Cell proliferation and expression of connexins differ in melanotic and amelanotic canine oral melanomas

Melanoma is a malignant neoplasm occurring in several animal species, and is the most frequently found tumor in the oral cavity in dogs. Melanomas are classified into two types: melanotic and amelanotic. Prior research suggests that human amelanotic melanomas are more aggressive than their melanotic counterparts. This study evaluates the behavior of canine melanotic and amelanotic oral cavity melanomas and quantifies cell proliferation and the expression of connexins. Twenty-five melanomas (16 melanotic and 9 amelanotic) were collected from dogs during clinical procedures at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo, Brazil. After diagnosis, dogs were followed until death or euthanasia. Histopathology confirmed the gross melanotic or amelanotic characteristics and tumors were classified according to the WHO. HMB45 or Melan A immunostainings were performed to confirm the diagnosis of amelanotic melanomas. Cell proliferation was quantified both by counting mitotic figures and PCNA positive nuclei. Expressions of connexins 26 and 43 were evaluated by immunohistochemistry, qRT-PCR and Western blot. Dogs bearing amelanotic melanomas presented a shorter lifespan in comparison to those with melanotic melanomas. Cell proliferation was significantly higher in amelanotic melanomas. Expressions of Connexins 26 and 43 were significantly reduced in amelanotic melanomas. The results presented here suggest that oral cavity melanotic and amelanotic melanomas differ regarding their behavior, cell proliferation and connexin expression in dogs, indicating a higher aggressiveness of amelanotic variants.

Risk factors for death from canine parvoviral-related disease in Australia

Canine parvovirus (CPV) is a highly contagious cause of serious and often fatal disease in dogs worldwide despite the availability of safe and efficacious vaccines. Although a number of studies have focussed on identifying risk factors in disease development, risk factors associated with death from CPV are largely unknown. In this study we analysed a total of 1451 CPV cases reported from an Australian surveillance system - using univariate and multivariate techniques - to determine significant risk factors associated with death and euthanasia. A crude case fatality rate of 42.3% was estimated - higher than has been reported previously. We found that 3.3% of CPV cases had a history of vaccination in the previous 12 months, despite having completed the primary puppy vaccination course. The majority (89.5%) of these cases occurred in dogs <12 months of age, indicating failure of the primary vaccination course to provide protective immunity (most likely due to interference of the vaccine antigen with maternal antibodies but other reasons are discussed). Extending the age at which the final puppy vaccination is administered might be one of several strategies to consider. The final multivariate model showed that in non-litter CPV cases, risk of death was significantly associated with season of diagnosis (summer) and pedigree type (hounds and non-sporting dogs). Euthanasia in non-litter CPV cases was significantly associated with season of diagnosis (summer), state of residence (Northern Territory/South Australia/Tasmania combined), age ( Collapse

Key Words

• canine parvovirus
• risk factors
• vaccination
• epidemiology
• surveillance
• australia

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MESH Headings

• Animals
• Australia/epidemiology
• Dog Diseases/epidemiology
• Dog Diseases/mortality
• Dog Diseases/prevention & control
• Dogs
• Female
• Incidence
• Male
• Parvoviridae Infections/epidemiology
• Parvoviridae Infections/mortality
• Parvoviridae Infections/prevention & control
• Parvoviridae Infections/veterinary
• Parvovirus, Canine
• Risk Factors
• Vaccination/statistics & numerical data
• Vaccination/veterinary

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Grants Collapse

[Patent ductus arteriosus in the dog: a retrospective study of clinical presentation, diagnostics and comparison of interventional techniques in 102 dogs (2003-2011)]

