Evaluation of Perceived Technical Skill Development by Students During Instruction in Dental Extractions in Different Laboratory Settings-A Pilot Study.

In veterinary general practice, dental extractions are common procedures that require a specific set of surgical skills. Veterinary medical educators are tasked with preparing students for general practice, equipping them with medical knowledge and surgical skills. Results of this pilot study demonstrate students' preference for circle-based laboratory setup, a perceived high value of immediate feedback when performing laboratory exercises, and a lack of preference for timing of the laboratory relative to the relevant material provided in lecture. The impact of lecture, supplemental information, and laboratory setup on development of these surgical skills are explored.

Developing Confidence in Uncertainty: Conflicting Roles of Trainees as They Become Educators in Veterinary and Human Medicine.

The important role of medical trainees (interns and residents) as teachers is increasingly recognized in veterinary and human medicine, but often is not supported through adult learning programs or other preparatory training methods. To develop appropriate teaching programs focused on effective clinical teaching, more understanding is needed about the support required for the trainee's teaching role. Following discussion among faculty members from education and veterinary and pediatric medicine, an experienced external observer and expert in higher education observed 28 incoming and outgoing veterinary and pediatric trainees in multiple clinical teaching settings over 10 weeks. Using an interpretative approach to analyze the data, we identified five dynamics that could serve as the foundation for a new program to support clinical teaching: (1) Novice-Expert, recognizing transitions between roles; (2) Collaboration-Individuality, recognizing the power of peer learning; (3) Confidence-Uncertainty, regarding the confidence to act; (4) Role-Interdisciplinarity, recognizing the ability to maintain a discrete role and yet synthesize knowledge and cope with complexity; and (5) Socialization-Identity, taking on different selves. Trainees in veterinary and human medicine appeared to have similar needs for support in teaching and would benefit from a variety of strategies: faculty should provide written guidelines and practical teaching tips; set clear expectations; establish sustained support strategies, including contact with an impartial educator; identify physical spaces in which to discuss teaching; provide continuous feedback; and facilitate peer observation across medical and veterinary clinical environments.

Each to their own: skeletal muscles of different function use different biochemical strategies during aestivation at high temperature.

Preservation of muscle morphology depends on a continuing regulatory balance between molecules that protect and molecules that damage muscle structural integrity. Excessive disruption of the biochemical balance that favours reactive oxygen species (ROS) in disused muscles may lead to oxidative stress, which in turn is associated with increased atrophic or apoptotic signalling and/or oxidative damage to the muscle and thus muscle disuse atrophy. Increases in the rate of oxygen consumption likely increase the overall generation of ROS in vivo. Temperature-induced increases in oxygen consumption rate occur in some muscles of ectotherms undergoing prolonged muscular disuse during aestivation. In the green-striped burrowing frog, Cyclorana alboguttata, both large jumping and small non-jumping muscles undergo atrophy seemingly commensurate with their rate of oxygen consumption during aestivation. However, because the extent of atrophy in these muscles is not enhanced at higher temperatures, despite a temperature-sensitive rate of oxygen consumption in the jumping muscle, we proposed that muscles are protected by biochemical means that, when mobilised at higher temperatures, inhibit atrophy. We proposed that the biochemical response to temperature would be muscle-specific. We examined the effect of temperature on the antioxidant and heat shock protein systems and determined the extent of oxidative damage to lipids and proteins in two functionally different skeletal muscles, the gastrocnemius (jumping muscle) and the iliofibularis (non-jumping muscle), by aestivating frogs at 24 and 30°C for 6 months. We assayed small molecule antioxidant capacity, mitochondrial and cytosolic superoxide dismutase activities and Hsp70 concentrations to show that protective mechanisms in disused muscles are differentially regulated with respect to both temperature and aestivation. High aestivation temperature results in an antioxidant response in the metabolically temperature-sensitive jumping muscle. We assayed lipid peroxidation and protein oxidation to show that oxidative damage is apparent during aestivation and its pattern is muscle-specific, but unaffected by temperature. Consideration is given to how the complex responses of muscle biochemistry inform the different strategies muscles may use in regulating their oxidative environment during extended disuse and disuse at high temperature.

Influence of elevated temperature on metabolism during aestivation: implications for muscle disuse atrophy.

