.55 +/- 0.73 mEq/l). This difference in potassium concentration between serum and plasma was positively correlated with platelet count (r2 = 0.86). In the blood of dogs with thrombocytosis, the serum-plasma potassium difference was further increased when the time period between blood collection and separation of serum or plasma from cells was lengthened. Differences between serum and plasma concentrations of sodium or chloride were not seen in any platelet group. These results suggest that a portion of the measured serum potassium concentration is released from platelets during the clotting process. In fact, profound elevations in serum potassium concentrations can occur factitiously in dogs with thrombocytosis. Therefore, the actual concentration of potassium in blood is determined more accurately by measuring the plasma concentration rather than the serum concentration of this electrolyte.
To determine whether use of hemoglobin glutamer-200 (bovine) as a partial blood volume replacemen... more To determine whether use of hemoglobin glutamer-200 (bovine) as a partial blood volume replacement in dogs undergoing cemented total hip replacement caused any deleterious effects on the bone-cement or cement-prosthesis interface, exerted any deleterious effects on body organs, or caused any complications during the anesthetic, immediate recovery, or long-term recovery period. 9 adult dogs. Dogs were anesthetized, and 15% of the blood volume was removed. Simultaneously, lactated Ringer's solution was infused, and 6 dogs were given hemoglobin glutamer (1 g/kg of body weight, IV). Unilateral total hip replacement was performed. Limb use was assessed visually, and force-plate and radiographic evaluations were performed before, and 8 weeks after, surgery. Eight weeks after surgery, dogs were euthanatized, necropsies were performed, and prosthetic component pullout forces were determined. There were no significant differences between treated and control dogs in regard to biomechanical (visual assessment of gait, force-plate analysis, femoral and acetabular component pullout forces) and pathologic evaluations (physical examination, CBC, serum biochemical analyses, necropsy, and histologic evaluations). Radiographic signs of loosening of the femoral component were seen in 4 dogs treated with hemoglobin glutamer. Administration of hemoglobin glutamer as a blood substitute did not appear to have any deleterious effects in dogs undergoing total hip arthroplasty. The radiographic findings, which were discordant with the biomechanical results, merit further investigation.
Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a ... more Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200X10(9) cells/L, 23 counts increased to >200X10(9) cells/L and 34 counts increased to >100X10(9) cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.
Most automated hematology analyzers cannot detect canine or feline basophils. However, many veter... more Most automated hematology analyzers cannot detect canine or feline basophils. However, many veterinary laboratories continue to report basophils as part of the automated 5-part differential leukocyte count for dogs and cats. The study objectives were to evaluate the performance of the Sysmex XT-2000iV, Advia 2120, and CELL-DYN 3500 hematology analyzers in detecting basophils using blood from dogs, cats, and rabbits with basophilia and to investigate the concurrence of basophilia and other hematologic changes, sex, and breed in dogs. One or more of the 3 hematology analyzers was used to analyze 11 canine blood samples with prominent basophilia (≥ 5%) based on a manual differential count. In addition, samples from 2 cats and 4 rabbits with basophilia were analyzed with the Advia 2120. Leukocyte cytograms were inspected for the likely location of basophil cell clusters. In a retrospective study of canine patients, reports of hematologic results that included a manual leukocyte differential count were identified using the laboratory information system and examined for the occurrence of basophilia and other hematologic changes, sex, and breed of the dogs. Canine basophils were not detected by the Sysmex XT-2000iV or CELL-DYN 3500 analyzers, and neither canine nor feline basophils were detected by the Advia 2120. The Advia was able to detect basophils in rabbits. On the Sysmex cytogram canine basophils were found slightly above or together with neutrophils. On the Advia Perox cytogram canine basophils were located in upper part of the lymphocyte box and in the area of large unstained cells (LUC). Dogs with marked basophilia often had concurrent eosinophilia, and basophilia may be found more frequently in Rottweiler dogs than in other breeds. In 5 dogs with marked basophilia and without eosinophilia, marked thrombocytosis and anemia were noted. Canine basophils were not detected by these automated hematology analyzers, and careful analysis of instrument graphical displays or increased LUC (Advia) may guide the need to examine a blood smear for basophils.