A left-to-right shunting patent ductus arteriosus (PDA) is a common congenital heart defect in dogs. If it is left uncorrected, life expectancy in most cases is decreased due to the development of left-sided congestive heart failure. The aim of this study was to describe the dogs diagnosed with PDA in the Utrecht University Companion Animal Clinic from 2003 to 2011. The medical records of 102 patients were retrieved, and the clinical presentation and outcome of PDA closure by surgical ligation or transarterial catheter occlusion (TCO) were reviewed. In the TCO group, the result of coiling was compared with the placement of an Amplatz Canine Duct Occluder (ACDO). A predisposition to PDA was found in the German Brak, Stabyhoun, and Schapendoes. Dogs treated with surgical ligation were significantly older and heavier than those treated with TCO; within the TCO group, dogs treated with ACDO were significantly older and heavier The initial success rate (complete disappearance of the audible murmur in a patient that survived the procedure) was not significantly different between the different treatment modalities. Major complications were more common with surgical ligation, but the incidence of minor complications was not significantly different. There was no diference in survival between dogs treated with surgical ligation and dogs treated with TCO. This study shows a previously unreported predisposition to PDA in certain breeds. Both surgical ligation and TCO are suitable techniques for PDA closure, although major complications were more common with surgical ligation. ACDO appears to be the method with the least complications and thus can be considered the safest method.

Postoperative treatment outcome in canine mammary tumors. Multivariate analysis of the prognostic value of pre- and postoperatively available information

OBJECTIVE

Mammary tumors belong to the most common canine neoplasias. Few data are available on postoperative outcome and independent prognostic value of variables including pre-operatively available parameters such as cytology. The aim of this study was to characterize outcome following surgery and identify independent prognostic factors in canine mammary tumors.

MATERIAL AND METHODS

Prospective study in which dogs with mammary tumors underwent surgical tumor removal followed by histopathologic examination of the neoplasias. Kaplan-Meier log rank analysis and multivariate regression analyses were used to evaluate survival, recurrence-free interval (RFI) and metastasis free interval (MFI) as well as independent influence of variables on outcome.

RESULTS

134 dogs with mammary tumors were included. In 126 dogs without distant metastasis, overall survival duration was 1113 d; median RFI and MFI were not reached. Histologic grade showed independent influence on duration of RFI (p=0.040), MFI (p=0.007), and survival (p=0.029). Median survival in benign (n=98), grade 1 (n=10) and grade 2 (n=16) malignant tumors was 1319 d, 670 d, 406 d, respectively. Cytology exerted independent influence on the likelihood for recurrence (p=0.013), duration of RFI (p=0.026) and survival (p=0.030).

CONCLUSION AND CLINICAL RELEVANCE

Histologic grade was of independent prognostic significance for postoperative outcome in this population of dogs with mammary tumors. As a pre-operatively available parameter, cytology may also possess prognostic value in canine mammary neoplasias.

[Transmission dynamics and cost-effectiveness of rabies control in dogs and humans in an African city]

Control of human rabies in developing countries depends on prevention in dogs. The purpose of this study was to evaluate the cost-saving potential for the public health sector of intervention to control rabies in animal-host reservoirs. An existing deterministic model was adapted to allow study of dog-to-human rabies transmission. Model parameters were fitted to data from routine weekly reports on the number of rabid dogs and human rabies exposures in N'Djamena, Chad. At the onset of study, the estimated effective reproductive ratio (Re) was 1.01 indicating stable low-level endemic rabies transmission. Simulations were performed to determine what effects mass vaccination and culling of dogs would have on the incidence of human rabies. Findings showed that a mass campaign allowing single parenteral vaccination of at least 70% of the canine population would be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to that of "postexposure prophylaxis" (PEP) which would not reduce future human exposure. Results showed that a sustained 5-year PEP program together with a dog-vaccination campaign would be as cost-effective as PEP alone. Beyond a time-frame of 7 years, combining parenteral dog vaccination campaigns with human PEP appeared to be more cost-effective than human PEP alone.

