Chapter 5 Parrots and related species
Members of the parrot family are the commonest avian pet and, therefore, the most likely to be presented to the veterinarian. Table 5.1 shows the most commonly encountered species.
Consultation and handling
Important non-specific clinical signs in parrots
From Malley (1996).
• Tail-bobbing. A sign of dyspnoea. Respiratory rates of psittacines are high, but a recovery time exceeding 3 min would be considered abnormal
1 It is best to attempt an initial assessment before handling a stressed or extremely ill bird, as this may allow you to take some diagnostic shortcuts thereby reducing handling time.
2 Remove the bird to as quiet and darkened area as possible so as to reduce stress, preferably into a heated chamber such as an incubator, and supply oxygen as close to the bird’s head as possible.
3 Allow the bird a few minutes to relax in this warm, high oxygen environment before continuing with the examination.
4 If it is imperative to handle the bird, warn the owner first that although you must do this, there is a chance of losing the bird. If necessary ask the owner to sign a consent form.
5 Handle the bird either with your hands or with a towel. Never use gloves or gauntlets. With larger psittacines, if necessary have an assistant grip the head firmly from behind if you are concerned about being bitten. Do not grip around or otherwise compress the sternum as this will compromise respiration.
Nursing care
Fluid therapy
2 Increased skin turgor over the foot or upper eyelid, collapse or poor filling of the ulnar vein, sunken or glazed eyes, dry and tacky mucus membranes, tachycardia, depression and red or wrinkled skin in psittacine neonates all indicate dehydration.
3 The daily maintenance water requirement for psittacine birds is around 50 mL/kg per day, with that of passerines and young birds being much higher.
4 A 500 g (0.5 kg) bird with 10% (0.1) dehydration, therefore, requires (0.5 × 0.1) litres = 0.05 L = 50 mL fluid. As in other species, which fluids are given depends upon the reason for giving fluids. Half of the fluid deficit should be replaced within the first 12–24 h. The remaining 50% is divided over the following 48 h, to be given alongside the daily maintenance.
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.
• 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.
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 |
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 |
Wing clipping of pet parrots
A badly clipped bird is not only at increased risk of damage to itself, but such clipping may predispose to feather picking and self-mutilation. Wing clipping can be controversial but the major justification for wing clipping is that by doing so it facilitates the necessary interaction between a pet parrot and the other family members, allowing the bird to become involved with, and behave as, part of the family (or ‘flock’) rather than it be confined to its cage. However, the ideal would be that the bird is left fully flighted and controlled verbally using commands such as ‘step up’, ‘step down’, ‘leave’ and ‘no’.
2 It is the primary flight feathers that allow lift and it is these that should be trimmed such that the cut end is tucked beneath the coverts.
Analgesia
Table 5.4 Parrots and related species: Analgesic doses
| Analgesic | Dose |
|---|---|
| Butorphanol | 0.5–4.0 mg/kg i.m. every 2–4 h |
| Carprofen | 1.0–4.0 mg/kg s.c. p.o. b.i.d. |
| Ketoprofen | 1.0–5.0 mg/kg i.m. b.i.d. or t.i.d. |
| Meloxicam | 0.1–0.5 mg/kg s.c., p.o. s.i.d. |
| Morphine | 0.1–3.0 mg/kg i.v. |
Anaesthesia
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).
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.
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
c Ketamine 5–20 mg/kg + midazolam 0.25 mg/kg i.v. or i.m. This gives good sedation, muscle relaxation and recovery
Air sac perfusion anaesthesia
Air sac perfusion anaesthesia technique
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.
Skin disorders
Avian skin is very thin with the epidermis only up to 10 cells thick in feathered areas. There are few cutaneous glands:
1 Uropygial gland. Not present in all species, e.g. Amazon parrots and Pionus parrots. When present, it lies dorsally near the tip of the tail. There can be up to 18 orifices depending upon species. Usually bare except for a tuft of down feathers known as uropygial wick. Secretes a lipoid sebaceous secretion – sebum – that is water repellent. It also helps to keep plumage supple and smooth, contains vitamin D3 precursors, has antibacterial and antifungal properties and enhances feather colouration. However, most sebum is produced from epidermal cells that contain keratin-bound phospholipids that coats the skin and feathers.
Feather types
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
• 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
• 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
Feather damage, pathology and loss
• 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).
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.
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
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
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
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.
