Effect of the interval between feeding and drug administration on oral ampicillin absorption in dogs

Eight dogs of various breeds received single oral doses of 20 mg/kg bodyweight ampicillin at four different time intervals relative to feeding a meal. In treatment A the dogs were fasted for 12 hours before and after ampicillin administration. In treatment B the dogs received ampicillin immediately after, in treatment C one hour before and in treatment D two hours after the meal. Each dog received these treatments during a period of feeding dry and canned dog food according to an 8 × 8 Latin square design. Blood samples were taken at specified time intervals after drug administration by jugular venepuncture. Antibiotic concentrations in plasma were determined by microbiological assay. Non-compartmental pharmacokinetic parameters were calculated from the individual concentration-time curves and were compared by non-parametric statistic tests between treatments and types of food. With both dry and canned food ampicillin absorption was impaired when the drug and food were given at the same time (treatment B) as compared to the absorption in fasting dogs (treatment A and C). On dry food, drug absorption was also decreased in treatment D. It is recommended for clinical purposes to give ampicillin to fasted dogs, and to wait at least one hour before feeding. After a meal (dry food) waiting two hours until drug administration is not sufficient to avoid impaired ampicillin absorption.     

A prospective, randomized comparison of Oxyglobin (HB-200) and packed red blood cell transfusion for canine babesiosis

Objective – To establish the efficacy of Oxyglobin (HB-200) in canine babesiosis and compare it to standard therapy, packed red blood cell transfusion (pRBCT) with respect to improvements in specific parameters of blood gas, acid-base, blood pressure, and subjective evaluations.
Design – Prospective, randomized, clinical trial.
Setting – Onderstepoort Veterinary Academic Hospital.
Animals – Twelve dogs (8–25 kg) naturally infected with Babesia rossi and a hematocrit of 0.1–0.2 L/L (10–20%).
Interventions – Treatment groups were randomized to receive either 20 mL/kg of Oxyglobin or pRBCT over 4 hours via a central venous catheter. Transfusions were followed by lactated Ringer's solution infusion. Rectal temperature, femoral arterial and mixed venous blood sampling, oscillometric blood pressure, and subjective assessment of patient status (habitus), and appetite were performed at time points 0, 1, 4, 8, 24, 48, and 72 hours.
Main Results – Dogs presented with a hypoalbuminemic alkalosis; hyperchloremic, dilutional acidosis; normotensive tachycardia; pyrexia; depression; and anorexia. Both treatments produced similar results, with the exception of significant differences in pH (4 h); PCO₂ (4 h); hemoglobin (8 h, 24 h); mean arterial pressure (48 h); albumin (4 h, 8 h); habitus (8 h, 48 h); and appetite (24 h). Arterial O₂ content was higher for pRBCT than Oxyglobin at 72 hours, but central venous PO₂ did not differ between groups or over time and was consistently subnormal.
Conclusions – Oxyglobin provides similar overall improvements to pRBCT in dogs with anemia from babesiosis, with respect to blood gas, acid-base and blood pressure, although patients receiving packed cells tended to have more rapid normalization of habitus and appetite.     

The effect of Hetastarch (670/0.75) in vivo on platelet closure time in the dog

Objective – To evaluate the effect of 6% hydroxyethyl starch (HES) solution in vivo, with an average molecular weight of 670 kDa and degree of substitution of 0.75, on canine platelet function.
Design – Prospective, controlled-experimental study.
Setting – University of California, Davis, Veterinary Medical Teaching Hospital.
Animals – Seven healthy employee-owned dogs.
Interventions – Seven dogs were included in the treatment group. Four of these dogs also served as the control group. Platelet closure time (CT) was measured using a platelet function analyzer and collagen/ADP cartridges. Dogs were given 20 mL/kg of either sodium chloride 0.9% (control group, n =4) or HES (treatment group, n =7) IV over 1 hour. CT was measured before the infusion, and at 1, 3, 5, and 24 hours after the start of the infusion.
Measurements and Main Results – There was a significant change over time from 0 to 24 hours ( P <0.001), a significant difference between groups across time ( P <0.001), and a significant group-by-time interaction ( P =0.007). At 3 hours, mean CT for the treatment group was 122.3±18.1 seconds, which was significantly different ( P <0.001) from the control group (71.0±3.5 s). At 5 hours, mean CT for the treatment group was 142.7±33.9 seconds, which was significantly different ( P =0.001) from the control group (75.0±8.6 s). Mean CT at 24 hours was within the reference interval for both the control and treatment group (66.0±2.9 and 81.8±11.9 s, respectively); however, CT in 3 individual dogs in the treatment group at this time point remained prolonged.
Conclusions – A clinically relevant dose of HES 670/0.75 prolongs CT in dogs for up to 24 hours. This may be due to platelet dysfunction in addition to the effects of hemodilution, and therefore, may increase the risk of bleeding.     

