Birds and Small Mammals

What are the different classes of birds of prey? Give an example for each

Hawks (long-winged)

• Harris Hawk

• Goshawk

• Red-tailed Hawk (buzzard)

Falcons (short-winged)

• Peregrine Falcon

• Saker

• Merlin

Eagles

• Golden Eagle

Owls

• Barn Owl

• Snowy Owl

What is meant by the term ‘falconry‘?

The keeping of falcons (or other birds of prey) and training them to hunt wild animals

What is meant by the term ‘flight weight‘?

Ideal weight for flying (lowest weight that allows optimal performance)

What is meant by the term ‘cast‘?

• Cast (1): the method to hold a bird for examination

• Cast (2): to regurgitate a pellet

• Cast (3): 2 or more birds flown together

What is meant by the term ‘cast off‘?

Released from the fist

What is meant by the term ‘casting‘?

Indigestible part of the diet

What is meant by the term ‘footing‘?

When a bird strikes with its feet

What is meant by the term ‘imping‘?

Replacement of damaged feathers, gluing a new tip onto a broken feather (allows precision in flying)

What is meant by the term ‘mutes‘?

Droppings/faeces

What is meant by the term ‘manned‘?

A bird that has been tamed and is used to humans

What is meant by the term ‘mews‘?

Building that a bird is kept/trained in

What is meant by the term ‘hood‘?

Leather cap that covers a bird's face, used to calm birds

What are the different types of flying ‘furniture’ used for bird of prey?

• Aylmeri/Anklet

• Jesse

• Swivel

• Leash

Describe the nutritional requirements of birds of prey

• Raptors eat an entire carcass, and then regurgitate the bones and feathers/fur 

• Do not feed raptors pure muscle- this is not a balanced diet

• Feeding the same prey each day is not balanced- use a mix of chicks, rodents, rabbit etc

• How food is sourced, kept, frozen and defrosted is very important

• Ca:P ratio is the important factor (2:1 in growing birds, 1.5:1 in adults)

• Always provide fresh water for bathing and drinking

• Diet should be tailored to activity- daily weighing allows for this

Describe how birds of prey should be handled and cast

Handling

• Always cast a bird of prey to examine it

• If the bird is used to a hood, always hood first to reduce stress

• Falconers weigh birds daily- so you can ask for this

Casting

• Using a towel, grasp the bird from behind- both hands should be around the wings/body

• Next, wrap the towel around the body- ideally cover the head if not hooded

• Place one side of the bird against your body and move one hand to place your fingers around the birds legs to hold the feet

• Once casted, an assistant/owner can hold the bird for you in the towel- tell them not to restrict breathing or let go of the legs

Describe how wing tip oedema affects birds of prey

WTONS: Wing tip oedema and necrosis syndrome

• Reduced blood flow to wing tips

• Causes feather loss, oedema, and damage to the tissue at the tips of the wings

• Prevention: keep birds warm and dry

Describe how pododermatitis affects birds of prey

Causes:

• Injury (e.g rodent bites)

• Self injury (own talon into sole of the foot)

• Incorrect perch/perch covering

• Poor perch hygiene

• Obesity

• Nutritional deficiencies 

These allow bacteria to enter the foot and cause infection to the skin, soft tissue and potentially bone

Prevention:

• Balanced diet

• Clean environment

• Cover perches with suitable material

• Hand and fly more or free loft

Describe how blunt trauma affects birds of prey

Head trauma:

• Commonly occurs when hunting or hit by cars

• Check the whole body for trauma (bleeds, fractures)

• Always do an ophthalmic exam on wild birds of prey

• Permanently poor/damaged eyesight= poor prognosis, they cannot be released if they cannot hunt with precision

Fractures:

• Leg and wing fractures due to traumas are very common

• It is important to assess the birds future chances of survival before starting any lengthy treatments or surgeries

• Unlike other wild birds, they need very neat healing of fractures (especially wing fractures), because they need precision to hunt and survive

• The aim is to restore limb function as soon as possible

Describe how enteritis affects birds of prey

• Abnormal mutes is the main clinical sign

• They can also vomit/regurgitate, have blood/undigested food in their faeces and/or have anorexia

