Feather plucking in a parrot

13 Feather plucking in a parrot




INITIAL PRESENTATION


Acute onset feather plucking in an Amazon parrot.



Introduction


Many companion species (e.g. dogs, cats and rabbits) present regularly at the veterinary clinic for routine vaccinations, thus giving the veterinary practitioner an opportunity to perform a full health assessment (including history and clinical examination). On the other hand, avian pets are often not seen at the clinic until significant signs of illness are noted. It is wise to nurture avian clients and encourage ‘well-bird checks’. If clients present a new bird, take the opportunity to obtain a detailed history and perform a full physical examination.



CASE PRESENTING SIGNS


A 1-year-old orange-winged Amazon parrot (Amazona amazonica) (Fig. 13.1, Box 13.1) was presented for nail clipping. It became evident during the consultation that the bird had been plucking feathers for the previous 2 weeks.


image

Figure 13.1 Orange-winged Amazon parrot.



BOX 13.1 Ecology of Amazon parrots



• Amazon parrots (Amazona spp) originate from central South America. Orange-winged Amazons are located in Columbia, Trinidad and Tobago, with their range extending south to Peru and central Brazil. They reside in forest and semi-open country.

• Amazons are sexually monomorphic. Gender identification is by DNA analysis of blood or feather pulp, or visualization of the gonads via coelioscopy.

• There are about 30 subspecies of Amazon parrot.

• They are generally quiet, feeding in treetops.

• The diet in the wild consists of various seeds and fruits, including fruit from palm trees and sometimes cocoa.

• Flocks accumulate for night roosting. Mated pairs usually pair for life, and stay close together.

• Although the species are not endangered in the wild, it is persecuted as an agricultural pest and captured for the pet trade. Some are hunted by locals as a food source. Orange-winged Amazons are listed on CITES Appendix II, restricting trade.


Husbandry


The parrot had been in the owner’s possession for 8 months. It was housed indoors in a large (1 m × 1.5 m × 2 m) metal cage, with free flight permitted in the living room for a total of 2 hours daily. A number of perches were present in the cage; all were round wooden dowel rods. Commercial parrot toys were provided on a rotational basis, of both plastic and wooden construction. The floor of the cage was lined with newspaper, which was changed daily.


The diet mainly comprised a dried seed and nut mix, sold for parrots. The bird also ate a small selection of fruit from time to time, including oranges and grapes. Fresh water was provided daily in a metal bowl.


A friend of the owner had been caring for the parrot 3 weeks previously, for a period of 1 week, while the owner was on holiday. The bird had remained in the owner’s home for the duration, but there had been some change in daily routine associated with the visiting carer.


The owner did not possess nor had come into contact with other birds. The carer did not have contact with other birds.



Case History


The owner noticed the Amazon’s claws becoming overgrown, and presented it for a nail trim. During the consultation, a history was taken and the bird examined. It transpired that the bird had started to pluck feathers from its sternal region 2 weeks previously (after the owner returned from holiday). The owner was persuaded to permit further investigation of the feather plucking problem.



Clinical Examination


Examination showed:


• Bird bright and alert

• Weight 480 g, overweight (keel not palpable due to fat layer overlying, usual weight range for the species is 440–470 g)

• Auscultation of air sacs was unremarkable

• Feather loss over the ventral sternum and axillary regions, with wings and legs unaffected

• Feathers present on sternum showed some dystrophy

• No locomotory problems detected.


DIFFERENTIAL DIAGNOSES


There are two main groups of aetiologies for feather plucking in birds – medical diseases and behavioural problems. It may be possible to suspect one or the other during the initial consultation, history taking and physical examination. However, in many cases, behavioural disease is diagnosed after ruling out medical problems. As this can be expensive for the owner, the list of differential diagnoses and investigations required should be discussed in full at the outset.


The medical differentials for feather plucking were:


• Malnutrition (’stress’ marks (horizontal bars or weaknesses) are usually present on the feathers, associated with interrupted feather growth): general malnutrition or specific (e.g. omega-3 fatty acid deficiency, excess salt)

• Systemic disease, e.g. hepatic disease

• Chlamydophilosis

• Air sacculitis

• Toxins, e.g. nicotine exposure (other signs may include excitability, vomiting, diarrhoea, and seizures), heavy metal toxicosis

• Environmental factors, e.g. low humidity, inappropriate photoperiod, noxious aerosols

• Metabolic disease, e.g. hypocalcaemia (principally grey parrots)

• Allergy, e.g. inhaled, contact, food (e.g. peanuts, sunflower seeds), insect hypersensitivity

• Endoparasites, e.g. giardiasis (common in cockatiels)

• Pain, e.g. over an arthritic joint

• Infectious causes of feather dystrophy (may present similarly to self-feather plucking, but the head may also be involved): psittacine beak and feather disease (PBFD, circovirus), polyomavirus (in older budgerigars that survive infection), ‘French moult’ (budgerigars, caused by PBFD or polyomavirus)

• Reproductive disease, e.g. ectopic egg, egg-related peritonitis

• Dermatitis, e.g. skin irritation, skin desiccation, folliculitis (bacterial or fungal), polyfolliculosis in lovebirds (usually ventral neck or dorsum, may be infectious aetiology (e.g. polyomavirus) or secondary to self-trauma)

• Uropygial gland infection

• Pancreatitis

• ‘Colic’

• Genetic, e.g. feather deformities (e.g. ‘feather duster disease’ in budgerigars)

• Neoplasia

• Hypothyroidism (few documented cases; ‘normal’ avian total thyroxine levels vary with species and season, so diagnosis is difficult)

• Ectoparasites (rare): mites and lice (highly host-specific).

The behavioural differentials for feather plucking were:


• Inadequate socialization (especially hand-reared birds)

• Failure to learn normal preening behaviours (again, especially hand-reared birds)

• Inappropriate daily routine, resulting in bird being ‘overtired’ (e.g. prolonged daylight period)

• Boredom

• Iatrogenic, e.g. after poor wing trim

• Reproduction-related, e.g. nesting frustration

• Fear/panic after a traumatic episode, cage-mate aggression.


Case Work-Up



History


Similar to other dermatological investigations, a detailed history should be obtained to gain as much information about the feather plucking bird’s current and previous environment. Suggestions for pertinent topics to cover include:


• Signalment: age, species, reproductive history, source

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Sep 3, 2016 | Posted by in SMALL ANIMAL | Comments Off on Feather plucking in a parrot

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