Preliminary studies on the effectiveness of the novel pulicide, spinosad, for the treatment and control of fleas on dogs

Spinosad is a novel mode-of-action insecticide produced from a family of natural products derived from fermentation of the actinomycete, Saccharopolyspora spinosa. Separate studies were undertaken to determine the minimum effective dose of spinosad given orally for the treatment of experimentally induced flea infestations (Ctenocephalides felis) on dogs, and to assess any potential impacts of feeding canned or dry food at the time of dosing. Both were randomized block (blocked by gender and pre-treatment flea counts), blinded parallel-arm studies, with dogs selected on health and ability to maintain pre-treatment flea populations. For dose selection, 48 dogs were allocated among six groups (8 dogs/group; 4 males, 4 females): placebo-treated negative control, spinosad in gelatin capsules at 15, 20, 30 and 40 mg/kg administered per os; and topical imidacloprid (10 mg/kg) as a positive control. Placebo and spinosad treatments were administered on Days 0, 30 and 60, imidacloprid only on Day 0. In a second study to assess the impact of food type at the time of dosing, three groups were formed: placebo-treated control (8 dogs; 4 males, 4 females), spinosad (30 mg/kg) administered with canned food (8 male dogs, 8 females); and spinosad (30 mg/kg) with dry food (8 males, 8 females). Treatments were administered on Days 0 and 30. To assess post-treatment persistent efficacy, flea infestations were repeated at regular post-treatment intervals, beginning on Day 5 through Day 89 in the dose selection study and Day 58 in the impact of food type and dosing study. Flea counts were performed 48 h post-infestation by study personnel who were blinded to treatments. In the dose selection study, compared to geometric mean live flea counts in the control group, each spinosad dose was highly effective (99.8–100%) at 7, 14 and 21 days after treatment. Only the 30 and 40 mg/kg doses maintained high efficacy (97.2–100%) until 30 days after treatment, with no difference between the two. Imidacloprid was highly effective at Day 30, with significant difference only from the 15 mg/kg spinosad group. Because there was no significant difference between the higher spinosad rates, 30 mg/kg was selected as the optimal minimum effective dose. In the second study, spinosad was highly effective at all post-treatment flea counts (98–100%). Taken together, these studies demonstrate that repeated monthly oral treatments with spinosad at 30 mg/kg provide sustained control of C. felis on dogs. There were no treatment-related adverse events in either study, indicating that spinosad has potential to be used monthly as a safe and effective flea adulticide, providing sustained activity that matches that of currently used topical products.     

The Effects of Active Peripheral Skin Warming on Perioperative Hypothermia in Dogs

Objective — This study evaluates the efficacy of three perioperative warming protocols to improve control of body temperature in anesthetized dogs.
Study Design — A randomized controlled clinical trial.
Animals or Sample Population — Thirty-two client-owned dogs.
Methods — We prospectively studied dogs entering the University of Pennsylvania Veterinary Teaching Hospital for orthopedic or dental procedures and assigned them to one of three perianes-thetic warming protocols. Group 1 (n = 10) had a single circulating warm water mattress applied over the trunk (single-trunk warming). Group 2 (n = 12) had two circulating warm water mattresses, one placed over and one under the trunk (double-trunk warming). Group 3 (n = 10) had warm circulating mattresses applied only around the feet and legs of all available limbs (peripheral warming). The warm water mattresses were prewarmed and maintained at 40°C (104°F) and applied immediately after induction of general anesthesia. All dogs had a layer of thick terry cloth toweling beneath and above the trunk. Body temperature measurements were recorded every 15 minutes for the first 2.5 hours of anesthesia.
Results — The lowest mean temperature for dogs in group 3 was 37.4 ± 0.2°C (99.5°F), compared with 36.4 ± 0.2°C (97.4°F) and 36.7 ± 0.2°C (98.0°F) in groups 1 and 2, respectively.
Conclusions — Dogs in the peripheral warming group maintained significantly higher core body temperatures than dogs in either trunk warming groups throughout the 2.5-hour study period.
Clinical Relevance — To maintain body heat in dogs during anesthesia, it is more effective to warm the feet and legs than to warm the trunk.     