Reactive oxygen species (ROS), produced commensurate with aerobic metabolic rate, contribute to muscle disuse atrophy (MDA) in immobilised animals by damaging myoskeletal protein and lipids. Aestivating frogs appear to avoid MDA in part by substantially suppressing metabolic rate. However, as ectotherms, metabolic rate is sensitive to environmental temperature, and the high ambient temperatures that may be experienced by frogs during aestivation could in fact promote MDA. In this study, we investigated the effect of temperature on the metabolic rate of the aestivating frog Cyclorana alboguttata and its skeletal muscles in order to determine their likely susceptibility to MDA. Compared with non-aestivating frogs, a significant decrease in metabolic rate was recorded for aestivating frogs at 20, 24 and 30°C. At 30°C, however, the metabolic rate of aestivating frogs was significantly higher, approximately double that of frogs aestivating at 20 or 24°C, and the magnitude of the metabolic depression was significantly reduced at 30°C compared with that at 20°C. Temperature effects were also observed at the tissue level. At 24 and 30°C the metabolic rate of all muscles from aestivating frogs was significantly depressed compared with that of muscles from non-aestivating frogs. However, during aestivation at 30°C the metabolic rates of gastrocnemius, sartorius and cruralis were significantly elevated compared with those from frogs aestivating at 24°C. Our data show that the metabolism of C. alboguttata and its skeletal muscles is elevated at higher temperatures during aestivation and that the capacity of the whole animal to actively depress metabolism is impaired at 30°C.

Clinical presentation of 26 anaplasma phagocytophilum-seropositive dogs residing in an endemic area.

Anaplasma (A.) phagocytophilum, the etiological agent of canine granulocytic anaplasmosis, is capable of inciting moderate to severe clinical disease in a variety of mammals and is endemic in the upper midwest. The purpose of this study was fourfold: to describe the range of clinical signs in dogs seropositive to A. phagocytophilum; to examine the prevalence of immune-mediated hemolytic anemia (IMHA) in this population; to evaluate whether specific clinical signs were associated with coexposure to Borrelia (B.) burgdorferi in actively infected dogs; and to determine whether clinical response to doxycycline was complete in treated dogs. Medical records of dogs seropositive for A. phagocytophilum were reviewed retrospectively. Peripheral blood smears were also reviewed retrospectively for granulocytic Anaplasma morulae. Lethargy (81%), inappetence (58%), and lameness (50%) were the most common clinical signs, followed by fever (46%). Thrombocytopenia was the most common laboratory abnormality, and IMHA was diagnosed in three dogs. Dogs that were thrombocytopenic and had antibodies to both A. phagocytophilum and B. burgdorferi had a median platelet count of 51,000/µL (range 20,000 to 171,000/µL), which was significantly lower than the count in dogs with antibodies only to A. phagocytophilum (P=0.04). Some dogs had an apparent relapse of clinical signs after an appropriate course of doxycycline. Testing for A. phagocytophilum by polymerase chain reaction, serum antibody assays, and/or blood smear evaluation should be considered in dogs with IMHA, cough, or epistaxis and that reside in A. phagocytophilum-endemic areas. If moderate to severe thrombocytopenia is present, testing for concurrent B. burgdorferi infection may be warranted.

Mucoid Pseudomonas aeruginosa infection in a cat with severe chronic rhinosinusitis.

A 6-year-old male neutered Bengal cat was presented to the University of Wisconsin Veterinary Care Hospital with a history of severe chronic rhinitis that was unresolved from kittenhood. In weeks prior to presentation, the cat's upper respiratory signs had significantly worsened and a left-sided facial swelling overlying the left frontal sinus was noted. Skull computed tomography, rhinoscopy, bilateral nasal biopsies, bacterial and fungal cultures of fluid from the left frontal sinus, and cryptococcal fungal antigen testing were performed. The cat was diagnosed with severe chronic rhinosinusitis and determined to have an infection with a mucoid variant of Pseudomonas aeruginosa (P aeruginosa). This case highlights an atypical cytomorphologic appearance of the well-known bacterial pathogen, P aeruginosa, an appearance that could be confused cytologically with other microorganisms, such as septate fungi. Mucoid variants of P aeruginosa are often associated with progressive lung or airway disease in people with cystic fibrosis and have not been previously documented in feline respiratory tract disease. This report also presents a brief review of chronic rhinosinusitis (CRS) in cats and describes a novel interventional treatment approach to feline CRS via sinusotomy and sinus flushing for severely affected cats.

