Consultation and handling

Psychologically, most pet birds are little different from their wild ancestors – the veterinary surgeon constitutes a potential predator so the bird is likely to exhibit a flight or fight response when handled. Exceptions to this are hand-reared parrots (or imprinted raptors and owls). However, in extremis, birds vary in their susceptibility to stress, and while some, such as the larger psittacines, can be handled relatively safely, others, such as canaries, carry a greater risk.

A great many captive-bred, hand-reared birds can be superficially examined while perched on the owner or on a freestanding perch, thereby minimizing stress. If care and patience is undertaken, then auscultation of the lungs and air sacs, plus some assessment of body condition can be achieved in this way.

It is important to weigh parrots at every consultation (Fig. 5.1); tame birds can be accurately weighed using a small perch designed to fit on to standard weighing scales.

Fig. 5.1 Weighing a young harlequin macaw (hybrid blue and gold X green-wing).

Aggressive birds, or birds unused to handling, may require to be ‘towelled’ in order to examine them. Use a large towel that will cover most of the bird. Drop or place it over the bird such that the head is covered and the bird cannot see your hands. With one hand, grab the bird’s head or neck from behind so that there is control of the beak, and use the other hand to gather up the rest of the bird into the towel. Do not in any way compress the sternum, as this will seriously compromise the bird’s breathing.

Birds will attempt to mask signs of illness and so may not exhibit clinical signs until a disease course is quite advanced. It is important to observe the bird from a distance for several minutes prior to handling, as a relaxed bird is more likely to show signs of ill-health.

Nursing care

Fluid administration

• Per cloaca. Water can be absorbed from the cloaca (and naturally from material refluxed into the colon) so this can be used as route for rehydrating with small volumes where there is a risk of aspiration pneumonia (Table 5.2).

• Oral fluids are usually given by crop tube. Not suitable for birds which are regurgitating, recumbent or fitting.

• Intravenous. Birds can tolerate fluid replacement rates of up to 10 mL/kg given in a bolus, if given slowly over 5–7 min. Sites include the right jugular vein, brachial vein (Fig. 5.2) and the medial metatarsal vein. Intravenous catheters are difficult to maintain in birds so bolus administration is preferred. Isotonic solutions should be administered slowly at a rate of 10–15 mL/kg. A ‘shock’ dose of 90 mL/kg can be used if large volumes are needed rapidly. Suggested individual bolus volumes are listed in Table 5.3.

• Subcutaneous fluids can be given into the interscapular area (not caudal neck to avoid the cervico-cephalic air sac) or the inguinal region. Small volume (5–10 mL/kg) should be given at each site and absorption may be poor.

• Intraosseous. Distal ulna and proximal tibiotarsus. Strict asepsis + anaesthesia. All types of fluid including blood transfusions. Do not use very acidic, alkaline or hypertonic solutions i.o. without diluting them first.

Choice of parenteral fluids

• Crystalloids. Only 25% of a crystalloid solution remains in the peripheral vasculature 30 min after administration. Hartman’s solution contains lactate that is converted to bicarbonate by the liver and so may help correct acidosis but is contraindicated with hypernatraemia.

• Hypertonic saline at 3–7.5% will help to correct circulatory collapse by triggering fluid shifts from the interstitial space into the circulation, followed quickly by isotonic solutions to prevent tissue dehydration. Do not use hypertonic solutions if cranial haemorrhages are suspected.

• Colloids. Bolus administration of hetastarch at 10–15 mL/kg i.v. t.i.d. for up to four treatments may be safe and effective for hypoproteinaemia.

• Oxyglobin can be given at a dose rate of up to 15 mL/kg i.v. or i.o.

• Whole blood. Birds are tolerant of anaemia but a transfusion should be considered if the PCV falls below 15.0 L/L. Use blood from the same or similar species; blood groups, etc., have been only poorly investigated.

Table 5.2 Parrots and related species: Cloacal administration

Species	Suggested volumes for cloacal administration (mL)
Budgerigar	0.5
Cockatiel	1
Amazon	4
Macaw	6–7

Fig. 5.2 Placement of an intravenous catheter into the brachial vein of a cockatoo. Use a collar if to be kept in place for several days.

