Avian dermatology Flashcards
What information can be gained from the condition of the skin and feathers of birds?
- General health
- Nutritional status
- Management
- Environmental conditions
What is dermatological disease usually associated with in birds?
More commonly nutritional or husbandry than infectious
List the potential causes of abnormal feather colour in birds
- Not moulting
- Fret lines (stress, nutrition)
- Retention of pin feathers
- Endocrine disease
What is the cause of pin feather retention?
Inadequate nutrition so feathers not being pushed through and only grow to half way
List the differential diagnoses for cutaneous lumps and swellings in birds
- Periorbital abscesses
- Lipoma
- Xanthoma
- Feather cysts
- Squamous cell carcinoma
- Cutaneous papillomas
- Melanomas
- Fibromas
- Uropygial gland disease
- Subcutaneous emphysaema
Describe the appearance of a periorbital abscess
- Swelling next to the eye
- May see pus coming out of side of the eye
Describe the contents of periorbital abscesses
- Not true abscesses, can be sterile
- Accumulation of cellular material within the sinuses
- Debris from metaplastic layers of mucosal epithelium
What causes periorbital abscesses?
- Respiratory infection
- Vitamin A deficiency (cannot differentiate, general malnutrition)
- No orbital bones in birds (except penguins and owls) so pressure from fluid in sinuses pops out at the eye
Outline the diagnosis of periorbital abscesses
Site specific, very typical
Describe the treatment of periorbital abscesses
- Correct the nutrition and surgical debridement
- Cut over lesion, remove abscess
Which species are prone to periorbital abscesses?
African grey, Chicken (mycoplasma induced)
Describe the appearance of lipomas in birds
- Smooth raised mass growing in subcutis
- Yellow in appearance
What causes lipomas in birds?
Obesity, breed predisposition
Describe the common distribution of lipomas in birds
- Mainly sternum
- Abdomen (amazons, budgies, cockatiels)
- Pericloacal region (Galahs)
Outline the treatment for lipomas in birds
- Consider removal or advise to leave
- Correct nutrition (+/- responsive but always necessary)
What are xanthomas?
- aka Yellow mass
- Not neoplasms
- Are cholesterol deposits
When might xanthomas become an issue?
Are benign, but can be problem if become large or bird self traumatises, causing bleeding
Describe the appearance of xanthomas
- Yellow
- Thickened
- Featherless areas of skin, often vascular and friable
Describe the common distribution of xanthomas
Anywhere, but mainly dorsum and wings
Outline the treatment of xanthomas
- Excision
- Problematic if on wing
- If very large can amputate tip of wing
Which birds are predisposed to developing xanthomas?
Budgies and small psittacine birds
Describe the appearance of feather cysts
- Lumpy, irregular masses of keratinous debris
- Necrotic feathers
- Sometimes closed resembling abscesses
- More often open exuding caseous material and bits of feather
Describe the cause of feather cysts
- Genetic and herditary
- Breed and feather type predisposition in canaries
- Double Buff feathers
Describe the common distribution of feather cysts
- Dorsum and wings
- Can be singular or extensive
- Progressive increase in number with each moult/age
Describe the treatment of feather cysts
- Excision often unrewarding as other cysts form
- Euthanasia if extensive and bleeding due to self trauma
- May be able to pop manually
- Often just live with it
What conditions of the uropygial gland diseases can lead to the appearance of lumps?
- Adenoma
- Adenocarcinoma
- Abscess/impaction
How does subcutaneous emphysaema develop in birds?
- Leakage due to ruptured airsac/bone
- Normally resolves
List common diseases of the legs and toes of birds
- Rings too tight
- Articular gout
- Pododermatitis
- Nails too long
What may cause a leg ring to become too tight?