Histiocytic sarcoma of macrophage origin in a cat: case report with a literature review of feline histiocytic malignancies and comparison with canine hemophagocytic histiocytic sarcoma.

Mild nonregenerative anemia was detected in a 9-year-old neutered male domestic shorthair cat during a routine examination. Bone marrow core biopsy revealed erythroid hyperplasia; however, a specific cause was not identified. Over the next 8 months the anemia progressed, eventually becoming mildly regenerative, and moderate thrombocytopenia developed. On ultrasonographic examination, marked splenomegaly, mild hepatomegaly, and abdominal lymphadenopathy were found. Cytologic evaluation of splenic aspirates revealed increased numbers of mildly to moderately pleomorphic histiocytes that frequently had phagocytosed RBCs, leukocytes, and occasionally platelets. Histopathologic examination of the spleen and liver revealed effacement of splenic architecture by a histiocytic sarcoma (HS), and neoplastic histiocytes in hepatic sinusoids. A second bone marrow aspirate revealed neoplastic infiltration by similar cells. The histiocytes in all tissues were mildly to moderately pleomorphic and markedly erythrophagocytic. The immunophenotype of histiocytes in the spleen was CD1c(-)/CD11b(+)/CD18(+)/MHC-II(+), supporting a macrophage cell lineage. The clinical, pathologic, and immunophenotypic findings in this cat were similar to those in hemophagocytic HSs in dogs. To our knowledge, this is the first report of a HS of purported macrophage phenotype in a cat.

mdm2 Is critical for inhibition of p53 during lymphopoiesis and the response to ionizing irradiation.

The function of the p53 tumor suppressor protein must be highly regulated because p53 can cause cell death and prevent tumorigenesis. In cultured cells, the p90MDM2 protein blocks the transcriptional activation domain of p53 and also stimulates the degradation of p53. Here we provide the first conclusive demonstration that p90MDM2 constitutively regulates p53 activity in homeostatic tissues. Mice with a hypomorphic allele of mdm2 revealed a heretofore unknown role for mdm2 in lymphopoiesis and epithelial cell survival. Phenotypic analyses revealed that both the transcriptional activation and apoptotic functions of p53 were increased in these mice. However, the level of p53 protein was not coordinately increased, suggesting that p90MDM2 can inhibit the transcriptional activation and apoptotic functions of p53 in a manner independent of degradation. Cre-mediated deletion of mdm2 caused a greater accumulation of p53, demonstrating that p90MDM2 constitutively regulates both the activity and the level of p53 in homeostatic tissues. The observation that only a subset of tissues with activated p53 underwent apoptosis indicates that factors other than p90(MDM2) determine the physiological consequences of p53 activation. Furthermore, reduction of mdm2 in vivo resulted in radiosensitivity, highlighting the importance of mdm2 as a potential target for adjuvant cancer therapies.

Correlation of ultrasonographic appearance of lesions and cytologic and histologic diagnoses in splenic aspirates from dogs and cats: 32 cases (2002-2005).

OBJECTIVE: To determine the accuracy of cytologic diagnosis, compared with histologic diagnosis, in determination of disease in ultrasound-guided fine-needle aspirates of splenic lesions. DESIGN: Retrospective study. SAMPLE POPULATION: Splenic specimens from 29 dogs and 3 cats. PROCEDURES: Records were searched for dogs and cats that had undergone ultrasound-guided splenic aspiration. Criteria for inclusion were ultrasonographic identification of splenic lesions and cytologic and histologic evaluation of tissue from the same lesion. Cytologic samples were obtained by fine-needle aspiration, and histologic specimens were obtained via surgical biopsy, ultrasound-guided biopsy, or necropsy. RESULTS: Cytologic diagnoses corresponded with histologic diagnoses in 19 of 31 (61.3%) cases and differed in 5 of 31(16.1%) cases, and 1 aspirate was inadequate for evaluation. In 7 of 31 (22.6%) cases, histologic evaluation of tissue architecture was required to distinguish between reactive and neoplastic conditions. On the basis of histologic diagnosis in 14 animals with nonneoplastic conditions, the cytologic diagnosis was correct in 11 cases, not definitive in 2 cases, and incorrect in 1 case. In 17 animals with malignant neoplastic diseases, the cytologic diagnosis was correct in 8 cases, not definitive but consistent with possible neoplasia in 5 cases, and incorrect in 4 cases. Multiple similar-appearing nodules were significantly associated with malignancy, whereas single lesions were more often benign. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided aspiration of splenic lesions is a minimally invasive tool for obtaining specimens for cytologic evaluation. Although cytologic diagnoses often reflect histologic results, if missampling or incomplete sampling occurs or tissue architecture is required to distinguish between reactive and neoplastic conditions, accurate diagnosis with fine-needle aspiration may not be possible.

