Avian Medicine Flashcards
1
Q
Describe how to take a good history in avian medicine
A
For how long have you had this bird? where did you get it from? is it living with other birds? when was the last introduction of birds? has this or any of your other birds been sick in the past? has it been tested for circovirus, chlamydia or other diseases? has the sex been confirmed by PCR? Describe the cage, situation and temperature of the rom, describe diet offered and diet consumed, including mineral /vitamin supplements and brand names, how much time does the bird spend outside its cage, is it allowed free flight, does anyone in the house smoke, is the bird location in or near the kitchen, what is the hunting and feeding schedule for raptors? what is the weight before hunting?
2
Q
What diseases can be diagnosed by tests such as PCR and Serology?
A
Chlamydia, psittacine beak and feather disease virus, polyomavirus or proventricular dilatation disease (caused by a bornavirus. The possibility of becoming infected after having been tested exists.
3
Q
Describe what may be seen on visual examination of a bird
A
may be fluffed up feathers - sick birds conserve energy and will fluff out feathers to conserve heat. Respiratory rate and effort should be noted, and dyspnoeic birds may be tail bobbing. A voice change is indicative of obstruction or infection of the syrinx. Severe dyspnoea together with a voice change is an emergency presentation, generally linked to aspergillosis or tracheal foreign bodies. Birds are experts at hiding illness so subtle changes in behaviour or weight are important observations which require immediate veterinary attention. Droppings should be examined to detect abnormalities such as diarrhoea, melena or biliverdinuria. Stressed birds usually produce watery droppings. Seed eating birds will have a darker central faecal component with small amounts of urates and minimal urine. Birds on extruded diets will have more voluminous faeces and higher moisture content.
4
Q
Describe what parts of the bird should be examined in the clinical exam
A
The birds weight should be determined to the nearest 1g for small birds. This is critical for drug, fluid and food calculations. comparing with previous weights form the same animal, comparing to reference weights for the species and assessing the response to therapy. Parts of the body that should be examined include the eyes, for swelling, discharge, cataracts, corneal ulcers. Nostrils - for secretion, assymetry, rhinoliths, Beak for symmetry, fractures, overgrowth. Cere- check colour and overgrowth, Oral cavity - check tongue, mucosae, choanae and papillae. Palpate the crop (full crop in a very sick bird may indicate acute presentation). Ears - otitis are a common cause of neurological signs. Feathers - presence/absence of and pattern of loss, abnormal growth, wear, stress lines, moult, ectoparasites, blood feathers. Pectoral muscle - palpate to assess body condition score, consider birds lifestyle to interpret. auscultate with paediatric stethoscope over sternum, dorsum and vetntrum caudal to sternum. Feet for pododermatitis, overgrown nails, missing toes, excessive faecal build up. Check grip by using a pen or finger and manipulate the legs NOT IN RAPTORS. Palpate the coelomic cavity and check for enlargement, masses, fluid retention, egg binding, hepatomegaly do not misidentify the normal gizzard for an egg or a mass. Check uropygial gland for impaction - not present in amazons and some macaws. Check pericloacal region for faecal build up on feathers. Cloacal mucosa - check for colour, presence of papillomas or prolapse. Examine the wings and check for feather damage, fractures, xanthomas and range of movement. Basillic vein - check for volume and refill, particularly when there is a suspision of dehydration or blood loss.
5
Q
What are the DDx for regurgitation?
A
Behavioural/sexual (male budgies), thyroid hyperplasia (budgies), crop burn (hand fet psittacines), crop candidiases, trichomoniasis.
6
Q
What are the DDx for Vomiting?
A
Gastric foreign body, gastric impaction or tumour, gastric ulcer, intestinal obstruction, peritonitis, liver disease, heavy metal toxicity, administration of some drugs (itraconazole, doxycyline)
7
Q
What are the DDx for crop stasis?
A
Crop infection or unspecific disease in neonates
8
Q
What are the ddx for diarrhoea in birds?
A
Infectious parasitic gastroenteritis, proventricular dilatation disease, intestinal intussusception, diet change with increased fruit content, liver disease, antibiotic therapy, heavy metal toxicity.
9
Q
What are the ddx for melena?
A
Gastroenteritis, cloacal papilloma, cloacal prolapse, egg binding
10
Q
What are the ddx for undigested food in faeces?
A
Proventricular dilatation disease, enteritis, exocrine pancreatic insufficiency.
11
Q
What are the differential diagnosis for Tenesmus in birds?
A
Egg binding, cloacal prolapse, cloacolith, GI parasitism, Organomegaly
12
Q
What are the differentials for abdominal distension?
A
organomegaly, abdominal hernia, obesity, ascites
13
Q
What are the differentials for biliverdinuria?
A
Hepatic disease, hamolysis
14
Q
What are the differentials for polyuria?
