Investigation of the effects of mTOR inhibitors rapamycin and everolimus in combination with carboplatin on canine malignant melanoma cells.

BACKGROUND: Malignant melanoma in dogs is considered to be largely resistant to conventional chemotherapy, although responses to carboplatin have been documented. Invasion and early metastasis are common features of certain melanoma subtypes that contribute to tumour progression despite aggressive local and systemic therapy. Upregulation of the PI3K/AKT/mTOR pathway has been observed in canine malignant melanoma and may represent a potential target for therapy. Rapamycin (sirolimus) and everolimus are commercially available small molecule inhibitors that target mTOR and therefore may have anticancer activity in canine melanoma. It was hypothesized that there is synergism between rapamycin or everolimus and platinum chemotherapy, and that combination drug treatment would inhibit target/downstream proteins involved in cell viability/proliferation and increase cell death in canine melanoma cells. It was further hypothesized that rapamycin or everolimus would impact metabolism by reducing glycolysis in these cells. Four canine melanoma cell lines were treated in vitro with rapamycin and everolimus as sole treatment or combined with carboplatin. Cell viability, apoptosis, target modulation, and glycolytic metabolism were evaluated by crystal violet colourimetric assay, Annexin V/PI flow cytometry, western blotting, and Seahorse bioanalyzer, respectively. RESULTS: When combined with carboplatin chemotherapy, rapamycin or everolimus treatment was overall synergistic in reducing cell viability. Carboplatin-induced apoptosis was noted at 72 h after treatment compared to the vehicle control. Levels of phosphorylated mTOR were reduced by rapamycin and everolimus in all four cell lines, but activation of the downstream protein p70S6K was not consistently reduced by treatment in two of the cell lines. Both mTOR inhibitors decreased the extracellular acidification rate of canine melanoma cells, indicating reduced cancer cell glycolytic activity. CONCLUSIONS: Inhibition of mTOR by rapalogs, such as rapamycin and everolimus combined with carboplatin chemotherapy may have activity in canine melanoma. Future mechanistic investigation is warranted, including in vivo assessment of this combination therapy.

Evaluation of treatment with a combination of mycophenolate mofetil and prednisolone in dogs with meningoencephalomyelitis of unknown etiology: a retrospective study of 86 cases (2009-2017).

BACKGROUND: Combination therapy with glucocorticoids and adjunctive immunomodulating drugs has been generally accepted as a standard treatment regimen for meningoencephalomyelitis of unknown etiology (MUE). We hypothesized that treatment with MMF as an adjunctive agent along with glucocorticoids would be effective and well-tolerated protocol in dogs with MUE. Eighty-six dogs with MUE between May 2009 and June 2017 were included (59 females and 27 males; mean age of 5.93 years; mean body weight of 3.83 kg). The medical records of dogs with MUE treated with prednisolone and MMF were retrospectively evaluated to determine the therapeutic response, survival time, and treatment-related adverse effects. RESULTS: A partial or complete response (CR) was recorded for 75 dogs. The overall median survival time from the initiation of treatment was 558 days. Dogs that showed CR with no relapse over the treatment period (from diagnosis to death) had significantly longer median survival times. A significantly higher mortality hazard ratio of 4.546 was recorded in dogs that failed to achieve CR. The interval between the onset of clinical signs and the clinical presentation was not significantly associated with CR, relapse rate, and survival time. Adverse effects included gastrointestinal upsets in 26 dogs (30.23%), sporadic infections in 17 dogs (19.77%), and pancreatitis in seven dogs (8.14%). CONCLUSIONS: The results suggest that adjunctive MMF treatment for MUE is safe and comparable to other immunosuppressive protocols. The treatment should focus on the achievement of CR and preventing relapse for successful management.

Inhibition of copper chaperones sensitizes human and canine osteosarcoma cells to carboplatin chemotherapy.