Spurious reticulocyte profiles in dogs with large form babesiosis: a retrospective study.

BACKGROUND: Erroneously high reticulocyte counts (pseudoreticulocytosis) have been reported in dogs with leukemia. Pseudoreticulocytosis and an abnormal reticulocyte profile were observed in a dog with large form babesiosis presented at our institution. OBJECTIVES: The aims of this retrospective study were to determine if dogs with babesiosis and other dogs had abnormal reticulocyte profiles, and to correlate these profiles with the primary diagnosis. METHODS: All canine CBCs obtained with the Sysmex XT-2000iV or Procyte DX were reviewed. Cases of large form babesiosis were identified and their reticulocyte dot plots were analyzed. Dogs with abnormal reticulocyte profiles but without microscopically apparent intraerythrocytic Babesia piroplasms were identified. The reticulocyte profiles and fluorescence ratios of dogs with and without babesiosis were compared. RESULTS: Twenty of 92 dogs with babesiosis had abnormal reticulocyte profiles, including 8 with a separation between the reticulocyte and mature RBC plots or a continuum of reticulocytes from the RBC plot but with a higher density of dots in the middle of the "comet tail" than in the left quarter of the dot plot. Thirteen of 6980 dogs without Babesia on the blood smear had abnormal reticulocyte profiles, including 3 with leukemia. The medium-fluorescence reticulocyte ratios tended to be higher in dogs with babesiosis and abnormal dot plots than in other dogs, whereas the high-fluorescence ratio was higher in one dog with leukemia. CONCLUSION: Abnormal reticulocyte dot plots and atypical reticulocyte fluorescence ratios may occur in dogs with babesiosis and alert clinical pathologists to consider this diagnosis.

Cutaneous mass aspirate from a Golden Retriever: "glandular guile".

A 3-year-old, neutered, male Golden Retriever was presented for evaluation of a 10 X 9 X 5 mm, firm, red, raised, cutaneous mass located over the left cranial thorax and noted incidentally by the owner. On cytologic evaluation of a fine-needle aspirate of the mass, the interpretation was a malignant tumor with predominantly mesenchymal features. Differentials included liposarcoma, atypical amelanotic melanoma, anaplastic sarcoma, and anaplastic carcinoma. Following complete excision of the mass, a diagnosis of sebaceous adenocarcinoma was made based on histologic features, positive immunostaining for pancytokeratin, and negative staining for vimentin, Melan-A, and S-100. There was no evidence of metastasis on physical examination or thoracic radiographs, and the prognosis was good. The unique and previously unreported cytologic features of this small, sebaceous adenocarcinoma were the extreme pleomorphism, including marked anisocytosis, anisokaryosis, and multinuclearity, and the paucity of epithelial features.

Using an independent quality control software program, EZ Runs, to monitor quality control procedures for a bench-top coagulation analyzer.

BACKGROUND: Comprehensive quality control (QC) procedures are necessary to ensure accurate analytic method performance. Highly automated systems typically have inherent QC programs that facilitate performance and maintenance of QC procedures; however, for bench-top analyzers that lack internal systems, independent QC programs must be used. OBJECTIVE: The goal of this study was to evaluate the adaptability of an independent QC program, EZ Runs (Westgard QC Inc, Madison, WI, USA), to the maintenance of QC procedures for a mechanical, bench-top coagulation unit and to compare the results with our current, manual, QC method in a qualitative way. METHODS: A QC application file for activated partial thromboplastin time (aPTT) performed on a STart4 (Diagnostica Stago, Parsippany, NJ) was created in EZ Runs. Results were recorded and interpreted using this software package as well as the current, manual, QC method. RESULTS: EZ Runs was adaptable to QC monitoring for the bench-top analyzer, and the program permitted identification of both random and systematic errors not detected by the manual QC system. CONCLUSIONS: EZ Runs improved the performance and maintenance of QC procedures for this bench-top coagulation analyzer. The results indicated the need to improve staff training in assay performance and QC interpretation. In addition, use of the software program indicated that a multirule QC design was needed to monitor assay performance.

