We conducted pharmacokinetic and toxicology studies on Quantum Dot 705 (QD705) in male ICR mice for up to 6 months after a single intravenous dose. Time-course sacrifices were carried out at 1, 4, and 24 h; 3, 7, 14, and 28 days; and 6 months on groups of six mice per time point. Mass balance studies were also carried out at 24 h, 28 days, and 6 months. Using inductively coupled plasma mass spectrometry, various tissues, urine, and feces were analyzed for cadmium (Cd111), which is a major (46%) component of QD705. On the basis of these experimental studies, a physiologically based pharmacokinetic computer simulation model was developed with excellent predictive capability for the time-dependent kinetic and distributional changes of QD705 in tissues. QD705 persisted and accumulated in the spleen, liver, and kidneys for at least 28 days with little or no disposition but was gradually and partially eliminated by 6 months. Although histological alterations of the spleen, liver, and kidney by light microscopy are unremarkable, investigation using electron microscopy on numerous renal samples revealed definitive mitochondrial alterations in renal tubular epithelial cells at 28 days and 6 months postdosing. Health implications and potential beneficial applications of QD705 are suggested.

Very little is known about the use of antibiotics on small dairy farms in lower/middle-income countries. The use of these drugs can have profound impacts on animal health, farmer income and public health. A survey of 156 farmers was conducted in Cajamarca, a major dairy-producing center in the highlands of Peru characterized by small farms (<15 cows) to assess patterns and determinants of antibiotic use and farmers’ knowledge of antibiotics. The reported incidence of disease on these farms was relatively low (0.571 episodes of disease per cow-year), but more than 83% of the reported episodes were treated with antibiotics. The most commonly used antibiotics were oxytetracycline, penicillin and trimethoprim-sulfamethoxazole drugs; antiparasitic drugs were also used to treat what were likely bacterial infections. An increased incidence of treated disease was significantly associated with smaller farm size, lower farmer income, the previous use of the Californian Mastitis test on the farm and antibiotic knowledge. Farmers’ knowledge of antibiotics was assessed with a series of questions on antibiotics, resulting in a “knowledge score”. Increased knowledge was significantly associated with the use of antibiotics for preventative reasons, the purchase of antibiotics from feed-stores, the experience of complications in animals after having administered antibiotics, the number of workers on the farm and the educational level of the farmer. Overall, antibiotics appeared to be used infrequently, most likely because therapeutic interventions were sought only when the animal had reached an advanced stage of clinical disease. Few farmers were able to define an antibiotic, but many farmers understood that the use of antibiotics carried inherent risks to their animals and potentially to the consumers of dairy products from treated animals. The results of this study are useful for understanding the patterns of antibiotic use and associated management, demographic and knowledge factors of farmers on small dairy farms in rural Peru.

DNA vaccines represent a new frontier in vaccine technology. One important application of this technology is in the veterinary arena. DNA vaccines have already gained a foothold in certain fields of veterinary medicine. However, several important questions must be addressed when developing DNA vaccines for animals, including whether or not the vaccine is efficacious and cost effective compared with currently available options. Another important question to consider is how to apply this developing technology in a wide range of different situations, from the domestic pet to individual fish in fisheries with several thousand animals, to wildlife programs for disease control. In some cases, DNA vaccines represent an interesting option for vaccination, while in others, currently available options are sufficient. This review will examine a number of diseases of veterinary importance and the progress being made in DNA vaccine technology relevant to these diseases, and we compare these with the conventional treatment options available.

OBJECTIVE To explore owners’ knowledge of and experiences with antimicrobial treatment of their pets and their perceptions of veterinarian-led antimicrobial stewardship initiatives. DESIGN Cross-sectional study. SAMPLE 25 pet owners visiting 1 of 3 clinic types (tertiary care, general practice, or low cost) in the greater Philadelphia area. PROCEDURES Semistructured interviews were conducted with pet owners to gather responses related to the study objectives. Responses were transcribed and analyzed by means of conventional content analysis. RESULTS Although participants were mostly unfamiliar with the mechanisms of antimicrobials and antimicrobial resistance, they generally understood what constituted the inappropriate use of antimicrobials. Few pet owners appeared concerned about the risk of antimicrobial resistance, and no owners were concerned that antimicrobials used for people were also used for pets. Overall, pet owners reported closely following veterinarians’ directions when administering antimicrobials at home, and the main reasons for not following directions included difficulty administering the medication and concern about overmedicating the pet. Most (21/25 [84%]) pet owners expressed trust in their veterinarian to meet their pets’ medical needs and prescribe antimicrobials appropriately. However, in situations when it was unclear whether antimicrobials would be effective, most owners nevertheless wanted their pet to receive them. Initiatives to promote the judicious use of antimicrobials, such as microbial culture and antimicrobial susceptibility testing and formal stewardship programs, were generally well received and appreciated by owners. CONCLUSIONS AND CLINICAL RELEVANCE Considerable opportunity was identified to leverage the trust that exists between veterinarians and pet owners to promote the judicious use of antimicrobials for pets.

