Cytologic features of canine melanotroph and corticotroph pituitary adenomas.

BACKGROUND: The introduction of intraoperative cytology revolutionized neurosurgical procedures in human medicine, providing real-time diagnostic guidance to surgeons and contributing to improved patient outcomes. In the realm of veterinary medicine, the understanding of pituitary tumors in dogs and cats remains limited due to challenges in obtaining antemortem samples of central nervous system lesions. OBJECTIVES: The aim of this study was to describe the cytologic features of pituitary adenomas in 12 dogs that underwent hypophysectomy. METHODS: The series included nine melanotroph adenomas and three corticotroph adenomas. Definitive diagnosis was based on histopathology and immunohistochemistry. RESULTS: Cytologically, the adenomas had high numbers of bare nuclei and intact cells that were round to polygonal and situated individually or in small clusters. The intact cells had round to oval, eccentric nuclei with finely stippled chromatin and one to three prominent nucleoli and ample to abundant lightly basophilic to amphophilic, grainy cytoplasm with distinct borders, and variable numbers of discrete vacuoles. Mild-to-moderate anisocytosis and anisokaryosis, occasional binucleation, rare and atypical mitotic figures, and nuclear molding were also observed. CONCLUSIONS: The results suggest that intraoperative cytology of canine pituitary adenomas holds promise as a valuable diagnostic tool, aiding swift differentiation from other sellar masses before histologic confirmation. Cytologic characterization of pituitary adenomas in dogs is exceptionally rare in the scientific literature, making this study one of the first to offer a comprehensive description of these cytologic features.

Radiographic analysis of the dorsal hoof wall thickness in clinically normal draft horses.

OBJECTIVE: To evaluate the radiographic thickness of the dorsal hoof wall in normal draft horse feet. ANIMALS: 33 adult draft horses with no history of laminitis, no clinically obvious lameness, and visibly unremarkable front feet were included. METHODS: This was a prospective, descriptive study of clinically normal draft horses' front feet. Lateromedial radiographs were acquired of the front feet. A ratio of the dorsal hoof wall thickness to the length of the distal phalanx (DHWP3 ratio) was calculated. RESULTS: The dorsal hoof wall thickness to length of the distal phalanx was calculated as 0.33 ± 0.03 (range of 0.28 to 0.39) in this population of draft horses. CLINICAL RELEVANCE: With very few exceptions, the heterogeneous population of draft horses evaluated in this study had a DHWP3 ratio greater than previously published values in lighter breeds (< 0.30).

Evaluation of platelet additive solution for prolonging storage of functional canine platelet concentrate.

OBJECTIVE: To assess storage lesion development, platelet function, and bacterial growth in canine platelet concentrates (PCs) stored in a platelet additive solution (PAS) or a plasma control at 4°C for 21 days. DESIGN: Prospective, ex vivo, experimental controlled study. SETTING: University veterinary teaching hospital. ANIMALS: Ten units of canine PCs collected from blood bank donations. INTERVENTIONS: The PCs were separated into 2 bags, 1 containing 100% plasma and the other containing 35% plasma and 65% of a PAS (Plasma-Lyte A), and stored at 4°C for 21 days. At days 0, 7, 14, and 21, PCs were analyzed for the presence of swirling, aggregate formation, platelet counts, platelet indices, glucose, lactate, lactate dehydrogenase, Pvco2 , Pvo2 , aggregation via light aggregometry, activation percentages using flow cytometry, and bacterial growth. MEASUREMENTS AND MAIN RESULTS: Cold-stored PCs in both PAS and plasma control maintained mean pH >6.8 and mean lactate <9.0 mmol/L over 21 days, with no difference in glucose utilization. Swirl was maintained in both solutions for most days (76/80 combined total samples), with no difference in aggregate formation between solutions. The Pvco2 was higher in plasma on all days (P < 0.001), with no difference in Pvo2 . Platelet indices did not reflect significant storage lesion development in either solution. Lactate dehydrogenase did not differ between solutions but did increase from day 7 to day 21. Mean maximal aggregation percentage was reduced overall but with no significant difference between solutions. The only observed difference in mean activation percentage between solutions was in PAS on day 7, which was significantly higher than plasma (P < 0.05). No bacterial growth occurred during storage. CONCLUSIONS: Cold storage in PAS and plasma allowed PCs to be stored for up to 21 days with minimal storage lesion development, maintenance of platelet function, limited platelet activation, and no bacterial growth within stored bags.

Ionized calcium-to-phosphorus ratio predicts neoplasia in azotemic dogs: a retrospective study of 105 cases.