Table 5.3 Parrots and related species: Suggested individual bolus volumes

Species	Bolus volume (mL)
Budgerigar	1–2
Cockatiel	2–3
Conure	4–6
Amazon	8–10
Macaw	15–25

Anaesthesia

From a practical point of view, induction and maintenance with gaseous anaesthesia is of choice. Atropine can be given as pre-medication at 0.05–0.1 mg/kg s.c. This reduces mucus and counters bradycardia from vagal stimulation during surgery.

Gaseous anaesthetic protocol

1 Hold the bird’s head into a mask or place into an induction chamber. Isoflurane offers a rapid induction and recovery (as does sevoflurane).

2 Intubate (uncuffed endotracheal tube) whenever possible.

3 During anaesthesia, regularly positive-pressure ventilates to reduce risk of CO₂ build up in the abdominal air sacs.

4 Main sources of heat loss are the extremities (especially the feet), and the air sacs. Wrap the feet with silver foil and maintain the bird on an external heat source.

5 If using halothane, start at low concentrations (0.5–1.0%) and gradually increase to 3.0–4.0%. Induction at high concentrations can lead to dangerously high levels of halothane present in posterior air sacs. Attempts to resuscitate bird by flushing through with oxygen or manual ventilation will only force this reservoir of halothane through the lungs further increasing blood concentrations.

Parenteral anaesthesia

1 Always weigh the bird accurately before using parenteral anaesthesia, and always intubate and maintain on oxygen whenever possible.

2 A range of anaesthetic protocols are available from the literature. The ones the author has used include:

a Ketamine at 5–30 mg/kg i.v. or i.m. No analgesic effect. Avoid birds with potential liver/kidney complications

b Ketamine 5 mg/kg + xylazine 0.25–1.0 mg/kg i.v. or i.m.

c Ketamine 5–20 mg/kg + midazolam 0.25 mg/kg i.v. or i.m. This gives good sedation, muscle relaxation and recovery

d Ketamine 3–6 mg/kg + medetomidine 150–300 μg/kg i.v. or i.m.

e Both medetomidine and xylazine can be reversed with atipamezole at 5× medetomidine dose.

Air sac perfusion anaesthesia

Avian respiratory anatomy means that the trachea can be ‘bypassed’ by insertion of a suitable cannula into one of the caudal air sacs (abdominal or caudal thoracic) for delivery of oxygen and anaesthetic gasses. This technique is suitable for oral or tracheal obstructions or if surgery is required at or around oral cavity. Glottal or tracheal foreign bodies or other obstructions will usually give their presence away by producing a whistling sound during the respiratory cycle. These birds are extremely liable to sudden death. The main priority is to establish a patent airway as quickly as possible, therefore the need to anaesthetize and insert an air sac tube.

Air sac perfusion anaesthesia technique

1 Use soft tube with holes in walls.

2 4 mm diameter tube for 350 g bird, increasing pro rata.

3 A left lateral approach is used with the left leg extended cranially and a small incision made behind the last rib and ventral to the flexor cruis medialis muscle (Fig. 5.3).

4 A small pair of haemostats can then be used to enter the coelom in a craniomedial direction, which will provide access to the caudal thoracic air sac.

5 A tube is then secured in place with a suture and attached to the anaesthetic machine. Note that a higher airflow rate (> 50% above normal) will be required to maintain anaesthesia this way.

6 Can be left in situ for 1–3 weeks.

Fig. 5.3 Anatomical markers for the placement of an air sac tube.

Recovery

• Keep quiet

• Wrap wings gently in towel/paper toweling to reduce injury from flapping

• Keep warm, preferably mid-20s °C

• Recovery must be fast from anaesthetic – birds under 100 g should be eating within 30 min.

Cardiopulmonary resuscitation

1 Can use doxapram at 5–7 mg/kg i.m. or sublingually.

2 Intubate if not already done so.

3 Intermittent positive pressure ventilation once every 5 s.

4 If in cardiac arrest, begin rapid chest compressions.

5 Give epinephrine at 0.5–1.0 mL/kg of 1:1000 i.t., i.c., i.o., i.p.

Skin disorders

Avian skin is very thin with the epidermis only up to 10 cells thick in feathered areas. There are few cutaneous glands:

Commensal bacterial numbers on the skin of birds are considered to be lower than those found on mammals. Yeasts are infrequent commensals. Malassezia not isolated from normal or self-mutilating birds (Preziosi et al 2006); in the same study, Candida albicans was isolated but significance was unclear.