A
Kidney failure, psychogenic polydipsia, increased water content of food
15
Q
What are the differentials of dyspnoea?
A
Pneumonia/air sacculitis, organomegaly, tracheal obstruction
16
Q
What are the differentials for feather loss?
A
Self mutilation, PBDF, Nutritional deficiencies, folliculitis
17
Q
what are the differential diagnosis for neurological signs in birds?
A
Heavy metal toxicity, gypocalcaemia, trauma, newcastle disease, Hepatic encephalopathy, compression of leg nerves (dystocia)
18
Q
What is ring compression?
A
Rings can compress the leg and compromise its viability. Causes include small rings placed in growing animals, accumulation of debris and dead skin the space between leg and ring, inflammation of the tarsometatarsal area and psittacine birds crushing rings with their beaks. In addition the ring can be caught on wire and produce fractures, luxations or inflammation. under anaesthesia the ring should be removed with bold croppers. PRovide analgesia antibiosis and dress wounds. Amputation is needed when distal leg is not viable.
19
Q
What is a wing clip?
A
Done to prevent escape or to provide help short term with training. Clipping wings should not be performed on welfare grounds. In addition, birds can develop other problems such as psychological problems by avoiding the flight response, keel damage from falling from a height this can lead to osteomyelitis and self mutilation on that area, poor moulting because of the weight of a feather is a trigger factor for the molt, feather picking of old splintered feathers which can lead to more generalised plucking.
20
Q
What is imping?
A
A traditional falconry technique used to replace a damage feather using another feather as a graft. Keep a store of frozen feathers. not as useful to solve a wing clip as in most cases the rachis is damaged making imping impossible. in these cases, feather stumps should be removed under anaesthesia and analgesia (primary feathers are attached to the periosteum)
21
Q
Describe what may lead to excessive claw overgrowth? When should the claws be trimmed?
A
The vet meeds to assess the need for this procedure as many owners request it when the nails of their bird are actually normal. Perch design and nutrition can be a cause of claw abrnormalities. Perches should be of variable diameter along their legnth with a rough surface. Malnutrition, high protein diets and in particular liver disease should be suspected in any bird with overgrowht claws as they lead to abnormal keratin metabolism. Use canine nail clippers or dremel. Anaesthesia / sedation may be used. Haemorrhage control with silver nitrate. Corn flour or cotton soaked with peroxide if emergency phonecall.
22
Q
When is a beak trim needed in birds?
A
Similar to claw trim, many times the owner requests beak trim and this is not actually needed for the bird. Information about normal beak length in parrots should be provided to the client. when there is a true overgrown, underlying problems include: congenital malocclusion or damage during the hand rearing process with syringe or spoon, distorting beak when still malleable, trauma liver disease or malnutrition in adults. dietary correction leads to an increase in the time between reshapes. The procedure should be done under anaesthesia and with a dremel. These rotary tools generate heat and a damp cotton bud or guaze should be used to cool the beak. Aggressive bak trims also need analgesia
23
Q
How can temperature be controlled in birds under anaesthesia?
A
Hypothermia is the mainc ause of anaesthetic deaths and complications. Body temperature of most birds is 40-42C. Birds under anaesthesia lose temperature very quick, and this is ven more pronounced in small birds. Whent he feathers are plucked from large areas of teh body, feathers are used by the bird to regulate its temperature, when the skin becomes wet e.g with the excessive use of disinfectants such as alcohol or when the procedures such as coelitomies are done. fluids should be warmed up to birds body temperature before administration. Temperature control suing a rectal thermometer is mandatory. Temperature setup in small animal surgical theatre is too cold for birds and a room temperature around 22-25C is recommended. Other ways to avoid hypothermia are the use of heat mats, heat lamps, hot air, heated sandbags or gloved filled with hot water.
24
Q
How can the respiratory system be controlled in a bird during anaesthesia?
A
Intubation and assisted ventilation is the best way to avoid respiratoy complications such as apnoea, hypoventilation, atelectasis or blockage of the endotracheal tube with secretions. Birds are easy to intubate, and lubricated uncuffed tubes are used as tracheal rings are closed (complete). Very small birds can also be intubated but the chances of obstructing the endotracheal tube with secretions increase. Open anaesthetic circuits are used because birds do not have the strength to move air through a close circuit. Birds in sternal recumbence breath better but this can be correcetd in other positions using assisted ventilation. A pre anaesthetic respiratory rate should be taken with the animal free of stress and that rate should be applied during anaesthesia. Or 10-20 breaths/ min can be used in those birds not breathing by themselves and 2breaths/2 min in those breathing spontaneously. The use of a capnograph is useful to monitor efficacy of ventilation. Should be kept at 30-4g mmHg. Ventilation using an ambubag or mechanical ventilator should not exceed 10-20cm H2o to avoid trauma to lungs and air sacs.