• Acute enteritis is an emergency → supportive care

• Causes: bacterial, fungal, viral, endoparasites, toxicity, other (e.g foreign bodies)

Describe how parasites affect birds of prey

• Can cause diarrhoea or white plaques in the mouth

• Causes: poor hygiene/biosecurity, poorly sourced/infected foods

  • Freezing pigeons before defrosting and feeding can prevent some infections 

• Wild birds will naturally have some parasite burden in balance- will not cause clinical disease

  • However, when they get ill/stressed, this can become unbalanced and make them clinically unwell- this is why all wild animals brought into captivity are routinely tested and treated for worms/parasites

Describe how crop stasis affects birds of prey

The crop is a store organ- if crop emptying is prolonged, the meat being stored inside will go rotten

Never feed a bird of prey if a cast has not yet been regurgitated= risk of gut obstruction 

Causes:

• Crop infection

• Inappropriate food 

• Dehydration

• Low body condition

• Over full crop/over gorging

What are the common husbandry issues for birds of prey?

• Poor housing

• Lack of exercise 

• Incorrect diet

• Lack of social interaction with humans and/or other birds of prey

What are the two basic housing systems for birds of prey?

1. Tethered on blocks or perches

2. Aviaries (or ‘free lofting’)

What are the different perch types and surfaces for birds of prey?

Perch types:

• Bow

• Block

Perch surfaces:

• Astroturf

• Nylon rope

• Natural materials

Describe the legislation around birds of prey

• It is illegal to take birds of prey from the wild and keep them without a DEFRA license, unless it is receiving treatment from a vet, or a person registered to treat and release

• Wildlife and Countryside Act 1981 is for the protection and management of wild animals

• Any species listed in Schedule 9 are considered non-native: these animals legally cannot be released or allowed to escape

  • Certain Schedule 9 wild animals can be re-released after a brief period of rehabilitation under a general license 

  • The general license applies to: barn owls, northern goshawks, red kites and white-tailed eagles

Describe the two types of indoor bird species

Psittacines

• Parrots/macaws/cockatoos/budgies

• Hooked beaks, short necks

• Zygodactyl feet

• Tropical and subtropical

• Predominantly seed eaters 

• Parrots kept for intelligence, trainability and mimicry

Passerines

• Perching/songbirds- canaries, finches

• Classified according to dietary preferences (hardbills vs softbills)

• Anisodactyl feet 

• Very high metabolic rate and higher temperature

• Individuals, flocks or same/mixed species

How can you sex indoor birds?

Sexual dimorphism:

• Budgies: blue cere in males, brown-red cere in females

• Cockatoos: black iris in males, brown iris in females

• Cockatiels: tail feather differences after first moult

Differences in behaviour (males are usually more vocal)
Endoscopy for visual assessment of the gonads

DNA analysis of blood/feather pulp

What are the general critical values for indoor birds?

• Very high metabolic rates

• High respiratory rates

• High heart rates

• High normal body temperature (higher in smaller birds, up to 42℃)

Describe how zinc toxicity affects indoor birds

• Signs of toxicity: lethargy, weakness, regurgitation, weight loss, anaemia, drinking and urinating more, neurological signs, feather plucking

• Caused by galvanised/powder coated metal: new cages, coins, car keys, wire, lead rings

Describe how bumble foot affects indoor birds

• Pressure sores on feet- ulcerative pododermatitis

• Secondary infections and abscesses can occur and cause bone involvement

• Predisposing factors: obesity, lack of activity, poor perching, nutritional problems, overgrown nails, poor hygiene

Describe how feather plucking affects indoor birds

• Many possible causes, often multifactorial (breeding relates, pain/behavioural issues)

• Other issues should be ruled out: nutritional deficiencies, improper husbandry, allergies, systemic disease, pain, zinc poisoning, poor wing clipping

Describe how over-bonding affects indoor birds

• Birds will be monogamous pair-bonded for life

• Certain interactions can result in an intense bond with one owner/themselves (mirrors)

• This can cause: regurgitation, frustration, stress, anxiety, feather plucking, aggression, excessive egg laying

• Prevention: share interaction and caring responsibilities equally

• Avoid stroking down length of back and mouth to beak feeding

• Do not positively reinforce courtship behaviours (e.g regurgitation)

