18 Jul 2016
Alex Gough runs the rule over latest studies and findings in veterinary medicine for dogs.
Alex Gough
Job Title
A prospective case series study was carried out to investigate ventricular arrythmias in Rhodesian ridgebacks with a family history of sudden death.
Some breeds are predisposed to cardiac arrhythmias and, in some cases, these can lead to sudden death.
Meurs et al1 performed a prospective case series study to investigate ventricular arrhythmias in Rhodesian ridgebacks with a family history of sudden death. The pedigrees of four young Rhodesian ridgebacks that had died suddenly were examined. A total of 21 close relatives of the deceased dogs were examined with 24-hour Holter monitoring, ECG and/or echocardiography.
A total of 8 dogs had ventricular tachyarrhythmias, although none of the 21 dogs had clinical signs of cardiac disease. No structural lesions were found in 7 of the 12 dogs considered to be affected (frequent ventricular premature complexes or sudden death) by echocardiography or postmortem examination. Examination of the pedigrees suggested an autosomal recessive inheritance pattern, although autosomal dominant inheritance with incomplete penetrance was also possible.
The authors recommended Holter monitoring of Rhodesian ridgebacks for dogs with a family history of arrhythmia or sudden death, and recommended against inbreeding of these dogs.
Surgery remains the mainstay of management of soft tissue sarcomas, but complete excision is not always possible.
Bergman et al2 performed a retrospective case series study to evaluate the use of intralesional cisplatin-impregnated bead placement in the management of soft tissue sarcomas.
The records of 62 dogs with soft tissue sarcomas treated with marginal excision and cisplatin-impregnated beads were examined. A total of 24 out of 51 dogs that were evaluated had evidence of toxic effects (12 mild and 10 moderate) and 29% of tumours recurred.
Grade 3 soft tissue sarcomas had a median disease-free interval (DFI) of 148 days, but the median DFI was not reached for grade 1 or grade 2 tumours. The disease-free survival rates for dogs with grade 1 and grade 2 tumours were 88% for one year, 75% for 2 years and 64% for 3 years. One dog was suspected to have systemic toxicosis.
The authors concluded cisplatin-impregnated beads were generally well-tolerated and good outcomes were seen in lower grade tumours. However, further studies would be needed to determine efficacy.
Dental disease, such as gingivitis and periodontitis, is widespread in pet dogs and various treatments have been suggested to improve oral health, such as pastes, brushing and diets. Jeusette et al3 performed a prospective, randomised, placebo-controlled
crossover trial to assess the effect of a dental treat on dental plaque formation and halitosis.
A total of 10 dogs were given a dental treat or placebo. After a four-week washout period, the opposite treatment was given. Plaque and breath samples were collected at regular intervals up to 24 hours after the treat was given. Volatile sulphur compounds (VSCs) were measured in breath samples and bacterial counts were assessed in plaque samples. Consumption of the dental treat led to significant decreases in breath VSC for 24 hours and a reduction in bacterial counts for up to 12 hours.
The optimal treatment for meningoencephalitis of unknown origin (MUO) has not yet been tested in controlled trials. Various immunosuppressive protocols have been suggestive and some recommend the use of cytosine arabinoside. IV cytosine arabinoside has superior pharmacokinetics to SC administration.
Lowrie et al4 performed a study to assess a constant rate infusion (CRI) of cytosine arabinoside and compared this to historical controls in which the drug was administered SC. A total of 80 dogs were included in the study – 39 of which had received SC cytosine arabinoside and 41 received the drug as a CRI.
All dogs received clinical examination, MRI and CSF analysis, and treated with prednisolone. A total of 44% of dogs receiving SC cytosine arabinoside were alive after 3 months, compared to 90% with CRI. Repeat MRI and CSF analysis after three months showed significant improvement in the dogs treated with CRI compared to SC cytosine. Clinically significant toxicity was not seen.
The authors recommended use of cytosine arabinoside as a first line therapy for MUO.
Adrenal tumours can be incidental findings or discovered when searching for an explanation for clinical or clinicopathological problems. Many are endocrinologically active, but they can be hard to differentiate based on imaging or routinely available blood tests.
Bargellini et al5 assessed the use of contrast-enhanced ultrasonography (CEUS) using microbubbles to assist in the differentiation of adrenal masses in 24 dogs. Assessment of both degree of enhancement and vascularity allowed CEUS to differentiate between adenoma, adenocarcinoma and phaeochromocytoma, with an accuracy of 91.7%.
Sensitivity of distinguishing benign from malignant adrenal tumours was 100% and specificity was 80%. The authors concluded CEUS was a useful technique for differentiating the different types of adrenal tumours.
Trace element levels and antioxidant status may contribute to behavioural problems. Soltanian et al6 performed a controlled study to investigate whether serum trace elements and antioxidant capacity was associated with abnormal behaviours, such as aggression, destructiveness and inappropriate elimination.
Owners were asked to complete questionnaires and, from the results, dogs were separated into two groups – 14 dogs were included in the group with no behavioural problems and 16 were included in the group with at least one behavioural problem. The zinc concentration and total antioxidant capacity were significantly lower in dogs with behavioural problems compared to controls.
The authors concluded this study supported the hypothesis supplementation with zinc and antioxidants may help with behavioural problems in dogs.
Angiostrongylosis is associated with a variety of pathological conditions, including hypercalcaemia, coagulation abnormalities and lung disease. Matos et al7 performed a study of dogs severely affected by angiostrongylosis, to assess whether they could recruit anatomical intrapulmonary arteriovenous anastomoses (IPAVAs) and whether this affected the severity of pulmonary hypertension (PH).
Eight dogs with severe angiostrongylosis with signs of severe dyspnoea and/or syncope were included in this prospective study. Screening by echocardiography for the presence of PH and IPAVAs was performed. In three dogs, open IPAVAs were detected, with mild to moderate PH. In five dogs, IPAVAs could not be detected and these cases had severe PH.
The authors concluded opening of IPAVAs could help regulate PH and also noted radiographic findings may not reflect the severity of the disease.