25
How can cardiac system be maintained during anaesthesia?
Cardiac output should be monitored with the use of a doppler generally over the cubital artery (radial). The presence and intensity of the pulse can also be appreciated placing a finger over the cubital artery. Pulsoximeters are not calibrated for avian haemoglobin and therefore do not provide reliable results. Heart arrests are usually fatal in birds and therefore the cardiovascular function should be supported using an intravenous or intra osseous catheter and fluid therapy. blood pressure can be obtained using a doppler and placing a small cuff in the proximal humerus or tibiotarsus.
26
Should food be withheld from birds before surgery?
Witholding foot not necessary for passerines and parrots although it is always recomended to have an empty crop before surgery. Carnivore and psicivore birds easily vomit under anaesthesia and food should be withheld for 4-12 hours depending on the size of the bird. For raptors it is worth checking that a cast has been produced after the last meal. Quick intubation reduces the chances of tracheal aspiration.
27
How is induction done with birds?
With gaseous agents with a face mask and the bird is ready of intubation in 1-2 minutes when using 1L/min o2 and the gas at maximum concentration. Isoflurane is the anaesthetic agent of choice. Sevoflurane can also be used, but it is more expensive and the efficacy is very similar. Injectable agents are rarely used, although there are also effective and safe protocols; alfaxalone, propofol or combination of ketamine with alpha 2 agonists can be used in birds both IV and IM.
28
How should a bird be intubated?
The tongue should be pulled forwards with atraumatic forceps. The glottis will be seen at the base of the tongue as birds do not have epiglottis. the lubricated tube is placed and secured and anaesthesia is maintained with oxygen and gas. An air sac tube placement can help relieving respiratory distress associated to partial or total blockage of the trachea and gas anaesthesia can also be delivered through the air sac tube when a tracheoscopy or surgical procedure in the trachea needs to be performed. Organomegaly, ascites or severe lung/air sac pathology may complicate the placement of an air sac tube and previous radiographs may help detect those complications.
29
Which reflexes should be present in a bird during surgery?
During surgical anaesthesia, palpebral reflex should be absent but corneal reflex should be present. The loss of corneal reflex indicates an excessively deep plane of anaesthesia.
30
What are the possible side effects of NSAIds in birds?
eg meloxicam, carprofen, celecoxib. Generally safe but watch renal and GI effects, particularly with high doses and long therapy. Can be given parenterally or orally. Ideal for short treatments given by the owner at home.
31
What suture materials are commonly used in birds?
Should be absorbable, synthetic, monofilament and degraded by hydrolysis. In a study, polydioxanone produced the least amount of tissue reaction and took more than 120 days degradation (PDS) while polyglactin 910 ( vicryl) produced more reaction but was degraded in less than 60 days. Cyanoacrylate tissue glue can also be used but may delay healing if it runs between the apposed tissues, creating a physical barrier for healing.
32
What may be the cause for a toe amputation?
Due to avascular necrosis (circumferential constriction by fibers or scrans) or trauma (aggression, open fractures). less common causes include frostbite, lymphoma, mineralisation of vessels, knemidocoptes infection. Place a tourniquet higher up in the leg and allow extra skin on incision to close up.
33
What is a feather cyst?
Common genetical condition in canaries. Also seen in psittacines. the feather cannot erupt and the cyst keeps growing. Multiple cysts may be affecting the same bird. Surgery is done for large cysts but other cysts will continue growing in other feathers. Most commonly found affecting the wings. A tourniquet is placed, the cysts is opened and emptied and the follicle is removed with scalpel or cauterised with radiosurgery. Bleeding should be controlled. Skin closure may not be possible and the area may need to heal by second intention with or without the use of bandages.
34
How can a cranial skin defect be corrected?
Trauma can produce loss of skin on teh dorsal area of the head. A pedicle advancing flap is recommended for these wounds. Two parallel incisions are done on the skin of the dorsal aspect of the neck between the defect and the shoulder area and the flap created is advanced to cover the skull defect. The skin edges are opposed with an interrupted suture pattern.
35
Why might crop surgery be performed? how is this approached?
Performed to take a biopsy or to resolve a crop burn. For biopsy an area on the lower right side of the crop is prepared for surgery. some feathers may need to be removed. the skin is incised taking care not to reach the crop which is right under the skin and attached to it. The crop is dissected away from the skin and then two stay sutures are placed to exteriorise a section of the crop. Using scissors, a piece of crop ideally 1x1cm is removed and the defect is closed with an apposing pattern, which can be reinforced with an inverting pattern on top of it. For crop burns it is advisable to wait a few days after the injury to better see the difference between dead and viable tissue, following the same technique as for biopsy the dead crop wall is removed.
36
When is a coeliotomy performed?