OBJECTIVE: To evaluate dogs with total hypercalcemia, azotemia, and normal serum phosphorus concentrations to determine whether a calcium-to-phosphorus ratio (Ca:P) or ionized Ca:P (iCa:P) could be utilized to predict underlying neoplasia. ANIMALS: 105 dogs were included in the study. Thirty-seven percent (n = 39) had known neoplasia, and 63% (66) had no evidence of neoplasia. PROCEDURES: A retrospective medical records search was performed. An observational cutoff of 2.5 for Ca:P and 0.33 for iCa:P was used for determining sensitivity and specificity between the neoplasia and nonneoplasia groups. RESULTS: Total hypercalcemia was higher in dogs with neoplasia compared to nonneoplastic cases of hypercalcemia. Ca:P of 2.5 had an 80% sensitivity and 46% specificity for predicting neoplasia. iCa:P of 0.33 had a 92% sensitivity and 77% specificity for predicting neoplasia in azotemic dogs. CLINICAL RELEVANCE: The sensitivity and specificity of Ca:P was low, making it an unreliable tool to predict neoplasia in this specific study population. However, iCa:P may have some usefulness in determining presence of neoplasia in patients with high calcium, azotemia, and normal phosphorus.

Clinical characteristics and outcome in 15 dogs treated with transsphenoidal hypophysectomy for nonfunctional sellar masses.

OBJECTIVE: To characterize the clinical features, neurological examination findings, diagnostic imaging results, histopathological findings, and outcome following transsphenoidal hypophysectomy (TSH) in dogs with nonfunctional sellar masses (NFSM). STUDY DESIGN: Multi-institutional retrospective study. METHODS: Medical records of dogs that underwent TSH for a NFSM were reviewed for clinical signs, physical and neurological examination findings, diagnostic imaging results, endocrine testing, surgery reports, and outcome. Magnetic resonance (MR) imaging was rereviewed, and tumors were classified using the previously described system according to pituitary tumor extension and vascular involvement. Owners of dogs that survived to discharge were contacted. RESULTS: The majority of dogs presented for mentation change (12/15). The mean pituitary to brain ratio (P/B ratio) was 1.05 (0.6-1.4). Eight dogs had a tumor imaging classification of 5B. Eleven dogs were diagnosed with a nonfunctional pituitary adenoma (NFPA). Perioperative mortality was 33% (5/15). The median survival for all dogs was 232 days (0-1658). When dogs that did not survive to discharge were excluded, the median survival time was 708 days. Seven of 10 dogs that survived the perioperative period received adjunctive therapy. Owner assessment of outcome was excellent (6/7) to good (1/7). CONCLUSION: The common presenting complaint for dogs with large NFSM causing mass effect was mentation changes. Dogs with NFPA that survived to discharge and received adjunctive therapy had good to excellent outcomes. CLINICAL SIGNIFICANCE: Transsphenoidal debulking with adjunctive therapy can be considered for the treatment of NFSM causing clinical signs of mass effect in dogs. Successful long-term outcomes are possible.

Medical errors: Experiences, attitudes and perspectives of incoming and outgoing final-year veterinary students in the USA.

BACKGROUND: Medical errors have an impact on veterinary patient safety. Studies in human medicine suggest that students can help prevent medical errors. However, there are no studies that address the role of veterinary students in patient safety. METHODS: An electronic survey was distributed to incoming final-year (IFY) and outgoing final-year (OFY) students at the Washington State University College of Veterinary Medicine. Response data were compared between class year groups with a Fisher's exact test and Mann-Whitney U test. RESULTS: The response rate was 26.8% (70/261). Most respondents (85.7%) reported being present during a medical error, and 60% reported causing a medical error. The OFY group indicated lower agreement with documenting an error in the patient record and whether all errors should be disclosed. The IFY group felt more distress surrounding potential errors and sequential career implications. Compared with the IFY group, the OFY group agreed more that errors occur frequently in veterinary medicine and disagreed more that hospital staffing is adequate to ensure patient safety. Open responses recognised a need for communication training and identified that the OFY group regarded errors more actionably, whereas the IFY group viewed errors more emotionally. CONCLUSION: Most veterinary students will experience medical errors prior to graduation, but some lack clarity around appropriate disclosure and documentation. Additional training on medical errors and error disclosure should be provided to veterinary students.

Use of a videofluoroscopic feeding evaluation to guide management of dogs with congenital idiopathic megaoesophagus.

BACKGROUND: Evidence-based guidelines for determining dietary management in dogs with megaoesophagus are lacking. OBJECTIVES: This study looked to compare oesophageal clearance times (ECT) of liquid and two food consistencies using a contrast videofluoroscopy feeding evaluation, and to assess if recommendations made based on findings could improve regurgitation and quality of life in dogs with congenital megaoesophagus. METHODS: Twenty-one dogs with congenital megaoesophagus and nine healthy dogs received liquid, slurry, and meatball diets containing barium while in an upright position. Follow-up was performed to determine response to recommendations. RESULTS: Healthy dogs had significantly shorter median ECT for all consistencies (p < 0.001). In the megaoesophagus group, ECT varied by consistency and individual. The number of dogs in the megaoesophagus group with complete clearance was four (median ECT 10 min) for liquid, five (median ECT 5 min) for slurry, and two (median ECT 5 and 30 min, respectively) for meatballs. Partial clearance was seen in 11 dogs (median clearance 25%) with liquid, seven with slurry (median clearance 50%), and five with meatballs (median clearance 60%). Recommendations included altering current medications (13/21 dogs), diet consistency (6/21), time upright (12/21), water delivery (21/21), and adding activity (7/21). Regurgitation episodes/week decreased significantly from 5.5 to 2.5 (p < 0.001) at follow-up 3-5 weeks post-evaluation, with 95% of owners reporting improvement in quality of life. Seventy percent were alive 46-777 days after last recheck. Three dogs died from megaoesophagus associated complications (median survival 461 days after diagnosis). CONCLUSIONS: The findings of this study suggest that a videofluoroscopic feeding evaluation may help guide management of dogs with congenital megaoesophagus.

