by Tony Nevin, BSc (Hons) Ost, DO Zoo Ost Ltd
FOR most manual therapists involved in animal care the thought of applying their skills to treat anything other than mammals usually raises an eyebrow or two. Many of the veterinary nurses I work with have a real feather phobia, usually discovered when I ask them to hold a bird I need to examine! So why is it that these magnificent creatures present us with so many obstacles when it comes to treating them?
For me they are just as fascinating as reptiles, but they do differ considerably, from a treatment program planning point of view from, say mammals. Or I should say, larger mammals such as dogs and horses.
They generally have faster metabolic rates for a start. Then their skeletal structures are highly modified with some bones acting as auxiliary air sacs, with bone density and matrix evolved for weight saving. Their skin very much gives the impression of having evolved from scales, and then there are the feathers, which insulate, and in most cases enable flight.
A huge difference when compared with mammals is the lack of a diaphragm with which to breathe, and a digestive tract and reproductive system much more akin to reptiles.
However, they do have an evolved musculoskeletal system (MSK), and a highly evolved central nervous system (CNS), and are governed by all the same laws of physics as the rest of us.
Most of the avian patients I get to see are wild, and as such my treatment is aimed solely at getting them back to that state. Being embedded within a wildlife hospital makes my involvement so much easier, as I have full access to all of the veterinary staff, and therefore we are much more able to accurately assess and treat these patients, aided as we are by an array of modern imaging equipment.
The species we see are pretty much any and all of the native British birds that live or pass through Gloucestershire/ Worcestershire area, and occasionally some that shouldn’t be, usually as a result of freak weather conditions. Most of them have suffered physical trauma, some are suffering from exhaustion, whilst others also have infections, or a combination of all three.
Trauma can be the result of collisions with manmade objects, such as windows, vehicles, barbed wire fencing; or due to deliberate wounding by firearm, crossbow etc.; or by cat attack.
Due to our geographical position some birds get blown off course when migrating and can find themselves swept up the Bristol Channel creating disorientation, and sometimes injury as well. I occasionally get to examine these to ensure that there are no minor MSK issues that could delay their release back into the wild in a more suitable location. Birds with ID rings that have been fitted by the British Trust for Ornithology (BTO) or other reputable organisations often aid the successful release.
With regard to the MSK of a bird probably the most intricate part is the forelimb apparatus, which has evolved for flight.
The occiput has a single, large condyle, which allows superb mobility, but can also easily luxate. Between C1-C2 there is vastly reduced mobility when compared to mammals, due to increases in fibrous connective tissue. What would be the thoracic sling in a dog or horse is modified with a hull shaped sternum that creates a large surface area for the flight muscles to attach to. The pectoral muscles themselves are much greater in mass, whilst the gleno-humeral and elbow joints will be familiar, the carpus differs considerably to allow the phalanges greater stability to aid control in flight. A phenomenon that aids stable flight is that the elbow and carpus joints work in total synchronization. The radius being able to glide along the ulna facilitates this. When one joint flexes or extends, so does the other. The metacarpals are ossified into a single bony union of major and minor metacarpals. The phalanges are substantially shorter and modified in shape than those of comparable sized mammals.
The thoracic vertebrae are ossified, as is the synsacrum (a blend of lumbar and sacral segments), which forms the caudal body of vertebrae. The only mobile area other than the neck is found in the final caudal segments, which make up the attachments for the tail feathers.
The lack of a muscular diaphragm also poses potential problems if anaesthesia is required for examination and/or treatment purposes.
When a bird is moving around, either on the ground, or in flight it passively inflates and deflates the various air sacs. This supplements its other muscles of respiration.
Due to their high metabolic rates, birds that present with any hint of infection, or high parasitic burden need to be treated with the appropriate medicines first, before any physical therapy is applied. Wild birds in particular can suffer signs of stress when handled in the form or mouth gaping, increased heart rate, and attempts at escape if not securely held.
As with all wildlife patients, light, noise, smells, and sudden movement are all kept to a minimum.
I prefer to have an assistant hold an avian patient whilst I examine and treat. This can be either the vet in charge, or one of the nursing staff. This reduces the chance of creating further injury to the patient, and occasionally the osteopath too!
With any bird there are certain safety protocols that one needs to adhere to. All birds can scratch and peck, however some have interesting adaptations to their beaks and talons. Diving sea birds such as gannets have internal nostrils, as well as serrated bills. If the holder keeps their beak shut they can cause death by suffocation.
Herons have a nasty habit of striking at handlers’ eyes, and many a wildlife worker has scars to prove it – and they are the lucky ones!
Raptors usually defend or attack with talons, although some will peck, which can clamp around and into your fingers or hand. Very often they will have traces of faecal and food matter on them, and as such the unlucky recipient gets that punched into their blood stream.
The best way to release oneself from raptor talons goes against our ingrained instincts. If the bird has snatched and grabbed you, the best way to release yourself unaided is by extremely quickly extending the birds leg joints. Basically pulling your hand or arm downwards whilst holding the rest of the bird in a fixed position. I won’t lie; it does hurt, but a lot less than trying to prize the individual talons out of you and at the same time avoiding anymore going in!
So far so good I hear you say, but there are other considerations before you even get to the hands on stuff. Where you are going to examine and treat are important. If in a smart veterinary clinic then the temperature needs to be right for the species, windows need securing shut, as do doors, lighting subdued, and sound reduced. Much like a first date you’re probably thinking, but that’s where the analogy should end.
Plumage is essential for both flight and protection from the elements, so anything we do mustn’t damage it. Obvious when said, but not so easy in practice. Owls not only have amazingly flexible cervical joints, but they also have asymmetric ear canals to help them locate prey. No point trying to go for perfect symmetry on these guys. Their feathers are, with the nocturnal species, evolved for silent running, and are not great at water repelling. If they get wet they can become hypothermic very easily.
Waterfowl love to defecate when handled, and most wiggle their caudal vertebral joints when so doing, which has an effect much like an agricultural muck spreader. I always stand to one side when working with these beauties. From a treatment approach, due to their metabolic rates, feathers, and mechanical make up I avoid any massage techniques, but do employ functional release work, rhythmic pump techniques, as well as tapping into the Involuntary Mechanism (IVM). Sometimes specific traction and joint articulations are required. Due to the nature of their skeletal structures I only like using any of the more vigorous techniques once radiographs have been taken, and if the tissues don’t respond to more gentle, global release methods.
The nature of their metabolic rates also means that a treatment will usually take no more than 3-5 minutes. From my experience more than this can result in shock.
So there you have the basics for successfully treating the avian patient. As long as you remember that less really is more when it comes to both the examination and treatment you wont go far wrong.
In 27 years of treating birds I have had the privilege of seeing close up some amazing species, and am looking forward to continually learning from these truly amazing creatures.
Tony Nevin qualified in 1988. He set up Zoo Ost Ltd to cater for humans and animals and birds. He is clinical director on the first ever MSc in Animal Osteopathy, which is run through the McTimoney College, Witney, Oxfordshire. He also lectures and runs workshops in the UK and abroad, and Zoo Ost Ltd now produces a regular radio show titled “The Missing Link” for Corinium Radio in Cirencester.