Abstract
As we continue to gain experience with chickens as pets and hobby birds kept in gardens, yards, and homes, it is important that we share and use the tremendous amount of data generated around this topic. These non-regulated small flocks are the source of fresh eggs, income, and therapy, as well as the mingling of breeds and infectious agents, especially through activities such as exhibitions, bird swaps, and outdoor contact with wild birds. Backyard birds are a continuing source of anxiety for commercial producers. The 2018–2019 virulent Newcastle disease outbreak initially detected in a backyard bird in California and its subsequent detection in Utah significantly continues to threaten commercial operations and small flocks alike. In general, the whereabouts of small flocks and the types and prevalence of conditions affecting them have been largely unknown. Furthermore, the possible inappropriate use of antimicrobials in backyard flocks may contribute to the serious issues we are facing with increased antimicrobial resistance. It is clear that there is a need for compilation and sharing of knowledge.
Many diagnostic laboratories started their backyard flock programs with government support in response to foreign avian disease outbreaks and in order to contribute to scanning surveillance. Given the attractiveness of subsidized testing, these programs took off in many jurisdictions, and allowed the early detection of avian influenza and Newcastle disease. In addition, the programs gave diagnosticians the opportunity to learn about and help our clients manage their flocks and to become a reliable resource on diseases and health trends of these small-scale flocks.
Many of us have experienced owners or veterinary colleagues at a loss about the status of small flocks and the possible need for action. While we started diagnosing and gathering information, the cooperative extension units of many universities also started providing great resources and aid for clinicians and owners. This work has made a substantial impact. In California, for example, the university extension service has developed an online mapping system for the location of flocks, as well as maintaining a list of private veterinarians who accept chickens and other poultry as patients. Training courses have been organized to better equip non-poultry veterinarians with information on dealing with disease prevention, diagnosis, and management in small flocks.
For this issue, we invited submissions to provide a variety of information, from a broad scope of topics to singly observed entities. The lead papers describe collective data of backyard poultry diseases by Dr. Cadmus in 8 representative states in the United States, Dr. Brochu in Ontario, Canada, and Dr. Bolfa in St. Kitts from the Caribbean. No matter the geographic location and rearing systems, the findings are parallel. Disease agents do not respect boundaries, and may move bidirectionally between backyard flocks and commercial flocks. Dr. Blakey’s work highlights that infectious laryngotracheitis in backyard birds is typically the result of the spread of vaccine strains from commercial poultry. And vice versa, healthy carriers of A. paragallinarum are not uncommon in the backyard world, according to Dr. Clothiers’ study, and this agent has caused significant losses on the commercial side over the last few years. On the management side, we have learned the need to be diligent to remove all sources of lead per Dr. Sobhakumari, and long fibrous plants and non-poultry feed as Huang et al. found. Neither hazard is a typical concern for commercial flocks. Intensive management practices spare commercial birds from such hazards, plus the birds benefit from rigorous vaccination schedules; lack of appropriate vaccination of backyard birds is apparent in the continuing occurrence of Marek’s disease in backyard birds.
It is our hope that the backyard flock movement continues well-informed growth, and that veterinary laboratorians continue to contribute to the monitoring of health and disease in this sector.