• Remove all mirrors or mirror toys from the enclosure to avoid self-bonding

Describe how hypocalcaemia affects indoor birds

• Calcium metabolism requires vitamin D- UV light converts vitamin D to an active form

• This is a problem for indoor pet birds due to inadequate UV light exposure and calcium/vitamin D deficient diets

• Clinical signs: neurological issues, osteodystrophy, beak deformities, reproductive issues, poor feather quality and feather plucking

Describe how hypovitaminosis A affects indoor birds

• Vitamin A is important for health and immune function

• Deficiency affects epithelial cells throughout the body (respiratory, reproductive and urinary tracts)

• Clinical signs: nasal discharge, periorbital swelling, abscesses, white plaques in mouth/nares, conjunctivitis, breathing difficulties, increased urination and drinking, poor feather quality and feather plucking, bumblefoot, recurrent infections

Describe how respiratory disease affects indoor birds

• Can be due to primary/secondary infections, but often caused by air quality issues:

  • Dry, warm, smoke, air fresheners, perfumes, dust, inadequate ventilation, teflon toxicity

Describe the different types of diets that can be given to indoor birds

Seed-Based Diets

• Variable in quality and nutritional composition

• Bacterial and fungal contamination is common

• High in fat, low in amino acids/vitamins A, E and D/iodine

• Inverse Ca:P ratio

De-Husked Seed Diets

• Less contamination, nutritionally poor

Pulse Diets

• Better than seeds (more protein)

• Nutrient deficient (especially Ca)

• Best as supplementary food

Formulated Diets

• Complete

• Nutritionally balanced

• At least 50% fruit and vegetables

Specialised Feeders

• Some birds need pollen and nectar

• Must be made up fresh to avoid bacterial contamination

Describe how diets should be transitioned for indoor birds

• Transition from a seed-based to formulated diet is hard

• Diet changes should be gradual (e.g over 6 months) to reduce risk of hepatic lipidosis

Describe why grit is needed for indoor birds

• Often found in ventricular (gizzard) of most wild birds

• Recommended for all birds- especially smaller species

• Helps break down food, improved digestibility

• Protects GI tract from damage by sharp objects

• Source of nutrients (e.g calcium)

• Reduced risk of infection

What are the requirements of indoor bird cages?

• Size: must be able to extend wings in all directions as an absolute minimum, should be provided additional opportunity for exercise outside of the cage

• Construction: stainless steel (not powder coated), horizontal bars for climbing, avoid curved edges to maximise space, should be easy to clean 

How can indoor birds be identified?

• Reasons: identify breeding pairs, recognise offspring from particular parents, trace origin/supplier, trace/prove ownership

• Methods: ringing (female= left leg, male= right leg), microchipping, tattooing, rubber stamping

How/why is wing clipping carried out in indoor birds?

• Usually bilateral

• Use sharp, sterile scissors to cut primary feathers 

• Flight is still possible- warn owner

• Flight test: if flies  >7.5m, clip again

• Never cut blood feathers

How/why is claw/beak trimming carried out in indoor birds?

• Reasons: overgrowth, malocclusion, infectious disease, beak/claw fractures, perching issues

• Method: use dremel tool for beak (not hand clippers)

Describe the consequences and solutions of:

• Small cages

• Isolation

• Lack of UV

• Poor air quality

• Scary stimuli

• Lack of inappropriate perching

for indoor birds

Describe the triage process for wild birds

Initial Triage

• Triage begins with a phone call to a practice 

• If appropriate, bring to practice with a dark covered box, no food, away from predators, water only, hot water bottle if young or injured 

• Fill out admission form with key details of reasons for rescue- location, finders contact number- for returning to wild if possible 

• Emphasise practice now has bird: some practices get MOP to formally sign over bird

Veterinary Triage and Treatment

• Quiet, dark room with closed doors and no open windows

• Wear PPE: small risk of zoonosis

• Confirm species, categorise if alive, as alert > moribund, weight

• Full clinical exam (consider stress- can take 4-6 hours to recover): feel keel bones, body condition score, oral/eye exam, feather condition, ability to perch, wounds

• Warm, give fluids- tube feed or via injection 

• X-rays if required

What should you consider when seeing a wild bird in practice?

