16 Jun 2020
Alex Gough MA, VetMB, CertSAM, CertVC, PGCert(Neuroimaging), MRCVS presents latest companion animal studies in this Research Review.
Alex Gough
Job Title
Diagnosis of pulmonary oedema traditionally relies on radiography, but more recently, ultrasonography is being explored to demonstrate its presence.
Hori et al1 performed a prospective study on 15 healthy controls and 26 dogs with degenerative mitral valve disease (DMVD) to see whether lung ultrasonography in the region of the heart where the lungs contact the pericardium could aid with the diagnosis of cardiogenic pulmonary oedema.
The dogs with DMVD were divided into two groups – with and without cardiogenic pulmonary oedema. Thoracic radiography, echocardiography and pericardial lung ultrasound were performed on all dogs.
The number of B lines was recorded on pericardial lung ultrasound using a left ventricular parasternal short axis view, with the dog in right lateral recumbency. The presence of four or more B lines had a sensitivity of 91% and a specificity of 100% for the diagnosis of cardiogenic pulmonary oedema.
The authors concluded the presence of multiple B lines extending from the left ventricle into the lung field may indicate the presence of cardiogenic pulmonary oedema.
However, it was uncertain whether this finding differentiated oedema from pneumonia.
High-grade soft tissue sarcomas are problematic to remove completely at surgery.
Crownshaw et al2 performed a study of 41 dogs with incompletely excised high‑grade soft tissue sarcomas that were treated with radiation therapy with or without chemotherapy, to assess prognostic factors associated with recurrence, metastasis and survival.
A total of 41 dogs underwent surgical resection, then definitive-intent radiotherapy. Of these, 16 also underwent chemotherapy.
The median overall survival time was 981 days, with a one-year survival rate of 85%. Almost a quarter (24%) developed metastasis and 20% had local recurrence.
Increasing mitotic index was associated with an increased hazard of disease progression. Hazard of death was associated with duration of radiotherapy and surgical scar length. Adjuvant chemotherapy did not improve survival times.
The authors concluded improved survival time and time to progression can be achieved by sticking strictly to the radiotherapy schedule.
Deciding on the margins required to prevent the recurrence of mast cell tumours is always a practical conundrum for surgeons due to the tendency of the neoplasms to recur locally.
Chu et al3 performed a retrospective study to assess whether conservative surgical margins were as good as wide margins for treatment of grade one and grade two cutaneous mast cell tumours.
Conservative margins were defined as 2cm, or the tumour diameter if the tumour was smaller than 2cm, and wide margins were defined as 3cm or greater.
A total of 83 tumours from 68 dogs were included in the study, with 93% of conservatively excised tumours having tumour‑free histological margins and 92% of those with wide margins.
The authors concluded taking conservative margins was non-inferior to wide margins in this population, and this could reduce the risk of postoperative complications.
It has been previously shown that urine protein:creatinine ratios (UPC) were lower in urine samples collected at home than in the veterinary clinic. It was thought stress may have contributed to this by causing prerenal proteinuria.
Citron et al4 performed a study to assess stress levels using urinary cortisol:creatinine ratios (UCCr) and to see if these correlated with UPC in urine samples from home and the clinic.
Thirty-six healthy dogs were included in this prospective, non-blinded study. Voided urine samples were obtained at home and in the hospital, on which full urinalysis, UCCr and UPC were performed. Clients also assessed their dogs’ stress levels at home, in transit and at the clinic.
UCCr was significantly higher in the hospital than at home, but UPC was not significantly different. UCCr did not correlate with UPC.
The authors concluded the claim that stress, as assessed by UCCr, may cause proteinuria in healthy dogs was not supported by this study.
It is recommended to perform ileoscopy in gastrointestinal endoscopic investigations in dogs and cats to avoid missing clinically significant lesions in the distal small intestine. However, the safety of this procedure has not been assessed.
Woolhead et al5 performed a multicentre retrospective case series study to characterise iatrogenic endoscopic ileocaecocolic (ICC) perforations.
Six ileal, five caecal and four colonic perforations were identified in the records. In five cases, diagnosis was not made for one to five days after the endoscopy.
Signs of perforation included inappetence, lethargy, abdominal pain and retching. All cases of perforations were treated surgically.
Survival to discharge was 93%. Underlying disease was not identified histologically at the performation sites.
The authors concluded ICC generally carries a good prognosis. Clinical deterioration after endoscopy should raise the concern of perforation.
Cholelithiasis in dogs is often dismissed as an incidental finding, but few recent studies on the subject exist.
Ward et al6 performed a retrospective cross-sectional study to estimate the prevalence, presentation and progression of this condition.
A total of 68 dogs were identified in the electronic database of a teaching hospital, which gave a prevalence in the hospital population of just less than 1%.
In 87% of cases, the cholelithiasis was classified as being incidental, while in 13% of cases, the dogs were symptomatic, with complications including biliary duct obstruction and biliary peritonitis.
Of the dogs with incidental cholelithiasis, only 8% available for follow-up developed complications associated with cholelithiasis within the subsequent two years.
The authors concluded cholelithiasis is, indeed, usually an incidental finding.
Facial nerve paralysis is one of the more common peripheral neuropathies and has a number of causes.
Chan et al7 performed a retrospective case study of 122 dogs in Sydney that presented with facial nerve paralysis. These were compared to a reference population of dogs without facial paralysis at the same hospital.
Idiopathic facial nerve paralysis was the most common diagnosis, affecting 30% of cases. Male dogs were more than twice as likely to get idiopathic facial nerve paralysis compared to females. Middle-aged and older dogs were also predisposed compared to younger dogs. Cavalier King Charles spaniels were predisposed to both the idiopathic and non‑idiopathic forms.
Half of dogs with idiopathic facial nerve paralysis also had vestibular signs, while 6 out of 16 dogs with idiopathic facial nerve paralysis and a known follow-up made a full recovery within three years.
The authors noted the prognosis for recovery was, therefore, guarded.