Atipamezole changes the antinociceptive effects of butorphanol after medetomidine–ketamine anaesthesia in rats

Objective  To investigate the effects of atipamezole administered before butorphanol, on tail-flick latency (TFL) and also following medetomidine–ketamine anaesthesia in rats.
Study design  Prospective, randomized experimental study.
Animals  Thirty-four adult male Sprague–Dawley rats weighing 260–390 g.
Methods  TFL in 50 °C water was used to measure antinociception. In the first experiment, rats received saline ( n  = 5) or atipamezole ( n  = 5) followed by butorphanol treatments. In the second experiment, three groups of rats received saline ( n  = 8), atipamezole ( n  = 8) or atimpamezole ( n  = 8) followed by butorphanol 60 minutes after medetomidine–ketamine administration.
Results  In the first experiment, butorphanol significantly increased TFL compared to baseline. Atipamezole significantly decreased this effect. In the second experiment, TFL was significantly increased after recovery from medetomidine–ketamine anaesthesia compared to baseline. This was almost completely blocked by atipamezole. Atipamezole with butorphanol after recovery from the anaesthesia significantly reduced TFL compared to saline but still significantly increased TFL compared to the baseline.
Conclusion and clinical relevance  Atipamezole attenuated the analgesic effects of butorphanol. When postoperative atipamezole is used to hasten recovery from anaesthesia in rats, it may interfere with the postoperative analgesic effect of butorphanol.     

The effect of omeprazole on oesophageal pH in dogs during anaesthesia

O bjectives : Intra-operative, gastro-oesophageal reflux may be associated with post-anaesthestic complications such as oesophagitis and oesophageal stricture in dogs. The aim of this study was to investigate the effect of preoperative administration of omeprazole, a proton pump inhibitor, on oesophageal pH in anaesthetised dogs.
M ethods : Forty-seven dogs undergoing elective pelvic limb orthopaedic surgery were enrolled into the study. These were randomly allocated to treatment group (n=22) or control group (n=25). The treatment group received one dose of omeprazole (1 mg/kg po) at least 4 h before anaesthesia. All dogs were anaesthetised by the same standardised protocol. A pH probe was inserted into the distal oesophagus after induction of anaesthesia and oesophageal pH was continuously monitored.
R esults : In the treatment group, four animals (18 per cent) showed a sudden decrease in oesophageal pH (<4). In the control group the same phenomenon was detected in 13 animals (52 per cent). Gastro-oesophageal reflux occurred more frequently in the control group compared with the omeprazole group (odds ratio 4·7, 95 per cent C.I. 1.1 to 24.7, P=0.032).
C linical S ignificance : This study suggests that the preoperative administration of omeprazole is effective in reducing the incidence of gastro-oesophageal reflux during anaesthesia in dogs.     

Activated coagulation times in normal cats and dogs using MAX-ACTTM tubes

Objective  To establish reference values for activated coagulation time (ACT) in normal cats and dogs, by visual assessment of clot formation using the MAX-ACT^TM tube.
Subjects  We recruited 43 cats and 50 dogs for the study; 11 cats and 4 dogs were excluded from the statistical analysis because of abnormalities on clinical examination or laboratory testing including anaemia, prolonged prothrombin time (PT) or activated partial thromboplastin time (APTT), or insufficient plasma volume for comprehensive laboratory coagulation testing.
Procedure  Blood samples were collected via direct venipuncture for MAX-ACT, packed cell volume/total solids, manual platelet estimation and PT/APTT measurement. Blood (0.5 mL) was mixed gently in the MAX-ACT tube at 37°C for 30 s, then assessed for clot formation every 5 to 10 s by tipping the tube gently on its side and monitoring for magnet movement. The endpoint was defined as the magnet lodging in the clot. The technique was tested with 10 dogs by collecting two blood samples from the same needle insertion and running a MAX-ACT on each simultaneously.
Results  In normal cats the mean MAX-ACT was 66 s (range 55–85 s). In normal dogs the mean was 71 s (range 55–80 s). There was no statistical difference between the first and second samples collected from the same needle insertion.
Conclusions and Clinical Relevance  In both cats and dogs, a MAX-ACT result >85 s should be considered abnormal and further coagulation testing should be performed. Additionally, failure to discard the first few drops of the sample does not appear to significantly affect results.     