Osteosarcoma (OSA) is the most common primary bone cancer in children, adolescents and dogs. Current combination surgical and chemotherapeutic treatments have increased survival. However, in recurrent or metastatic disease settings, the prognosis significantly decreases, representing an urgent need for better second-line and novel chemotherapeutics. The current gold standard for combination chemotherapy in OSA often includes a platinum agent, for example, cisplatin or carboplatin. These platinum agents are shuttled within the cell via copper transporters. Recent interest in targeting copper transport has been directed towards antioxidant protein 1 (Atox1) and copper chaperone for superoxide dismutase 1 (CCS), with Atox1 demonstrating the ability to aggregate platinum agents, preventing them from forming DNA adducts. DC_AC50 is a small molecule inhibitor of both Atox1 and CCS. To assess the impact of targeting these pathways on chemotherapy response, two human and two canine OSA cell lines were utilized. After treatment with single agent or combination drugs, cell viability was evaluated and pharmacological synergism calculated using the combination index method. Apoptosis, cell cycle distribution, clonogenic survival and migration were also evaluated. DC_AC50 synergised with carboplatin in combination treatment of human and canine OSA cells to reduce cancer cell viability. DC_AC50-treated cells were significantly less mitotically active, as demonstrated by decreased expression of phospho-histone H3 and cell cycle analysis. DC_AC50 also potentiated carboplatin-induced apoptosis in OSA cells and decreased clonogenic survival. Finally, DC_AC50 reduced the migratory ability of OSA cells. These results justify further investigation into inhibiting intracellular copper chaperones as a means of reducing/preventing acquired chemotherapy resistance.

Evaluating the use of cytosine arabinoside for treatment for recurrent canine steroid-responsive meningitis-arteritis.

BACKGROUND: Relapses in steroid-responsive meningitis-arteritis (SRMA) are frequently observed but specific treatment protocols to address this problem are sparsely reported. Standard treatment includes prolonged administration of glucocorticoids as monotherapy or in combination with immunosuppressive drugs. The aim of this study was to assess the safety and efficacy of cytosine arabinoside (CA) in combination with glucocorticoids for treatment of SRMA relapses in 12 dogs on a retrospective basis. METHODS: Dogs with recurrent episodes of SRMA and treated with a combination of CA and prednisolone were included. Information about clinical course, treatment response and adverse events was collected from medical records. Ethical approval was not required for this study. RESULTS: Ten dogs (10/12) responded well to the treatment with clinical signs being completely controlled. One dog is in clinical remission, but still under treatment. One dog (8%) showed further relapse. Mean treatment period was 51 weeks. Adverse events of variable severity (grade 1-4/5) were documented in all dogs during treatment according to the veterinary cooperative oncology group grading. Three dogs developed severe adverse events. Laboratory findings showed marked changes up to grade 4. Diarrhoea and anaemia were the most often observed adverse events (6), followed by dermatitis (4), alopecia (3) and pneumonia (3). Including blood chemistry changes (13), 50 adverse events were found in total. CONCLUSION: Treatment with CA and glucocorticoids resulted in clinical remission in 10/12 dogs, but a high incidence of adverse events occurred requiring additional measures. All adverse events could be managed successfully in all cases.

The interaction between RUNX2 and core binding factor beta as a potential therapeutic target in canine osteosarcoma.

Osteosarcoma remains the most common primary bone tumour in dogs with half of affected dogs unable to survive 1 year beyond diagnosis. New therapeutic options are needed to improve outcomes for this disease. Recent investigations into potential therapeutic targets have focused on cell surface molecules with little clear therapeutic benefit. Transcription factors and protein interactions represent underdeveloped areas of therapeutic drug development. We have utilized allosteric inhibitors of the core binding factor transcriptional complex, comprised of core binding factor beta (CBFß) and RUNX2, in four canine osteosarcoma cell lines Active inhibitor compounds demonstrate anti-tumour activities with concentrations demonstrated to be achievable in vivo while an inactive, structural analogue has no activity. We show that CBFß inhibitors are capable of inducing apoptosis, inhibiting clonogenic cell growth, altering cell cycle progression and impeding migration and invasion in a cell line-dependent manner. These effects coincide with a reduced interaction between RUNX2 and CBFß and alterations in expression of RUNX2 target genes. We also show that addition of CBFß inhibitors to the commonly used cytotoxic chemotherapeutic drugs doxorubicin and carboplatin leads to additive and/or synergistic anti-proliferative effects in canine osteosarcoma cell lines. Taken together, we have identified the interaction between components of the core binding factor transcriptional complex, RUNX2 and CBFß, as a potential novel therapeutic target in canine osteosarcoma and provide justification for further investigations into the anti-tumour activities we describe here.

Opioid-sparing effect of a medetomidine constant rate infusion during thoraco-lumbar hemilaminectomy in dogs administered a ketamine infusion.