• Age of bird (nestling, fledgeling, juvenile, adult)

• What enclosure is best in the practice with what resources

• What the bird eats in the wild: what to feed in practice

• Disease risk in the practice

• Are any medications/immediate interventions required

• Urgency of transfer to rehabber

What are the husbandry standards for pet rabbits?

• Somewhere enclosed to hide/sleep

• Area to exercise 

• Should be able to take 3 consecutive hops, lie fully outstretched in any direction and stand up on their hind legs without their ears touching the roof

• For 2 rabbits: single enclosed area of at least 3m x 2m x 1m high 

• Sleeping quarters 

• Should have access to both areas all the time

What are the husbandry standards for pet guinea pigs?

• RSPCA minimum for a pair of guinea pigs should be 2m x 0.5m x25cm high, but ideally larger

• RWAF recommend 4ft x 2ft and access to an exercise area of 6ft x 4ft 

• They do not dig like rabbits, but should be given tunnels to run through and hide in

What are the substrate, water and enrichment recommendations for keeping small pet mammals?

Substrates

• Toilet area: absorbent, dust free substrate materials 

• Bedding: insulating materials

• Toilet area should be cleaned every day and the whole home should be thoroughly cleaned regularly- approximately once a week

Water

• Provide both a bottle and a bowl for rabbits and guinea pigs to give a choice

• Check ball bearing is flowing smoothly

• Change water daily 

Enrichment

• Toys 

• Food puzzles

• Foraging

Describe the ideal diet for guinea pigs and rabbits, and give the reasons for this

Ideal Diet

Guinea pigs:

• 85% hay (not alfalfa)

• 12% vegetables

• 3% pellets 

Rabbits:

• 85% hay (not alfalfa)

• 10% vegetables 

• 5% pellets 

Incorrect Diet

• Dental disease → gut stasis

• Obesity → arthritis/spondylosis → bladder disease

• Excessive dietary calcium → bladder disease

• Hypovitaminosis C → swollen joints → pain

Diet Basis

• Herbivores 

• They metabolise calcium differently: do not feed excess calcium

• Hind gut fermenters with continuously growing teeth- need lots of fibre for good gut and dental health 

• Muesli mix encourages selective feeding- complete pellets are best 

• Do not give alfalfa hay- but for some life stages, a limited quantity can be beneficial

What are the consequences of an incorrect diet in small mammals?

Incorrect Diet

• Dental disease → gut stasis

• Obesity → arthritis/spondylosis → bladder disease

• Excessive dietary calcium → bladder disease

• Hypovitaminosis C → swollen joints → pain

Gut Stasis

• Causes: pain, stress, incorrect diet, gastrointestinal issues

• Slowing or stopping of movement of material through the digestive tract: this can be fatal in hind gut fermenters

Describe the husbandry requirements for pet gerbils

• Best in a gerbilarium: offering space to shelter, dig and exercise- with solid glass walls and a secure wire-mesh top (metal bars can cause them to slip and injure legs/feet)

• Provide suitable bedding material: deep enough (20-30cm) so they can create a system of burrows. Non-toxic peat, wood chips and hay can be used (sawdust should NOT be used)

• Nesting material: should always be accessible (e.g cardboard, egg containers, empty toilet rolls but NOT cotton wool or similar ‘fluffy’ materials)

• Places to hide: dark nesting boxes with multiple entrances which do not allow light are ideal

Give the reasons for keeping small mammals

• Pets

• Breeding 

• Laboratory 

• Wildlife rehabilitation

Describe the behaviour of guinea pigs

• Prey species

• Crepuscular

• Not burrowers, but hide in abandoned burrows/under structures

• Live in social groups

• Use their voice (high pitched squeals) to raise alarm when scared

• ‘Purr’ to each other when content, whistle when excited

• Grinding/bruxism indicates pain

• Guinea pigs should also be kept in pairs, but thrive in bigger groups

• Never keep a guinea pig and a rabbit together

Give the critical values of guinea pigs

• Temperature: 37.5-39.5℃

• Heart rate: 230-380bpm

• Gestation: 59-72 days

• Respiratory rate: 40-120bpm

What should you first visually assess in rabbits?

