30 Jun 2021
Latest research for companion animal veterinary medicine is reviewed by Alex Gough in his latest column in Vet Times.
Alex Gough
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Image: © teamjackson / Adobe Stock
Leishmaniosis is becoming more frequently recognised in the UK, particularly with increased numbers of dogs being rescued from abroad.
Quantitative anti-Leishmania antibodies are used in the diagnosis and follow-up treatment of affected dogs.
In countries where Leishmania is endemic, the sandfly is the main vector, but little attention has been paid to the variation of anti‑Leishmania antibodies in relation to sandfly seasonality.
Cavalera et al1 performed a study comparing blood samples from clinically healthy and Leishmania infantum-seropositive dogs in June during sandfly season, and again in February‑March when transmission does not occur.
A reduction in antibody titres was found during the non-transmission season, and 44% of affected dogs became seronegative.
The authors noted it is important to take the sandfly season into account when interpreting antibody titres and that annual screening for leishmaniosis should take place in the non‑transmission season.
Platinum-based chemotherapy drugs are used for the treatment of various malignancies in dogs. In humans they are useful when combined with surgery for the treatment of ovarian cancers, but less is known about their efficacy for this in dogs.
Itoh et al2 performed a study to assess the long‑term outcomes of dogs with malignant effusions due to ovarian tumours.
Seven dogs were included in the study, all of which had ovariohysterectomy performed. Four of the dogs had ovarian adenocarcinoma that had disseminated throughout the peritoneum and, in two cases, caused a pleural effusion. Three cases had granulosa cell tumours with no gross dissemination visible, although one of these also had a pleural effusion.
The effusions resolved in all seven dogs post‑ovariohysterectomy. Six of the dogs received treatment postoperatively with carboplatin. Two of the dogs with granulosa cell tumours had no recurrence or metastasis. One had a recurrence nearly five years later.
All the dogs with adenocarcinoma suffered recurrence with a range of 171 to 584 days postoperatively, but this resolved after administration of intracavitary cisplatin or carboplatin. The overall survival for dogs with granulosa cell tumours was 822 to 1,840 days, while for those with adenocarcinomas survival was 617 to 841 days.
The authors concluded that dogs with malignant effusions due to ovarian carcinomas can survive for long periods of time if treated with platinum-based chemotherapy in addition to surgery. Granulosa cell tumours have a better prognosis than adenocarcinomas.
Making a definitive diagnosis of FIP can be challenging, and history, physical examination, imaging findings and clinicopathological findings may be needed to be as diagnostically accurate as possible.
Meazzi et al3 performed a study to evaluate whether paraoxonase-1 (PON-1) was useful as a biomarker in the investigation of FIP. PON-1 is a negative acute phase protein produced by the liver.
A total of 159 cats were included in the study – 71 healthy, 34 with FIP and 54 with another disease, but with clinical signs that were consistent with FIP.
In cats with FIP, PON-1 activity was lower than in healthy cats and in cats with other non‑FIP diseases. However, low PON-1 was also seen in cats with septic peritonitis.
A threshold of 73.8U/L yielded a sensitivity of 100%, but a specificity of 50.4%, while a threshold of 24.9U/L gave a sensitivity of 44.1%, but a specificity of 94.4%.
The authors believed that using these thresholds provided a good level of diagnostic performance in differentiating FIP from other inflammatory diseases.
Gorilla Glue is a US brand of adhesive. It contains methylene diphenyl diisocyanate, which expands and hardens when it meets moisture.
Friday et al4 reported a case series of 22 dogs that had ingested Gorilla Glue. The most common presenting sign was vomiting, seen in 11 dogs, which occurred on average 42 hours post‑ingestion. A total of 13 dogs showed pain on abdominal palpation.
Some 18 dogs had radiography performed, and the foreign material was described as granular or mottled soft tissue density in the stomach. Surgery was required in 15 dogs, with 14 requiring gastrotomy and 1 requiring duodenotomy. One dog was treated endoscopically and one dog was euthanised due to financial constraints. Five dogs were managed conservatively.
The short-term prognosis with appropriate treatment was found to be good.
Many dogs, especially older individuals, are treated with long-term NSAIDs – for example, for musculoskeletal conditions. The prevalence of gastrointestinal lesions associated with long‑term NSAID use has not previously been reported.
Mabry et al5 performed a prospective study of 12 medium to large-breed dogs that had been receiving an NSAID for at least 14 days. These were compared to 11 retrospectively evaluated control dogs, and all underwent video capsule endoscopy. Nine dogs were receiving carprofen, two dogs meloxicam and one dog firocoxib, for a median duration of six months.
Erosions were seen in at least 1 dog taking each of the NSAIDs, with 10 of the 12 treated dogs having erosions, compared to 3 of the 11 control dogs.
The authors concluded that dogs receiving chronic NSAID treatment had subclinical gastrointestinal erosions more commonly than dogs not treated with NSAIDs, and suggested caution using the drugs, especially in cases with comorbidities that predispose to gastrointestinal ulceration.
Spontaneous pneumothorax can cause acute dyspnoea without an obvious presenting cause.
Dickson et al6 performed a retrospective study of 110 dogs with primary spontaneous pneumothorax that had undergone surgical management to describe the outcomes.
In total, 90% of dogs underwent median sternotomy, while 9% underwent an intercostal sternotomy and 2 cases underwent thoracoscopy as the only intervention.
Most bullae were found in the right and left cranial lung lobes.
Some 13% of cases followed up for more than 30 days had a recurrence. Recurrence was significantly more likely in the first 30 days of surgery than later. In most cases treated with a median sternotomy, lung lobectomy led to resolution.
Most cases that recurred had a recurrence in the immediate postoperative period – suggesting a failure to spot additional lesions.
With vaccine hesitancy and anti-vaccination sentiment more of a public health issue than ever, it is important to be reminded that outbreaks of preventable diseases are still common.
Iverson et al7 described the features of an outbreak of leptospirosis in a region with previously low prevalence.
A total of 71 case dogs were compared to 281 control dogs – 54 dogs were considered to have confirmed disease, with 17 probable. In one household cluster, 5 dogs were confirmed cases and 3 probable.
The highest titre in this series was for the Djasiman serovar. In a community outbreak, the highest titre was for serovar Canicola.
The case dogs were more likely to have visited boarding kennels or dog day care facilities than the control dogs within the 30 days prior to developing clinical signs.
The authors suggested considering dogs’ exposure to places where other dogs congregate when making vaccine recommendations.