Feathers serve a number of functions including insulation, protection from trauma, accessories to flight, species recognition patterns and display. There are several types and sub-groups of feathers.

Feather types

1 Contour feathers are divided into:

a Flight feathers

i Remiges (carried on the wing)

(1) Primary – borne on the manus

(2) Secondary – borne on the antibrachium

ii Retrices (carried on the tail).

b Body feathers

c Coverts – cover the bases of the retrices or remiges

d Ear coverts – screen the external opening of the ear and improve hearing.

2 Other feathers include down feathers, filoplumes, bristles, semi-plumes. Various intermediate forms of feather will be encountered. Powder feathers usually structured like down feathers, occasionally semi-plumes and contours shed a fine white powder of keratin on to contour feathers to provide waterproofing. Particularly obvious in African grey parrots and cockatoos.

Signs of skin disease

Pruritus

• Flies

• Hippoboscids (flat flies/louse flies) occasionally encountered especially with aviary birds. Can transmit haemoparasites such as Haemoproteus and Leukocytozoon, as well as transfer mites and lice between individuals

• Lice. Can reach significant numbers on debilitated birds

• Ticks. Occasionally on new imports. Sudden death associated with tick attachment to head. Suggested aetiologies include hypersensitivity reactions, toxin injection or a tick-borne infection. Can also transmit other diseases such as haemoprotozoa, Borrelia spp and louping-ill

• Red mite, Dermanyssus avium and other species

• Northern fowl mite, Ornithonyssus spp

• Feather mites. Found between the barbs on the ventral surfaces of feathers. Often niche specific so in the budgerigar, Protolichus lunula is found on the wing and tail feathers, whereas Dubininia melopsittaci occurs on the smaller body feathers

• Quill mites. Live inside quills

• Sarcoptid mites present on the feather shafts may be encountered occasionally. Treat as above

• Quill wall mites

• Skin mites

• Epidermoptid mites

• Cnemidocoptid mites. Common is Cnemidocoptes pilae (scaley face/scaley leg)

• Harpirhynchid mites. Attach to feather bases. May induce hyperkeratotic epidermal cysts

• Cnemidocoptid mites

• Cheyletiellid mites. Rare

• Polyfolliculitis. Common in lovebirds. Multiple feathers arise from single feather follicle.

Ulceration/folliculitis

• Erysipelas

• Staphylococcus

• Aspergillus.

Feather damage, pathology and loss

• ‘Stress’ lines (see Findings on Clinical Examination) (Fig. 5.4)

• Dystrophic feathers sometimes occur secondary to folliculitis

• Polyomavirus (papovavirus). Usually presents in chicks but carried asymptomatically by adults. Signs include a distended abdomen, lack of or malformed down feathers, multifocal follicular and feather pulp haemorrhages, retarded growth of tail and contour feathers (infected budgie chicks may be referred to as ‘walkers’). There may be a urate soaked vent because the virus also infects the liver and the kidneys. Also slow weight gain, slow emptying crop and vomiting. This virus is responsible for budgerigar fledgling disease, which usually is rapidly fatal

• Psittacine beak and feather disease (PBFD) (circovirus) (Fig. 5.5). Usually affects birds less than 3 years of age. Signs include loss of feathers, decrease in down feathers on flanks, retained pin feathers, short clubbed feathers, deformed feathers. Beak may change in colour, grow abnormally and become necrotic beginning with a palatine crust in the maxillary beak. Secondary bacterial infections make the condition worse. Older, chronically infected African grey parrots may produce red feathers in abnormal position such as the covert feathers (Fig. 5.6).

Fig. 5.4 Stress lines in the primary and secondary flight feathers in an African grey parrot. Note also the abnormal red pigmentation.

Fig. 5.5 Psittacine beak and feather disease (PBFD) in a sulphur crested cockatoo.

Fig. 5.6 Abnormal red pigmentation in an African grey parrot with psittacine beak and feather disease (PBFD).

Diet

• In macaws especially, thinning of the feathers and retention of keratin sheaths of pin feathers, in particular the flight and tail feathers, is linked to poor diet.

• Unsupplemented seed diets are deficient in minerals, sulphurous amino acids and vitamins; birds on unsupplemented diets show increased feather replacement intervals (Wolf et al 2003) and may exhibit old, tattered feathers.

Self trauma

• Secondary to ectoparasites

• Hand-reared parrots may never learn the normal species-specific methods of preening

• Grossly abnormal feathers in budgerigars – so-called ‘feather dusters’ or ‘chrysanthemum disease’. This is a genetically recessive condition.