A randomized crossover study of compounded liquid sildenafil for treatment of generalized megaesophagus in dogs.

OBJECTIVE: To determine whether delivery of compounded liquid sildenafil directly to the stomach of dogs with megaesophagus (ME) would affect esophageal clearance, regurgitation frequency, body weight, or quality of life. ANIMALS: 10 client-owned otherwise healthy dogs with stable ME. PROCEDURES: A randomized crossover study was performed. Dogs received either sildenafil (1 mg/kg, PO, q 12 h) or a placebo for 14 days, followed by a 7-day washout period, then the opposite treatment for 14 days. Esophageal clearance time was assessed by means of videofluoroscopy prior to treatment and on day 1 of each treatment period. Owners maintained logs of regurgitation episodes and quality of life. RESULTS: Compounded liquid sildenafil moved into the stomach during 21 of 30 (70%) videofluoroscopy sessions. Sildenafil resulted in a significant reduction in the number of regurgitation episodes (median, 3.5 episodes/wk; range, 0 to 14.5 episodes/wk), compared with baseline (median, 6.5 episodes/wk; range, 1.5 to 19.5 episodes/wk) and the placebo (median, 4 episodes/wk; range, 0 to 28 episodes/wk), and a significant increase in body weight (median, 22.05 kg; range, 6 to 26.3 kg), compared with baseline (median, 21.55 kg; range, 5.1 to 26.2 kg) and the placebo (median, 22.9 kg; range, 5.8 to 25.9 kg). There were no differences in esophageal clearance times or quality-of life-scores between sildenafil and placebo. CLINICAL RELEVANCE: Although significant differences with placebo administration were identified, clinically relevant improvements were not seen with the use of compounded liquid sildenafil in dogs with ME.

Anicteric gallbladder rupture in dogs: 5 cases (2007-2013).

OBJECTIVE: To describe clinical, laboratory, and surgical findings in dogs with confirmed gallbladder rupture and in which serum total bilirubin concentration was within reference limits. DESIGN: Retrospective case series. ANIMALS: 5 dogs. PROCEDURES: Medical records were searched to identify dogs with gallbladder rupture that underwent treatment at the Kansas State University Veterinary Health Center from November 2007 through November 2013. Dogs were included if they had undergone abdominal ultrasonography, serum total bilirubin concentration was ≤ 0.4 mg/dL, and abdominal exploratory surgery confirmed the presence of gallbladder upture. RESULTS: An exploratory celotomy was performed in all dogs because of ultrasonographic findings of mild to marked abdominal effusion and either an unidentifiable gallbladder (n = 1 dog) or a distended gallbladder with a suspected gallbladder mucocele (4 dogs). Serum total bilirubin concentration was within reference limits (median, 0.2 mg/dL; range, 0.1 to 0.4 mg/dL; reference range, 0.1 to 0.4 mg/dL) in all dogs before surgery. In 1 dog, bile acids concentrations in serum and in peritoneal fluid were compared and the results (48 µmol/L and 1,070 µmol/L, respectively) were supportive of the diagnosis of gallbladder rupture. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that even when serum total bilirubin concentration is within reference limits, gallbladder rupture should be considered in dogs with acute signs of abdominal pain when a mucocele is suspected on abdominal imaging and free abdominal fluid is present. Results suggested that a comparison of serum to peritoneal fluid bile acids concentrations may provide additional support for a diagnosis of gallbladder rupture.

Retinopathy associated with ivermectin toxicosis in five cats.

CASE DESCRIPTION: 5 cats from the same household were examined because of a sudden onset of tremors, obtundation, blindness, and dilated pupils. Approximately 12 hours prior to evaluation, the owner had attempted to treat the cats for suspected ear mite (Otodectes cynotis) infestation by aural administration of a dose of an ivermectin paste intended for oral administration to horses (approx 22 mg/cat; half of the dose was administered into each ear canal). CLINICAL FINDINGS: None of the cats had a menace response; all cats had dilated pupils and decreased pupillary light reflexes. Findings of fundic examination were unremarkable. Electroretinography was performed for 4 cats, and b-wave responses were identified as diminished. Toxicological assay results for serum samples from 2 cats confirmed the presence of ivermectin (450 and 610 µg/L). TREATMENT AND OUTCOME: All 5 cats made a complete recovery. Neurologic abnormalities resolved, electroretinographic responses improved, and vision was restored with no residual pathological changes detected during fundic examination. CLINICAL RELEVANCE: To the authors' knowledge, the information reported here provided the first description of ophthalmic and electroretinographic findings in cats with ivermectin toxicosis resulting from transdermal administration. Clinical signs, including blindness, resolved with time, without additional medical intervention.