Clinical application of reticulocyte counts in dogs and cats.

Reticulocytes are anucleate immature red blood cells that contain a network of RNA, organelles, and mitochondria, which stain with supravital dyes. Both aggregate and punctate reticulocytes are present in domestic cats, and aggregate reticulocytes are used to assess the degree of regeneration in anemic dogs and cats. Multiple factors influence the degree of regenerative response to anemia. These factors include time of reticulocyte measurement, concurrent diseases, species, and ongoing therapy. Although many automated systems for reticulocyte enumeration exist, manual counts remain the gold standard in veterinary medicine.     

Evaluation of six cytometric methods for reticulocyte enumeration and differentiation in the cat

Six protocols utilizing three fluorescent nucleic acid dyes (thiazole orange, auramine 0, and acridine orange) were evaluated by flow cytometty for clinical utility in the analysis of feline reticulocytes. The dyes showed good to poor correlations with each other and with manual counts. Thiazole orange was the preferred stain. Thiazole orange dye showed distinct peaks corresponding to aggregate and punctate reticulocytes from specimens with marked reticulocytosis. The other dyes detected increases in reticulocyte numbers but subpopulations could not be distinguished. Standardized instrument and gate settings, applied to specimens stained with thiazole orange dye, enumerated aggregate and punctate reticulowes in low celfularity specimens that lacked distinct peaks. Percentages of these cells correlated well with manual counts, offering a simplified technique for routine laboratory use.     

The value of plasma fibrinogen estimations in dogs. A comparison with total leucocyte and neutrophil counts

Plasma fibrinogen levels were measured by a simple refractometry method on 552 dog blood samples submitted from clinical cases for routine haematological examination. Sixty samples with total leucocyte and neutrophil counts within the defined normal range had elevated fibrinogen levels. The majority of these samples were from animals with a disease condition. It was concluded, because of this, and because of the simplicity of the method, that fibrinogen estimations are a worthwhile addition to the routine haematological examination of dog blood.     

Bovine paratuberculosis II. A comparison of fecal culture and the antibody response.

Fecal culture for Mycobacterium paratuberculosis and a complement fixing serological test using a carbohydrate antigen were compared for diagnostic efficiency in cattle naturally infected with M. paratuberculosis. Serological reactivity was associated with the persistent fecal shedding of large numbers of bacteria and in the absence of false positives in the population studied, was considered an efficient method for the identification of this segment of infected cattle. Minimally infected cattle, which inconsistently shed small numbers of bacteria, were generally serologically negative. One persistent fecal shedder demonstrated a fluctuating serological response to the carbohydrate antigen following abortion. The advantages and disadvantages of this serological diagnostic procedure in relationship to fecal culture are discussed.     

A comparison of five methods for assessing veld condition in the natal midlands

Abstract

Site rankings obtained from five methods of scoring veld condition in the highland sourveld and the moist tall grassveld of the Natal Midlands were correlated with rankings from methods of multivariate analysis. With few exceptions, all methods gave rankings which were strongly correlated with rankings from detrended correspondence analysis, thus indicating that they all provide a practical means of indexing the relative veld condition of sites with reasonable precision. The weighted quantitative climax and key species methods were superior to the other three methods in this respect. The key species method has the advantage of simplicity and speed, and should stimulate farmers to undertake routine monitoring of their veld in these two regions.     

A comparison of toxicity of two dosing schemes for doxorubicin in the cat

Doxorubicin is a commonly used and effective treatment for a variety of tumors in both people and cats. However, the use of this drug in cats has been associated with side effects such as renal injury, myelosuppression, anorexia, and weight loss. The goal of this study was to compare the toxicities associated with two dosing schemes for doxorubicin in tumor-bearing cats. Group A cats received 1mg/kg of doxorubicin, while group B cats received 25mg/m2 of doxorubicin plus 22ml lactated Ringer's solution per kilogram body weight subcutaneously. Toxicities were evaluated using laboratory data, physical examination, and history, and were graded using a standardized scale and compared between groups. Post-treatment neutrophil counts were significantly lower among cats in group B compared to cats in group A (P< or =0.001), although complete blood counts were not evaluated at identical intervals in all cases. No other significant differences in the type, frequency or severity of clinical or laboratory toxicities were noted between groups, and no episodes of sepsis were recognized in either group. The results of this study suggest that higher doses of doxorubicin may not be associated with an increased risk of toxicity in the cat. Additional studies are still indicated to determine optimal dosing for doxorubicin in this species.     

Cost comparison of anesthetic regimens in the dog and cat

Comparative costs of anesthetic regimens for the dog and cat were calculated. Various combinations of currently popular sedatives, tranquilizers, and anti-muscarinics (preanesthetic drugs), and anesthetic induction and maintenance drugs were studied. The preanesthetic drug affected overall anesthetic cost through its own cost, its effect on the amount of anesthetic drug necessary for intubation, and its effect on the amount of anesthetic necessary to maintain anesthesia. The combination of acetylpromazine-thiamylal-halothane was the least expensive regimen for both the dog and cat, whereas drug combinations that included isoflurane as the maintenance drug were the most expensive. In the cat, induction of anesthesia by use of N2O, O2, and halothane in a plexiglas chamber was more expensive than by the use of thiamylal.     

