16 Dec 2019
Alex Gough discusses a common and life-threatening problem, typically of large-breed dogs, plus other latest research in his latest Research Review.
Alex Gough
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Image © James Steidl / Adobe Stock.
Gastric dilatation-volvulus (GDV) is a common and life-threatening problem typically seen in larger-breed dogs.
Fox-Alvarez et al1 performed a randomised controlled study aimed at assessing the feasibility of using a temporary percutaneous gastropexy to provide sustained gastric decompression for dogs suffering from acute GDV, and compare the results with cases that underwent trocarisation. A total of 16 dogs were randomly assigned to receive either percutaneous trocarisation or a temporary T-fastener gastropexy (TG) and gastrotomy catheter (GC) placed using ultrasound guidance.
When the gastric volvulus was surgically corrected, the decompression sites were examined. No significant difference existed between the proportion of dogs successfully decompressed between the two groups. After two cases failed to be decompressed in the TG and GC group, the technique was modified to include ultrasound guidance. Once the trochar or gastrotomy cathether were successfully placed, time to decompression was similar in the two groups. In the TG and GC group, inadvertent splenic or jejunal placement was noted in two dogs. All dogs survived for at least two weeks.
The authors concluded TG and GC placement was safe and effective at providing sustained gastric decompression in dogs with GDV, and suggested the technique may be useful in cases where there is likely to be a delay until definitive surgical correction.
Making full-thickness surgical incisions into the large intestine is considered to be more risky than the small intestine – particularly because of the more highly contaminated environment.
Latimer et al2 performed a retrospective study to review the complications of dogs undergoing this procedure. Signalment, history, treatments, surgical procedures and laboratory data were obtained from the records of four veterinary referral hospitals. The rates for postoperative intestinal dehiscence and mortality after seven days were 10% and 17%, respectively.
Preoperative anorexia, hypoglycaemia, toxic changes in neutrophils and administration of preoperative antibiotics were associated with a poorer prognosis. Pre-existing colon trauma or dehiscence, pre-existing peritonitis and open management of the peritonitis after the surgical procedure were associated with increased chance of intestinal dehiscence.
Despite this, the authors believed these results showed the dehiscence rate for large intestinal incisions may not be as high as reported in previous studies.
Collection of capillary blood samples is useful for the measurement of blood glucose, both because of its reduced invasiveness, and its relative ease, meaning the technique can be performed by the owner at home.
Guevara et al3 performed a prospective study using a veterinary-specific portable blood glucose meter to compare the glucose concentrations in samples obtained from the carpal pad, medial pinna and oral mucosa with samples obtained from the lateral saphenous vein.
A total of 96 blood samples were taken from 12 dogs after a 12-hour fast, and again after food. Glucose concentration in blood collected from the pinna was not significantly different from the peripheral venous blood sample concentration, but a difference was found between the peripheral venous samples, and samples from the carpal pad and oral mucosa. No significant difference existed between preprandial and postprandial blood glucose concentrations.
The authors concluded the medial pinna is a superior location from which to collect blood for glucose estimation than the carpal pad or oral mucosa.
Urinary retention is a known complication of spinal injury and surgical treatment of the injury, due to damage to the nerves within the spinal cord that innervate the bladder. Management of urinary retention is often required, and sometimes involves medications to relax the urethral sphincter.
Barnes et al4 performed a retrospective study to evaluate the effect of administration of prazosin and diazepam on hospitalisation duration, urinary continence and development of bacteriuria. The authors searched medical records for dogs that had undergone CT or MRI followed by thoracolumbar hemilaminectomy for intervertebral disc herniation.
In total, 71 dogs were included in the analysis and grouped according to whether they received prazosin, diazepam, both or neither. No significant association was found between use of these drugs and length of hospitalisation or urinary continence score at the time of discharge. However, bacteriuria was associated with the administration of urethral sphincter relaxants.
It is common to find nodules or heterogeneous parenchyma in the spleen, and it can be difficult to know whether these are clinically significant. Yankin et al5 performed a retrospective study of ultrasound-guided fine needle cytology reports of the spleen to determine the association between the cytology and ultrasonographic findings.
A total of 125 dogs with splenic nodules or heterogeneous parenchyma identified by ultrasound were included in the study. The images were assessed by lesion size, number, echogenicity, distal enhancement, the amount of heterogeneity of the spleen and the presence of ascites.
The cases were divided into two groups according to the clinical importance of the lesions; 25 dogs were in the clinically important group, which consisted of 22 malignancies and 3 suppurative inflammatory lesions. Nodules 1cm to 2cm in diameter, the presence of ascites and the presence of more than one targetoid nodule were correlated with having clinically important cytology. A scoring rubric was produced to help identify clinically important lesions.
Probiotics are frequently recommended and prescribed in the treatment of chronic and acute gastrointestinal disease, but the evidence for benefit is conflicting. Jensen and Bjørnvad6 performed a systematic review to assess the overall effectiveness of this treatment compared to no treatment, symptomatic treatment or conventional treatment.
Databases were searched for publications up to April 2017. The studies were rated on level of evidence and methodological quality, using factors such as similarities in baseline groups, risk of bias and number of patients. A total of 165 studies were identified, of which 17 met the inclusion criteria.
The evidence level ranged from randomised controlled trials to uncontrolled crossover studies. Generally, the sample sizes were small and the risk of bias was moderate to high. The authors concluded a very limited and possibly clinically unimportant effect of the use of probiotics in acute gastrointestinal disease, and probably no effect in chronic gastrointestinal disease. However, the studies often had too small sample sizes, and the authors recommend larger, multi-centre trials.
Assessment of the size of the liver with radiography can be difficult since it is affected by factors such as positioning, obesity and radiographic technique. An et al7 performed a prospective and retrospective cross-sectional study to evaluate the liver length to 11th thoracic vertebral length (LL/TT11) ratio.
A total of 25 healthy cats were included in the prospective part of the study, and 324 cats with no evidence of liver disease were included in the retrospective part of the study. In the prospective arm, LL/T11 ratio was compared to CT measurements of liver volume.
In the retrospective group, the LL/T11 ratio was compared among groups categorised by age, sex, bodyweight and body condition. LL/T11 ratio was significantly correlated with liver volume measured by CT, and this wasn’t affected by radiographic technical factors. The reference range did not differ significantly between the groups of different signalment.
The authors concluded this study supports the use of the LL/T11 ratio as a quantitative radiographic index of liver disease in cats.
