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Summary

Medical records of 60 thrombocytopenic dogs in which platelet volume analysis was performed between 1984 and 1993 were reviewed. Information collected from the records included signalment, mean platelet volume, the clinical pathologist's assessment of the adequacy of the megakaryocyte population in the bone marrow, and the causes of thrombocytopenia. In all dogs, the bone marrow aspirate had been collected within 48 hours of platelet volume analysis. Sensitivity and specificity of using platelet volume analysis (mean volume ≤ 12.00 μm3 vs mean volume > 12.00 μm3) as a test for bone marrow megakaryocyte response (adequate vs inadequate) in thrombocytopenic dogs was determined. Sensitivity was 88%, specificity was 80%, predictive value of a positive test was 96%, and predictive value of a negative test was 57%. Results suggested that megathrombocytosis in a thrombocytopenic dog was a good predictor of adequate bone marrow response (normal or hyperplastic bone marrow megakaryocyte population); however, a mean platelet volume ≤ 12.00 μm3 in thrombocytopenic dogs was not strongly predictive of inadequate bone marrow response.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine the RBC lifespan of Greyhounds, using an in vitro labeling technique.

Design

RBC from dogs were labeled with NHS-biotin and their disappearance measured over time to determine RBC lifespan.

Sample Population

5 Greyhounds that had been vaccinated against distemper, adenovirus 1 and 2 infections, parainfluenza, leptospirosis, parvovirus, and coronavirus infections, Bordetella bronchiseptica infection, and rabies the previous year; 3 sexually intact 14-month-old Beagles served as controls.

Procedure

After venipuncture for CBC, catheters were inserted in the cephalic vein of each dog. Butorphanol was then administered to achieve mild sedation and analgesia, and glycopyrrolate was administered to ensure maintenance of adequate heart rate during phlebotomy. Dogs were positioned in lateral recumbency; blood was removed via jugular venipuncture, using a standard laboratory donor blood bag containing citrate-phosphate-dextrose solution. Blood was transferred aseptically into sterile polystyrene containers and NHS-biotin was added. After incubation, the labeled RBC were reinfused into the dogs and the blood was allowed to recirculate for 1 hour before the first postinfusion sample was taken. At frequent intervals, blood to be analyzed was taken by jugular venipuncture, and the percentage of labeled cells was determined by flow cytometry.

Results

The mean RBC lifespan of non-Greyhounds was significantly longer than that of Greyhounds (104.3 ± 2.2 days vs 53.6 ± 6.5 days; P = 0.001). A negative linear correlation was also found between age of the Greyhounds and their RBC lifespan (P = 0.01, R2 = 0.91).

Conclusions

The shorter RBC lifespan of the Greyhounds may explain the finding of macrocytosis reported in earlier work. The reason for the shorter RBC lifespan in Greyhounds may be caused by differences in Greyhound RBC membrane structure or accelerated RBC removal from the circulation. (Am J Vet Res 1996; 57:739–742)

Free access
in American Journal of Veterinary Research

Summary

Hematologic characteristics of 36 Greyhounds were studied and compared with characteristics of 22 non-Greyhound controls. Fourteen of the Greyhounds were tested and found to be seronegative for Ehrlichia canis and Babesia canis. Compared with the non-Greyhounds, Greyhounds had higher mean hemoglobin concentration, pcv, mean corpuscular volume, and mean cellular hemoglobin, and lower mean rbc count, hemoglobin P50 value, Hill coefficient, platelet count, and total plasma protein concentration. The lower mean hemoglobin P50 value in Greyhounds suggested that the higher mean hemoglobin concentration and pcv were not solely a result of selective breeding for superior racing abilities, but that Greyhound hemoglobin may have a greater affinity for oxygen than does the hemoglobin of non-Greyhounds.