OBJECTIVE: To evaluate the perioperative opioid-sparing effect of a medetomidine (MED) infusion compared to a saline (SAL) infusion in otherwise healthy dogs undergoing thoraco-lumbar hemilaminectomy surgery. STUDY DESIGN: Randomized, partially blinded, clinical study. ANIMALS: A total of 44 client-owned adult dogs. METHODS: All dogs were administered a 1 µg kg-1 MED loading dose, followed by a 1.7 µg kg-1 hour-1 constant rate infusion (CRI) intravenously or equivalent volumes of SAL. Infusions were started 10-15 minutes before surgical incision and continued throughout the surgical procedure. All dogs were administered a standardized anaesthetic and analgesic protocol (including a ketamine CRI). Multiparametric monitoring, including invasive arterial blood pressure, was performed. A trained investigator, unaware of the treatment, performed pain scores for 4 hours postoperatively. Rescue analgesia consisted of fentanyl administered intraoperatively and methadone postoperatively. Data were tested for normality and analysed with Fisher's exact test, Mann-Whitney U-test, analysis of variance and Kaplan-Meier survival analysis. Data are shown as median (interquartile range) and p-value was set at < 0.05. RESULTS: The total dose of fentanyl was significantly lower with MED 0 (0-0.8) µg kg-1 hour-1 compared to SAL 3 (1.8-5.3) µg kg-1 hour-1 (p = 0.004). In the MED group, one dog compared to 12 dogs in the SAL group required a fentanyl CRI (p = 0.001). There were no statistically significant differences between groups regarding the total dose of methadone administered. CONCLUSIONS AND CLINICAL RELEVANCE: The addition of a low-dose medetomidine CRI to the anaesthetic protocol decreased the need for a fentanyl CRI in otherwise healthy dogs undergoing thoraco-lumbar hemilaminectomy surgery during administration of a ketamine CRI.

Influence of Anesthesia on Grading of Canine Hip Dysplasia.

This study aimed to evaluate the effect of anesthesia on grading of canine hip dysplasia. For this purpose, 20 middle-sized healthy dogs from different breeds were used. Radiographs were taken using 4 different imaging methods, including the hip-extended, subluxation, distraction, and compression. This procedure was repeated 4 times for each dog, while the dogs were unanesthetized and anesthetized with 3 different anesthetic protocols at 15-day intervals (propofol [5 mg/kg, IV]; diazepam [0.5 mg/kg, IV] / ketamine [20 mg/kg, IV]; medetomidine [0.05 µg/kg, IM] / ketamine [20 mg/kg, IM]). The radiographs were taken and evaluated by the same investigator to prevent interobserver variation. Because of the radiographic positioning difficulty, unanesthetized radiographic imaging revealed higher repetition number than the anesthetized; therefore, radiation safety decreased. The administration of diazepam/ketamine and medetomidine/ketamine was sufficient in terms of both muscle relaxation and duration of the anesthesia; however, some dogs under propofol anesthesia were required maintenance doses to complete radiographic imaging procedure. Unanesthetized radiographic images of the dogs had significantly lower (P < .001) hip score, distraction index (DI), subluxation index (SI), and higher compression index (CI) (P< .001), when compared with anesthetized radiographic images. When compared the anesthetic protocols, propofol revealed lower (P< 0.001) hip score, DI, SI, and higher (P < .001) CI than medetomidine/ketamine. Medetomidine/ketamine is the most appropriate anesthetic protocol for detailed radiographic evaluation of CHD considering both muscle relaxation and duration of action.

Co-induction of anaesthesia with alfaxalone and midazolam in dogs: a randomized, blinded clinical trial.