The glutathione-activated thiopurine prodrugs trans-6-(2-acetylvinylthio)guanine and cis-6-(2-acetylvinylthio)purine cause less in vivo toxicity than 6-thioguanine after single- and multiple-dose regimens.

trans-6-(2-Acetylvinylthio)guanine (trans-AVTG) and cis-6-(2-acetylvinylthio)purine (cis-AVTP) are glutathione-activated prodrugs of 6-thioguanine (6-TG) and 6-mercaptopurine, respectively. In tumor cell lines, these prodrugs exhibit similar IC50 values that are comparable to or lower than those of 6-TG and 6-mercaptopurine, respectively. In this study, the in vivo toxicity and metabolism of the prodrugs were assessed. Mice given multiple treatments of 6-TG and, to a lesser extent, trans-AVTG exhibited decreased peripheral WBC and RBC counts and increased myeloid:erythroid ratios in bone marrow; no change was observed in mice given cis-AVTP. Similarly, intestinal epithelial crypt cell apoptosis was more extensive in mice treated with 6-TG than in those treated with trans-AVTG, whereas mice given cis-AVTP had little apoptosis. Epithelial crypt cell apoptosis was more extensive in the small intestine than in the large intestine in all treatment groups. Histopathological examination detected no kidney or liver toxicity, whereas mild increases in the activities of hepatocellular leakage enzymes were observed in mice treated with trans-AVTG. Only metabolites of trans-AVTG and cis-AVTP were recovered in urine. A higher fraction of the dose was recovered in urine as the parent thiopurine and the metabolites thiopurine riboside, thioxanthine, and thiouric acid after 6-TG treatment than after trans-AVTG treatment; cis-AVTP recovery was slightly less than that of 6-TG. Thioxanthine and thiouric acid comprised a higher fraction of the recovered dose after cis-AVTP treatment than after trans-AVTG or 6-TG treatment. Overall, the results suggest that the prodrugs exhibit less in vivo toxicity than 6-TG. Thus, investigations into their antitumor efficacy are warranted.

Awareness of "Predatory" Open-Access Journals among Prospective Veterinary and Medical Authors Attending Scientific Writing Workshops.

Authors face many choices when selecting a journal for publication. Prospective authors, especially trainees, may be unaware of "predatory" online journals or how to differentiate them from legitimate journals. In this study, we assessed awareness of open-access and predatory journals among prospective authors attending scientific writing workshops; our long-term goal was to inform educational goals for the workshops. We surveyed participants of writing workshops at veterinary and medical schools and an international conference over a 1-year period. The survey included 14 statements for respondents to indicate agreement level on a Likert-like scale and four questions on awareness of resources about predatory journals; respondents also defined "predatory journal." A total of 145 participants completed the survey: 106 (73.1%) from veterinary schools and 86 (59.3%) graduate students or residents. Fewer faculty (vs trainees) agreed that open access was an important factor in deciding where to publish; faculty and postdoctoral researchers were more likely to expect to pay more to publish in an open-access journal. Most respondents (120/145, 82.7%) agreed/strongly agreed that the decision to accept a manuscript should not be influenced by publication charges, but 50% (56/112) indicated that they "didn't know" how publishing costs were supported. Of the 142 respondents who answered, 33 (23.0%) indicated awareness of the term "predatory journal"; 34 (23.9%) were aware of the Directory of Open Access Journals; 24 (16.9%) were aware of the Science "sting" article about predatory journals; and 7 (4.8%) were aware of Beall's list. Most (93/144, 64.5%) definitions of predatory journals described poor but not predatory journal practices, and some respondents misunderstood the term completely. Mentors should help novice authors to be aware of predatory journals and to distinguish between legitimate and illegitimate open-access journals, thus selecting the best journal for their work.

Species and tissue differences in the toxicity of 3-butene-1,2-diol in male Sprague-Dawley rats and B6C3F1 mice.