Automated hematology instruments commonly are used for mammalian blood analysis, but there is a l... more Automated hematology instruments commonly are used for mammalian blood analysis, but there is a lack of accurate automated methods available for avian leukocyte analysis. The aim of this study was to validate differential leukocyte counts in blood from chickens using the Cell-Dyn 3500 hematology system and avian-specific software. Blood samples were collected in lithium-heparin tubes from 2 groups (n = 84 and n = 139) of laying hens. Manual 200-cell differential counts were done on routinely-stained blood smears, and manual total granulocyte counts (heterophils and eosinophils) were done using an eosinophil stain in a counting chamber. Automated differential counts were done using VET 2.3, a research and development version of avian-specific software for the Cell-Dyn 3500. Results were analyzed using Pearson's correlation and difference plots. Automated granulocyte counts from the Cell-Dyn were in good agreement with manual granulocyte counts (r = 0.93 and 0.80 for the 2 study groups). No correlation was found between automated and manual lymphocyte counts. Correlation coefficients for monocyte counts were 0.70 and 0.43. Automated leukocyte results from the Cell-Dyn using VET 2.3 software were not fully accurate. Total granulocyte counts may be of clinical usefulness, but results obtained for other parameters were unreliable.
Determination of the plateletcrit (PCT) is the most effective way to evaluate platelet mass in do... more Determination of the plateletcrit (PCT) is the most effective way to evaluate platelet mass in dogs, such as Cavalier King Charles spaniel (CKCS) dogs, with macrothrombocytopenia. The IDEXX VetAutoread hematology analyzer, which performs quantitative buffy coat (QBC) analysis, has been validated to determine platelet mass in CKCS dogs. The Advia 2120 reports a PCT, but the validity of this value has not been evaluated for dogs with macrothrombocytopenia. The goal of this study was to validate MPV and PCT determined by the Advia 2120 in dogs, including CKCS dogs, comparing values with those obtained from QBC analysis. Advia PCT was compared with QBC results from 43 CKCS dogs and 15 dogs of other breeds in one study. Advia PCT, platelet count, and MPV were evaluated to identify biologic patterns in 31 clinically healthy CKCS dogs and 66 dogs of 3 other breeds and to generate values used for comparisons. Advia PCT agreed well with QBC results in general, but had a negative bias and appeared to underestimate PCT in CKCS dogs with the lowest PCTs. Advia PCT and MPV results followed expected biologic patterns in CKCS dogs and dogs of other breeds with MPVs being highest in dogs with the lowest platelet counts. Advia 2120 PCT and MPV satisfactorily identified changes in platelet mass and size in CKCS dogs, but PCTs were lower than expected, especially in CKCS dogs with the lowest PCTs, when compared with QBC results.
A study was carried out to test the accuracy and consistency of veterinary pathologists, not spec... more A study was carried out to test the accuracy and consistency of veterinary pathologists, not specialists in hematopathology, in applying the World Health Organization (WHO) system of classification of canine lymphomas. This study represents an initiative of the ACVP Oncology Committee, and the classification has been endorsed by the World Small Animal Veterinary Association (WASVA). Tissue biopsies from cases of canine lymphoma were received from veterinary oncologists, and a study by pathologists given only signalment was carried out on 300 cases. Twenty pathologists reviewed these 300 cases with each required to choose a diagnosis from a list of 43 B and T cell lymphomas. Three of the 20 were hematopathologists who determined the consensus diagnosis for each case. The 17 who formed the test group were experienced but not specialists in hematopathology, and most were diplomates of the American or European Colleges of Veterinary Pathology. The overall accuracy of the 17 pathologists on the 300 cases was 83%. When the analysis was limited to the 6 most common diagnoses, containing 80% of all cases, accuracy rose to 87%. In a test of reproducibility enabled by reintroducing 5% of cases entered under a different identity, the overall agreement between the first and second diagnosis ranged from 40 to 87%. The statistical review included 43,000 data points for each of the 20 pathologists.
