2 May 2023
Alex Gough MA, VetMB, CertSAM, CertVC, PGCert(Neuroimaging), MRCVS, looks at several more pieces of veterinary research in his latest Vet Times column.
Alex Gough
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Image: © adogslifephoto / Adobe Stock
Differentiating between generalised tonic-clonic seizures (GTCS) and syncope can sometimes be challenging since an overlap exists between the clinical signs of these two presentations.
In humans, a transient reduction in serum phosphorus concentration is often noted after a GTCS. Kelmer et al1 performed a retrospective study to assess whether hypophosphataemia is a useful marker to help differentiate GTCS and syncope.
In total, 87 dogs with GTCS and 26 dogs with syncope were included in the study. Dogs with high serum creatinine or aged less than one year were excluded. Dogs were included if phosphate was measured within three hours of an episode. In total, 28% of the dogs with seizures and none of the dogs with syncope had hypophosphataemia. The mean phosphate in the seizure group was lower than the syncope group. With a cut off point of 0.97mmol/L for phosphate concentrations, the specificity was 100% and sensitivity 44%.
The authors concluded serum phosphate may, in some cases, help differentiate seizure from syncope.
Lyme disease is a tick-borne infection that can cause signs of fever, lameness and anorexia, and can lead to nephritis.
Carney2 performed a case-crossover study to assess whether increased precipitation in the months prior to diagnosis of Lyme disease was a risk factor for Lyme nephritis.
A total of 87 dogs with presumed Lyme nephritis were included in the study, with 41 of the dogs Labrador or golden retrievers. Each case was linked to their nearest precipitation monitoring station, and the total monthly precipitation for the four months prior to diagnosis was compared to the monthly total precipitation 12 months before and after diagnosis.
Possible peaks were seen in spring and autumn. Increasing levels of precipitation increased the odds of developing Lyme nephritis. The author suggested this might help guide future studies regarding risk factors for this disease.
Topical ear medications are some of the most commonly prescribed treatments in veterinary clinics. However, they have the potential to be irritant if accidentally administered to the eye.
Tater et al3 performed a retrospective study to determine the epidemiology of exposure and toxicity of dog and cat eyes from otic products.
A total of 79 dogs and cats were included in the study. Of those, 95% of cases involved prescription products and 5% over-the-counter products.
Ocular signs caused by the otic medication administration included conjunctivitis, blepharospasm, epiphora and ocular discharge, with some cases suffering corneal ulceration.
Confusing otic and ophthalmic medication was the reason for the problem in 86% of cases. In 4 cases, otic medication had been mistakenly dispensed instead of ophthalmic medication; in 11% of cases accidental ocular exposure occurred while an otic medication was being applied; in 2 cases the otic medication was applied on purpose.
The authors recommended separate storage and distinctive packaging for otic and ophthalmic medication is used to prevent accidental administration of otic preparations into eyes.
Salivary gland carcinomas can cause swelling, dysphagia, dysphonia and halitosis and have the potential for local and distant metastasis.
Bush et al4 performed a retrospective case series to describe the features, prognostic factors and outcomes in dogs with salivary gland carcinoma that were treated surgically.
A total of 72 dogs were included in the study. The median survival time was above five years. In total, 42% of cases had local recurrence, with a disease-free interval of around six months; 32% of dogs had metastatic disease with a disease-free interval of around 10 months; 29% of dogs had lymph node metastatic disease at the time of surgery, and these dogs had shorter disease-free intervals and median survival times.
The authors concluded that generally dogs with salivary gland carcinoma treated with surgery had better outcomes than previously reported, but that local metastasis was a negative prognostic indicator.
The authors recommended considering surgical intervention for salivary gland carcinoma.
Injuries caused by elevators (lifts) are uncommon in dogs, but have the potential to be serious.
Bartling et al5 report a retrospective study of elevator-related injuries in dogs. A total of 13 dogs with injuries that occurred while using an elevator were included in the study.
The mean age was five years, but with a wide range. Dogs with elevator injuries were significantly smaller than dogs presenting for other types of trauma in the same time period. Nine dogs suffered a crush injury to limb or tail, and seven of these required surgery; four dogs had their leads trapped in the lift doors, but none of these required surgery; two dogs needed to be hospitalised.
None of the dogs died, but recovery was prolonged in some cases. Fortunately, none of the dogs had serious long-term problems resulting from their injuries.
Another retrospective study on trauma, by Davros et al6, aimed to compare the outcomes of different trauma types – blunt or penetrating – in dogs.
Trauma registry data was used, and more than 20,000 dogs were included in the study.
A total of 53 per cent of dogs suffered penetrating trauma; 41% blunt trauma; and 6% a combination of the two.
Dogs that only sustained a penetrating trauma had a 97% survival rate, while dogs with blunt trauma had a 90% survival rate. Dogs that had both blunt and penetrating trauma had an 86% survival rate. Dogs that had both blunt and penetrating traumas had lower modified Glasgow Coma Scale scores, higher Animal Trauma Triage scores, and were more likely to be admitted to an intensive care unit.
Trauma type, Animal Trauma Triage score and modified Glasgow Coma Scale score were all found to be predictive of survival.
Enucleation is a common procedure for eyes with cancer, or with severe disease or injury.
A number of potential complications with the procedure exist, with blood loss being one of the most important.
Lenihan et al7 performed a prospective observational study to quantify the surgical blood loss following enucleation in dogs.
A total of 121 dogs – from which 130 eyes were enucleated – were included in the study.
Blood loss was estimated by the difference in weight between wet and dry surgical materials. The median absolute blood loss was 12ml, with a range of 2ml to 116ml, with the relative blood loss ranging from 0.1% to 6.7%.
Higher relative blood loss was associated with a bupivacaine splash block compared to a retrobulbar nerve block, and with a transpalpebral rather than a subconjunctival approach.
Small dogs had higher relative blood loss than large dogs. A significant difference in blood loss was seen between surgeons.
Other factors, such as ocular hypertension, systemic illness, surgical time or administration of meloxicam, did not affect the amount of haemorrhage. No dog required further intervention as a result of surgical haemorrhage.
The authors recommended subconjunctival enucleation is used for dogs with increased risk of haemodynamic complications.
