Identifying individual birds that are suffering or that have compromised health and welfare is key to maintaining high standards of poultry care. Knowing your birds and when they are ill or in pain is imperative for identifying birds that need treatment or that might need to be euthanized. On-farm euthanasia is a necessary aspect of flock management; however, deciding whether to treat or euthanize can be difficult. In this volume, we will examine some considerations for treatment and euthanasia of poultry. Specific euthanasia methods will be discussed in a future newsletter.
IDENTIFYING BIRDS THAT ARE ILL OR IN PAIN
Generally, birds that are in pain or that are sick display certain changes in their behavior. Our previous newsletter, Volume 18, describes sickness behavior in detail: briefly, poultry that are ill perform their typical behaviors less frequently or for shorter durations and may appear lethargic, depressed, may isolate themselves, eat or drink less than typical, may have a hunched posture and may lose weight. Similarly, poultry behavior changes when birds are in pain.
Behavioral indicators of pain
(modified from Gregory, 2004)
- Escape – animals may try to get away from or avoid a situation that might cause pain
- Guarding or favoring an injured body part, which may impact how the bird sits, stands or moves
- Vocalizing or being aggressive when someone tries to move or handle them
- Withdrawing from a stimulus, situation or person, or showing avoidance behavior
- Pecking or scratching the injured or painful body part
- Changing body posture; appearing restless and/or uncomfortable
- Behavioral changes such as hiding more than usual, being depressed, slow or sluggish, being motionless or having sleeplessness
- Having difficulty breathing or breathing more rapidly or slower than typical
- Having muscle spasms, tremors or tightness
THE FUNCTION OF PAIN
Pain serves a biological function in all animals:
- Learning about pain is important for animals to be able to avoid subsequent situations or things that might cause pain
- Pain helps animals heal and recover from injuries because animals will avoid using their injured limb or other body part
- Although pain is functional, pain reduces welfare and can reduce productivity
- When animals are experiencing pain for long periods of time (chronic pain) and cannot avoid further pain, then pain leads to suffering and decreases welfare even further
Just like other species, poultry have nociceptors(pain receptors) in their skin and other parts of their body and will avoid certain situations. The experience of pain involves consciousness as well as an emotional component and is therefore more than simply reacting to something.
It can be difficult to identify pain in some animals because some animal species do not express behavior associated with pain as much as humans do; for example, some prey species, such as poultry, hide or mask pain to avoid drawing the attention of other flockmates or potential predators (whether predators are actually present or not). This does not mean that the animals cannot experience pain, only that they do not show signs of pain to the same extent as other animals.
Some common situations and conditions that can lead to pain in poultry
- Diseases and parasites (see PEC volumes15 and 17)
- Skeletal fractures (see PEC volume 12)
- Joint disorders such as arthritis and other leg issues (see PEC volume 11)
- Conditions causing inflammation (see PEC volume 18)
- Injurious pecking behavior (see PEC volume 7)
- Footpad dermatitis-see image to the right (and see PEC volume 9)
WHEN TO TREAT AND WHEN TO EUTHANIZE
When an individual animal is sick or injured, the animal should be treated or euthanized promptly (euthanasia methods will be discussed in a future newsletter). Seeking advice from a veterinarian is important to determine the feasibility of, and options for, treatment. (Information modified from Linares et al., 2018).
It is a good idea to have a hospital pen (or “sick” pen); an area where animals can be moved to and separated from the rest of the flock so that they can recover from injuries or illnesses (however; if there is a contagious disease, veterinary input is needed because hospital pens located close to the rest of the flock may not prevent disease from spreading). Hospital pens enable the animals to recover without having to compete with other animals for food and water and prevent them from being targets of pecking and aggression. Once the animal has recovered, it can be returned to the flock. However, the reintroduction should be supervised because fighting can occur during reintroduction.