The differential leukocyte counts performed by an automated hematology analyzer, the Technicon H-... more The differential leukocyte counts performed by an automated hematology analyzer, the Technicon H-1E Hematology System, and traditional microscopic method (M-Diff) from blood samples of 129 horses, 40 cattle, and 140 cats were compared. The comparison was repeated after selected subsets of data were created by deleting samples with certain patterns suggesting error with the automated differential cell count (A-Diff). The two methods had good comparison of results for neutrophils and lymphocytes in all three species. Results for equine monocytes correlated moderately well between the two methods and the correlation improved in the selected data set Monocyte results did not compare well for the bovine and feline samples. The A-Diff for feline eosinophils was inaccurate. The A-Diff may be accurate for bovine and equine eosinophils but too few examples of eosinophilia were present in the sample set to prove this. Basophils were too rarely seen in cattle and horses to validate A-Diff accuracy, but basophilia identified by the M-Diff in a cat was not identified by the A-Diff.
Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a ... more Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200X10(9) cells/L, 23 counts increased to >200X10(9) cells/L and 34 counts increased to >100X10(9) cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.
The Sysmex XT-2000iV is a laser-based, flow cytometric hematology system that stains nucleic acid... more The Sysmex XT-2000iV is a laser-based, flow cytometric hematology system that stains nucleic acids in leukocytes with a fluorescent dye. A 4-part differential is obtained using side fluorescence light and laser side scatter. The purpose of this study was to validate the Sysmex XT-2000iV for determining differential leukocyte counts in blood from ill dogs, cats, and horses. Blood samples from diseased animals (133 dogs, 65 cats, and 73 horses) were analyzed with the Sysmex XT-2000iV (Auto-diff) and the CELL-DYN 3500. Manual differentials were obtained by counting 100 leukocytes in Wright-stained blood smears. Leukocyte populations in the Sysmex DIFF scattergram were usually well separated in equine samples, but were not as well separated in canine and feline samples. Correlation among the Sysmex XT-2000iV, CELL-DYN 3500, and manual counts was excellent for neutrophil counts (r >or=.97) and good for lymphocyte counts (r >or=.87) for all three species. Systematic differences between the 3 methods were seen for lymphocyte and monocyte counts. The Sysmex reported incomplete differential counts on 18% of feline, 13% of canine, and 3% of equine samples, often when a marked left shift (>10% bands) and/or toxic neutrophils were present. Eosinophils were readily identified in cytograms from all 3 species. Neither the Sysmex nor the CELL-DYN detected basophils in the 7 dogs and 5 cats with basophilia. The Sysmex XT-2000iV automated differential leukocyte count performed well with most samples from diseased dogs, cats, and horses. Basophils were not detected. Immature neutrophils or prominent toxic changes often induced errors in samples from cats and dogs.
Journal of the American Veterinary Medical Association
A breeding colony was established to investigate the inheritance of associated ocular and skeleta... more A breeding colony was established to investigate the inheritance of associated ocular and skeletal dysplasia in Labrador Retrievers; 124 pups were produced. These pups were evaluated for the presence of ocular lesions, including cataracts, vitreous strands, persistent hyaloid remnants, retinal folds, retinal dysplasia, peripapillary hyperreflectivity, and rhegmatogenous retinal detachments, and skeletal abnormality, which was recognized by shorter than normal forelimbs and an abnormal morphologic appearance of the radius and ulna. Analysis of the distribution of lesions in pups indicated that the syndrome is caused by one abnormal gene, which has recessive effects on the skeleton and incompletely dominant effects on the eye. This would suggest that suspect carrier dogs could be identified by test matings with a known homozygote.
Journal of the American Veterinary Medical Association
A young female Labrador Retriever-type dog had a 4 1/2-month history of respiratory distress, whi... more A young female Labrador Retriever-type dog had a 4 1/2-month history of respiratory distress, which eventually became severe, leading to cyanosis. Physical examination suggested an upper airway obstructive lesion, which was confirmed by bronchoscopy and radiography to be a mass in the thoracic portion of the trachea. The mass was removed surgically and, on histologic examination, was found to be an osteochondroma. Six months after surgical extirpation, there was no indication of recurrence of tumor.
Journal of the American Veterinary Medical Association
Osteochondritis dissecans of the tarsocrural joint was diagnosed in three canine siblings. The le... more Osteochondritis dissecans of the tarsocrural joint was diagnosed in three canine siblings. The lesion, unilateral in one dog and bilateral in two dogs, was on the caudomedial aspect of the trochlea of the talus. Surgical treatment resulted in marked improvement of hindlimb gait.
