Budgerigars, canaries, lovebirds, cockatiels, and African Grey parrots are among South Africa’s most popular pet birds. However, these companion species are prone to a range of health and behavioural problems, including infectious diseases such as mycobacteriosis, and psittacosis, as well as nutritional deficiencies linked to unbalanced seed diets.^1,2

Stress-related behaviours, including feather plucking, are also common and often stem from inadequate stimulation or poor housing conditions. These issues underscore the importance of proactive husbandry, balanced nutrition, and regular veterinary care to ensure avian wellbeing.^1,2

Tackling avian TB and psittacosis

Avian TB: What you can’t see matters

Avian mycobacteriosis, or avian tuberculosis (TB), is a chronic, progressive bacterial infection primarily caused by Mycobacterium avium (serotypes 1–3). The disease predominantly affects the gastrointestinal (GI) tract and liver, although lesions may also develop in the spleen, lungs, joints, and, less commonly, the heart, skin, and bone marrow.³

Unlike mammalian tuberculosis, avian mycobacteriosis is mainly enteric. Infection often begins with a latent phase, during which birds show no visible signs, followed by lesion development and eventual cachexia leading to death.³

Clinical signs vary according to disease progression. Early infection may be asymptomatic or present with non-specific signs. As disease advances, birds may exhibit depression, ruffled feathers, fatigue, whitish mucoid diarrhoea, dyspnoea, ocular swelling, anaemia, emaciation, loss of pectoral muscle, abnormal gait, paralysis, and ultimately death. Lesions may range from deep intestinal ulcers to tuberculous nodules across multiple organs and can occasionally cause internal haemorrhage or liver rupture.³

Diagnosis is challenging due to the chronic, intracellular nature of the infection and the non-specific clinical presentation. Gold-standard methods include culture on selective media, and molecular detection using polymerase chain reaction (PCR) targeting genes IS6110, IS901, and IS1245.³

Serologic tests, including enzyme-linked immunosorbent assay (ELISA), haemagglutination, and agglutination assays, provide supportive evidence but may be species-specific or produce false positives. Tuberculin tests are a rapid field method but are unreliable in some bird species.³

Treatment of avian mycobacteriosis can be prolonged, often requiring 12- to 18-months. Currently, azithromycin is the most effective antibiotic for this infection, and recent in vitro studies show that combining azithromycin with clofazimine enhances antibacterial activity against M. avium.³

The sneaky spread of psittacosis

Psittacosis in birds, also known as parrot fever, avian chlamydiosis or ornithosis, is caused primarily by Chlamydia psittaci, though other species such as C. avium, C. gallinacea, C. buteonis, C. ibidis, and C. abortus can also cause disease.⁴

Clinical signs vary by species, age, and stressors. Many infections remain latent, while others manifest as lethargy, ruffled feathers, anorexia, ocular and nasal discharge, respiratory distress, diarrhoea, and decreased egg production. Stress, overcrowding, poor nutrition, or environmental changes can trigger symptomatic disease.⁴

Diagnosis is complicated by non-specific signs and intermittent bacterial shedding. Laboratory confirmation includes serological testing (ELISA, complement fixation, immunofluorescence, immuno-peroxidase) and PCR for detection of C. psittaci DNA. PCR and next-generation sequencing are increasingly preferred due to higher sensitivity and faster turnaround times than culture or older serologic methods. Different C. psittaci genotypes may produce variable clinical presentations in birds.⁴

Early detection and differentiation from other avian respiratory diseases are critical, as birds serve as reservoirs for zoonotic transmission. Maintaining strict hygiene, quarantine, and surveillance in breeding and pet bird populations is essential.⁴

Doxycycline (100mg twice daily for 10- to14-days) is the treatment of choice, with macrolides, chloramphenicol, or fluoroquinolones as alternatives. Prognosis is generally favourable if treatment is initiated early, although recurrence is more common in cockatiels, budgerigars, and lovebirds.³

Nutrition matters: Keeping feathered pets fit

Improper nutrition is a widespread issue in pet bird medicine. Deficiencies in proteins, fats, carbohydrates, vitamins, and minerals compromise health, immunity, and recovery from systemic disease.⁵

Malnutrition often occurs alongside illness, as sick birds reduce feed intake, creating simultaneous primary disease and nutritional deficiency. Periods of high demand such as reproduction, molting, growth, or stress, exacerbate vulnerability, making young and breeding birds the most at risk. Stressors such as handling, quarantine, temperature fluctuations, and treatment can further increase nutrient requirements or impair absorption.⁵

Clinical signs are typically chronic and subtle, often involving multiple organ systems. Integumentary manifestations include poor feathering, ruffled or brittle feathers, incomplete molts, and pigment changes. Protein and amino acid deficiencies, particularly lysine and arginine, are common contributors.⁵