Bovine erythrocytic, granulocytic and macrophage colony formation in culture. A preliminary report.

Bovine erythrocytic colonies containing up to 300 cells each were produced by using a plasma clot technique with five percent CO2 at 37 degrees C. with high humidity and 2.5 units of sheep step III erythropoietin per milliliter. Erythropoietin was essential for colony formation. The number of colonies ranged from 24 to 823 per 10(5) nucleated marrow cells plated, in different animals. Some of the erythroid colonies were mixed with granulocytes. Granulocyte/macrophage colonies were produced in methyl cellulose cultures. Colonies contained up to 1000 cells and the number of colonies ranged from 13 to 981 per 10(5) nucleated marrow cells plated, from different animals. Glass adherent cells appeared to produce colony stimulating activity in culture. In both culture systems, there was a direct linear relationship between the number of nucleated marrow cells plated and the number of colonies produced.     

A comparison of survival models for assessing risk of racehorse fatality

Survival analysis was used to assess risk factors for fatal injuries on UK race courses. This allowed assessment of variation due to temporal horse-level effects, including previous racing intensity and historical distribution of race types, as well as race-level factors. Comparisons were made between measuring survival time as number of days and as number of races to injury from the first race. Two related models were presented for time as number of races to injury: a Cox regression model fitted using partial likelihood, with the Efron approximation to handling ties, and a discrete-time logit model fitted using maximum likelihood. The latter approach had the advantages of being computationally more efficient and enabling the testing of different functional forms for the dependence of hazard on time. Retrospective data were available from all race starts on the 59 courses in Britain from 1990 to the end of 1999, as analysed by . The analysis was conducted on the data for the 47,424 horses that had started racing in the UK: 538,895 starts with 1,228 fatal injuries. Horses starting racing abroad were excluded, but some included horses would have raced abroad at some stage during their racing career. The results for the selected models were broadly consistent with each other and with previously published studies. Steeplechase and hurdle races had a higher risk of fatal injury than flat races (relative hazards 1.5 and 1.7, respectively). Risk increased with the firmness of surface, age and race distance (reaching a plateau at 20 furlongs) and decreased with previous racing intensity (reaching a plateau after seven races run in the last 12 months). Horses running their first race of a new type were also found to be at higher risk (relative hazard 1.5). The main difference between the models for time as number of days and number of races concerned the role of age: age at race was identified as the more important factor in the latter model, whereas, age at first race was more significant in the former model.     

Hypervitaminosis A in a cat.

A 10-year-old cat that was kept on a diet consisting largely of raw liver was evaluated because of lethargy, partial anorexia, and weight loss of several months' duration. The cat's head and neck were rigidly extended, and a hard mass was palpable in the ventral cervical region. Cervical and thoracic radiography revealed proliferative bony lesions of the cervical and thoracic vertebrae as well as of the sternum and costal cartilages. Serum vitamin A concentration was 4 times normal. For reasons unrelated to hypervitaminosis A, euthanasia and necropsy were performed 6 months after evaluation. The skull and the cervical and first few thoracic vertebrae were rigidly fused, and the vertebral architecture was altered by deposition of new bone. The sternum and costal cartilages were similarly affected. The historical, physical, radiographic, laboratory, and postmortem findings were consistent with the diagnosis of hypervitaminosis A. On the basis of findings in this cat, hypervitaminosis A should be suspected in any sick cat fed a diet consisting partly or completely of raw liver.     

Culture and initial characterization of the secretory response of neoplastic cat mast cells.

Mast cells isolated from feline splenic mastocytomas were cultured to study their structural and functional properties. Isolated cells from various cats were grown as monolayer cultures for a mean of 56 days (range, 30 to 76 days). Cat mast cells released allergic mediators in response to compound 48/80, anti-cat serum antibodies, and concanavalin A. On the basis of the finding that secretion from cat mast cells was stimulated by anti-cat serum antibodies and concanavalin A, these cells contain surface-bound immunoglobulins. The presence of mast cell-sensitizing antibodies has been suspected in cats, but never before directly demonstrated. Cultured cat mast cells have cytochemical and functional characteristics common to connective tissue-type mast cells and provide one of the few non-rodent models of cultured cells for the study of this type of mast cell.     

A comparison of manual and electronic counting for total nucleated cell counts on synovial fluid from canine stifle joints.

Synovial fluids collected from the stifle joints of 20 physically normal adult dogs were subjected to cytological examination. A total nucleated cell count was performed on each sample using both an electronic cell counter and a hemocytometer. The mean of the total counts done with the electronic counter was significantly higher (1008 cells/microL) than that obtained manually with the hemocytometer (848 cells/microL).     

A practical approach to hemoperitoneum in the dog and cat.

Hemoperitoneum can occur in animals of any age and can result from many different disease processes. Neoplastic and traumatic conditions are the most common causes. Many of these patients present with hemodynamic instability but stabilize with rational intravenous fluid therapy and abdominal counterpressure. Surgical exploration of the abdomen is indicated in many situations. Surgical therapy is aimed at resection or control of the bleeding focus, removal of any devitalized tissue, and biopsy of additional sites of suspicion. Optimal treatment for all patients with hemoperitoneum frequently requires advanced critical care, anesthesia, and surgical techniques. Finally, the treatment outcome is variable and dependent on the underlying cause and its severity.