Survival and echocardiographic data in dogs with congestive heart failure caused by mitral valve disease and treated by multiple drugs: a retrospective study of 21 cases

This retrospective study reports the survival time [onset of congestive heart failure (CHF) to death from any cause] of 21 dogs with mitral regurgitation (MR) and CHF treated with a combination of furosemide, angiotensin-converting enzyme inhibitor (ACEI, benazepril, or enalapril), pimobendan, spironolactone, and amlodipine. Baseline echocardiographic data: end-systolic and end-diastolic volume indices (ESVI and EDVI), left atrium to aorta ratio (LA/Ao), and regurgitant fraction (RF) are reported. Median survival time (MST) was 430 d. Initial dosage of furosemide (P = 0.0081) and LA/Ao (P = 0.042) were negatively associated with survival. Baseline echocardiographic indices (mean ± standard deviation) were 40.24 ± 16.76 for ESVI, 161.48 ± 44.49 mL/m(2) for EDVI, 2.11 ± 0.75 for LA/Ao, and 64.71 ± 16.85% for RF. Combining furosemide, ACEI, pimobendan, spironolactone, and amlodipine may result in long survival times in dogs with MR and CHF. Severity of MR at onset of CHF is at least moderate.

Evaluation of the use of chemotherapy and other prognostic variables for surgically excised canine thyroid carcinoma with and without metastasis

This retrospective study compared the efficacy of surgery alone versus surgery in combination with chemotherapy in the treatment of canine thyroid carcinoma; potential prognostic factors were evaluated. Forty-four dogs with biopsy-confirmed thyroid carcinoma met the inclusion criteria. Twenty-eight dogs were treated with surgery alone and 16 with surgery and chemotherapy. The median survival of dogs treated with surgery and chemotherapy was 518 d, which was not statistically different from that of the dogs treated with surgery alone. The number of thyroid lobes removed at surgery was prognostic with respect to survival. Despite an overall metastatic rate of 48%, the addition of chemotherapy to surgical excision did not improve survival; however, this finding may be due to inadequate power to demonstrate a difference.

[Quality of life and life expectancy of dogs undergoing chemotherapy for malignant lymphoma. An owner survey]

OBJECTIVE

The outcome of palliative chemotherapy in dogs with lymphoma was evaluated. Special emphasis was placed on the quality of life during chemotherapy. In addition, factors which were important for the owners in estimating their dogs' quality of life and for the assessment of therapy were recorded.

MATERIAL AND METHODS

In a retrospective study the owners of 207 dogs that had undergone chemotherapy at the Clinic of Small Animal Medicine, University of Munich during the previous 13 years, were asked about their dogs' course of disease and therapy by using a specially designed questionnaire.

RESULTS

A total of 123 owners (59.4%) responded to the questionnaire. Quality of life improved in 64 dogs (53.3%) during chemotherapy. In only 24 dogs (20.0%) was a decline in the quality of life recorded, that directly correlated with remission status and side effects. The overall remission rate in dogs undergoing chemotherapy was 83.7%.

CONCLUSION

Despite treatment complications, the majority of the owners (65.0%) were satisfied by the chemotherapy of their dogs. Ninety owners (73.2%) would have treated their animal with chemotherapy again; for this decision prolonged survival was an important factor.

CLINICAL RELEVANCE

In dogs with cancer the quality of life needs to be monitored constantly during palliative chemotherapy. This assessment helps to choose the appropriate chemotherapy protocol and facilitates the decision on further treatment options by the owner and the veterinarian.

Product quality risk perceptions and decisions: contaminated pet food and lead-painted toys

In the context of the recent recalls of contaminated pet food and lead-painted toys in the United States, we examine patterns of risk perceptions and decisions when facing consumer product-caused quality risks. Two approaches were used to explore risk perceptions of the product recalls. In the first approach, we elicited judged probabilities and found that people appear to have greatly overestimated the actual risks for both product scenarios. In the second approach, we applied the psychometric paradigm to examine risk perception dimensions concerning these two specific products through factor analysis. There was a similar risk perception pattern for both products: they are seen as unknown risks and are relatively not dread risks. This pattern was also similar to what prior research found for lead paint. Further, we studied people's potential actions to deal with the recalls of these two products. Several factors were found to be significant predictors of respondents' cautious actions for both product scenarios. Policy considerations regarding product quality risks are discussed. For example, risk communicators could reframe information messages to prompt people to consider total risks packed together from different causes, even when the risk message has been initiated due to a specific recall event.