Fluticasone Propionate Aerosol is More Effective for Prevention than Treatment of Recurrent Airway Obstruction

Background: Efficacy of inhaled fluticasone propionate (FP) for management of recurrent airway obstruction (RAO) has only been evaluated after several weeks' treatment.
Objectives: To compare efficacy of (1) 3-day treatments with FP to dexamethasone (DEX) for management of RAO; and (2) FP and DEX to no treatment in prevention of acute RAO exacerbations.
Animals: Nine RAO affected horses.
Methods: Crossover studies in RAO-affected horses compared (a) 3-day treatment of RAO exacerbation with FP (3 and 6 mg q12h) and DEX (0.1 mg/kg q24h) and (b) FP (6 mg q12h) and DEX (0.1 mg/kg q24h) to no treatment for prevention of acute exacerbations of RAO. Treatment efficacy and unwanted effects were judged from maximal change in pleural pressure (ΔPpl_max), serum cortisol (COR), bronchoalveolar lavage (BAL) cytology, and subjective scores for respiratory distress and lameness.
Results: In treatment trial, DEX and FP (6 mg) significantly decreased ΔPpl_max by 48 and 72 hours, respectively; FP (3 mg) had no significant effect. DEX decreased COR more than did FP. In prevention trial, both DEX and FP (6 mg) prevented the increase in ΔPpl_max that occurred in untreated horses. Both treatments decreased COR to the same degree. FP and DEX had no effects on bronchoalveolar lavage fluid (BALF) cytology and there was no evidence of laminitis.
Conclusions and Clinical Importance: FP (6 mg q12h) is as effective as DEX for prevention of acute exacerbations of RAO and lower doses should be evaluated. High-dose FP is not as effective as DEX for treatment of RAO exacerbations.     

Effect of Preoperative Erythromycin or Dexamethasone/Vitamin C on Postoperative Abomasal Emptying Rate in Dairy Cows Undergoing Surgical Correction of Abomasal Volvulus

Objective— To determine the effects of preoperative erythromycin or combined dexamethasone/vitamin C treatment on postoperative abomasal emptying rate in cows undergoing surgical correction of abomasal volvulus (AV).
Study Design— Prospective, controlled, clinical study using a convenience sample.
Animals— Lactating Holstein–Friesian cows (n=45) with AV were alternately assigned to 3 groups (n=15): group C: untreated (control); group E: erythromycin (10 mg/kg intramuscularly [IM]); group D: dexamethasone (0.02 mg/kg intravenously [IV]) and vitamin C (10 mg/kg IV).
Methods— Drugs were administered 1 hour before surgical correction of AV. d -xylose solution (50%, 0.5 g/kg body weight) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum d -xylose concentration were periodically obtained. Time to maximal serum d -xylose concentration (T_max-model) was pharmacokinetically determined.
Results— Abomasal emptying rate was significantly ( P <0.05) faster in group E (T_max-model=182±69 min; mean±SD) than in group C cows (T_max-model=237±64 min). Abomasal emptying rate was similar in group D (T_max-model=196±47 min) and group C. Both treatments improved postoperative milk yield within 1 day after surgery.
Conclusion— Preoperative injection of erythromycin (10 mg/kg IM) is an effective method for ameliorating postoperative abomasal hypomotility in cows with AV.
Clinical Relevance— Parenteral erythromycin can be recommended for preoperative treatment of cows with AV.     

