Evaluation of low-molecular-weight heparin for the prevention of equine laminitis after colic surgery

Objectives – The aim of this study is to describe the prevalence of postoperative laminitis in colic cases and to determine if low-molecular-weight heparin (LMWH) is effective in preventing this complication.
Design – Retrospective clinical study.
Animals – Client-owned horses.
Interventions – SC administration of enoxaparin during the postoperative period.
Measurements and Main Results – Medical records of 360 horses undergoing surgery for colic and surviving at least 3 days were evaluated. Fifty-six horses admitted before 1995 did not receive LMWH (control group) and 304 admitted after 1995 received LMWH as a prophylaxis for laminitis (treatment group). Three grades of severity were defined for laminitis. Prevalence and severity of laminitis were compared between the 2 groups. Several parameters recorded on admission (sex, age, breed, site and nature of the disease, heart rate, PCV, gravity score, and shock score) and the administration of LMWH were tested as risk factors in the development of laminitis in a logistic regression procedure. Prevalence and grade of laminitis were significantly lower in the treatment group. Only the absence of LMWH was recognized as a significant risk factor in the logistic regression model.
Conclusions – The administration of LMWH appears to be effective in the prophylaxis of laminitis following colic surgery and may be useful in the postoperative management of these horses.     

Pulmonary thromboembolism

Objective – To review the pathophysiology, clinical signs, diagnosis, and treatment of pulmonary thromboembolism (PTE) in small animals. Data Sources – Human and veterinary clinical studies, reviews, texts, and recent research in canine and feline PTE diagnosis and thromboembolic therapeutics. Human Data Synthesis – In humans, clinical probability assessment and point‐of‐care D‐dimer‐based algorithms are widely used. Computed tomography pulmonary angiography is the gold standard for PTE diagnosis in humans. Echocardiography is increasingly used for bedside assessment of affected patients. In low‐risk human patients anticoagulants alone are recommended while patients with cardiogenic shock are treated with thrombolytics followed by anticoagulation. Veterinary Data Synthesis – PTE is associated with numerous predisposing conditions causing hypercoagulability, blood flow stasis, or endothelial injury. Identifying at‐risk patients is key to diagnosis in small animals. Thromboelastography provides a method for identifying hypercoagulable patients. Computed tomography pulmonary angiography may replace selective pulmonary angiography as the imaging technique of choice for PTE diagnosis. PTE therapy consists of supportive treatment combined with appropriate, individualized thromboembolic pharmacotherapy for acute treatment and chronic management. Thrombolytic therapy for PTE remains controversial but may be indicated in hemodynamically unstable acute PTE. Thromboprophylaxis in specific conditions is rational although evidence of efficacy is limited. Prognosis depends upon degree of cardiopulmonary compromise and patient response to therapy. Mortality rates in small animals are unknown. Conclusions – New diagnostic techniques and advances in therapy offer significant potential for improvements in the identification and treatment of PTE in small animals. Further study must be directed to validating new diagnostic modalities and evaluating therapeutic regimes.     

Characteristics and outcomes in surgical management of severe acute pancreatitis: 37 dogs (2001–2007)

Objective – Describe clinical characteristics and outcomes associated with canine patients undergoing surgical intervention for treatment of acute pancreatitis.
Design – Retrospective outcome study from 2001 to 2007.
Animals – Thirty-seven dogs.
Interventions – None.
Measurements and Main Results – The following data were collected for dogs who underwent surgical intervention in the course of treatment for severe acute pancreatitis: preoperative clinicopathologic and physical data, ultrasonographic findings, surgical procedure detail, histopathologic findings, and transfusion requirements. The survival rate was 80.8% in dogs with extrahepatic biliary obstruction, 64.3% in dogs undergoing necrosectomy, and 40.6% with pancreatic abscess. Overall survival was 63.6%. Surgical complications included intraoperative and postoperative hemorrhage in 12 dogs, postoperative development of diabetes mellitus in 3 dogs, exocrine pancreatic insufficiency in 1 dog, and bacterial peritonitis in 2 dogs.
Conclusion – Surgical intervention and aggressive postoperative care may be pursued in select dogs with severe acute pancreatitis. In dogs with extrahepatic biliary obstruction secondary to acute pancreatitis, surgical intervention may be associated with a good prognosis whereas dogs with pancreatic abscess formation may have a more guarded prognosis.     

Disseminated candidiasis secondary to fungal and bacterial peritonitis in a young dog

Objective – To describe a severe case of bacterial sepsis and disseminated candidiasis in a previously healthy dog.
Case Summary – Fungal sepsis was identified in a 2-year-old dog following intestinal dehiscence 4 days after abdominal surgery. Septic peritonitis was identified at admission and evidence of dehiscence at the previous enterotomy site was found during an exploratory laparotomy. Both gram-positive cocci and Candida albicans were cultured from the abdominal cavity. Candida sp. was also subsequently cultured from a central venous catheter. Euthanasia was performed due to failure to respond to therapy. Fungal organisms, morphologically consistent with Candida spp., were found in the lungs and kidney on postmortem histopathologic examination indicating disseminated candidiasis.
New or Unique Information Provided – Candida peritonitis is a well-recognized entity in humans and contributes to morbidity and mortality in critically ill patients. Abdominal surgery, intestinal perforation, presence of central venous catheters, and administration of broad-spectrum antibiotics are all considered to be suspected risk factors. This report describes the first known case of systemic candidiasis occurring secondary to Candida peritonitis and bacterial sepsis in a critically ill dog.     