[Protein-losing enteropathy in Rottweilers]

OBJECTIVES

To describe the signs, histopathological features, and treatment outcome of a not previously described protein-losing enteropathy (PLE) in Rottweiler dogs.

METHODS

A retrospective study involving 17 Rottweilers referred for PLE. Data on sex, age, presenting signs, histopathological diagnosis, and treatment outcome were collected. The canine inflammatory bowel disease activity index (CIBDAI) score was calculated, to quantify disease severity. Endoscopic intestinal biopsies were evaluated according to the guidelines of the World Small Animal Veterinary Association (WSAVA) gastrointestinal standardization group.

RESULTS

Presenting signs were watery diarrhoea and weight loss. In all dogs with PLE in this study, the abnormalities found were consistent with a form of inflammatory bowel disease. Some of the dogs had a secondary infection with Giardia or Cyniclomyces guttulatus. In 10 dogs (59%) the CIBDAI score was 9 or higher, indicative of severe disease. Histopathological findings revealed lymphoplasmacellular enteritis, with lymphangiectasia in 14 (82%) dogs and eosinophil infiltration in 10 (59%) dogs. Eleven (65%) dogs were euthanized or died because of the intestinal disease. Kaplan-Meier analysis revealed a median survival time of 5 months, with a 1-year survival rate of 47%. Seven (4%) dogs were disease-free after treatment with immunosuppressants and dietary measures, but some relapsed (median disease-free interval 21 months).

CLINICAL SIGNIFICANCE

In Rottweilers presenting with chronic diarrhoea and weight loss, clinicians should consider the presence of severe PLE, which has a poor prognosis.

Clinical outcome in dogs with nasal tumors treated with intensity-modulated radiation therapy

Intensity-modulated radiation therapy (IMRT) is a valuable tool in human radiation oncology, but information on its use in veterinary medicine is lacking. In this study, 12 dogs with nasal tumors were treated with IMRT at a median radiation dose of 54 Gy. Patient survival times and frequency and severity of side effects on ocular structures, oral mucosa, and skin were recorded. Eight dogs (67%) had resolution of clinical signs during radiation therapy. Median overall survival time was 446 d with a 50% 1-year and a 25% 2-year survival rate. Minimal grade 2 or 3 acute skin toxicity, no grade 2 or 3 late skin toxicity, and no grade 2 or 3 toxicity to oral mucosa or the eye opposite the tumor were identified in the dogs treated with IMRT in this study. The ipsilateral eye could not be routinely spared due to its proximity to the tumor.

[Evaluation of different prognostic markers in dogs with primary immune-mediated hemolytic anemia]

Canine primary immune-mediated hemolytic anemia (IMHA) is associated with a high mortality rate. Hypothesis of this study was that laboratory parameters not only determined initially but also in the course of the disease might be useful as prognostic markers. Included in the study were dogs with primary IMHA. Inclusion criteria were anemia (PCV < 0.30 L/L), a positive Coombs'test or persistent autoagglutination of erythrocytes, and the exclusion of underlying diseases. Dogs were divided into two groups based on survival: dogs that were still alive 14 days after start of treatment (group 1) and dogs that died or were euthanized before day 14 (group 2). Hematological and biochemical analyses as well as a coagulation profile were performed initially and on day 3. Out of 37 dogs with primary IMHA 28 belonged to group 1 and 9 to group 2. Significantly associated with mortality were thrombocytopenia (p = 0.001), lymphopenia (p = 0.026), a prolonged PT (p = 0.003) and aPTT (p = 0.005), hypofibrinogenemia (p = 0.028), disseminated intravascular coagulation (DIC) (p = 0.019), and high plasma ALT (p = 0.003) and AST (p = 0.004) plasma activities on initial presentation, as well as a decrease in hemoglobin (p = 0.034) and an increase in WBC count (p = 0.034), plasma bilirubin (p = 0.012) and urea concentration (p = 0.003) between day 0 and 3. In conclusion various laboratory parameters were useful as prognostic

Cardiac troponin I as a marker for severity and prognosis of cardiac disease in dogs

The use of cardiac troponin I (cTnI) to assess the severity of disease and prognosis in 120 dogs presented for cardiac evaluation was analysed. cTnI concentrations were measured using a commercially available assay. Dogs were placed into three groups: group 1, cTnI0.15ng/mL; group 2, cTnI 0.151-1.0ng/mL; group 3, cTnI>1.01ng/mL. Dogs in group 1 were significantly younger (P<0.0001) and had no or stable cardiac diseases and longest survival times, whereas those in groups 2 and 3 had severe cardiac diseases and significantly reduced survival times (P<0.0001). Thirty dogs with initially increased cTnI concentrations had a repeat assay less than 2months later with significant reductions in cTnI concentrations (P=0.005). Initial cTnI concentrations could not differentiate dogs that survived in group 3 from those that did not. However, dogs that survived showed significant cTnI reductions (P=0.015) in the repeated assay in contrast to the dogs that died (P=0.22). It was concluded that cTnI is useful in assessing the prognosis and severity of cardiac diseases in dogs, and progression and response to treatment can be assessed by repeat sampling. cTnI concentrations >1.0ng/mL and persistent increases in cTnI concentrations are indicators of a poor prognosis in dogs with cardiac disease.

Haemostatic abnormalities and clinical findings in Vipera palaestinae-envenomed dogs

The venomous viper Vipera palaestinae (Vp) is responsible for most envenomations in humans and animals in Israel. Its venom contains proteases, haemorrhagins, L-amino acid oxidase and phospholipase A2 but its effects on haemostasis have yet to be characterised. This prospective study aimed to characterise haemostatic abnormalities in Vp-envenomed dogs from presentation to discharge or death, and their association with mortality. Samples from 39 Vp-envenomed dogs were collected periodically and examined for haematology, prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin activity (ATA), fibrinogen level and D-dimer concentration. All dogs presented with severe local signs and most (79%) had systemic signs. Six dogs (15%) died. Haemostatic abnormalities were present in 37/39 dogs. Increased D-dimer concentrations were detected in 28/31 dogs. Disseminated intravascular coagulation was diagnosed in 10 dogs and in all non-survivors. Platelet and leucocyte counts at presentation, maximum PT and aPTT, and minimum ATA during hospitalisation were significantly different between survivors and non-survivors and were good predictors of the outcome. The results show that hypercoagulability, consumption and derangement of haemostasis are common in Vp-envenomed dogs and are associated with mortality. Haemostasis should be closely monitored in such dogs.

Hypernatremia

Salt toxicity can be fatal in dogs and cats. Whether toxicity occurs accidentally or iatrogenically, it is important to recognize the clinical signs of sodium toxicosis, which are mainly caused by hypernatremia and associated cerebral edema. Treatment involves prompt initiation of fluid therapy along with careful monitoring of neurologic status, serum and plasma electrolytes, and serum osmolarity. Salt was once recommended as an emetic for dogs and cats but has fallen out of favor because of the lethal complications that can arise from overzealous administration.

Immunosuppressive therapy for canine immune-mediated hemolytic anemia

The mortality for dogs with severe immune-mediated hemolytic anemia (IMHA) is unacceptably high, and better immunosuppressive regimens are needed to increase survival. Understanding the basic immunology of the disease and the mechanisms of action of the available immunosuppressive therapies will help clinicians choose an appropriate immunosuppressive protocol. Prospective, randomized clinical studies must be conducted to evaluate the efficacy and safety of different combined immunosuppressive modalities to treat canine IMHA and improve patients' outcomes.