Scaling and crusting

• Papillomavirus – reported in Timneh African grey parrot. Proliferative cutaneous lesions seen on head especially eyelids, beak commissure and skin contiguous with lower beak

• Herpes virus. Described in cockatoos and macaws as dry proliferative lesions on the toes that are limited to extremities; not life-threatening.

Erosions and ulceration

• Neoplasia (squamous cell carcinoma) (Klaphake et al 2006).

Nodules and non-healing wounds

• Avian pox virus (skin pox)

• Wart-like lesions of the skin. Yellowish nodules form on the beak, eyelids and other areas of the skin that disintegrate and discharge a serosanguineous fluid. The areas then scab over. When present on the feet, lesions may occlude distal vasculature resulting in tissue necrosis of the lower extremities. Note can occur as a diphtheritic form or a septicaemic form

• Staphylococcus may occasionally be encountered as a cause of dermatitis. More often it is isolated as a secondary invader in bumblefoot

• Candidiasis has been seen as focal raised lesions as well as more generalized ulcerations. Head lesions reported in Eclectus parrots, Amazons and cockatiels. Aspergillus lesions, Trichosporon asahii and dermatophytosis are both occasionally encountered

• Feather cysts. Secondary to follicle damage; the developing feather is unable to emerge and forms a large, cyst-like structure

• Cryptococcosis (Berrocal 2004)

• Mycobacteria (Ferrer et al 1997)

• ‘Bumblefoot’ – typically chronic infection and abscessation of the feet, especially the plantar surfaces. Often due to Staphylococci or Streptococci.

Changes in pigmentation

• Erysipelothrix infections may cause an erythema of the skin. In an acute infection with sudden death.

Chronic ulcerative dermatitis (CUD)

• Usually associated with chronic conditions such as mycobacteriosis, tumours, abscesses or xanthomas. Poor nutrition may also contribute. Four main presentations are:

a Prepatagial CUD. Wing web area. Possibly linked to Giardia or hypovitaminosis E. Usually very pruritic and painful. Patagium may also be affected. Commonly seen in chronic self-mutilating African greys (Fig. 5.7)

b Proventer CUD. Keel area – common in African greys and large Amazons. Secondary to trauma following hard landings. Bruises or splits forming ulcers

c Postventer CUD. Between cloaca and tail. Possibly similar aetiology to proventer CUD. Poor nutrition also implicated

d Squamous cell carcinoma (Klaphake et al 2006).

• Ectoparasites (see ‘Pruritus’, above).

Fig. 5.7 Prepatagial chronic ulcerative dermatitis in an African grey parrot.

Alopecia

• Pruritic (self-mutilation) versus non-pruritic. PBFD is provisionally differentiated from self-inflicted trauma in single birds as feathers on head also affected; normally bird cannot reach these to self-damage.

Neoplasia

• Lipomas (Fig. 5.8), fibrosarcomas, liposarcomas and squamous cell carcinomas are some of the commoner skin neoplasms reported from birds. Xanthomas common especially in budgerigars. These are non-neoplastic yellowish nodules or plaques caused by an accumulation of cholesterol and fats. Can be ulcerative. Often found over an area of pathology such as a lipoma.

Fig. 5.8 Lipoma in a budgerigar.

Allergies

• There is a strong suggestion that allergies may be the cause of skin disease in some cases, especially old world psittacines.

Findings on clinical examination

• Observe bird in cage or at rest on owner. Assess if it show signs of typical sick bird – ruffled, fluffed up feathers, sleepiness, and tail ‘pumping’. Is it pruritic?

• Assess the surroundings. Are faeces normal? Stress or sudden influx of fruit may trigger very loose faeces

• Handle the bird:

• Examine nares, beak, eyes and buccal cavity including choana. Look particularly for signs of vitamin A deficiency (see Nutritional Disorders)

• Examine skin – note signs of inflammation, hyperkeratosis, ulceration, and trauma

• Assess feather quality:

• Stress lines – lines visible on the vanes of the feather that denote areas of poor quality of the barbs. Thought to be linked to release of endogenous corticosteroid

• Frayed, dirty or matted. Inappropriate sized caging may cause repeated damaged to the retrices of those birds with long tails such as parakeets and macaws

• Abnormal feather colouration may result from nutritional deficiencies, hepatopathies or PBFD

• Examination for parasites:

• Pluck one or two feathers for examination under a light microscope for ectoparasites and feather pulp examination

• Examine uropygial (preen) gland, cloaca and feet

• Auscultate heart, lungs, air sacs

• Palpate abdomen

• Anaesthesia may be required for anaesthesia with birds difficult to handle safely (Fig. 5.9).