- Wrong size
- Ring trauma (self, other bird, cage/toy)
- Increase in size of leg (trauma, hyperkeratosis aka tasselfoot, foreign body wedged in gap causing swelling)
Describe the removal of leg rings from birds
- Need to make 2 cuts with cutters or jewellers wire
- Care not to fracture leg as ring twists
Describe the treatment of a leg that has been damaged by a leg ring
- Can withstand large amounts of tissue damage
- Cannot apply stitches
- Only debride if infected or necrotic
- may need to be bandaged, antibiotics and pain relief
Describe the appearance of articular gout in birds
- Crystals readily visible around tarsal joint as discrete, hard, raised, white/yellow lesions 1-3mm diameter
- Care not to confuse with abscess
- Very haemorrhagic if incised
How is articular gout diagnosed in birds?
Confirm diagnosis by staining for uric acid
Outline the treatment of articular gout in birds
- Ensure husbandry and perching appropriate
- Possible pain relief
- Allopurinol
- Euthanasia, treatment often not effective at this stage
Describe the appearance of pododermatitis in birds
- Most common in raptors, psittacine birds and waterfowl
- Inflammation and abscessation of sole of foot and plantar aspect of digits
What are the potential causes of pododermatitis in birds?
- Nutrition
- Obesity
- Inappropriate perches
- Lack of exercise
- Poor blood circulation to foot
- Cardiovascular changes at end of hunting season
Outline the treatment available for pododermatitis in birds
- Consider euthanasia if type 4+ on humane grounds
- Surgical removal of necrotic tissue (type 3)
- Suture to attempt closure by first intention (may require hydrocolloid dressing, culture of necrotic debris for accurate antimicrobial therapy)
- Use of foam snow shoe and conforming bandage
- Correction of predisposing causes
Outline the prevention of pododermatitis in birds
- Address husbandry issues
- Routine application of foot creams
In birds, what does the need to clip nails suggest?
- Poor husbandry
- Or underlying causes: mites, nutrition, arthritis, gout, malformed feet, inappropriate perching
List causes of feather loss without plucking
- Normal moult/escape moult
- Abnormal moult (malnutrition)
- Apteria (non-feather areas)
- Hormonal disorders
- Genetic
- Mate mutilation
- Popva and polyoma virus (French moult in budgies)
- Cutaneous pox virus
- Psittacine Beak and Feather Disease
- Knemidocoptic mites
- Bacterial and fungal folliculitis
What are the 3 groups of causes of feather loss with feather picking?
- Pathological
- Psychological
- Physiological
What is the causative agent of Psittacine Beak and Feather Disease?
Circovirus
Describe the clinical signs of Psittacine Beak and Feather disease
- Dystrophic feather growth, feathers appear pinched off, progressively worsens with successive moults
- Abnormal feather colouration(red streaks)
- +/- necrotic beak lesions
- Lack of powder don feathers leading to shiny beak
- Can affect liver
How is Psittacine Beak and Feather disease diagnosed?
- Always suspect until rule out
- Clinical signs
- Lack of powder don feathers leading to shiny beak
- PCR test (+ve = +ve, -ve = test again)
Which species have a high incidence of Psittacine Beak and Feather disease?
White cockatoos and African Greys
How does Psittacine Beak and Feather disease cause its clinical signs?
Affects growing hair follicles
Where do knemidocoptic mites typically infect?
- Non-feathered areas of face (cere and beak)
- Legs of budgies
Describe the appearance of infection with knemidocoptic mites
- Honeycomb appearance of tissue or hypertrophy of scales of legs
- Causes excessive growth of beak
- Nutritional and immune status of individuals
What is an important differential diagnosis for knemidocoptic mite infestation?
Benign hypertrophy of the cere with age
How is infestation with knemidocoptic mites diagnosed?
Scraping and microscopy
Outline the treatment for knemidocoptic mites
- 2-3 drops ivomectin direct to site, 3x weekly applications
- Soften heavy scaling with liquid paraffin a few days before application
- Trim beak
- Treat infection
Describe the appearance of bacterial and fungal folliculitis of birds
- Necrotic, malformed, easily damaged blood feathers
- Esp. of tail
What is important an underlying cause of bacterial and fungal folliculitis of birds?
Malnutrition
How is bacterial and fungal folliculitis of birds diagnosed?