Free access
in Journal of the American Veterinary Medical Association

Summary

Changes in platelet indices (platelet count and platelet size) and pcv associated with thyroid disease were studied in 7 dogs with hypothyroidism and 21 cats with hyperthyroidism that were admitted to the veterinary teaching hospital. Compared with control (euthyroid) dogs, dogs with hypothyroidism had higher platelet count (P = 0.003), smaller platelet size (P = 0.01), and lower pcv (P = 0.02). Comparison of the group of hyperthyroid cats with a group of similarly aged, clinically normal cats with normal thyroxine values indicated that the group of hyperthyroid cats had significantly (P = 0.03) higher mean platelet size than did control cats, but differences were not found in mean platelet count or pcv. Results of this investigation indicate that the changes in platelet size reported in human beings with thyroid endocrinopathies also are found in animals so-affected. Although the pathogenesis of platelet abnormalities in animals with thyroid derangement is unclear and likely is multifactorial, the observed relation between platelet and erythrocyte production in this group of dogs is consistent with reports of an inverse relation between thrombocytopoiesis and erythropoiesis in iatrogenically hyperthyroid mice and in mice exposed to hypoxia.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To explore whether early analysis of spatial data may result in identification of variables associated with epidemic spread of foot and mouth disease.

Sample Population—37 farms with infected cattle (ie, case farms) reported within the first 6 days of the 2001 Uruguayan foot-and-mouth disease epidemic.

Procedure—A georeferenced database was created and retrospective analysis was performed on case farm location in relation to farm density, cattle density, farm type (ie, beef vs dairy cattle production), road density, case farm distance to the nearest road, farm size, farm ownership, and day of infection. Mean or median results of 1 to 3 day versus 4 to 6 day spatial data were compared. Spatial-temporal associations were investigated by correlation analysis.

Results—Comparison of mean or median values between the first 3 days and days 4 to 6 of the epidemic and results of correlation analysis indicated a significant increase in road density, cattle density, and dairy cattle production and a significant decrease in farm size and case farm distance to the nearest road that developed over time. A route that linked most case farms by the shortest possible distance and also considered significantly associated variables was created. It included 86.1% of all case farms reported by 60 days into the epidemic.

Conclusions and Clinical Relevance—Epidemic direction can be assessed on the basis of road density and other spatial variables as early as 6 days into an epidemic. Epidemic control areas may be more effectively identified if local and regional georeferenced data are considered. (Am J Vet Res 2003;64:1519–1527)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors.

ANIMALS

82 rabbits.

PROCEDURE

Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020.

RESULTS

The prevalence of liver lobe torsion was 0.7% (82/11,402). In all 82 rabbits, the diagnosis was made by means of abdominal ultrasonography. Fifty (60.1%) rabbits underwent liver lobectomy, 23 (28%) received medical treatment alone, and 9 (10.9%) were euthanized or died on presentation. Overall, 32 (39%) rabbits died within 7 days of initial presentation and 50 (61%) survived. Seven-day survival rate did not differ significantly between medical treatment alone and surgical treatment. However, median survival time following medical treatment (530 days) was shorter than that following surgical treatment (1,452 days). Six of 14 rabbits had evidence of systemic inflammatory disease on necropsy. Rabbits with right liver lobe torsion were less likely to survive for 7 days than were those with caudate torsions (P = 0.046; OR, 3.27; 95% CI, 1.04 to 11.3). Rabbits with moderate to severe anemia were less likely to survive for 7 days than were rabbits that were not anemic or had mild anemia (P = 0.006; OR, 4.41; 95% CI, 1.55 to 12.51). Other factors associated with a decreased 7-day survival rate were high heart rate at admission (P = 0.013) and additional days without defecation after admission (P < 0.001). Use of tramadol was associated with an increased survival rate (P = 0.018).

CLINICAL RELEVANCE

The prognosis for rabbits with liver lobe torsions was more guarded than previously described. Rabbits that underwent liver lobectomy had a longer median survival time than did rabbits that only received medical treatment.

Full access
in Journal of the American Veterinary Medical Association