OBJECTIVE: To qualitatively assess the co-induction of anaesthesia with midazolam and alfaxalone and to determine cardiovascular or respiratory alterations compared with alfaxalone alone. STUDY DESIGN: A randomized, blinded, clinical trial. ANIMALS: A total of 29 American Society of Anesthesiologists grade I or II, client-owned dogs undergoing elective orthopaedic or soft tissue surgery. METHODS: All dogs received 0.02 mg kg-1 acepromazine and 0.3 mg kg-1 methadone intramuscularly 30 minutes prior to anaesthesia. Measurements of heart rate (HR), respiratory frequency and blood pressure (BP) were assessed pre-induction and at 0, 2 and 5 minutes post-induction. Anaesthesia was induced with 0.5 mg kg-1 alfaxalone followed by either 0.4 mg kg-1 midazolam intravenously (group M) or an equal volume of saline (group S). Conditions were assessed for intubation and further boluses of 0.25 mg kg-1 alfaxalone were given as required. Response to co-induction, ease of intubation and quality of induction were scored, and total dose of alfaxalone required for intubation was recorded. Repeated measures one-way analysis of variance with post hoc Tukey's test was used to assess within group changes over time and Student t tests were used to compare between groups. Incidence of apnoea was assessed using a Fisher's exact test. Data are shown as mean ± standard deviation. RESULTS: Group M included 14 dogs and group S 15 dogs. There was a significant difference in the total dose of alfaxalone required for intubation, 0.65 ± 0.20 mg kg-1 group M and 0.94 ± 0.26 mg kg-1 group S (p = 0.002). Apnoea occurred significantly more frequently in group M (p = 0.007). There were no clinically significant differences in HR or BP at the measured time points between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Co-induction with midazolam had significant alfaxalone-sparing effects with no clinically detectable cardiovascular changes. Apnoea is common after co-induction.

Comparative evaluation of different therapeutic protocols for contagious caprine pleuropneumonia in Himalayan Pashmina goats.

Therapeutic management of contagious caprine pleuroneumonia (CCPP) involves mostly the use of oxytetracycline followed by enrofloxacin and rarely tylosin. In many parts of the world including India, the former antibiotics are commonly available than the latter. Therefore, prolonged use of the same leads to the development of antibiotic resistance and decreased efficacy of drug. Besides, inflammatory and allergic pathogenesis of CCPP envisages combination therapy. In this study, we evaluated the effectiveness of the combination therapy using different antibiotics (oxytetracycyline @ 10: group I, enrofloxacin @ 5 group II, and tylosin: group III, @ 10 mg/kg body weight), along with anti-inflammatory (meloxicam @ 0.5 mg/kg) and anti-allergic (pheneramine maleate @ 1.0 mg/kg) drugs. These drugs were given intramuscularly at the interval of 48 h for four times in three test groups (n = 10) of Pashmina goats, viz. groups I, II, and III, respectively, affected with CCPP. Group IV (n = 10) was kept as healthy control when group V (n = 10) treated with oxytetracycline @ 10 mg/kg alone was used as positive control. Clinical signs, clinical parameters, pro-inflammatory cytokine (tumor necrosis factor alpha (TNF-α)), and oxidative stress indices (total oxidant status (TOS), total antioxidant status (TAS)) were evaluated at hours 0, 48, 96, and 144 of experimental trial. Tylosin-based combination therapy resulted in a rapid and favorable recovery resulting in restoration of normal body temperature (102.46 ± 0.31 °F), respiration rate (16.30 ± 0.79 per minute), and heart rate (89.50 ± 2.63 per minute) compared to the oxytetracycline (102.95 ± 0.13, 21.30 ± 1.12, 86.00 ± 2.33, respectively) and enrofloxacin (102.97 ± 0.19, 21.00 ± 1.25, 90.00 ± 2.58, respectively) treated groups. By hour 144, all the groups showed restoration of clinical parameters of normal health and diminishing signs of CCPP, viz. fever, dyspnea, coughing, nasal discharge, weakness, and pleurodynia. Significant (P ≤ 0.05) decrease in levels of TNF-α and non-significant (P > 0.05) decrease in levels of TOS and an increase in levels of TAS were noted from hour 0 to 144 in all the test groups. Within the groups, no significant (P > 0.05) change was noted in TNF-α, TOS, and TAS levels; however, TNF-α levels were comparatively lower in group III. Hematological parameters did not differ significantly (P > 0.05). From these findings, it can be inferred that tylosin-based combination therapy is relatively better for early, rapid, and safe recovery besides minimizing inflammatory and oxidative cascade in CCPP affected Pashmina goats compared to oxytetracycline- and enrofloxacin-based therapies.

Successful management of persistent tachycardia using esmolol in 2 dogs with septic shock.