Feather pulp cytology and culture
Outline the treatment of bacterial and fungal folliculitis of birds
- Nutritional modification
- Appropriate oral antimicrobials
- Wash/spray affected area with antimicrobias
What are blood feathers?
During feather growth, period of time where they have blood supply, then is lost. Called blood feathers while have blood supply
How might damage to blood feathers occur?
- Poor wing clipping
- Malformation (nutritional, infection)
- Self trauma (chewing due to pain, causes more damage, chews more etc.)
What advice could you give to an owner for the treatment of a damaged blood feather?
- Pull out bleeding feather depending on site
- Pinch with fingers or forceps to assist clotting, need to restrain bird well
- Dust with cornflower
What treatment can be provided in surgery for a damaged blood feather?
- Pull out feather +/- GA
- Administration of pain relief: oral meloxicam (or injection), local pain relief
- Correct/discuss underlying cause
Why is pruritus uncommonly the cause of feather picking?
Birds have little subcutis, few cells present (incl. histiocytes) so little histamine release and pruritus uncommon
Why are steroids not commonly used in the treatment of feather picking in birds?
- Contraindicated due to immune system complications
- Pruritus also rarely cause of feather picking
Explain how fret lines in feathers develop
- Corticosteroids regulate sugar, and produced when stressed
- Hyperglycaeamia in stress due to gluconeogenesis which requires proteins
- Consistent stress means no protein left for production of feathers leading to fret lines
How is feather picking in birds identified?
- Healthy head feathers and feather loss and/or mutilated feathers in body areas accessible to bird’s beak
- Detailed history required
- Common sites include propatagium, inner thighs and sternum
What is required for the diagnosis of the underlying cause of feather picking?
- Thorough history
- Physical examination
- +/- Faecal examination
- Haematology
- Radiography
- Laparoscopy
- Culture and biopsy of affected sites
In what order should the groups of causes of feather picking be investigated?
- First pathological
- Then psychological
- Then physiological
List the potential pathological causes of feather picking and how these are diagnosed
- PBFD, chlamydophila, fungal, bacterial: PCR, cytology, culture
- Zn and Pb poisoning: Blood tests
- Liver disease, hypocalcaemia: biochem, haematology
- Internal disorders and organopathies: radiographs
- Internal parasites and gut based disease: faecal exam (grams, wet mount and flotation)
- Quill mites, lice: microscopy
List the potential psychological/physiological causes of feather picking
- Attention getting device
- Boredom
- Crowding
- Environmental changes
- Exaggerated preening
- Teerritorial
- Jealousy
How are physiological/psychological causes of feather picking diagnosed?
Ruling out pathological causes and history
Outline the treatment for feather picking
- Depends on cause
- Nutritional/husbandry correction
- Behavioural counselling
- Medical treatment where appropriate
Compare the prevalence of pathological, physiological and psychological causes of feather picking in different bird species
- Amazons more commonly path
- Cockatiel often physological
- African grey most commonly psychological, rarely physiological (intelligent)
What are the common sites for self mutilation in birds
- Wing webs
- Mid back
- Feet, toes, inner thighs
- Pectoral areas around anterior sternum
Outline the treatment for self mutilation in birds
- Isolate reason and correct
- Prevent further damage using collars for short periods (cotton wool and tape)
- Debride and repair lesions
- Antibiotic cover (+/- culture)
- Consider psychoactive drugs e.g. haloperidol, diazepam
What are the common signs of external parasitism in birds?
- Irritation
- Agitation
- Poor feathering
- UNCOMMON cause of feather loss
What needs to be an important consideration when treating a bird for external parasites?
Underlying conditions that predispose to infestation
Which birds are more commonly affected by lice?
- Canaries
- Pigeons
- Swans
- Poultry
Describe ticks in birds
- Serious cause of individual death
- Aviary birds and birds of prey common
- Cause haematomas
Discuss the importance of Dermanyssus gallinae in birds
- Serious problem in bird rooms
- Disrupt incubating hens and kill chicks due to anaemia
- Difficult to control as live in environment
Name the species of mite that commonly affect birds
Knemidocoptes mutans and pilae