Vitamin and mineral deficiencies (A, biotin, zinc, selenium, calcium, manganese, magnesium, niacin, and pantothenic acid) cause brittle feathers, scaly skin, and keratinized beak and nails.⁵

Vitamin A deficiency affects epithelial surfaces, producing crusty mucous membranes, white plaques in the oral cavity, and ocular involvement. Growth retardation, skeletal deformities, and osteomalacia or rickets result from deficiencies in protein, calcium, phosphorus, vitamin D3, and other nutrients. Essential fatty acids are necessary for growth, energy, and vitamin absorption. Deficiencies may cause fatty liver, poor skin condition, and susceptibility to infection.⁵

Vitamin K deficiency leads to haemorrhages and prolonged clotting times, while deficiencies in water-soluble vitamins (eg B1, B2) and vitamin E can cause neurological signs, muscle weakness, and encephalomalacia in young birds.⁵

Diagnosis relies on detailed dietary history, clinical examination, and evaluation of feed composition. Radiography can reveal skeletal and hepatic changes, while droppings or choanal swabs help assess intestinal flora.⁵

Clinical pathology may show nonspecific abnormalities, such as elevated liver enzymes (vitamin A) or SAP (calcium). Early recognition and dietary correction are essential to prevent chronic morbidity and support recovery from concurrent illnesses.⁵

The cornerstone of treating nutritional deficiencies in pet birds is providing a balanced, species-appropriate, and palatable diet. Nutrient requirements vary widely among species, so diets adequate for one bird, such as a budgerigar, may not suit exotic parakeets or larger psittacines. Seed type and quality are critical, as monocultures or poor-quality seeds often lack protein, fats, vitamins, and minerals. Sprouted seeds are especially beneficial for breeding birds due to higher protein and vitamin content.⁵

Psittacine diets typically include a mixture of millet, canary seed, wheat, and oats, with larger seeds for bigger birds. Fat-soluble vitamins are provided through natural feedstuffs: vitamin A from green leafy vegetables or cod liver oil, vitamin E from cereals and eggs, vitamin D3 from eggs or milk products for confined birds, and vitamin K from leafy greens.⁵

Vitamin and mineral supplementation, preferably via drinking water rather than feed, ensures consistent intake while avoiding over-supplementation. Natural sources such as cuttlebone, oyster shell, and mineral blocks complement commercial products.⁵

Pelleted diets offer a complete nutritional alternative, though acceptance may require gradual introduction, mixing with familiar foods, or presenting as a mash. Birds usually adapt over four- to 12-weeks with repeated exposure and careful management.⁵

Feathers and follies: Understanding pet bird behavioural disorder

Behavioural disorders are among the most frequent challenges in avian veterinary practice, often intertwined with underlying medical conditions. Companion birds such as parrots, cockatiels, canaries, and lovebirds are prone to behaviours including feather plucking, aggression, excessive vocalisation, and stereotypies. Effective management requires attention to both physical health and psychological wellbeing, as most behavioural issues are multifactorial in origin.²

Feather-damaging behaviour

Feather plucking, or feather-damaging behaviour, is a common self-directed problem caused by medical, nutritional, or psychological factors. Medical contributors include malnutrition, metabolic disorders, allergies, infections (eg C. psittaci, polyomavirus, circovirus), parasites, heavy metal toxicity, and neoplasia. In certain species, a genetic predisposition has been noted.²

Psychological causes include chronic stress, boredom, sexual frustration, sleep deprivation, and insufficient social interaction. Repetitive plucking may become obsessive and self-reinforcing.²

Management involves treating both medical and behavioural triggers. Comprehensive diagnostics should include physical examination, blood work, and screening for infections and metabolic disorders. Behavioural therapy focuses on environmental enrichment, adequate sleep, diet improvement, and structured social interaction. Owners must avoid reinforcing plucking. Ignoring the behaviour is often recommended. In severe or chronic cases, psychotropic medications may be necessary.²

Feather pecking in aviary species

Distinct from self-plucking, feather pecking occurs when birds remove feathers from conspecifics. Causes include nutrient deficiencies and frustration of natural behaviours like foraging or dust-bathing. Management strategies involve ad libitum feeding, balanced diets, enrichment to encourage natural behaviours, and improved housing with lower stocking densities.²

Aggression and biting

Aggression is a natural but undesirable behaviour, particularly in hand-reared parrots. Triggers include territoriality, dominance, fear, sexual frustration, and imprinting on humans. Wild-caught birds may display fear-based aggression due to negative prior experiences.²

Management begins with identifying the motivation behind the behaviour. Owners should learn avian body language, avoid reinforcing aggression, and implement environmental adjustments such as lowering perch height or relocating cages. Consistent handling and training help reduce stress and restore trust.²