OBJECTIVE: To describe the successful management of 2 dogs with septic shock and persistent tachycardia using norepinephrine and esmolol, a short-acting beta receptor antagonist. SERIES SUMMARY: Two cases are reviewed. In the first case, septic shock with ventricular tachycardia was diagnosed in a 4-year-old neutered female Great Dane that underwent jejunoileal resection and anastomosis for a partial mesenteric torsion. The patient's tachyarrhythmias failed to respond to lidocaine, and an esmolol infusion was used for heart rate control. The condition of the dog improved and she was discharged after 4 days of hospitalization. The second case was a 7-year-old neutered female Cavalier King Charles Spaniel with septic peritonitis. Following surgery for intestinal resection and anastomosis, supraventricular tachycardia developed that was not responsive to volume resuscitation and was treated with an esmolol infusion. The condition of the dog improved and she was discharged after 6 days of hospitalization. Both patients were doing well at the time of long-term follow-up. NEW OR UNIQUE INFORMATION PROVIDED: This case series highlights a novel method of managing dogs in septic shock with persistent tachycardia based on recently published data in the human literature. The use of esmolol may be considered in certain veterinary patients with septic shock to improve persistent tachycardia not related to hypovolemia.

Effects of Intramuscular Alfaxalone/Acepromazine on Echocardiographic, Biochemical, and Blood Gas Measurements in Healthy Cats.

The effects of intramuscular injection of alfaxalone ([ALF] 5 mg/kg), acepromazine ([ACE] 0.05 mg/kg), and an ALF-ACE combination ([AA] 0.025 mg/kg ACE followed by 2.5 mg/kg ALF) on the sedation, echocardiographic, biochemical, and blood gas indexes and recovery were evaluated in seven cats. No sedation was obtained with ACE, and sedation scores were higher with ALF than with AA treatment. Compared with baseline, an increase in heart rate occurred after ACE, and all treatments caused a decrease in systemic arterial pressure. Decreased left ventricular internal dimension in diastole, end-diastolic volume of the left ventricle, stroke volume, and left atrial dimension were identified after AA. There were minimal changes in echocardiographic variables after ALF. Biochemical and blood gas analysis showed no significant changes after all treatments. Although the difference in quality of recovery between the AA and ALF treatment groups was insignificant, all cats treated with AA or ALF showed ataxia. The AA combination did not change the recovery score, and tremor and twitching were identified more frequently with AA than ALF. ALF had no significant effects on echocardiographic, biochemical, or blood gas variables. ALF could be considered a useful sedative option for diagnostic procedures and echocardiography in cats.

Treatment of canine postoperative ocular hypertension with combined latanoprost 0.005% and atropine 1% ophthalmic solutions.

OBJECTIVE: To compare the effects of topical 0.005% latanoprost (L) vs combined 0.005% latanoprost and 1% atropine (LA) on control of postoperative ocular hypertension (POH), development of posterior synechiae formation, pupil size, and blindness after phacoemulsification surgery in dogs. ANIMAL STUDIED: Dogs with postoperative ocular hypertension were included in the study: L-group, latanoprost (eight dogs, 14 eyes) and LA-group, latanoprost and atropine (nine dogs, 15 eyes). PROCEDURES: Complete ophthalmic examinations including tonometry were performed at 1, 7, and 21 days following phacoemulsification. RESULTS: No significant differences were found between the measured intraocular pressure (IOP) at days 1 and 7 postphacoemulsification surgery in the L-group and the LA-group (P = 0.26 [14.12 ± 1.76 mmHg vs 16.96 ± 1.68 mmHg] and P = 0.71 [15.45 ± 1.43 mmHg vs 16.20 ± 1.36 mmHg], respectively). No significant differences were found between pupil sizes at day 7 for the two groups (P = 0.25 [13.83% vs 24.77%]). No significant differences were found between odds of posterior synechiae formation at day 21 (P = 0.92) with a probability ± SE for L-group vs LA-group at 0.27 ± 0.14 vs 0.25 ± 0.13. No significant differences were found in odds of postoperative blindness between groups (P = 0.58) with a probability ± SE of 0.21 ± 0.11 vs 0.13 ± 0.09, respectively for L and LA. CONCLUSIONS: Combined topical latanoprost and atropine in dogs maintains normal postoperative IOPs but does not seem to cause increased mydriasis compared to latanoprost alone.

Prognostic significance of circulating microRNA-214 and -126 in dogs with appendicular osteosarcoma receiving amputation and chemotherapy.