Antibiotic use data are critical for drawing conclusions about the epidemiological connections between antibiotic use in farms animals, antibiotic resistance, animal health, and human health. The goal of this study was to quantitatively and qualitatively characterize antibiotic use on dairy farms in Pennsylvania, the state with second largest number of dairy farms nationally. A survey was sent to 10% of the 6,580 dairy farms registered in Pennsylvania and completed by 235 producers (response rate of 36%). Data on antibiotic use in the previous month and in the previous 6 mo were collected based on farmer self-report, using either recall or treatment records. Two metrics were used to quantify antibiotic consumption: animal-defined daily doses (ADD) and days of therapy (DOT), a metric used in human medicine for purposes of antimicrobial stewardship. Across all farms, 24,444 ADD and 19,029 DOT were reported, representing treatment incidences of 4.2 ADD/1,000 animal-days and 3.3 DOT/1,000 animal-days. These rates were generally lower than those found in other states and countries. The main indication for antibiotic use was mastitis, and firstgeneration cephalosporins were the most commonly used class of antibiotic for all indications, followed by penicillins and third-generation cephalosporins. Trends in use were similar for ADD and DOT, but the numbers of recorded DOT and associated treatment incidences were generally lower than the number of ADD and associated treatment incidences. Rates of treatment were significantly associated with herd size. This study is the first to quantify antibiotic use on dairy farms in Pennsylvania and the first to use the DOT metric in a dairy setting.

This study aimed to describe and compare the role of veterinarians and feed-store vendors in the use of antibiotics on small dairy farms in Cajamarca, Peru, a major dairy-producing center characterized by small, rural farms with poor, mostly uneducated farmers. We used a purposive sampling strategy to recruit 12 veterinarians into 2 focus group discussions and supplemented these data with 8 semi-structured interviews with feed-store vendors. Participants reported that inappropriate antibiotic usage was widespread among their clients, which may prevent the efficient use of drugs on farms where animal disease can be devastating to the livelihood of the farmer. Participants also identified many barriers to appropriate prescribing and use, including availability of drugs, competition from other prescribers, economic constraints and habits of farmers, and limited farmer knowledge of drugs and disease. Veterinarians expressed mistrust toward nonprofessional prescribers, whereas feed-store vendors felt that veterinarians were important partners in promoting the health of their clients’ animals.

Antimicrobial resistance is a growing public health threat driven by antimicrobial use-both judicious and injudicious-in people and animals. In animal agriculture, antimicrobials are used to treat, control, and prevent disease in herds of animals. While such use generally occurs under the broad supervision of a veterinarian, individual animals are often treated by farm owners or managers. The decision to administer antimicrobials is therefore influenced not only by the clinical situation but also by the motivations and priorities of different individual actors. Many studies have examined the drivers of external forces such as costs, workload and time constraints, or social pressures on antimicrobial use by veterinarians and producers, but none have explored the role of individually held values in influencing decision-making related to antimicrobial use. Values are deeply held normative orientations that guide the formation of attitudes and behaviors across multiple contexts. Values have been shown to be strongly tied to perceptions of and attitudes toward polarizing topics such as climate change, and preliminary evidence suggests that values are also associated with attitudes to antimicrobial resistance and stewardship. In this article, we draw on lessons learned in other fields (human health care, climate change science) to explore how values could be tied to the extrinsic and intrinsic factors that drive antimicrobial use and prescribing in animal agriculture. We also provide suggestions for ways to build a bridge between the veterinary and social sciences and incorporate values into future research aimed at promoting antimicrobial stewardship in animal agriculture.

Antibiotics are commonly used in animal agriculture; they can improve animal health and productivity, but their use may also represent a public health threat. Very little is known about antibiotic use on small farms in lower/middle income countries. To understand antibiotic use on these farms and promote the judicious use of these drugs, pharmacoepidemiologic data are necessary. However, acquiring such data can be difficult, as farmers are often illiterate (and therefore cannot participate in written surveys or keep treatment records), antibiotics can be obtained over-the-counter (in which case no prescriptions are generated) and monitoring and surveillance systems for drug use are often non-existent. The goal of this study was to compare two methods of acquiring pharmacoepidemiologic data pertaining to antibiotics that are well-adapted to farms in lower-middle income countries: self-report and the collection of discarded drug packaging. A convenience sample of 20 farmers in Cajamarca, Peru, participated in the study. Farmers placed discarded antibiotic packaging in bins for six months. At the end of the six-month period, farmers were interviewed and asked to recall the antibiotic usage that occurred on their farm over the past month and past six months; these self-reported data were quantitatively and qualitatively compared to the bin contents collected in the last month and previous six months. We found that the agreement between the bins and self-report was relatively poor for both the quantity and types of antibiotics used. The bins appeared to perform better than self-report when bottles and mLs of antibiotics were measured, while self-report appeared to perform better for intra-mammary infusions. The bins also appeared to perform better when data pertaining to an extended time period (six months) were collected. The results of this study will provide guidance to investigators seeking to collect pharmacoepidemiologic data in similar environments.