The effect of volatile anaesthetics on the relative sensitivity of facial and distal thoracic limb muscles to vecuronium in dogs

ObjectiveTo compare n. facialis-m. nasolabialis (nF-mNL) and n. ulnar-mm. carpi flexorii (nU-mCF) sensitivity to vecuronium during halothane or isoflurane anaesthesia.Study designRandomized, prospective, experimental study.AnimalsForty-four client-owned dogs (19 male, 25 female) undergoing surgery; mean age: 5.0 years; mean body mass: 24.7 kg.MethodsThirty minutes after acepromazine (0.05 mg kg^?1) and morphine (0.5 mg kg^?1), anaesthesia was induced with intravenous (IV) thiopental and maintained with either halothane (n = 22) or isoflurane (randomly allocated) in oxygen. The lungs were mechanically ventilated and end-tidal inhaled anaesthetic (Fe’_IAA) maintained at 1.2 × MAC values. Neuromuscular transmission at nF-uNL and nU-mCF was monitored using the train of four count. Vecuronium (50 μg kg^?1 IV) was injected (t = 0) after 15 trains, 50-60 minutes after inhalational anaesthesia began, when Fe’_IAA had been constant for >15 minutes. Times of the disappearance (-) and reappearance (+) of the fourth (T4) and first twitch (T1) were recorded allowing the calculation of: latent (t = 0 to T4-) and manifest onset times (t = 0 to T1-) duration of blockade (T1- to T1+) and drug effect (T4- to T4+) and recovery time (T1+-T4+). Student’s paired t-test was used to compare simultaneous responses at nF-uNL and nU-mCF. An unpaired t-test was used to compare anaesthetic effects.ResultsLatent and manifest onset times were significantly (p < 0.05) briefer, blockade and drug effects were significantly longer and recovery from blockade were significantly slower in the nF-mNL unit in both halothane and isoflurane recipients. Profound block duration and drug action were significantly longer and recovery from blockade were significantly slower in halothane recipients at both nerve-muscle units.Conclusion and clinical relevanceThe nF-mNL was more sensitive than nU-mCF to vecuronium, particularly in halothane-anaesthetized dogs.     

The use of lingual venous blood to determine the acid‐base and blood‐gas status of dogs under anesthesia

ObjectiveTo assess the suitability of lingual venous blood (LBG) as an alternative to arterial blood (ABG) samples in determining acid–base balance and blood–gas status in dogs anesthetized for elective procedures and with medetomidine and isoflurane administration under experimental conditions.Study designProspective, randomized clinical and experimental study.AnimalsClinical population of 18 ASA I/II dogs for elective surgery and five healthy Beagles (3 females and 2 males) for the experimental study.MethodsBlood sampling was simultaneously performed at dorsal pedal arterial and lingual venous sites, generating paired data. Two paired samples were collected from each dog in the clinical part and four from each dog in the experimental part (two during isoflurane anesthesia and two during isoflurane plus medetomidine). A modified Bland and Altman method was used to examine data from the clinical part and the experimental data were subjected to a paired sign's test following transformation where appropriate.ResultsThe pH of LBG overestimated ABG, with limits of agreement of (?0.01, 0.02). The partial pressure of carbon dioxide (PCO₂) of LBG overestimated ABG by 0.6 mmHg [0.1 kPa], with limits of agreement of (?3.5, 4.6) mmHg [?0.5, 0.6 kPa]. The partial pressure of oxygen (PO₂) of LBG underestimated ABG by 86.3 mmHg [?11.5 kPa], with limits of agreement of (?199.8, 27.3) mmHg [?26.6, 3.6 kPa]. During medetomidine administration values for PO₂ (p = 0.03) and lactate (p = 0.03) were lower for LBG when compared with ABG. The LBG value of PO₂ was lower (p = 0.03) during medetomidine and isoflurane administration versus isoflurane alone.Conclusions and clinical relevanceThe pH and PCO₂ of LBG samples provide clinically acceptable substitutes of ABG samples in the dog population studied. The wider limits of agreement for PO₂ render it less reliable as a substitute for ABG. The difference in PO₂ identified between LBG and ABG during medetomidine administration may not preclude the use of LBG as substitutes for ABG samples.     

Use of mycophenolate mofetil as a rescue agent in the treatment of severe generalized myasthenia gravis in three dogs

Objective – To describe the use of IV and oral mycophenolate mofetil (MMF) as adjunctive therapy in 3 dogs with severe generalized myasthenia gravis.
Case Series Summary – Three dogs suffering from severe generalized myasthenia gravis as confirmed by acetylcholine antibody titers were treated with MMF as part of their treatment regimens. All 3 dogs had radiographic evidence of megaesophagus and suffered from severe regurgitation. Each dog was initially treated with pyridostigmine and supportive agents. When clinical remission was not achieved, IV MMF was administered to all dogs. Signs of clinical remission were apparent within 48 hours and all dogs were later maintained on oral MMF following resolution of regurgitation.
New or Unique Information Provided – This is the first report of the use of IV MMF as adjunctive treatment in dogs with severe generalized myasthenia gravis. Outcome was favorable in all 3 dogs and no adverse effects were noted from the MMF.