BACKGROUND: Dogs with appendicular osteosarcoma (OSA) receiving standard amputation and adjuvant chemotherapy demonstrate variable outcome with treatment; however, additional biomarkers would be helpful for predicting their outcome. In the present study, we assessed the potential of circulating microRNA-214 (miR-214) and - 126 (miR-126) to predict time to metastasis and death in dogs with OSA treated with amputation and chemotherapy. RESULTS: Seventy-six dogs that fully met inclusion criteria were included in the analysis. The criteria included (1) a diagnosis of appendicular OSA without metastases at diagnosis, (2) treatment by amputation and chemotherapy using carboplatin, doxorubicin, cisplatin, or a combination of these agents. Circulating miR-214 and -126 levels at the time before treatment were measured by using RT-qPCR. High circulating miR-214 and serum alkaline phosphatase (ALP) significantly predicted short disease-free survival (DFS) and overall survival (OS). Conversely, high circulating miR-126 significantly predicted prolonged DFS and OS. An integrated approach using circulating miR-214, - 126, and serum ALP showed better accuracy in the prediction of DFS and OS and identification of long-term survivors than prediction using only ALP. Other variables (age, weight, sex, monocyte counts, and primary tumor site) were associated with neither DFS nor OS. miRNA levels did not strongly correlate with histopathological indices. CONCLUSIONS: Circulating miR-214, - 126, and an integrated prognostic score have strong potential to predict the outcome of canine appendicular OSA patients receiving amputation and chemotherapy.

Effects of the potassium-sparing diuretic amiloride on chemotherapy response in canine osteosarcoma cells.

BACKGROUND: Osteosarcoma (OSA) is a common bone tumor of mesenchymal origin in dogs. Chemotherapy delays metastasis, yet most dogs die of this disease within 1 year of diagnosis. The high metabolic demand of cancer cells promotes proton pump upregulation, leading to acidification of the tumor microenvironment and chemoresistance. The potassium-sparing diuretic amiloride is among a class of proton pump inhibitors prescribed for refractory heart failure treatment in dogs. OBJECTIVE: We hypothesized that amiloride treatment improves chemotherapy response by reducing acidification in canine OSA cells. Our objective was to assess the in vitro effects of amiloride on cell viability, apoptosis, and metabolism. METHODS: In vitro study. Assessments of cell viability and apoptosis were performed after single agent or combination treatment, along with calculations of pharmacological synergism using the combination index. Protein signaling during apoptosis was evaluated by Western blotting. Metabolic profiling was performed using a Seahorse bioanalyzer. RESULTS: Amiloride strongly synergized with doxorubicin in combination treatment and exhibited additive or antagonistic effects with carboplatin in canine OSA cells. Combination treatment with doxorubicin significantly upregulated p53-mitochondrial signaling to activate apoptosis and downregulate Akt phosphorylation. Amiloride-treated cells further exhibited metabolic switching with reductions in glycolytic capacity and maximal respiration. CONCLUSION AND CLINICAL IMPORTANCE: Amiloride synergized with doxorubicin to potentiate apoptosis in canine OSA cells. These results justify further investigation into repurposing of amiloride as an oncology drug for the treatment of OSA in dogs.

Alfaxalone-Xylazine Anesthesia in Laboratory Mice (Mus musculus).

Since its recent reformulation, alfaxalone has gained popularity as an injectable veterinary anesthetic, including promising studies demonstrating the use of alfaxalone-xylazine for anesthesia in mice. Here we sought to expand these studies by testing additional dose ranges, elaborating on physiologic monitoring, testing sex- and strain-associated differences, and evaluating efficacy during actual surgical conditions. C57BL/6J mice showed significant sex-associated differences in anesthetic sensitivity, with males requiring higher doses of alfaxalone (80-120 mg/kg IP alfaxalone with 10 mg/kg IP xylazine) than females (40-80 mg/kg IP alfaxalone with 10 mg/kg IP xylazine) to achieve a surgical plane of anesthesia. In addition, female outbred CD1 mice were less sensitive to alfaxalone than female inbred C57BL/6J mice. When used during actual surgery, alfaxalone-xylazine administered intraperitoneally provided adequate anesthesia for a model of orthopedic surgery, whereas the same anesthetic regimen during laparotomy resulted in unacceptably high mortality; survival during laparotomy increased when drugs were administered subcutaneously. These results indicate that alfaxalone-xylazine may be a viable option for injectable surgical anesthesia in mice, although strain- and sex-associated differences and alternative routes of administration should be considered when optimizing the anesthetic regimen for specific experimental conditions.

Retrospective analysis of doxorubicin and prednisone as first-line therapy for canine B-cell lymphoma.