Journal of the American Veterinary Medical Association
The efficacy of clindamycin in the treatment of experimentally induced, posttraumatic Staphylococ... more The efficacy of clindamycin in the treatment of experimentally induced, posttraumatic Staphylococcus aureus osteomyelitis was studied in dogs. At the end of the experiment, bacteria could not be isolated from bone marrow of 15 of 16 (93.7%) dogs treated with clindamycin, whereas bacteria could not be isolated from similar specimens obtained from 6 of 13 (46.1%) untreated dogs. None of the 16 dogs treated with clindamycin had histopathologic evidence of osteomyelitis at the end of the experiment. Five of the 13 untreated control dogs had histopathologic evidence of osteomyelitis. The recovery rate was 31% in untreated dogs, whereas 94% of dogs treated with clindamycin recovered from osteomyelitis. Clindamycin, 11 mg/kg of body weight, given orally, q 12 h, for 28 days, was efficacious in the treatment of experimentally induced, posttraumatic S aureus osteomyelitis in dogs.
To determine the effect of platelet count on the accurate assessment of serum electrolyte concent... more To determine the effect of platelet count on the accurate assessment of serum electrolyte concentrations, simultaneous platelet counts and electrolyte determinations were performed on serum and plasma from 40 dogs. Dogs were grouped according to platelet count as follows: thrombocytopenic (less than 150,000/microliters), normal (150,000 to 600,000/microliters), or thrombocytotic (greater than 600,000/microliters). Serum potassium concentration was significantly higher than plasma potassium concentration in normal dogs (mean difference, 0.63 +/- 0.17 mEq/l) and in dogs with thrombocytosis (mean difference, 1.55 +/- 0.73 mEq/l). This difference in potassium concentration between serum and plasma was positively correlated with platelet count (r2 = 0.86). In the blood of dogs with thrombocytosis, the serum-plasma potassium difference was further increased when the time period between blood collection and separation of serum or plasma from cells was lengthened. Differences between serum and plasma concentrations of sodium or chloride were not seen in any platelet group. These results suggest that a portion of the measured serum potassium concentration is released from platelets during the clotting process. In fact, profound elevations in serum potassium concentrations can occur factitiously in dogs with thrombocytosis. Therefore, the actual concentration of potassium in blood is determined more accurately by measuring the plasma concentration rather than the serum concentration of this electrolyte.
To determine whether use of hemoglobin glutamer-200 (bovine) as a partial blood volume replacemen... more To determine whether use of hemoglobin glutamer-200 (bovine) as a partial blood volume replacement in dogs undergoing cemented total hip replacement caused any deleterious effects on the bone-cement or cement-prosthesis interface, exerted any deleterious effects on body organs, or caused any complications during the anesthetic, immediate recovery, or long-term recovery period. 9 adult dogs. Dogs were anesthetized, and 15% of the blood volume was removed. Simultaneously, lactated Ringer's solution was infused, and 6 dogs were given hemoglobin glutamer (1 g/kg of body weight, IV). Unilateral total hip replacement was performed. Limb use was assessed visually, and force-plate and radiographic evaluations were performed before, and 8 weeks after, surgery. Eight weeks after surgery, dogs were euthanatized, necropsies were performed, and prosthetic component pullout forces were determined. There were no significant differences between treated and control dogs in regard to biomechanical (visual assessment of gait, force-plate analysis, femoral and acetabular component pullout forces) and pathologic evaluations (physical examination, CBC, serum biochemical analyses, necropsy, and histologic evaluations). Radiographic signs of loosening of the femoral component were seen in 4 dogs treated with hemoglobin glutamer. Administration of hemoglobin glutamer as a blood substitute did not appear to have any deleterious effects in dogs undergoing total hip arthroplasty. The radiographic findings, which were discordant with the biomechanical results, merit further investigation.
Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a ... more Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200X10(9) cells/L, 23 counts increased to >200X10(9) cells/L and 34 counts increased to >100X10(9) cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.