Prothrombotic and Inflammatory Effects of Intravenous Administration of Human Immunoglobulin G in Dogs

Background: Intravenous administration of human immunoglobulin G (hIVIgG) has been suggested to potentiate thromboembolism in dogs, but supportive scientific reports are lacking.
Objectives: To determine if hIVIgG therapy promotes hypercoagulability and inflammation in dogs.
Animals: Twelve healthy Beagle dogs.
Methods: Prospective, experimental trial. An hIVIgG/saline solution was infused IV at 1 g/kg BW over 8 hours to 6 dogs, and physiological saline was infused to the other 6 dogs. Blood samples were drawn before, during, and after infusion for serial measurement of indicators of coagulation and inflammation. Data were analyzed by 2-way repeated measures analysis of variance.
Results: Dogs administered hIVIgG developed mildly decreased blood platelet concentrations without thrombocytopenia (median, 200 × 10³/μL; range, 150–302 × 10³/μL; P < .01), leukopenia (median, 3.5 × 10³/μL; range, 20–62 × 10³/μL; P < .001), and mildly increased plasma total protein concentrations (median, 6.3 g/dL; range, 5.6–6.7 g/dL; P < .001). Administration of hIVIgG was also associated with increases in fibrin/fibrinogen degradation products in all dogs (either 5 μg/mL or 10 μg/dL), thrombin-antithrombin III complexes (median, 7.2 ng/mL; range, 4.9–14.2 ng/mL; P < .001), and C-reactive protein concentrations (median, 2.5 mg/dL; range, 0.5–4.3 mg/dL; P < .01).
Conclusion and Clinical Importance: Administration of hIVIgG to dogs promotes hypercoagulability and an inflammatory state. This should be further evaluated and considered when using hIVIgG in dogs with IMHA or other prothrombotic conditions.     

Effects of Prednisone on Blood Lactate Concentrations in Healthy Dogs

Background: Glucocorticoids affect carbohydrate and lactate metabolism.
Hypothesis: Administration of prednisone to healthy dogs will result in clinically relevant hyperlactatemia.
Animals: Twelve healthy adult Beagle dogs.
Methods: Prospective, controlled experimental study. Twelve healthy adult Beagles were divided into 2 groups (3 of each sex per group). One group served as control. The other group received 2 treatments: low, 1 mg/kg prednisone PO q24h for 2 weeks; high, 4 mg/kg prednisone PO q24h for 2 weeks. A washout period of 6 weeks separated the treatments. Blood samples were drawn for whole blood lactate measurement on day (D) 0, D4, and D14 and measured in duplicate.
Results: Compared with the control group, low and high groups had significantly higher blood lactate concentrations at D4 and D14. There was no difference at D0. There was no effect of time within the control group. In the low and high groups, blood lactate concentration was increased at D4 and D14 versus D0. Blood lactate concentration was greater in the high group than the low group at D14 only.
Conclusions and Clinical Importance: Dogs treated with prednisone experience statistically significant increases in blood lactate concentrations, which can result in type B hyperlactatemia. In such cases, improving tissue perfusion, treatment for the commonest form of hyperlactatemia (type A) would be unnecessary.     

Hepatic Volume Measurements in Dogs with Extrahepatic Congenital Portosystemic Shunts before and after Surgical Attenuation

Background: In dogs with congenital portosystemic shunts (CPSS), the ability of the hypoplastic liver to grow is considered important for recovery after surgical shunt attenuation.
Objectives: This study investigated hepatic growth after extrahepatic shunt attenuation in dogs using magnetic resonance imaging (MRI) and computed tomography (CT).
Animals: Ten client-owned dogs with single extrahepatic CPSS.
Methods: Abdominal MRI, CT, or both were performed before and 8 days, 1, and 2 months after shunt attenuation. Liver volumes were calculated from the areas of the MRI or CT images.
Results: Before surgery, median liver volume was 18.2 cm³/kg body weight. Liver volume increased significantly after surgery. Growth was highest between days 0 and 8 and decreased afterward. Median liver volume was 28.8 cm³/kg at 2 months after attenuation. No significant differences in growth were found between dogs with complete or partial shunt closure or between dogs with complete or incomplete metabolic recovery. Volumes measured from consecutively performed MRI and CT images correlated well ( r = 0.980), but volumes from MRI images were significantly larger than volumes from CT images (6.8%; P = .008).
Conclusion and Clinical Importance: After shunt attenuation, rapid normalization of liver size was observed. Hepatic growth was not decreased in dogs after partial closure of CPSS or in dogs with subclinical, persistent shunting 2 months after surgery. CT is the preferred imaging method for volumetric estimation because of speed.     