BACKGROUND: A doxorubicin (DOX)-based chemotherapy protocol, CHOP, is the most effective treatment for canine high-grade B-cell lymphoma; however, the cost and time requirements associated with this protocol are not feasible for many pet owners. An alternative treatment option is the use of DOX, the most effective drug, in combination with prednisone. Prior studies with single-agent DOX included dogs with T-cell lymphoma, a known negative prognostic factor, which may have resulted in shorter reported survival times than if dogs with B-cell lymphoma were analyzed separately. The purpose of this study was to evaluate the outcome of dogs with high-grade B-cell lymphoma when treated with DOX and prednisone with or without L-asparaginase (L-ASP). Identification of prognostic factors was of secondary interest. RESULTS: Thirty-three dogs were included in the study; 31 dogs were evaluable for response with an overall response rate of 84%. The median progression free survival (PFS) and overall survival (OS) were 147 days and 182 days, respectively. The one-year survival fraction was 23%. No variable other than protocol completion was found to be significant for either PFS or OS including historical prognostic factors such as substage, thrombocytopenia, and body weight. CONCLUSIONS: Dogs with high-grade B-cell lymphoma treated with DOX and prednisone with or without L-ASP have similar response rates, PFS, and OS to prior studies that did not differentiate between lymphoma immunophenotype. This protocol is not a replacement for CHOP; however, it is an alternative if time and cost are factors, while providing therapeutic benefit greater than prednisone alone.

Safety of topical administration of fluralaner plus moxidectin concurrently with praziquantel in cats.

BACKGROUND: Fluralaner provides efficacy against feline ectoparasites following topical administration. Moxidectin is routinely used to treat gastrointestinal nematode infections and prevent heartworm disease caused by Dirofilaria immitis. Praziquantel is routinely used to treat feline tapeworm infections. The safety of a fluralaner plus moxidectin combination topical solution (Bravecto™ Plus, MSD Animal Health) was assessed when administered concurrently with a commercially available praziquantel topical solution (Droncit™ Spot-on, Bayer Animal Health GmbH). The highest dose rates in clinical use were tested. RESULTS: Concurrent topical administration of a fluralaner plus moxidectin and a praziquantel product did not result in adverse findings. One out of ten cats receiving praziquantel only (control group), and two out of ten cats receiving fluralaner plus moxidectin and praziquantel (treatment group) had dandruff-like flakes in their coat at the application site. Two out of the ten control cats and three cats out of the ten treatment group cats had very small amounts of unidentified material (minute crusts or crumbs) at the application site which was only visible during close inspection. CONCLUSIONS: The concurrent treatment of cats with fluralaner plus moxidectin and praziquantel at the maximum dose in clinical use was well tolerated.

Comparison of the efficacy of 0. 03% tacrolimus eye drops diluted in olive oil and linseed oil for the treatment of keratoconjunctivitis sicca in dogs / Comparação do colírio tacrolimus 0, 03% em óleo de oliva e linhaça no tratamento da ceratoconjuntivite seca em cães

ABSTRACT Objective: To compare the efficacy of 0.03% tacrolimus eye drops diluted in two different vehicles (linseed oil and olive oil) for the treatment of keratoconjunctivitis sicca (KCS) in dogs. Methods: This study included 60 dogs. Of this group, 20 were healthy and allocated to the control group, and 40 were diagnosed with bilateral KCS and randomly allocated to either the TO (tacrolimus in olive oil) or the TL (tacrolimus in linseed oil) groups. Ophthalmic examinations, Schirmer Tear Test-1 (STT-1), Tear Film Break-up Time (TBUT) and Fluorescein Test (FT) were carried out monthly, along with cytological and histopathological examinations at the beginning and end of the study. Results: The clinical signs, corneal ulcers, Schirmer Tear Test-1 values, and Tear Film Break-up Time values improved in both groups after one month of treatment. Cytological examination at the end of the study showed decreased lymphocytes, neutrophil, metaplastic, and squamous cell counts in both groups, while the histopathological analysis showed decreases in lymphocytes and neutrophils and an increase in goblet cell density (cells/mm2). The decreases in neutrophil count were more significant (p<0.05) in the TL group for both types of examination. Conclusion: In sum, 0.03% tacrolimus eye drops diluted in olive oil and linseed oil were effective in the treatment of keratoconjunctivitis sicca. None of the evaluated parameters differed significantly between the two groups, except for neutrophil count which was significantly lower in the TL group. Thus, linseed oil may be considered as an alternative diluent for tacrolimus eye drops.