Screaming and excessive vocalisation

Excessive vocalisation is often linked to attention-seeking, fear, boredom, or attempts to communicate. Environmental stressors such as isolation, poor lighting, or unstable routines exacerbate the problem.²

Complete elimination is unrealistic. Management focuses on reducing frequency by rewarding quiet periods, ignoring unwanted noise, providing mental stimulation, predictable routines, and social interaction.²

Stereotypies and Obsessive-Compulsive Disorders

Stereotypies, such as pacing, wire-chewing, or route tracing, emerge in restrictive environments and often reflect coping mechanisms for mental under-stimulation. Avian obsessive-compulsive disorders (OCDs) are anxiety-driven repetitive behaviours, including compulsive preening or self-mutilation.²

Differentiating between stereotypies and OCD can be difficult, but management generally combines environmental enrichment with pharmacologic intervention. Drugs such as fluoxetine, clomipramine, or amitriptyline may reduce compulsive behaviours under veterinary supervision.²

Sexual and reproductive behaviours

Sexual frustration and inappropriate human bonding are common in imprinted, hand-reared birds, manifesting as chronic egg-laying, regurgitation, or courtship displays. Proper socialisation during rearing prevents overbonding. Hormonal modulation with medroxyprogesterone may be indicated in refractory cases.²

Anxiety, phobias, and depression

Anxiety arises without a clear threat, often manifesting as hypervigilance, trembling, or escape attempts. Phobias involve intense fear of specific stimuli, while depression and apathy develop secondary to chronic stress, isolation, or environmental monotony. Management includes enrichment, social interaction, predictable routines, improved lighting, and, in severe cases, pharmacologic support with tricyclic antidepressants.²

Pharmacologic support

Medication should complement, not replace, environmental and behavioural interventions. Options include antihistamines for mild sedation, benzodiazepines for acute anxiety, selective serotonin reuptake inhibitors for compulsive or depressive behaviours, dopamine and opioid antagonists for self-mutilation, and progestins or tricyclics for hormonal or anxiety-related issues. Careful dose titration and monitoring are essential due to species-specific variability in drug metabolism and response.²

Practice pearls

1. Avian mycobacteriosis is a chronic bacterial infection primarily affecting the GI tract and liver, often requiring 12- to 18-months of azithromycin-based treatment.
2. Psittacosis, caused by psittaci, can remain latent or cause respiratory and gastrointestinal signs. Early detection is key to prevent zoonotic spread.
3. Malnutrition in pet birds manifests subtly with feather changes, brittle beaks, skeletal deformities, and poor growth. Deficiencies often involve multiple nutrients simultaneously.
4. Treatment relies on a balanced, species-specific diet with appropriate protein, fat, vitamins, and minerals, supplemented via feed or water and gradually introduced pelleted diets.
5. Feather-damaging behaviour and feather pecking stem from medical, nutritional, and psychological factors. Management combines medical treatment with environmental enrichment.
6. Anxiety, aggression, excessive vocalisation, and obsessive-compulsive behaviours require a combination of routine, enrichment, social interaction, and pharmacologic support when indicated.

Conclusion

Companion birds, including budgerigars, cockatiels, and African Greys, face intertwined challenges of infectious disease, nutritional deficiencies, and behavioural disorders. Early recognition and proactive management are essential for avian health. Infectious diseases such as avian mycobacteriosis and psittacosis require timely diagnosis and species-appropriate treatment to prevent chronic illness and zoonotic transmission. Nutritional deficiencies, often subtle and chronic, demand carefully balanced diets tailored to species, life stage, and activity level, with supplementation and gradual introduction of pelleted feeds. Behavioural disorders, including feather plucking, aggression, and obsessive-compulsive behaviours, arise from medical, nutritional, and psychological causes, requiring environmental enrichment, social interaction, and, in some cases, pharmacologic intervention. Integrated husbandry, veterinary care, and owner education are key to ensuring optimal health, wellbeing, and longevity in pet birds.

References

1. Peng S, Broom DM. The Sustainability of Keeping Birds as Pets: Should Any Be Kept? Animals, 2021.
2. Samour J. Avian Medicine 3^rd 2016 [Internet]. Available at: https://birdictionary.ir/uploads/fef80fb189b544df91561e9cc811be9d.pdf
3. Abd El-Ghany WA. A review of avian mycobacteriosis: An emerging bacterial disease of public health concern Wafaa A. Abd El-Ghany. International Journal of One Health, 2022.
4. Dembek ZF, Mothershead JL, Owens AN, et al. Psittacosis: An Underappreciated and Often Undiagnosed Disease. Pathogens, 2023.
5. Villm DL, O’Brien SE. An Overview of Pet Bird Nutrition. [Internet]. Available at: https://dr.lib.iastate.edu/server/api/core/bitstreams/dc8ad198-7c67-44a9-b7f2-7a6764af2338/content