3-Butene-1,2-diol (BDD) is a major metabolite of 1,3-butadiene (BD), but the role of BDD in BD toxicity and carcinogenicity remains unclear. In this study, the acute toxicity of BDD was investigated in male Sprague-Dawley rats and B6C3F1 mice. Of the rats given 250 mg/kg BDD, 2 out of 4 died within 24 h; rats experienced hypoglycemia, significant alterations of liver integrity tests, and had lesions in the liver 4 h after treatment, but no lesions were detected in extrahepatic tissues. Rat hepatic GSH and GSSG levels were significantly depleted at both 1 and 4 h after the BDD treatment. Rats administered 200 mg/kg BDD also had liver lesions but no death or hypoglycemia was observed four or 24 h after treatment; these rats had depleted hepatic GSH and GSSG levels at 1 h but not at 4 or 24 h after treatment. Mice administered 250 mg/kg BDD exhibited modest alterations of liver integrity tests, but no death, hypoglycemia, or lesions in any tissue, and hepatic GSH and GSSG levels were depleted at 1 h but not at 4 h. The plasma half-life of BDD was four times longer in rats than in mice. Additional studies in rats showed the depletion of hepatic GSH and GSSG preceded the BDD-induced hypoglycemia and hepatotoxicity. Thus, the long half-life of BDD in rat plasma and the sustained depletion of hepatic GSH and GSSG may in part explain the higher sensitivity of the rat to BDD-induced hepatotoxicity. Furthermore, the results indicate that BDD may play a role in BD-induced toxicity.

Effects of flunixin meglumine or etodolac treatment on mucosal recovery of equine jejunum after ischemia.

OBJECTIVE: To examine the effects of flunixin meglumine and etodolac treatment on recovery of ischemic-injured equine jejunal mucosa after 18 hours of reperfusion. ANIMALS: 24 horses. PROCEDURE: Jejunum was exposed to 2 hours of ischemia during anesthesia. Horses received saline (0.9% NaCl) solution (12 mL, i.v., q 12 h), flunixin meglumine (1.1 mg/kg, i.v., q 12 h), or etodolac (23 mg/kg, i.v., q 12 h). Tissue specimens were obtained from ischemic-injured and nonischemic jejunum immediately after ischemia and 18 hours after recovery from ischemia. Transepithelial electric resistance (TER) and transepithelial flux of tritium-labeled mannitol measured mucosal permeability. Denuded villous surface area and mean epithelial neutrophil count per mm2 were calculated. Western blot analysis for cyclooxygenase (COX)-1 and -2 was performed. Pharmacokinetics of flunixin and etodolac and eicosanoid concentrations were determined. RESULTS: Ischemic-injured tissue from horses treated with flunixin and etodolac had significantly lower TER and increased permeability to mannitol, compared with that from horses treated with saline solution. Epithelial denudation after ischemia and 18 hours after recovery was not significantly different among treatments. Both COX-1 and -2 were expressed in ischemic-injured and nonischemic tissues. Ischemia caused significant upregulation of both COX isoforms. Eicosanoid concentrations were significantly lower in tissues from flunixin and etodolac-treated horses, compared with that from horses treated with saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Flunixin and etodolac treatment retarded recovery of intestinal barrier function in jejunal mucosa after 18 hours of reperfusion, whereas tissues from horses treated with saline solution recovered baseline values of TER and permeability to mannitol.

Relationship between automated total nucleated cell count and enumeration of cells on direct smears of canine synovial fluid.

Canine osteoarthritis is a common disorder seen in veterinary clinical practice and causes considerable morbidity in dogs as they age. Synovial fluid analysis is an important tool for diagnosis and treatment of canine joint disease and obtaining a total nucleated cell count (TNCC) is particularly important. However, the low sample volumes obtained during arthrocentesis are often insufficient for performing an automated TNCC, thereby limiting diagnostic interpretation. The aim of the present study was to investigate whether estimation of TNCC in canine synovial fluid could be achieved by performing manual cell counts on direct smears of fluid. Fifty-eight synovial fluid samples, taken by arthrocentesis from 48 dogs, were included in the study. Direct smears of synovial fluid were prepared, and hyaluronidase added before cell counts were obtained using a commercial laser-based instrument. A protocol was established to count nucleated cells in a specific region of the smear, using a serpentine counting pattern; the mean number of nucleated cells per 400 × field was then calculated. There was a positive correlation between the automated TNCC and mean manual cell count, with more variability at higher TNCC. Regression analysis was performed to estimate TNCC from manual counts. By this method, 78% of the samples were correctly predicted to fall into one of three categories (within the reference interval, mildly to moderately increased, or markedly increased) relative to the automated TNCC. Intra-observer and inter-observer agreement was good to excellent. The results of the study suggest that interpretation of canine synovial fluid samples of low volume can be aided by methodical manual counting of cells on direct smears.