Most automated hematology analyzers cannot detect canine or feline basophils. However, many veter... more Most automated hematology analyzers cannot detect canine or feline basophils. However, many veterinary laboratories continue to report basophils as part of the automated 5-part differential leukocyte count for dogs and cats. The study objectives were to evaluate the performance of the Sysmex XT-2000iV, Advia 2120, and CELL-DYN 3500 hematology analyzers in detecting basophils using blood from dogs, cats, and rabbits with basophilia and to investigate the concurrence of basophilia and other hematologic changes, sex, and breed in dogs. One or more of the 3 hematology analyzers was used to analyze 11 canine blood samples with prominent basophilia (≥ 5%) based on a manual differential count. In addition, samples from 2 cats and 4 rabbits with basophilia were analyzed with the Advia 2120. Leukocyte cytograms were inspected for the likely location of basophil cell clusters. In a retrospective study of canine patients, reports of hematologic results that included a manual leukocyte differential count were identified using the laboratory information system and examined for the occurrence of basophilia and other hematologic changes, sex, and breed of the dogs. Canine basophils were not detected by the Sysmex XT-2000iV or CELL-DYN 3500 analyzers, and neither canine nor feline basophils were detected by the Advia 2120. The Advia was able to detect basophils in rabbits. On the Sysmex cytogram canine basophils were found slightly above or together with neutrophils. On the Advia Perox cytogram canine basophils were located in upper part of the lymphocyte box and in the area of large unstained cells (LUC). Dogs with marked basophilia often had concurrent eosinophilia, and basophilia may be found more frequently in Rottweiler dogs than in other breeds. In 5 dogs with marked basophilia and without eosinophilia, marked thrombocytosis and anemia were noted. Canine basophils were not detected by these automated hematology analyzers, and careful analysis of instrument graphical displays or increased LUC (Advia) may guide the need to examine a blood smear for basophils.
Automated hematology instruments commonly are used for mammalian blood analysis, but there is a l... more Automated hematology instruments commonly are used for mammalian blood analysis, but there is a lack of accurate automated methods available for avian leukocyte analysis. The aim of this study was to validate differential leukocyte counts in blood from chickens using the Cell-Dyn 3500 hematology system and avian-specific software. Blood samples were collected in lithium-heparin tubes from 2 groups (n = 84 and n = 139) of laying hens. Manual 200-cell differential counts were done on routinely-stained blood smears, and manual total granulocyte counts (heterophils and eosinophils) were done using an eosinophil stain in a counting chamber. Automated differential counts were done using VET 2.3, a research and development version of avian-specific software for the Cell-Dyn 3500. Results were analyzed using Pearson's correlation and difference plots. Automated granulocyte counts from the Cell-Dyn were in good agreement with manual granulocyte counts (r = 0.93 and 0.80 for the 2 study groups). No correlation was found between automated and manual lymphocyte counts. Correlation coefficients for monocyte counts were 0.70 and 0.43. Automated leukocyte results from the Cell-Dyn using VET 2.3 software were not fully accurate. Total granulocyte counts may be of clinical usefulness, but results obtained for other parameters were unreliable.
Determination of the plateletcrit (PCT) is the most effective way to evaluate platelet mass in do... more Determination of the plateletcrit (PCT) is the most effective way to evaluate platelet mass in dogs, such as Cavalier King Charles spaniel (CKCS) dogs, with macrothrombocytopenia. The IDEXX VetAutoread hematology analyzer, which performs quantitative buffy coat (QBC) analysis, has been validated to determine platelet mass in CKCS dogs. The Advia 2120 reports a PCT, but the validity of this value has not been evaluated for dogs with macrothrombocytopenia. The goal of this study was to validate MPV and PCT determined by the Advia 2120 in dogs, including CKCS dogs, comparing values with those obtained from QBC analysis. Advia PCT was compared with QBC results from 43 CKCS dogs and 15 dogs of other breeds in one study. Advia PCT, platelet count, and MPV were evaluated to identify biologic patterns in 31 clinically healthy CKCS dogs and 66 dogs of 3 other breeds and to generate values used for comparisons. Advia PCT agreed well with QBC results in general, but had a negative bias and appeared to underestimate PCT in CKCS dogs with the lowest PCTs. Advia PCT and MPV results followed expected biologic patterns in CKCS dogs and dogs of other breeds with MPVs being highest in dogs with the lowest platelet counts. Advia 2120 PCT and MPV satisfactorily identified changes in platelet mass and size in CKCS dogs, but PCTs were lower than expected, especially in CKCS dogs with the lowest PCTs, when compared with QBC results.