Performed in cases of dystocia, prolapse, neoplasia, peritonitis, gastrointestinal foreign body, abdominal hernias or reproductive disease. It should be avoided when the same procedure can be performed using endoscopy. Coeliotomy carries a bad prognosis in very small patients such as canaries and budgies. Depending on the organ affected, a lateral or ventral approach can be performed.
37
How can fractures be managed in birds?
Fractures of the long bones (humerus, ulna, radius, femur, tibiotarsus and tarsometatarsus) are resolved using external fixation or a combination of an intramedullary pin and external fixation. Fractures of the tibiotarsus and tarsometatarsus in very small patients can be managed with a tape splint i.e compressing the leg between layers of tape. Fractures of the metatarsus in smalla nd medium birds can be managed with a shroeder thomas splint. the humerus and femur are pneumatic bones. In fracturesinvolving the radius and ulna, if one of those bones is intact, then an IM pin can be used to stabilise the fractured bone using the intact bone as an external stabilisation.
38
How can bandages be used for injuries in birds?
Bandages can be used to treat fractures, stabilise fractures before orthopaedic surgery or treat other conditions such as luxations or wounds. Performing physiotherapy in between banage changes can help limit complications. Som efractures like those affecting the coracoid bone are beter managed with bandages. Two bandaging techniques are used for the immobilisation of the wing;; figure of eight bandage (does not stabilise the humerus) and full wing bandage (stabilises the humerus). A ball bandage is commonly used to treat foot problems such as fractures, luxations and pododermatitis.
39
Which diagnostic imaging techniques can be used in birds?
Radiology is most commonly used. Ct and MRI are also useful but less availablt. Ultrasound has limited use due to the presence of air sacs. Endoscopy is also very useful for imaging, sample collection and resolution of some problems. The high avian respiratory rate requires very short exposure times usually between 0.01-0.05 seconds. Two views are required generally VD and LL. Contrast studies can be used and 1-2% barium sulphate can be given by crop tube. Iodine compounds should be used if a perforating ulcer is suspected. Transit time in psittacines is about 3h. Radiographs are commonly taken immediately after barium administration and at 30,60,90,120 and 180 minutes. CARE should be taken to avoid aspiration in anaesthetised patients.
40
Why may enlargement of the upper hourglass silhouette be seen in radiograph?
Due to cardiomegaly or hydropericardium
41
Why may enlargement of the lower hourglass silhouette be seen on radiograph?
Commonly due to organ enlargement such as hepatomegaly, dilatation of the proventriculus or enlargement of the reproductive system.
42
How are enlarged follicles seen on radiograph?
Round structure immediately ventral to the cranial kidney with variable size.
43
How is splenomegaly seen on radiograph?
Round structure immediately dorsal to the isthmus between proventriculus and ventriculus
44
What is air sacculitis?
The membranes of the air sacs are clearly seen.
45
What blood cells are found in birds?
Erythrocytes, thrombocytes, lymphocytes, monocytes, heterophils, eosinophils and basophils. All these cells are nucleated. the heterophil is the equivalent to the mammalian neutrophil and increases with sterss and infection. Infections particularly those with some chronicity also produce a monocytosis. An assessment of blood smear stained with Diff quick can provide an estimate. total blood count can be performed using a haemacytometer. Both heparin and EDTa can be used in birds although EDTA can produce haemolysis in some species not commonly kept in captivity.
46
What should cytological analysis reveal on faeces in psittacines
typically psittacines should have a high percentage of gram positive bacteria. a high level of gram negative rods can imply disease particularly of gastrointestinal origin. Typically a healthy gram stain has less than 30% gram negatives. Gram staining may also reveal macrorhabdus ornithogaster (avian gastric yeast). little point on performing routine faecal cultures unless indicated clinically.
47
Why is a crop wash performed?
In birds with vomiting or regurgitation, the technique is similar to crop feeding. Species that do not have a crop include owls, toucans, penguins and other aquatic species, ostriches. Aspirated material should be examined microscopically . culture is not commonly indicated as there is a normal population of bacteria in the crop. common pathogens include trchimonas, macrorhabdus and candida. Trichomonas gallinae produces caseous material in mouth and crop of pigeons and less commonly raptors feeding on pigeons.
48
What is macrorhabdus ornithogaster?
Avian gastric yeast - a common cause of weight loss in small psittacines such as budgies and passerines such as canaries. it can be detected on faecal smears.
49
Why may candidiasis occur?
Very common in birds particularly young ones, it is usually considered secondary to stress or prolonged treatment with antibiotics.
50
Why is skin cytology done in birds?
Commonly done to detect the mite knemidocoptes in budgies and passerines which produces scaly face and legs. Red mites (dermanyssus gallinae) can be found in birds particularly fowl. Lice are also commonly found on wildlife casualty or birds or those in contact with wild birds from outdoor aviaries. Bacteria and malazessia may be identified from skin samples of birds with feather plucking.