Efficacy of open patch-grafting under cardiopulmonary bypass for pulmonic stenosis in small dogs

Objective   To assess the efficacy of an open patch-graft technique under cardiopulmonary bypass (CPB) in small dogs.
Design and methods   A retrospective analysis of 10 dogs with pulmonic stenosis. Records between 1992 and 2002 were reviewed. The effect of surgical correction was evaluated and perioperative parameters were compared between survivors and non-survivors.
Results   The postoperative pulmonary pressure gradient was reduced in all seven surviving patients. Mean ± SE was 21.5 ± 7.4 mmHg (range 3.0–54.2 mmHg) and 6/7 dogs were < 40 mmHg at 3 months postoperatively. Comparing the data between those patients that survived and those that did not, the preoperative pressure gradient (P = 0.04) and volume of the Glucose-Insulin-Kalium solution used (P = 0.001) were significantly higher in those that did not survive.
Conclusion   Open patch-grafting can be performed in small-breed dogs and decreased the pulmonary pressure gradient in survivors at 3 months postoperatively. However, this technique is more invasive than balloon valvuloplasty and should be used cautiously in severely stenosed patients.     

Gastric hemorrhage in dogs given high doses of methylprednisolone sodium succinate.

OBJECTIVE: To determine whether healthy dogs given high doses of methylprednisolone sodium succinate (MPSS) develop gastrointestinal tract ulcers and hemorrhage. ANIMALS: 19 healthy male hound-type dogs. PROCEDURE: Dogs were assigned randomly to intravenously receive high doses of MPSS (30 mg/kg of body weight, initially, then 15 mg/kg 2 and 6 hours later, and, subsequently, every 6 hours for a total of 48 hours; n = 10) or an equal volume of saline (0.9% NaCl) solution (9). Gastroduodenoscopy was performed before and after treatment. Endoscopic evidence of gross hemorrhage in the cardia, fundus, antrum, and duodenum of each dog was graded from none (0) to severe (3), and a total stomach score was calculated as the sum of the regional gastric scores. Number of ulcers were recorded. The pH of gastric fluid and evidence of occult gastric and fecal blood were measured. Food retention was recorded. RESULTS: Gastric hemorrhage was evident in all dogs after MPSS administration and was severe in 9 of 10 dogs but not visible in any dog after saline treatment. Occult gastric blood was detected more commonly (9/10 vs 2/9), median gastric acidity was greater (pH 1 vs pH 3), and food was retained more commonly (7/10 vs 1/9) in the stomach of MPSS-treated dogs. CONCLUSIONS AND CLINICAL RELEVANCE: High doses of MPSS cause gastric hemorrhage in dogs. All dogs treated with high doses of MPSS should be treated with mucosal protectants or antacids to prevent gastric hemorrhage.     

Efficacy of C/B‐OPP rescue for the treatment of relapsed canine lymphoma (1998–2004)

Introduction:  MOPP chemotherapy is useful for relapsed canine lymphoma. This study evaluates the efficacy of this protocol after substitution of CCNU (lomustine) or BiCNU (carmustine) for mechlorethamine (C/B‐OPP).
Methods:  Patient signalment, response to chemotherapy, toxicity and survival data were abstracted from medical records of dogs from receiving C/B‐OPP between 1998 and 2004.
Results:  Fifty‐eight dogs received C/B‐OPP rescue chemotherapy during the study period. The median remission duration after initial chemotherapy, consisting of CHOP‐based therapy in 91% of dogs, was 133 days (range, 10 to 932 days). Thirty‐eight of fifty‐eight dogs (66%) responded to C/B‐OPP rescue after relapse (22 CR, 16 PR), for a median of 48 days (range, 2 to 359 days). Overall, C/B‐OPP extended survival by a median of 90 days (range, 2 to 426 days). Twenty‐four dogs (41%) experienced one or more episodes of Grade II or higher gastrointestinal toxicity. Forty‐one dogs (71%) experienced one or more episodes of Grade II or higher hematologic toxicity. Twelve dogs (20%) developed regenerative anemia with diarrhea consistent with gastrointestinal hemorrhage. Treatment delays due to hematologic toxicity occurred in 37 dogs (63%). There were 16 nonfatal treatment‐related episodes of sepsis requiring hospitalization. 5 dogs died due to sepsis and/or chemotherapy‐related complications.
Conclusions:  C/B‐OPP chemotherapy has activity against relapsed canine lymphoma which is similar to that of traditional MOPP rescue therapy. Moderate to severe hematologic toxicity was observed. Further work is warranted to optimize drug doses and scheduling.     

