27 Feb 2017
Alex Gough provides a review of the latest studies in companion animal veterinary medicine.
Alex Gough
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Image: @ Fotolia/aspen rock.
Hospitalisation is a stressful event for humans and veterinary patients alike. Gilbert-Gregory et al1 performed a prospective observational study to assess whether administration of trazodone reduced the observable signs of stress in hospitalised dogs.
A total of 60 dogs were observed for stress-related behaviour up to 45 minutes then approximately 90 minutes after receiving trazodone. Another 60 dogs, acting as controls, and not given the drug, were observed at the same time points. Signs assessed included pacing, panting, yawning, pinning back ears and aggression. Lip licking, panting and whining were reduced in the treated group, but not in the control group.
The number of stress-related behaviours was lower at the later time point in the treated dogs compared to the earlier time point. The authors concluded trazodone reduces stress-related behavioural signs in hospitalised dogs, which may improve patient welfare.
Another way of reducing stress in the clinic involves the use of pheromones.
Pereira et al2 performed a double-blinded, randomised, placebo-controlled trial to assess the effect of Feliway spray in feline consultations. Two consulting rooms were used – in one, Feliway was applied to the table and, in the other, a placebo spray.
After a 15-day “washout” period, the allocation of the sprays to the rooms was switched. At the end of each consultation, an observer recorded a “cat stress” score and an “ease of handling” score. Feliway led to significantly lower stress levels than the placebo, although no detected effect on ease of handling was apparent. The authors concluded Feliway reduces stress and improves cat welfare in consultations.
Incidental findings in advanced imaging studies are common and adrenal gland masses may be unexpectedly encountered.
Baum et al3 performed a retrospective case series of 270 dogs that had undergone abdominal CT for reasons other than investigation of clinical signs of an adrenal gland mass or disease.
Various clinicopathological data were collected, as well as findings of ultrasound, if performed. Incidental adrenal gland masses were detected in 9.3% of dogs. These cases tended to be older than cases that did not have adrenal gland masses. Only three of these cases had histopathology performed, which revealed two cortical adenomas and one case with a phaeochromocytoma and cortical adenoma. The authors noted an important number of dogs undergoing abdominal ultrasound will have incidental adrenal masses.
Frailty is a recognised medical syndrome in humans associated with ageing and involves disorders such as muscle mass loss and osteoporosis. Frailty has effects on mortality, morbidity and the rate of postoperative complications.
Hua et al4 performed a study of 116 aged guide dogs, with the aim of defining a frailty phenotype in dogs.
A clinical geriatric assessment was performed and the dogs were followed until death or the study ended. During the study period, 76 dogs died and the median time from clinical geriatric assessment was 4.4 years.
Dogs that had positive findings of two or more components of the five-point assessment were significantly more likely to die in the follow-up period than those with one or zero components, and this remained significant after adjusting for clinical and subclinical disease. The authors concluded frailty is a risk factor for death in dogs.
Thoracostomy tubes or chest drains are commonly placed to remove abnormal collections in the pleural space, such as air
or fluid.
Hung et al5 performed a study to characterise pleural fluid in healthy dogs in which thoracostomy tubes had been placed. Eight coonhound-cross dogs had a thoracic CT performed before placement of a thoracostomy tube then daily after placement for seven days.
Fluid volume was calculated from the CT scans and any fluid was drained. The average volume of pleural effusion forming was 1.4ml/kg, as detected by CT, and 0.5ml/kg, collected by drainage. The fluid collected was cytologically an exudate, with suppurative inflammation in six dogs. Four dogs had their tubes removed before day seven due to three cases of pyothorax and one of tube damage. Staphylococcus pseudintermedius and Streptococcus equi were cultured. The authors concluded effusion due to the presence of chest drains is minimal in healthy dogs, but pyothorax can develop after day four and it could be necessary, on the basis of this study, to remove chest drains after four days.
Septic peritonitis is a potentially fatal sequel to events, such as enterotomy wound dehiscence, bowel perforation and penetrating wounds of the abdomen.
Bush et al6 performed a retrospective study of 55 cases of secondary peritonitis to examine whether the time to intervention affected the outcome of these cases.
No correlation was noted between the time from admission to the hospital, to surgical intervention and outcome. Other factors did affect prognosis, however, including age, lactate, preoperative PCV and postoperative albumin.
Pyometra is a life-threatening condition of bitches, which can lead to septicaemia.
Höglund et al7 performed a preliminary investigation into the intraoperative stress response caused by surgery in these cases.
Eight dogs with pyometra were compared to eight healthy controls, using systolic blood pressure and heart rate as measures of stress. The surgical procedure was divided into four time phases:
No difference in heart rate or blood pressure was noted between the two groups, but, in both groups, blood pressure increased when manipulating and ligating the ovaries, suggesting this as being the most noxious part of the procedure.