A study was carried out to test the accuracy and consistency of veterinary pathologists, not spec... more A study was carried out to test the accuracy and consistency of veterinary pathologists, not specialists in hematopathology, in applying the World Health Organization (WHO) system of classification of canine lymphomas. This study represents an initiative of the ACVP Oncology Committee, and the classification has been endorsed by the World Small Animal Veterinary Association (WASVA). Tissue biopsies from cases of canine lymphoma were received from veterinary oncologists, and a study by pathologists given only signalment was carried out on 300 cases. Twenty pathologists reviewed these 300 cases with each required to choose a diagnosis from a list of 43 B and T cell lymphomas. Three of the 20 were hematopathologists who determined the consensus diagnosis for each case. The 17 who formed the test group were experienced but not specialists in hematopathology, and most were diplomates of the American or European Colleges of Veterinary Pathology. The overall accuracy of the 17 pathologists on the 300 cases was 83%. When the analysis was limited to the 6 most common diagnoses, containing 80% of all cases, accuracy rose to 87%. In a test of reproducibility enabled by reintroducing 5% of cases entered under a different identity, the overall agreement between the first and second diagnosis ranged from 40 to 87%. The statistical review included 43,000 data points for each of the 20 pathologists.
The differential leukocyte counts performed by an automated hematology analyzer, the Technicon H-... more The differential leukocyte counts performed by an automated hematology analyzer, the Technicon H-1E Hematology System, and traditional microscopic method (M-Diff) from blood samples of 129 horses, 40 cattle, and 140 cats were compared. The comparison was repeated after selected subsets of data were created by deleting samples with certain patterns suggesting error with the automated differential cell count (A-Diff). The two methods had good comparison of results for neutrophils and lymphocytes in all three species. Results for equine monocytes correlated moderately well between the two methods and the correlation improved in the selected data set Monocyte results did not compare well for the bovine and feline samples. The A-Diff for feline eosinophils was inaccurate. The A-Diff may be accurate for bovine and equine eosinophils but too few examples of eosinophilia were present in the sample set to prove this. Basophils were too rarely seen in cattle and horses to validate A-Diff accuracy, but basophilia identified by the M-Diff in a cat was not identified by the A-Diff.
Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a ... more Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200X10(9) cells/L, 23 counts increased to >200X10(9) cells/L and 34 counts increased to >100X10(9) cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.
The Sysmex XT-2000iV is a laser-based, flow cytometric hematology system that stains nucleic acid... more The Sysmex XT-2000iV is a laser-based, flow cytometric hematology system that stains nucleic acids in leukocytes with a fluorescent dye. A 4-part differential is obtained using side fluorescence light and laser side scatter. The purpose of this study was to validate the Sysmex XT-2000iV for determining differential leukocyte counts in blood from ill dogs, cats, and horses. Blood samples from diseased animals (133 dogs, 65 cats, and 73 horses) were analyzed with the Sysmex XT-2000iV (Auto-diff) and the CELL-DYN 3500. Manual differentials were obtained by counting 100 leukocytes in Wright-stained blood smears. Leukocyte populations in the Sysmex DIFF scattergram were usually well separated in equine samples, but were not as well separated in canine and feline samples. Correlation among the Sysmex XT-2000iV, CELL-DYN 3500, and manual counts was excellent for neutrophil counts (r >or=.97) and good for lymphocyte counts (r >or=.87) for all three species. Systematic differences between the 3 methods were seen for lymphocyte and monocyte counts. The Sysmex reported incomplete differential counts on 18% of feline, 13% of canine, and 3% of equine samples, often when a marked left shift (>10% bands) and/or toxic neutrophils were present. Eosinophils were readily identified in cytograms from all 3 species. Neither the Sysmex nor the CELL-DYN detected basophils in the 7 dogs and 5 cats with basophilia. The Sysmex XT-2000iV automated differential leukocyte count performed well with most samples from diseased dogs, cats, and horses. Basophils were not detected. Immature neutrophils or prominent toxic changes often induced errors in samples from cats and dogs.
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