51
What are the common faecal parasites found in birds?
Techniques to detect faecal parasites in birds are not different from those used in other species - mainly fresh smear and flotations. Ascarids have a direct cycle and are a problem in smaller psittacines (especially from austaralia). Most commonly seen is ascardia spp and wild passerines and pigeons can also carry ascarids. Heavy burdens can Cause severe weight loss or even fatal intestinal impaction. Capilllaria is a parasite with bipolar eggs that requires an intermediate host. coccidiosis can be seen producing diarrhoea in many species of birds, particularly passerines. Giardia, hexamita and other protozoa can also be seen producing gastrointestinal disease.
52
What is syngamus worm?
Syngamus particularly in wildlife casualties found in the trachea and bronchi. It can be visualised on endoscopic examination of the respiratory tract or on PM. the eggs are double operculated (similar to capillaria) and can be seen in respiratory secretions or faecal examination.
53
What are birds on seed diets commonly deficient in and when may this be seen?
Seed types may produce deficiencies in vitamin A, calcium, aminoacids and other nutrients. It should be considered that adult birds that do not reproduce have very low requirements for many nutrients and therefore those deficiencies are most commonly seen in growing animals. Adult birds in poor diets may frequently show bad feathering due to deficiencies on amino acids.
54
What should birds be fed?
A diverse diet consisting of a mixture of different seeds, vegetables and some fruits is adequate provided that the bird does not select. growing animals may need a supplement of calcium vitamins and protein. pelleted food can be provided as supplement of nutrients but a sole diet of pellets is not recommended as they are high in most nutrients. if a pelleted diet is provided it should not account for more than 50% of the total diet. Abrupt diet changes in sick birds should be avoided. Fresh water should always be provided.
55
What may aquatic zoo birds may need supplemented for?
Birds that feed on frozen fish (mainly aquatic zoo birds) need a supplement of thiamine and vitamin E.
56
What is hypovitaminosis A?
Vitamin A deficiency is widely regarded as the most common vitamin deficiency suffered by captive parrots being fed a seed based diet. however the prevalence of hypovitaminosis A has been exagerrated for decades as most adult parrots don't require large amounts of vitamin A. Typically presents as squamous metaplasia of the epithelial membranes leading to changes in function such as vision, reproduction, immunity, cellular differentiation, growth and embryonic development. Birds with hypovitaminosis A may present with white plaques in the mouth, rhinoliths, respiratory infections and atrophy of the choanal papilla. although these lesions can have other causes. Vitamin A can be stored in the liver for years and a bird with good reserves can survive a diet deficient in vitamin A for a long time. Plentiful in mangos, carrots, spinach, red pepper and sweet potato.
57
When is iodine deficiency seen and what are the clinical signs?
most commonly seen in budgerigars on seed diets. It produces hypothyroidism with thyroid hyperplasia & goitre. Enlarged thyroids compress oesophagus and trachea and clinical signs include regurgitation, change of voice and inspiratory noises. responds well to iodine supplementation.
58
When is hypocalcaemia seen in birds?
Growing chicks and laying females have high calcium requirements. when calcium or vitamin D are not available, growing birds exhibit bone deformities and laying females may produce soft shelled eggs and suffer from dystocia. Grey parrots are particularly susceptible to this condition and even adult animals may exhibit twitching and convulsions due to lack of calcium or UV light. A hypocalcaemic bird may be presented as an emergency. When investigating hypocalcaemia it is more useful to measure serum ionised calcium levels rather than total calcium levels. Treatment consists of the provision of appropriate levels of calcium and UV light. Cases that do not respond to this should be investigated for other problems. Nuts, beans and spinaches are a good source of calcium.
59
What are the clinical signs of excess energy in the diet? which birds is obesity common in?
Many diets for captive birds are very high in energy. Obesity is common in budgies and amazons, and atherosclerosis is common in medium to large parrost. Dermal lipomas (discrete accumulation of fat) and xanthomas (discrete accumulation of cholesterol crystals) are also common, particularly in budgies. All these conditions are nearly always associated with reduced activity. Prevention should include the provision of exercise and the reduction of the energy content in the diet. Most lipomas and xanthomas require surgical resection if they pose a problem. Diets high in saturated fats (pal or coconut oil) may predispose to atherosclerosis. Obesity can also be common in other species of birds such as raptors.
60
What does an excess of calcium supplementation cause?
In an attempt to prevent hypocalcaemia and other deficiencies some breeders and keepers over supplement the diets with minerals and vitamins. Several excesses can occur particularly calcium and vitamin D which cause renal failure and gout. Raptors eat whole pray and they do not generally need any supplement which make them a lot less likely to develop problems due to excess of nutrients.
