29 May 2017
More companion animal studies and research go under the spotlight in Alex Gough's latest Research Review.
Alex Gough
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A six-year study was made of 366 petit basset griffon Vendéens. IMAGE: Fotolia/Vincent.
Glaucoma is known to be more prevalent in certain breeds, such as the beagle.
Bedford1 reported the results of breed screening at breed society clinics for glaucoma for the petit basset griffon Vendéen in the UK. Over a six-year period, 366 dogs were examined using slit lamp, ophthalmoscopy, tonometry and gonioscopy. Thirty-eight cases had glaucoma – a prevalence of 10.4%. Clinical signs were seen from the age of three years. Elevated intraocular pressure was usually the first sign, often accompanied by lens luxation and globe enlargement.
The author notes the presentation is similar to primary open-angle glaucoma of beagles and elkhounds. The high prevalence in the breed suggests a possible genetic origin.
Multidrug-resistant meticillin-resistant staphylococci are being increasingly reported as a cause of pyoderma in dogs. De Lucia et al2 performed a retrospective review to assess the safety and efficacy of rifampicin in dogs, which is more commonly used to treat this condition, despite a lack of data. Thirty-two dogs, which were treated with rifampicin for rifampicin-susceptible multidrug-resistant meticillin-resistant staphylococcal pyoderma, were included in the study.
The antibiotic was effective as a sole systemic treatment in 72% of cases, although most also had topical antimicrobials. Treatments lasted, on average, for around four to five weeks – 15% of cases suffered gastrointestinal effects, and alanine aminotransferase and alkaline phosphatase were commonly observed after treatment. The authors concluded oral rifampicin was an effective treatment for resistant pyoderma and speculated liver enzyme induction might be responsible for the rise in liver enzymes observed.
Most pedigree dog breeds are susceptible to multiple breed-related disorders – sometimes as a result of deliberate breeding for certain characteristics, such as brachycephalics, and sometimes as an unintended consequence of inbreeding, such as mitral valve disease in cavalier King Charles spaniels. Wang et al3 used data from kennel organisations in Sweden, France and the UK to assess whether pedigree databases could be merged to improve the monitoring of genetic variability and health disorders of pedigree dogs. The bullmastiff, English setter, Bernese mountain dog and Labrador retriever were included in the study.
Merging the databases allowed the authors to calculate the effects of founder dogs. They discovered the proportion of inbred animals remained stable or decreased, except for French Labrador retrievers. Over time, populations in countries were found to become more diverse, with increased flow of genes between countries.
The authors concluded inbreeding could be reduced by exchanging breeding animals between different countries and increasing the population size studied by merging databases helped confirm this.
Congenital vertebral malformations are often encountered in certain small breeds of dogs and, in many cases, do not cause overt clinical problems. Ryan et al4 performed a retrospective study of 171 neurologically normal and 10 neurologically abnormal dogs of brachycephalic screw-tailed breeds. The neurologically normal dogs were selected from the records of those that had undergone CT for non-neurological reasons, whereas the neurologically abnormal dogs had undergone MRI. The normal dogs consisted of French bulldogs, pugs and English bulldogs. The neurologically abnormal dogs consisted of nine pugs and one French bulldog.
More than 80% of the neurologically normal dogs had at least one vertebral malformation. Thoracic vertebral malformations occurred significantly more often in normal French and English bulldogs. Hemivertebrae were more common in neurologically normal French bulldogs. Pugs often had transitional vertebrae and spina bifidia. Clinically important thoracic vertebral malformations were found in 4.7% of pugs.
The authors concluded thoracic vertebral malformations were common in the brachycephalic screw-tailed breeds and, while they may be incidental, they may be more important in pugs.
Both urolithiasis and chronic kidney disease (CKD) are common in cats. Cleroux et al5 performed a retrospective case control study of cats to assess whether urolithiasis was associated with CKD. Of 126 cats included in the study, 59 were found with urolithiasis and 67 without. The prevalence of CKD was found to be significantly higher in the group of cats with urolithiasis than in the control group without. No association was found between urolithiasis and the stage of CKD.
The authors recommend cats with urolithiasis are assessed for the presence of CKD.
General anaesthesia is necessary for many medical and surgical procedures, but is associated with known risks. Matthews et al6 performed a matched case control study using the medical records of 822 primary care veterinary hospitals to identify dogs and cats that had undergone general anaesthesia or sedation and then died within seven days. In total, 115 dogs and 89 cats were found, compared to 122 control dogs and 92 control cats that had survived for more than seven days after general anaesthesia.
The risk was higher for cats, with a 0.11% mortality rate – whereas for dogs, the mortality rate was 0.05%. Increased risks for death were found with increasing age and non-elective procedures. Dogs had higher mortality rates when there was no record of pre-anaesthetic physical examination and when pre-anaesthetic haematocrit was outside the reference range. Cats were more likely to die if there was no record of pulse oximetry measurements. Underweight dogs were 15 times more likely to die, while increased bodyweight (but not body condition) was associated with an increased risk in cats.
The authors hope these data can help with strategies to reduce anaesthetic risks and to inform owners of the risks.
A vast amount of information is imparted during a veterinary education, and retaining and using it appropriately is a challenge. Ober7 noted fourth-year veterinary students struggled to produce appropriate lists of differential diagnoses for changes on thoracic radiographs. A board game was developed that focused on thoracic radiographic differential diagnosis. One hundred fourth-year vet students were enrolled into a study, in which brief tests were performed before and after playing the game. Scores were significantly higher after the board game than before.
The author concluded the board game improved the short-term ability to formulate thoracic radiographic differential diagnosis, and that the game may be a useful educational tool.