Fig. 5.9 Anaesthesia of a cockatoo for further skin investigation.

The self-mutilating parrot

Self-mutilation, like stereotypies, is a form of abnormal repetitive behaviour exhibited in captive parrots. Often psychological in origin, the alternative of an underlying causal disease should not be ruled out, either as differential diagnoses or as contributing factors. Epidemiological evidence (Garner et al 2005) points towards there being an inherited susceptibility, an increased incidence in females and a link to certain stressful environmental conditions. There are no ‘quick fixes’ and investigation is often prolonged and expensive. A methodical and holistic approach is required. This should take into account the background of the bird, its environment, its disease status and its psychological well-being.

Findings on clinical examination

• Note if the condition is symmetrical. Self-mutilation due to psychological causes is often not symmetrical in early stages.

• Handle the bird:

• Examine nares, beak, eyes and buccal cavity including choana. Look particularly for signs of vitamin A deficiency.

• Examine skin – note signs of inflammation, hyperkeratosis, ulceration, trauma and seborrhea.

• Assess feather quality:

• Stress lines – lines visible on the vanes of the feather that denote areas of poor quality of the barbs. These may indicate that a significant stressor has happened to the bird at a crucial point in the development of that feather. This may have been a disease or nutritional deficiency.

• Frayed, dirty or matted. Inappropriate sized caging may cause repeated damage to the retrices of those birds with long tails such as parakeets and macaws.

• Abnormal colouration may result from nutritional deficiencies, hepatopathies or PBFD.

• Parasites:

• Pluck one or two feathers for examination under a light microscope for ectoparasites and feather pulp examination.

• Feather scoring. This allows a structured approach to defining and monitoring the extent of the self-mutilation. A final score is arrived at and noted, allowing an objective view of improvement or deterioration to be assessed. Feather scoring may prove difficult with a recalcitrant bird and should a GA be needed, e.g. for radiography – this would provide an ideal opportunity to assess this. (The feather scoring system in Figure 5.10 is from Meehan et al 2003a.)

Fig. 5.10 Feather scoring system.

Upper respiratory tract disorders

Nasal tract

Cere colour in budgerigars is a secondary sexual characteristic; in most sexually mature males it is a smooth, bright blue structure, while in most females it has a rougher texture, and is brown in colour. Young female light blue birds may have a pastel blue cere leading to incorrect sexing; these darken to a more normal female-type cere with maturity. Gonadal tumours may secrete inappropriate sex hormones that can lead to a change in cere colour of adult birds.

Rhinitis

Viral

• Paramyxovirus (see Lower Respiratory Tract Disorders, below)

• Influenza A (orthomyxovirus) (see Lower Respiratory Tract Disorders, below).

Bacterial

• Chlamydophilosis

• Mycoplasmosis

• Other bacteria.

Fungal

• Aspergillus

• Candida (see Treatment in Lower Respiratory Tract Disorders, below).

Dietary

• Hypovitaminosis A (see Nutritional Disorders).

Neoplasia

Other non-infectious problems

• Choanal atresia

• Allergies

• Rhinoliths. Require surgical removal followed by antibiotic cover. Often linked to hypovitaminosis A (Fig. 5.11).

Fig. 5.11 Blocked nares in an African grey parrot.

Investigations

1 Radiography

2 Rhinogram

3 Routine haematology and biochemistry

4 Culture and sensitivity

5 Endoscopy of choana

6 Biopsy.

Sinusitis

• Typically presents as swelling of the infra-orbital sinus

• For possible aetiologies, see both Rhinitis and Lower Respiratory Tract Disorders, below

• Bacterial

• Mycobacterium spp

• Mycoplasmal

• Fungal

• Papillomas

• Sunken eye sinusitis. Collapse of the outer delineating skin due to negative pressure in the infraorbital sinus, which results from blockage of normal connecting diverticuli. Should return to normal when sinus problem resolved

• Neoplasia

• Teratoma (Diaz-Figueroa et al 2005)

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