61
What sort of birds does excess iron occur in and what are the clinical signs?
Haemosiderosis and haematochromatosis are a cause of disease in birds, particularly frugivorous and nectarivorous species such as starlings, toucans and lorikeets. Clinical signs of severe iron storage disease include hepatomegaly and problems secondary to liver disease Haemosiderosis is increasingly being diagnosed in granivorous parrots, and may be associated with hypervitaminosis A.
62
What is the effect of feeding excess protein?
Excess of protein can produce kidney disease in adult birds and growing problems in chicks. Angelwing is a condition commonly seen in growing ducks and geese on high protein diets, the distal carpometacarpal bone rotates laterally, giving an irreversible twisted appearance to the distal wing. the condition is easily prevented by reducing the protein content in the diet.
63
What is aspergillosis?
The infection with fungus aspergillus sp is a common cause of respiratory disease in birds such as parrots, raptors and aquatic species. The fungus is ubiquitous in the environment and infection occurs by inhalation of spores from the environment but it is not a contagious disease. environments with decomposing vegetable material or damp litter or those with faecal and urine contamination provide ideal conditions for fungal proliferation. In addition, lack of ventilation and immune suppression facilitate infection. Some species are particularly predisposed such as pionus parrots, gyrfalcons, goshawks snowy owls, golden eagles and aquatic species. the infection can be caused by inhalation of small numbers of spores over a prolonged period of time or by inhalation of a large quantity of spores acutely.
64
What are the clinical signs of aspergillosis?
It is commonly a chronic disease with the formation of granulomas in the respiratory system, particularly lungs nad air sac.s clinical signs include weight loss, voice changes and dyspnoea. development of granulomas in the syrinx may produce acute dyspnoea and should be treated as an emergency. Diagnosis can be made on clinical signs, blood results with increase in globulins, leucocytosis with monocytosis and heterophilia, toxic heterophils, or detection of antibodies or antigen in blood. Endoscopy is the best diagnostic technique and allows direct visualisation of lesions and collection of biopsies for histopathology and culture, in addition it allows for granuloma removal and intra lesional treatment with anti fungals.
65
What is the treatment of aspergillosis?
Very advancd cases or those in nervous animals are usually unresponsive to atreatment. The acute presentation of a bird with a syringeal granuloma carries a better prognosis if the granuloma is removed via tracheal endoscopy. Tame psittacines and raptors respond in an acceptable way to medical treatment. During endoscopy large granulomas should be removed if possible and amphotericin B can be instilled into the lesions. surgery to remove large granulomas may also be indicated. An intravenous injection of amphotericin B before the animal wakes up from anaesthesia should be followed by long term medical treatment at least 1-2 months with oral and nebulised antifungals. Response to treatment should be assessed with endoscopy.
66
What treatment options are available for aspergillosis?
Amphotericin B - to be given IV but nephrotoxic for prolonged treatments. nebulise or topical via endoscope.Itraconazole -oral liquid or capsules. Three days to achieve therapeutic levels, toxic to grey parrots.Voriconazole - oral liquid or tablets , minimal resistance.F10 disinfectant - nebulisation long term or topical therapy when diluted.
67
What is candidiasis in birds?
The yeast candida albicans is normal part of the avian gastrointestinal flora. disease is seen with the indiscriminate or prolonged use of antibiotics or in young birds with poorly developed immune systems. Hand reared birds fed improperly prepared rearing formulas are also at risk. The crop is the main site of infection. clinical signs include regurgitation and vomiting, a distended slow emptying crop, beak necrosis and white /cream plaques in the oral cavity. Rarely the infection will spread systemically. the diagnosis is by cytology or culture of lesions. treatment by direct application of nystatin which is only active in the GI tract.
68
What is avian gastric yeast?
Macrorhabdus ornithogaster morphologically resemble large gram positive rods. They require microaerophilic conditions for growth. the disease is most often seen in canaries, finches, budgies, lovebirds cockatiels and small parrots. megabacteria causing proventricular and ventricular disease. clinical signs include wasting, lethargy and passage of undigested food. radiography may show proventricular dilatation. necropsy lesions include proventricular ulceration and dilatation. diagnosis is by demonstration of large quantities of organisms on gram stain or wet mounts. Macrorhabdus ornithogaster is a long straight narrow rod that is 3-4uM wide. The infection responds to treatment with oral amphotericin B or sodium benzoate. Very common problem in wasting canaries and budgies.
69
What is avian chlamydiosis?
Chlamydia psittaci is an obligate intracellular bacterium that produces mostly respiratory and liver disease in parrots and other birds. Avian chlamydiosis is a zoonosis and can produce serious disease in humans. it is shed in body secretions (fecal, nasal and ocular fluids) and can survive in the environment for several weeks.