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)
• 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
Investigations
1 Routine haematology and biochemistry
a Zinc and lead levels may be appropriate to investigate low-grade heavy metal poisoning. Collect samples for zinc in either heparin or plain tube (without gel as this may contain zinc). Although blood levels can be indicative of zinc toxicity there is no absolute correlation between blood zinc levels and clinical signs. As a general rule, if zinc levels are >32.0–50.0 μmol/L and there are consistent clinical signs (see Neurological Disorders and Gastrointestinal Tract Disorders), then zinc toxicity should be suspected. Significant zinc levels are often accompanied by an absolute or relative monocytosis
4 Radiography. A standing view using horizontal beam is useful for detecting metallic foreign bodies in the conscious bird, otherwise lateral and VD views, under GA, are required for meaningful radiography
6 Serology for PBFD, polyomavirus, Aspergillus antigen and Chlamydophila antigen should be taken if thought necessary
7 Fresh faecal samples for parasitic examination – look for Giardia, nematode eggs, etc. Smears can be dried and stained
Management
• Optimize diet – consider converting on to pelleted foods; use of multivitamin supplements; reducing seed intake and increasing fruit consumption where appropriate
• Where there is significant feather loss, consider supplementary heating to counter loss of insulation
• If pruritic consider analgesia – meloxicam (Metacam oral suspension) at 1 drop/500 g body weight twice daily. Do not use steroids
• Collars
• Collars are inherently very stressful to parrots – they interfere with normal feeding (many parrots transfer their food to their mouth with a foot), flight, climbing and crop function. They are heavy relative to the weight of the bird and generally alienate the bird from its immediate surroundings. They also do not address any underlying cause or pathology and if these are not addressed then feather plucking/self-mutilation may resume when the collar is removed
• If possible hospitalize the parrot for 24–48 h to enable the bird to get used to the collar, as well as allowing any minor adjustments and reassessments to be made
• A collar should be removed only after the bird has been clinically well for a reasonable period of time, as it is likely that, as in other species, abnormal or triggering sensations will persist for some time following the clinical resolution of lesions. Early removal often results in repeat damage.
Treatment/specific therapy
• Cnemidocoptid mites, e.g. Cnemidocoptes pilae:
• Ivermectin at 0.2 mg/kg p.o., s.c. or i.m. A small drop may be applied topically over the jugular vein or on to the back of the neck and seems to work well. Injection is not recommended in birds weighing <500 g due to problems with toxicity. Treat Harpirhynchid, Epidermoptid and Cheyletellid mites as for Cnemidocoptid mites.
• PBFD
• In early viraemic form avian interferon has been used successfully, but no data exist for its use in more cases showing dermatologic signs. PBFD positive birds that show no feather abnormalities may be transiently viraemic and so should be retested. If negative after 90 days then are clear of the infection
• Neoplasia
• Cisplatin given intralesional at 17.5 mg/m2 (Klaphake et al 2006). Cisplatin is potentially nephrotoxic, ototoxic and has been linked with anorexia, diarrhoea, seizures, peripheral neuropathies and haematological disturbances. A dose rate of 30 mg/m2 has been linked with fatal toxicity (Manucy et al 1998)
• Lipomas in budgerigars can respond to L-carnitine supplementation at 1000 mg/kg of feed (De Voe et al 2004)
• Xanthomas typically occur over other lesions such as neoplasms or sites of previous haemorrhage and trauma such as at wing tips. Often require surgical excision
• Polyomavirus. In some countries such as the USA vaccination may be available. The virus may persist in the environment for some time so testing with PCR should be undertaken
The self-mutilating parrot
Background
• Captive bred/hand reared (CBHR) or wild caught? Wild caught individuals may be more prone to parasitic or psychological causes whilst nutritional may be commoner in CBHR. Hand-reared parrots may never learn the normal, species-specific methods of preening
• House bird or aviary. Again parasites commoner in aviary than living rooms. If aviary, are others affected?
• Is the parrot a recent introduction/acquisition of unknown clinical history, or a long-standing pet of known clinical history that has not been exposed to any new birds. Note that even long-standing pets become can be at risk of ‘new bird’ problems if introduced or exposed to other birds it has not previously been with, e.g. if the owner buys another bird, or the parrot is boarded at the local pet shop.
• Is it constant or recurrent, and if recurrent is it associated with anything (time of year, owner holidays, perceived periods of sexual activity). Does it occur at a particular time of day?
• Was there an apparent initial trigger? Building work? New dog/child/partner? Birds not used to change may not tolerate it well
• Does the bird self-mutilate when owner present or absent. If seen, how does bird behave whilst self-mutilating? Does it appear pruritic, vocalize or scream or even interrupt a favoured activity in order to self-mutilate?
• Try to find out what the bird’s normal demeanor is. Is the bird normally relaxed, fearful, aggressive?
• How has the self-mutilation progressed? Where did the bird start plucking and how did it progress?
Environmental
Lighting
• Photoperiod. Many of the birds kept as pets are equatorial in origin and so are physiologically attuned for a 12 h day/night cycle.
• Intensity. The majority of psittacines are open scrub (budgerigars) or high canopy (parrots) species that are exposed to high-intensity sunlight. This would include UV light that may act as a natural anti-parasiticide, bacteriocide and fungicide.
Diet
• Seed-based diets are inappropriate for sole, long-term maintenance of many psittacines. Fat and hence energy levels are too high, protein levels relatively low and of poor quality. They are also low in vitamin levels.
