Backyard Chickens! What's this urban hen movement all about? [Podcast]
- The "urban hen movement" has taken the United States and mny other countries by storm, harking back to the days when chicken keeping was much more common. Those who choose to keep chickens commonly cite that the birds are relatively easy and inexpensive to maintain (when compared to most other pets), they produce eggs that are fresh, flavorful and nutritious. When these birds are kept as companions, the nature of the human-animal bond can be quite strong, and they are increasingly being presented for veterinary evaluation, diagnosis and appropriate therapy. Necropsy, as a preferred diagnostic tool of poultry medicine, is overall not an acceptable first-choice option for the pet bird owner in most settings. Awareness of how these birds are housed and treatment options is important for veterinarians whom may be called upon to treat these birds.
- Many of the medical conditions of backyard chickens have roots in deficits of husbandry methods, and a good understanding of chicken husbandry and their anatomy will greatly help veterinarians provide informed care.
- The common disease processes that backyard chickens may manifest are at least in part different in their manners of presentation and diagnosis as compared to the commonly kept companion parrot species.
- The choices of drugs that can be administered to chickens are limited, and the veterinary selection of drugs, use of Food Animal Residue Avoidance Databank (FARAD), and avoidance of banned drugs is important.
The commercially manufactured diets are an excellent maintenance food for keeping backyard laying hens and rearing chicks. Chicken scratch, composed primarily of cracked corn, is a very inadequate diet.
The trachea of chickens is relatively smaller in diameter than one would initially think, has complete tracheal cartilage rings, and non-cuffed endotracheal tubes between 2 and 4 mm are commonly used.
Surgical problems requiring entry into the intestinal peritoneal cavity are not uncommon, and careful palpation, diagnostic imaging and ultrasound examinations may help distinguish the nature of what many problems are likely to be.
Fluoroquinolones (Baytril), should not be used in chickens, as there can be significant human health concerns, and the drug has been banned from use by the FDA since 2005.
Pain management is an important but sometimes neglected part of the veterinary care for many conditions in backyard chickens, and current dosages and dosing intervals should be used.
Q: What are the most common and appropriate diets that backyard chickens should be reared on?
A: Most chickens should be fed and maintained on a commercially manufactured ration. These typically come in starter, grower, maintenance and layer formulations, and are sold as mash, crumble or pellet forms. Converting mash feeds into pellets or crumbles adds a given cost per ton of feed, however there are some advantages to feeding pellets or crumbles. Because feed is compacted in pellet form, the bird is able to consume and metabolize a greater amount of feed. Pelleted feeds are a complete unit of feed, and the birds are unable to pick out different feed ingredients. Some mash feeds are extremely dusty and are difficult to handle. Pelleting these feeds improves their handling quality. Crumbles or mashes, on the other hand, are more easily consumed by chicks. Layer mashes and crumbles should not be fed to young growing chicks. Medicated chick starters often contain amprolium, which is a thiamine-binding coccidiostat. Leafy greens, vegetables, and a variety of additional foods may be offered over and above the base ration. Large amounts of spinach and chard should be avoided in layers or growing chicks, due to their oxalic acid content and resultant binding of available calcium in the gut. Chickens are omnivorous, and eat worms, insects and even small reptiles or mammals. Oyster shell and/or recycled egg shells may fed as additional calcium supplementation. A primary diet of table scraps or hen scratch grains is not recommended, and can set the stage for nutritional or metabolic disease problems. Hens being fed a suboptimal diet can deplete as much as 40% of their skeletal calcium stores to lay six eggs.
Q: A number of predators may target and kill backyard chickens. When a client reports that a number of adult birds were killed and their heads removed, what are the more common predators that should be considered?
A: A raccoon typically attacks birds by biting the head or upper neck area. The heads of adult birds are usually bitten off and left some distance from the body. The crop and breast may be torn and chewed and the entrails eaten. Raccoons have been known to mutilate chickens in cages by pulling heads or legs off. Weasels may also remove heads from their victims.
Q: What is the deep body temperature of a mature chicken, and what relevance does this have clinically?
A: The deep body temperature of mature chickens is about 107.4 F. Core body temperature is a reasonable parameter to monitor under anesthesia, but has uncertain meaning in clinical examination, other than documentation of hypothermia.
Q: How much blood can safely be taken from a 1.5 kg hen?
A: Approximately 1% of the body weight, or ML
Q: What categories of drugs are banned from use in chickens? What groups of drugs may be fair to consider using?
A: Fluoroquinalones, Cephalosporins, Chloramphenicol, antivirals, Gentian violet, and glycopeptides are all banned. Macrolides, lincosamides, tetracyclines, sulfonamides, aminoglycosides, penicillins, spectinomycin, bacitracin, NSAIDs and opioids are all fair game for use with FARAD recommendations of withdrawal times.
Q: What was the reason for the ban of use of fluoroquinolones in chickens?
A: This was the first group of antimicrobials prohibited from extra label use by the FDA because of their potential for creating antimicrobial-resistant strains that posed a threat to human health. Fluoroquinolones are commonly used as a treatment for multidrug-resistant Salmonella spp in humans; therefore, their use in food-producing species was been questioned. Consequently, the FDA banned the extra label use of fluoroquinolones in 1997. Use of marketed products was still allowed, providing label directions were followed. At the time of the prohibition, the use of these marketed products included sarafloxacin and enrofloxacin in poultry. Surveillance of resistance to fluoroquinolones in bacteria isolated from food-producing animals was continued, and an increase in fluoroquinolone-resistant Campylobacter spp in poultry was linked to an increased incidence of infection with resistant Campylobacter spp in humans. Therefore, the FDA proposed a withdrawal of fluoroquinolone products labeled for use in poultry on the basis of the proposed risk to human health, and sarafloxacin products were voluntarily withdrawn from the market by the sponsor. However, in 2005, the FDA withdrew the approval for enrofloxacin products in poultry and effectively made use of these drugs in poultry species illegal.
Q: What are some of the more common problems you see in backyard chickens in your practice?
A: Pet chickens represent the third single most common species in patient accessions in our avian-exclusive practice in 2015 and 2016. Common problems we are called to diagnose and treat include oviductal impactions, reproductive tract neoplasia, predator attack wounds, Marek’s disease, Lymphoid leucosis, Mycoplasmosis, ectoparasitism.
Q: What drugs and doses do you prefer to use for pain management in chickens?
A: Carprofen 1 mg/kg IM or SC or 5-8 mg/kg PO BID, Meloxicam 1 mg/kg IM or 1.6 mg/kg PO BID, Butorphanol 2 mg/kg IM, tramadol 30 mg/kg PO BID-TID. Lidocaine up to 4 mg/kg is an excellent drug for local analgesia, when indicated.
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