21 Oct 2019
Alex Gough runs the rule over research on foreign body removal in dogs and congenital sensorineural deafness in kittens, among other topics, in his monthly column.
Alex Gough
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Enterotomy is frequently necessary for the removal of foreign bodies that are causing partial or complete intestinal obstruction.
It has previously been reported that dehiscence of the surgical enterotomy site was a relatively common complication, with serious consequences.
Strelchik et al1 performed a retrospective study to assess the intestinal incisional dehiscence rate for foreign body removal in 247 dogs. A total of 3.2% of the dogs had septic peritonitis prior to surgery, but all 8 of these dogs survived to hospital discharge. In total, 5 dogs (2%) suffered intestinal dehiscence after the enterotomy, but only two of these dogs did not survive to hospital discharge. However, the duration of hospitalisation was longer for dogs that suffered dehiscence.
The authors concluded the rate of dehiscence was lower in this group of dogs than had previously been reported. However, they cautioned that the low rate of dehiscence should not be used as a reason to avoid an enterectomy when it was indicated and that thorough bowel evaluation is still a necessary component of intestinal foreign body removal.
A non-surgical way of removing gastric foreign bodies is to induce emesis, but this has a variable success rate.
Kirchofer et al2 performed a retrospective study of 495 dogs with gastric foreign bodies that were treated with an IV injection of apomorphine. Records were searched for signalment, type of foreign material ingested, how long between ingestion of foreign material, and induction of emesis and the amount of apomorphine administered, as well as whether induction of emesis was successful.
In 363 cases, emesis successfully removed the foreign body with just a single dose of apomorphine and in a further 11 dogs with a second dose. Younger dogs had a higher success rate and successful removal was more likely for fabric, leather and bathroom waste foreign bodies.
An increased time between ingestion and emesis reduced the success rate, as did prior administration of opiates, sedatives and antiemetics. Only four dogs had adverse events noted, which were recorded as being minor. The authors concluded IV administration of apomorphine is a good alternative in the management of gastric foreign bodies.
Migrating vegetal foreign bodies can be highly problematic to diagnose and treat, due to their small size and ability to move to parts of the body distant from the entry sites.
Cola et al3 described the anatomic locations and treatments of vegetal foreign bodies in 10 cats, for which surgical removal was required. In 4 cases the foreign bodies were in the thoracic cavity, in 2 cases in the retroperitoneal space and, in 1 case, in the para-tracheal region. These were all diagnosed by ultrasound examination. However, 2 cases were found in the perineum or penile urethra and 1 in the peritoneum, which were diagnosed by surgical exploration.
In total, 8 of the cases had a complete resolution of signs, 1 case had a recurrent draining fistula and 1 was euthanised.
The authors noted the intrathoracic location was the most common region in which the foreign bodies were found.
Toceranib phosphate is a tyrosine kinase inhibitor that is licensed “for the treatment of non-resectable Patnaik grade II (intermediate grade) or III (high grade), recurrent, cutaneous mast cell tumours in dogs”.
Gustafson and Biller4 performed a retrospective study of cases where toceranib phosphate was used in the treatment of canine bladder tumours. In total, 37 cases were included in the study; 56% of the cases had progression of azotaemia while being treated with the drug, but apart from this, the drug was generally well tolerated.
In 6.7% of cases, a partial response was seen and in 80% of cases stable disease was achieved, which lasted a median duration of 129 days. The median time to progression was 96 days and the median survival time from commencing treatment was 140 days.
The authors suggested these results mean toceranib phosphate may be of use in the treatment of canine bladder transitional cell carcinomas, but monitoring of renal function is recommended.
Antibiotic treatment can induce gastrointestinal side effects due to alterations of the intestinal microflora. Synbiotics are combinations of prebiotics and probiotics, and have been previously associated with decreasing antibiotic-associated gastrointestinal signs in cats.
Whittemore et al5 included 22 healthy dogs in a randomised, double-blinded, placebo-controlled crossover study.
An eight-week washout period was included between the two treatments.
The dogs were given enrofloxacin and metronidazole, with a synbiotic or placebo an hour later. Faecal score and vomiting were measured, as well as food intake. The antibiotic administration was associated with a high frequency of adverse gastrointestinal side effects.
Synbiotic administration reduced the level of inappetence. Milder gastrointestinal side effects were present in the second study period in the placebo group, suggesting the clinical effects of the synbiotics lasts more than nine weeks after they are discontinued.
White blue-eyed cats are thought to suffer from an increased prevalence of congenital sensorineural deafness (CSD), but data is mainly from research colonies.
Mari et al6 performed a retrospective and prospective study of 132 client-owned UK-based white kittens between 6 and 21 weeks of age. They were compared to 61 coloured littermates.
Hearing was assessed by brainstem auditory evoked response (BAER) testing. CSD was found only in pure white kittens, with a prevalence of 30.3%. Roughly half of these cases were bilateral.
The presence of blue irises significantly increased the risk of CSD. The Norwegian forest, Turkish Vankedisi and Maine coon cats seemed to be predisposed to CSD.
The authors concluded CSD had a high prevalence in purebred white kittens in the UK.
Gall bladder mucocoeles (GBM) are commonly diagnosed ultrasonographically, leading to a difficult decision of whether to remove them surgically, which carries a risk, or leave them in situ.
Jaffey et al7 performed a retrospective study of 1,194 dogs that had a gross and histopathological diagnosis of GBM. Dogs with abnormal clinical signs were at a greater than four times risk of death, compared to those that were subclinical.
Multivariate analysis showed increased risk of death for owner-recognised jaundice, concurrent hyperadrenocorticism, and in Pomeranians.
Vomiting as a clinical sign was associated with a decreased risk of death. Increased age and increased bilirubin levels were associated with an increased risk of death, but the clinical utility of bilirubin as a marker for risk of death had poor sensitivity and specificity.
Neither the presence of hypothyroidism nor diabetes mellitus were associated with outcome.