Environmental toxins
• Zinc, often from galvanized caging or cheap metallic toys. Blood levels can be indicative of zinc toxicity, but as with lead, there is no absolute correlation between blood zinc levels and clinical signs. As a general rule if zinc levels are >32.0–50.0 μmol/L and there are consistent clinical signs (see Neurological Disorders and Gastrointestinal Tract Disorders) then zinc toxicity should be suspected. Significant levels often accompanied by an absolute or relative monocytosis. Feather plucking can be associated with chronic low-grade zinc toxicity; gut problems may be seen as can cause gut stasis. In acute poisonings can damage liver and kidneys causing vomiting, polyuria, haematuria. Consider radiography to look for metallic foreign bodies in the gizzard. Other heavy metals such as lead, copper and iron may cause similar signs.
• Sodium calcium edetate at 35 mg/kg bid for 5 days, stop for 3–4 days then repeat. Continue until zinc levels fall
• Dimercaptosuccinic acid (DMSA) at 30 mg/kg p.o. b.i.d. for 10 days or 5 days per week for 3–5 weeks
• Toys. Psittacines are gregarious creatures. Most live as a pair within a flock and are constantly interacting with their flock members. All single psittacines should have a toy ‘friend’ that they can feed, huddle up to, beat up, and generally completely dominate. Other toys should be rotated or changed with great frequency. Particularly useful toys are:
• Wooden objects, as these can be systematically destroyed, exercising the beak and claws and occupying valuable time
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.
• 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.
• 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.)
Investigations
1 A general blood screen is highly recommended. Especially interested in WBC count and differential, liver and kidney biochemistry and zinc
Pathological causes of self-mutilation
Refer to Skin Disorders, above.
Otherwise significant conditions include:
• Staphylococcus has been linked to feather-picking in a budgerigar and feather loss in an unspecified psittacine (Hermans et al 2000)
• Endocrinological
• Sex hormone disturbances. Self-mutilation can be associated with seasonal changes or sexual activity. May pick at leggings. It is normal in many species to remove a patch of feathers ventrally at nesting time to form the brood patch whereby eggs can be kept warm. Consider measuring serum oestrogen or androstenedione levels. Possible sex predisposition towards females.
Psychological causes of self-mutilation
• True cause not yet elucidated. Adverse environmental stimuli likely to be involved in many cases (see Garner et al 2005); may in some cases be linked to commercial bird-rearing techniques and practices that nestling parrots are exposed to at a time of neurological development with high psychological sensitivity and receptivity
• Suggested manifestations include:
• Attention seeking. Abnormal behaviour is reinforced by the owner paying attention when bird self-mutilates
• Displacement behaviour. In the wild stressful situations can be avoided by flying off. In captivity this may not be an option and so fear/aggression may be channelled into exaggerated ‘normal’ behaviour such as preening
• Boredom, including the concept of time budgets. In the wild, a parrot will spend a significant amount of time flying to and from roosts and food sources, interacting with flock mates, avoiding predators and so on. In captivity this time void can be filled by extending other normal behavioural repertoires that it can undertake such as eating (esp. Amazon parrots) or preening
Psychotropic drugs
2 Doxepin at 0.6 mg/kg i.m. or i.v. s.i.d. or 2 drops of 5.0 mg/kg solution per 30 mL drinking water
Management
1 Correct diet. Ideally change to pelleted foods. At the very least, begin supplementation with multivitamin and/or calcium (if appropriate)
4 Consider environmental enrichment techniques (more/different toys; companion of same species if no risk of infection), etc. If left alone for long periods, consider leaving radio or TV on. Birds naturally inhabit noisy environments – silence usually means there is a predator about. Environmental enrichment (including provision of a conspecific companion) has been found to be beneficial in birds displaying both self-mutilation (van Hoek & King 1997) and stereotypies (Meehan et al 2003b, Meehan et al 2004)
5 If pruritic consider analgesia – meloxicam (Metacam oral suspension) at drop/500 g body weight twice daily
6 Attend to any obvious wounds. Application of topical amorphous hydrogel dressings, e.g. IntraSite Gel (Smith and Nephew Healthcare Ltd.) encourage secondary healing
7 Where there is significant feather loss, consider supplementary heating to counter loss of insulation
9 Avoid the use of collars unless absolutely necessary. May stress bird and interfere with normal behaviour including feeding and crop function
10 Basic training – ‘Step up’, ‘Step down’, ‘No’, and ‘Stay’ – can be useful in both interacting with the bird in a controlled manner and filling in valuable time. The ideal is to establish a parent:child or leader:follower relationship rather than a partner:partner one
11 Do not forget the owner. They are likely to be embarrassed at the state of the bird and feel guilty if they have been feeding their bird on the wrong food, or if some other managemental deficit is identified, but you need them on board for what is liable to be a prolonged haul. They must be encouraged not to lose heart, as improvement may take some time.