RESUMO Objetivo: Comparar a eficácia do tacrolimus 0,03% colírio, diluído em óleo de linhaça e óleo de oliva, no tratamento de ceratoconjuntivite seca em cães. Métodos: Foram utilizados 60 cães; 20 cães saudáveis como grupo controle, e 40 cães com diagnóstico de ceratoconjuntivite seca bilateral, distribuídos aleatoriamente em dois grupos: Tacrolimus em óleo de oliva (TO) e Tacrolimus em óleo de semente de linhaça (TL). Os animais foram avaliados mensalmente com exames oftálmicos, Teste lacrimal de Schirmer-1 (TLS-1), Tempo de ruptura do filme lacrimal (TRFL) e Teste de Fluoresceína (TF), e mensalmente com citologia conjuntival e com exame histopatológico no início e final do estudo. Resultados: Nos dois grupos de tratamento os sinais clínicos, Teste lacrimal de Schirmer-1, óleo de semente de linhaça e Tempo de ruptura do filme lacrimal apresentaram melhora após um mês de tratamento. E no final do estudo, na análise citológica, ambos apresentaram diminuição de linfócitos, neutrófilos, células metaplásicas e células escamosas, e na análise histopatológica houve diminuição de linfócitos, neutrófilos e o aumento de células caliciformes. No grupo óleo de semente de linhaça, a diminuição de neutrófilos foi mais significativa (p<0,05) em ambas análises. Conclusão: Em suma, tacrolimus 0,03% colírio diluído em óleo de oliva e óleo de linhaça foram eficientes no tratamento de ceratoconjuntivite seca. Nenhum dos parâmetros avaliados diferiu significativamente entre os dois grupos, exceto a contagem de neutrófilos, que foi significativamente menor no grupo TL. Assim, o óleo de linhaça pode ser considerado como um diluente alternativo para o colírio tacrolimus.

An Alternative Treatment Against Acanthocephala ( Prosthenorchis elegans) in Captive Squirrel Monkeys ( Saimiri sciureus) in Mexico.

We provide the first report of Acanthocephala ( Prosthenorchis elegans) in Mexican non-human primates. There has been no known treatment against this parasite except for surgical removal, and this has been relatively ineffective because of the small juveniles. We report the presence of P. elegans in a captive breeding colony of squirrel monkeys ( Saimiri sciureus) in Mexico, and we describe a successful treatment protocol. Treatment involved 2 steps: oral administration of the drugs loperamide chlorhydrate (0.5 mg/0.9 kg/3 days) and niclosamide (0.2 mg/0.9 kg/3 days) followed by surgical removal of adult worms from the intestine. Fecal examination during treatment revealed live adults but no living juveniles and no eggs. Surgery after 1 wk of treatment revealed the presence of adults and an absence of juvenile parasites. All adults were physically extracted during the surgery. All subjects recovered from surgery within 1 wk.

Comparison of the efficacy of 0.03% tacrolimus eye drops diluted in olive oil and linseed oil for the treatment of keratoconjunctivitis sicca in dogs.

OBJECTIVE: To compare the efficacy of 0.03% tacrolimus eye drops diluted in two different vehicles (linseed oil and olive oil) for the treatment of keratoconjunctivitis sicca (KCS) in dogs. METHODS: This study included 60 dogs. Of this group, 20 were healthy and allocated to the control group, and 40 were diagnosed with bilateral KCS and randomly allocated to either the TO (tacrolimus in olive oil) or the TL (tacrolimus in linseed oil) groups. Ophthalmic examinations, Schirmer Tear Test-1 (STT-1), Tear Film Break-up Time (TBUT) and Fluorescein Test (FT) were carried out monthly, along with cytological and histopathological examinations at the beginning and end of the study. RESULTS: The clinical signs, corneal ulcers, Schirmer Tear Test-1 values, and Tear Film Break-up Time values improved in both groups after one month of treatment. Cytological examination at the end of the study showed decreased lymphocytes, neutrophil, metaplastic, and squamous cell counts in both groups, while the histopathological analysis showed decreases in lymphocytes and neutrophils and an increase in goblet cell density (cells/mm2). The decreases in neutrophil count were more significant (p<0.05) in the TL group for both types of examination. CONCLUSION: In sum, 0.03% tacrolimus eye drops diluted in olive oil and linseed oil were effective in the treatment of keratoconjunctivitis sicca. None of the evaluated parameters differed significantly between the two groups, except for neutrophil count which was significantly lower in the TL group. Thus, linseed oil may be considered as an alternative diluent for tacrolimus eye drops.