70
What are the clinical signs of chlamydiosis?
Clinical signs include conjunctivitis, nasal discharge, ocular swelling, sneezing, lethargy, ruffled feathers, weight loss, inappetance and bright green urates. Asymptomatic carriers are common, particularly cockatiels, budgerigars and pigeons. The severity of clinical signs depends on the virulence of the strain, the species of bird affected and the immunocompetence of the bird. Diagnosis is better done by combining a serological test with a PCR from a choanal faecal swab. For the detection of carriers a PCR from faeces collected over 3-5 days is indicated as shedding may be intermittent. The liver is commonly affected and increases of AST and bile acids are common. Radiography may show signs of hepatosplenomegaly and air sacculitis. endoscopic examination will allow a direct evaluation of these organs and the collection of biopsies for histopathology or PCR.
71
What is the treatment of birds with chlamydiosis?
Treatment involves doxycycline for 4-6 weeks either once a week by injection or once /twice a day orally. Injections produce significant tissue necrosis but it is the best method to treat birds that will not take oral medications. Different protocols of doxycyline in drinking water or in food have been tried with success. Fluoroquinolones have some activity against chalmydia but they are not as good as doxycycline to eliminate infection. Azithromycin is also effective. All infected birds will require isolation, and those critically ill will need supportive care as well. follow up testing 2-3 weeks after treatment is required to confirm elimination.
72
What is psittacine beak and feather disease? (PBFD)
It is caused by a circovirus which are viruses that can remain stable in the environment for ap rolonged period of time. the virus is shed in feather dander and faeces and is transmitted by inhalation or ingestion. vertical transmission is also possible. the virus favours rapidly dividing cells and the clinical signs are related to its effects on dividing tissues and the targeted systems are the epithelial cells, GI tract and immune system. Birds that are exposed to the virus can develop a wide variety of clinical signs and have a varying incubation period.
73
Describe the clinical signs of the classical chronic form of Psittacine beak and feather disease?
They develop feather loss and feather deformity as the most common clinical signs. feathers grow abnormally, are dysplastic with retained sheaths, haemorrhage can occur within the pulp cavity, feather shafts can fracture and eventually complete feather loss can occur. The condition worsens with each new moult. there can also be oral ulceration and hyperkeratosis, overgrowth or fracture of the beak. Secondary infections are common as the disease produces marked immune suppression. The disease is always fatal but death can occur years after the initiation of clinical signs.
74
Describe the acute form of PBFD?
Affects young birds during first feather formation and is characterised by depression and diarrhoea followed by the rapid development of dystrophic feathers. these birds usually have severe anaemia and leucopaenia particularly grey parrots. change of the colour of the feathers can occur in some animals and sudden death is also possible.Burdiges can carry PBFD and juveniles can exhibit normal feathering except for complete absence of primary and secondary flight feathers or become severely alopecic.. Mild cases can survive and can regrow feathers at the first moult (12 weeks old). the same signs occur with polyomavirus infection in budgies, although PBFD is reported to be far more common. Polyoma is more likely to lead to nestling death with leucopaenia anaemia and haemorrhages.
75
How is diagnosis of PBFD infection made?
Based on a PCR to detect the genetic material of the virus. ideally samples should be taken from abnormal feathers, although blood samples are also good. severe leucopaenia can produce false negative results in the PCR. histopathology of the abnormal feathers can also yield a diagnosis. if the bird has died the most important organs to be collected are the bursa of fabricius and liver spleen and skin with abnormal feathers. the infection produces basophilic intracytoplasmic inclusions and lymphoid depletion. Any suspect carcases should be kept frozen as a PCR can be performed on frozen tissue. Positie birds that are healthy should be quarantined and re tested in 90 days to see if they have cleared the virus. There is no specific treatment for infection.
76
What do pox viruses cause in birds?
Lead to skin disease. The virus is environmentally resistant and excreted in saliva, nasal and lacrimal secretions and sometimes faeces. Transmission is via mosquitoes, direct contact, fomites, inhalation, ingestion and wounds. Infection can be seen in lovebirds canaries pigeons new world parrots and raptors. but it is more common in wild birds. there are three forms; cutaneous (dry pox causes nodular lesions and scabs on the face), Diptheritic (wet pox - lesions on mucous membranes and respiratory disease), And septicaemic (common in passerines - rapidly fatal causing pneumonia with or without diptheritic enteritis. Diagnosis is by clinical signs, history of exposure, biopsy/cytology, cytoplasmic inclusion bodies in epithelial cells are found. It is believed that ectoparasites are linked to disease leading to skin trauma and allowing entry of the virus.
77
What is proventricular dilatation disease?