Coagulation effects of low molecular weight heparin compared with heparin in dogs considered to be at risk for clinically significant venous thrombosis

Objective – Compare the effects of 3 anticoagulation protocols on anti-factor Xa activity (AXa).
Design – Prospective, randomized, double-blind study.
Setting – University veterinary teaching hospital.
Animals – Eighteen dogs considered to be at risk for venous thrombosis.
Interventions – Each dog was randomly assigned to 1 of the following 3 groups ( n =6/group) and was treated for 24 hours: low-dose heparin (LDH), high-dose heparin (HDH), and dalteparin (DP). Dogs in the LDH group received a constant rate infusion (CRI) of unfractionated heparin (UFH) at 300 U/kg/d, the HDH group received a bolus of 100 U/kg of UFH IV, then a CRI of 900 U/kg/day, and the DP group received 100 U/kg DP SC at 0, 12, and 24 hours.
Measurements and Main Results – A total of 54 samples for activated partial thromboplastin time (aPTT) and AXa assays were collected at 0, 4, and 28 hours. Six samples had an AXa >0.1 U/mL, 5 of those were from the HDH group at hour 4. Two samples from the HDH group at hour 4 had a prolonged aPTT (93 and 200 seconds) and the highest AXa (0.6 and 1.0 U/mL, respectively). Four additional dogs in the HDH group did not complete the study due to hemorrhage; none of the dogs completing the study showed signs of hemorrhage.
Conclusions: Neither DP nor LDH increased AXa to values considered therapeutic in humans (0.5–1 and 0.35–0.75 U/mL, respectively), and both protocols appear to be inadequate to increase AXa in dogs with clinical illness. HDH increased AXa to this range in 2 of 6 dogs, but had unpredictable effects on aPTT and resulted in hemorrhage in some dogs.     

Combined Gemcitabine and Carboplatin Therapy for Carcinomas in Dogs

Background: Response and adverse reactions to combined gemcitabine (GEM) and carboplatin (CARBO) therapy in dogs with carcinomas are not documented.
Hypothesis: GEM and CARBO are safe for the treatment of dogs with carcinomas.
Animals: Thirty-seven dogs with histologically or cytologically confirmed carcinomas.
Methods: Prospective clinical trial. Dogs were treated with GEM (2 mg/kg, 20–30-minute infusion IV) on Days 1 and 8 and 4 hours later, CARBO (10 mg/kg IV) on Day 1. The cycle was repeated on Day 22.
Results: Thirty-seven dogs (29 with measurable tumor) received a median of 2 cycles (range 0.5–6) for a total of 101 cycles administered. Twelve dogs (32%) developed neutropenia (3 Grade 3, and 5 Grade 4) and 9 (24%) thrombocytopenia (2 Grade 3, and 1 Grade 4). Dogs >20 kg were twice as likely to develop thrombocytopenia ( P = .023). Twenty-seven dogs (73%) had evidence of gastrointestinal (GI) toxicosis, but most signs were of mild to moderate severity and self-limiting. One dog died of treatment-related complications. Overall tumor response rate was 13%. One dog with metastatic prostatic carcinoma achieved a complete remission and 1 dog with intestinal adenocarcinoma and 1 with tonsillar squamous cell carcinoma achieved partial remission. Twelve dogs achieved stable disease for a median of 72 days.
Conclusion and Clinical Importance: GEM and CARBO combination causes mild to moderate hematologic and GI toxicosis in dogs with carcinoma. Response rate in this study was modest, and optimization of dosing of this combination is required.     

In vitro validation of a Pitot-based flow meter for the measurement of respiratory volume and flow in large animal anaesthesia

Objective  To remodel and validate commercially available monitors and their Pitot tube-based flow sensors for use in large animals, using in vitro techniques.
Study design  Prospective, in vitro experiment.
Methods  Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied.
Results  Both the original and the remodelled sensor showed similar static flow–pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between −0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 ± 0.2, range 5.91–6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity.
Conclusion  The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia.
Clinical relevance  This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia.