Antimicrobial resistance in companion animals - Veterinarians' attitudes and prescription drivers in Portugal

Antimicrobial resistance transmitted from companion animals is a threat to public health increased by the pet's relationship with humans. This study aims to understand the attitude and drivers of antimicrobial (AM) prescription among companion animal veterinarians in Portugal and identify actions to combat antimicrobial resistance (AMR). This cross-sectional study is based on a questionnaire with 417 respondents representing the Portuguese veterinary population. The results allowed grouping the respondents according to the attitude of prescription. Two types of veterinarians were identified: those who prefer to prescribe treatments based on the animals' signs and their own experience - empirical-oriented type - and those who refer to a guidance protocol to assist the prescription decision - protocol-oriented type. Respondents working in hospitals displayed a positive association with the use of guidance protocols. Efficacy was the main driver of prescription for both groups, suggesting that no matter the attitude in prescribing, the veterinarian's aim is achieving positive clinical results. Most respondents prefer empirical-oriented prescriptions, declare the absence of protocols for the prudent use of AM at the workplace and do not refer to AMR issues nor the need for hygiene reinforcement measures with owners. Owners are less likely to request AMs from veterinarians aged over 43 years old. It was discovered that communication between owners and veterinarians about risks associated with AMR was poor and must be improved and the adoption of a national guideline for the adequate use of AM directed for companion animals would be beneficial.

Incidence, characteristics and geographical distributions of canine and human non-Hodgkin's lymphoma in the Porto region (North West Portugal)

Lymphoma is one of the most common neoplasms in dogs and it is one of the top five causes of cancer-related deaths, similar to human lymphoma. Companion animal epidemiological studies define dogs as sentinels of potential risk factors for human health, mainly due to shared environments, shorter disease latencies, and spontaneous disease. The aims of this study were to describe human and canine epidemiologic features of non-Hodgkin's lymphoma (NHL) and their similarities, and to investigate a possible geographical association in the incidence risks in the Greater Porto area, in north-western Portugal. The postal codes of human NHL patients diagnosed between 2005 and 2010 residing in the Greater Porto, Portugal, were obtained from North and Central Region Cancer Registries of Portugal. Available data from dogs diagnosed with lymphoma between 2005 and 2016 from several veterinary centres were also collected. Descriptive epidemiology, mapping cases, and age-standardised risks of NHL incidence (ASR) were determined for both species. The results showed a higher risk (P<0.05) of NHL in men (ASR men: 18.1 cases/100,000 inhabitants; women: 14.2 cases/100,000 inhabitants) and in male dogs (ASR males: 82 cases/100,000 dogs; females: 70 cases/100,000 dogs). The geographical distribution of human and canine ASR was well correlated (r=0.664, P<0.05), with the highest values for human and canine ASR detected in the same urban municipalities of the Greater Porto: Porto, Matosinhos and Maia. These findings suggest the existence of exposure similarities, supporting the relevance of cancer surveillance in pet animals as efficient tools to predict health hazards for humans.

Immunocytochemical study of canine lymphomas and its correlation with exposure to tobacco smoke

Aim:

Canine lymphoma is one of the most common canine neoplasms, but little is known regarding the effects of exposure to tobacco smoke on their biologic behavior. As cytology is the most frequent diagnostic method of canine lymphoma, the aims of this study were to perform an immunocytochemical study of canine lymphomas, including subtyping and cell proliferation analysis, and to establish their correlation with tobacco smoke exposure.

Materials and Methods:

A total of 23 dogs diagnosed with lymphoma were subjected to careful fine-needle biopsies of enlarged lymph nodes. The smears were air-dried, fixed with cold acetone, and immunocytochemically stained using CD3, PAX5, and Ki-67. Owners were requested to complete an epidemiologic questionnaire.

Results:

According to the updated Kiel classification, 65% were B-cell lymphomas - three low grade (LG) and 12 high grade (HG) and 35% were T-cell -two LG and six HG. Thirteen tumors presented high Ki67 indexes (>40%) (11 HG and 2 LG), two revealed moderate ones (20-40%) (1 HG and 1 LG), and three had low indexes (≤20%) (1 HG and 2 LG). Both a significant positive correlation and a significant linear-by-linear association (p=0.018) were observed between high Ki67 indexes and smoking owners (r=0.753, p=0.002) as well as with the number of smokers in the household (r=0.641, p=0.001). Moreover, the mean percentage of Ki67⁺ cells from the group of “smoker owners” was statically higher (p=0.011) than that from the “non-smoker owners.”

Conclusion:

The results suggest that cytological diagnosis of canine lymphomas benefits from being complemented with immunocytochemical studies that include subtyping and assessment of proliferative activity, both contributing for the prognosis and therapeutic planning. Furthermore, exposure to tobacco smoke seems to be related to the biological behavior of canine lymphomas.

Pfaffia paniculata (Brazilian ginseng) methanolic extract reduces angiogenesis in mice

Pfaffia paniculata (Brazilian ginseng) roots have been indicated for the treatment of several diseases. Our studies have shown that P. paniculata roots present antineoplastic effects and cancer chemopreventive activity in a mouse hepatocarcinogenesis model. The purpose of this study was to investigate the effects of the Brazilian ginseng on corneal angiogenesis in mice. We first conducted a toxicological study employing 250, 500, or 1000mg/kg/day of the methanolic extract of P. paniculata roots by gavage to BALB/c mice. Animals did not lose weight during the treatment nor presented histopathological alterations. The effect of this root on angiogenesis in the cornea of BALB/c mice was then assessed. Male mice were treated, by gavage, once a day, with doses of 250, 500, or 1000mg/kg of methanolic extract of P. paniculata powdered root for 10 days; filtered water was used as control. Corneal cauterization was accomplished by the contact of a silver nitrate crystal on the central area of the cornea, in the 5th day of treatment with P. paniculata, which continued thereafter; the animals were euthanized on the 6th day after cauterization. Newly formed blood vessels were filled with India ink, and the corneas were routinely processed. Blood vessels were quantified in an image analysis system. A smaller total area of neovascularization in the mouse cornea was observed in animals treated with 1000mg/kg of the methanolic extract of P. paniculata. These results indicate an antiangiogenic effect of this extract. The mechanisms of this antiangiogenic activity of P. paniculata should be further investigated.

Effects of Pfaffia paniculata (Brazilian ginseng) extract on macrophage activity

The roots of Pfaffia paniculata (Brazilian ginseng) have been indicated for the treatment of several diseases and as an analgesic and antiinflamatory drug. Treatment of mice with 200 mg/kg of the powdered root of P. paniculata reduced the Ehrlich ascitic volume [Matsuzaki, P., Akisue, G., Salgado Oloris, S.C., Gorniak, S.L., Zaidan Dagli, M.L., 2003. Effect of Pffafia paniculata (Brazilian ginseng) on the Ehrlich tumor on its ascitic form. Life Sciences, Dec 19; 74 (5), 573-579.]. One of the putative means to control the Ehrlich tumor growth is by increasing macrophage activity [Kleeb, S.R., Xavier, J.G., Frussa-Filho, R., Dagli, M.L.Z., 1997. Effect of haloperidol on the development of the solid Ehrlich tumor in mice. Life Sciences, 60 (4/5), 69-742.]. The aim of this study was to investigate experimentally the effects of the methanolic extract of P. paniculata roots on macrophage activity. Male mice received, by gavage, once a day, different doses (100, 250, or 500 mg/kg) of the methanolic extract of P. paniculata or filtered water, as control, for 10 days. Macrophage activity was evaluated through the phagocytosis index (PI), spreading index (SI), production of peroxide oxigen and nitric oxide. The peritoneal cells were activated with ip inoculation of Ehrlich ascitic cells, 24 h before the macrophage harvesting. The methanolic extract raised significantly the SI of mice from group of 500 mg/kg in comparison with the control group and group of 100 mg/kg. This raise of SI possibly induced the higher phagocytic activity observed in the experimental situation. Increased macrophage activity may be one of the effects contributing to inhibition of the Ehrlich ascitic tumor growth in mice.