• Alert and responsive

• Normal hopping

• Nose constantly twitching

• Coordinated

• No abnormal breaths/open mouth breathing

• Faeces normal, dry and round

• Chest movement not excessive

• Exploring environment and companions

• No teeth grinding

• No changes to eating/drinking etc

• No facial/eye/whisker shape changes

• No wounds, discharge, erythema or masses

Individually look at: ears, eyes, nose, mouth, feet, skin, coat and anogenital region

Describe the behaviour of rabbits

• Prey species

• Crepuscular 

• Burrowers

• Live in social groups

• Thumping with the hindleg is used as an alarm call

• Fear causes immobility or a flight response 

• Bruxism indicates pain

• Companion animals

• Rabbits should be kept in pairs- neutered male and female

Give the critical values of rabbits

• Temperature: 38.5-40℃

• Heart rate: 130-325bpm

• Gestation: 29-35 days

• Respiratory rate: 30-60bpm

Describe how small enclosures affects small mammals

• Lack of movement → arthritis → bladder disease 

• Poor ventilation → respiratory infections 

• Poor hygiene → pododermatitis and fly strike

Describe how dental disease affects small mammals

• Teeth continuously grow

• If rabbits/guinea pigs temporarily stop eating/have a dental malocclusion, their teeth overgrow

• Dental disease can therefore be a consequence of many things

Describe how arthritis/spondylosis affects small mammals

• Arthritis: painful inflammation of joints 

• Spondylosis: a type of arthritis that affects the spine

• Arthritis can be caused or worsened by obesity and lack of movement

• Spondylosis can be caused or worsened by lack of movement and the inability to stretch

Describe how bladder disease affects small mammals

• Increased calcium in the diet causes calcium build up/precipitate in the urine

• Arthritis can cause less movement and the inability to properly stance when urinating, and therefore rabbits do not fully void the bladder

• These cause ‘sludgy bladder’ or bladder stones, and can block the bladder entirely

Describe how hypovitaminosis C affects small mammals

• Guinea pigs only

• Caused by out of date dry food or an incorrect diet

• Greater requirement for vitamin C if pregnant so will need supplementation

Describe how pododermatitis affects small mammals

• Also known as bumblefoot: painful inflammation of the footpads

• Can progress to affect the bones in the feet 

• Causes: obesity, poor hygiene, incorrect flooring/substrates, lameness, lack of exercise, hypovitaminosis C

Describe how respiratory disease affects small mammals

• Very common in rabbits and guinea pigs 

• Caused by poor biosecurity, poor ventilation, dusty environments, weakened immune systems

Describe how myiasis/fly strike affects small mammals

• Dirty environments, urine staining or faecal accumulation can all attract flies

• Flies lay eggs → maggots → eat flesh → emergency

What are the causes of:

• Trauma

• Pododermatitis

• Respiratory disease

in small mammals?

Causes of Trauma

• Fighting (inappropriate enclosure, incorrect social grouping, inappropriate resources)

• Poor handling techniques 

• Enclosure design/maintenance

Causes of Pododermatitis

• Enclosure surfaces

• Enclosure design not supporting natural movement/behaviour 

• Hygiene

• Obesity

Causes of Respiratory Disease

• Poor ventilation and hygiene- ammonia levels

• Inappropriate bedding (not dust free)

• Mixed infections

What are the critical values for:

• Hedgehogs

• Rabbits

• Rodents

• Squirrels

How should you manage nutrition of small wild mammals in practice?

• Mimic natural diet where possible 

• Species-specific, pellet-based diet

• Carnivores/omnivores should be given road-killed wildlife, earthworms, chicks or mice

• Insectivores should be given earthworms, maggots or mealworms

• Herbivores should be given weeds, salad, vegetables, seeds or grain

• Should not be seed/muesli diet: causes selective feeding, nutritional deficiencies and obesity

• Enrichment (nuts, seeds, fruit, vegetables) can be given

What are the commonly treated wild species and their issues

Commonly Treated

• Hedgehogs

• Rabbits

• Rodents

• Squirrels

• Deer

• Badgers

• Foxes

Common Issues

• Injuries: cat/dog attacks, strimmer wounds, broken legs, RTA, fighting, traps

• Disease: myxomatosis, endoparasites, respiratory infection, renal disease

• Kits/pups/cubs: genuine or assumed abandonment