Caused by Avian bornavirus. histologically the disease is characterised by a lymphoplasmacytic ganglioneuritis in the nerves of the gastrointestinal tract, particularly the ventriculus and proventriculus. Lesions can also be found in other organs, most importantly the brain. The nerve lesion produces dilatation of the GI tract and increase in the gastrointestinal transit time. The proventriculus becomes dilated, sometimes also the ventriculus and intestines and the birds starts with symptoms of weight loss, abnormal faeces, undigested seeds on faeces and lethargy. Neurological signs can also occur. the disease is more common in large psittacines. Incubation periods can vary between 2 weeks and a maximum of 4 months.The disease is always fatal.
78
Describe lead poisoning in birds, clinical signs and how this occurs
Lead poisoning is a common condition in watefowl, some raptors and psittacines. common sources include lead shot in raptor pray items, lead fishing weights, paint, putty, lead batteries. IT can be absorbed from the GI tract and stored in bones and soft tissue. IT is excreted slowly over months by the kidneys. Clinical signs inclue neurological signs, lethargy, weakness, vomiting, PUPD, haemoglobinuria. Radiography shows presence of extremely radiodense material in ventriculus and whole blood lead analysis. Treatment with chelation therapy should start immediately either with CaEDTA or oral penicillamine.
79
Describe how zinc poisoning may occur
Commonly seen in captive birds. many wire cages are coated with zinc powder, toys for birds may contain zinc and there may also be some source of zinc in the house. clinical signs and treatment are similar as in lead poisoning. Parrots that roam free at home are predisposed to heavy metal toxicity.
80
What is gout?
The consequence of a kidney problem or an excess of dietary protein. there are two types of gout in birds - articular, deposition of white material (uric acid crystals) within the joints particularly in the legs. and Visceral - deposition of white material in the serosal surfaces of the organs, mainly liver, kidneys and pericardium but also air sacs etc. Diagnosis is made by a combination of FNA and cytology of the articular lesions, endoscopy to visualise visceral gout and measurement of uric acid in the blood. Initial cases can be controlled with aggressive fluid therapy, elimination of the initiating cause and the administration of allopurinol to reduce uric acid levels in blood. Advance cases will eventually end up in the death of the bird and many cases of severe visceral gout are just found on necrospy.
81
Why does feather picking occur in birds?
Normally seen in parrots and can be consequence of medical or behavioural problems. Medical causes include viral infections such as PBFD or polyomavirus, hypothryioidism, systemic disease, bacterial or fungal folliculitis, liver disease, air sacculitis, coelomic masses, ectoparasites, neurological disease or reproductive disease, behavioural problems include boredom, sexual frustration, excitation. A complete medical examination should be performed including physical exam, radiographs, bloodwork, endoscopy and tests for PBFD/polyomavirus. Improve diet and husbandry and photoperiod and provide UV light. Use of sedatives haloperidol and antidepressants fluoxeitine or drugs to control reproductive behaviour deslorelin may be considered. Elizabethan collars should only be used as a last resort or in cases where significant self trauma is likely.
82
Why does chronic egg laying occur? what is the treatment?
This condition is particularly common in pet cockatiels. it is cuased by excessive stimulation of breeding behaviour by the presence of another bird, inanimate object cage furniture, toy, mirror or a person with whom the bird has bonded. Excessive feeding and artificial photoperiods can also have an influence. Laid eggs should not be removed from the nest as the bird will continue laying to replace them. Consider medical treatment with deslorelin or cabergoline together with husbandry modification. Remove nest boxes and items that may stimulate laying, artificially reduce day length to eight hours by covering the cage and reduce caloric intake. If treatment is unsuccessful, hysterectomy is indicated. Birds that are chronic egg layers are predisposed to other conditions such as dystocia, egg yolk peritonitis and hypocalcaemia.
83
What is egg binding? Why does this occur?
Dystocia - can be caused by calcium/vitamin D3 deficiencies, oversized or misshapen eggs, uterine inertia due to excesive laying, metritis and obesity. In many cases the cause cannot be found. clinical signs include dyspnoea the egg compresses the air sacs and lungs, hindlimb weakness the egg compresses the nerves of the legs, lethargy, abnormal faeces and a wide non perching stance. the lower coelom may be swollen and an egg may or may not be palpable. Egg retention more common in smaller birds such as tiels, lovebirds and budgies. Radiographs and serum calcium determination can be indicated for diagnosis and to better guide treatment. the patient should be stabilized and left in a quiet place. injectable calcium is commonly given and the use of hormones such as oxytocin or topical prostaglandins should be tried. if medical treatment is unsuccessful, consider manual massage with lubrication, ovocentesis (the collapsed egg will be passed over the next day or so) or even surgery. All these best performed under anaesthesia.
84
What is egg yolk peritonitis?
Caused by ectopic ovulation but may also be seen with salpingitis, metritis, neoplasia or a ruptured oviduct. these can be sterile or septic. some birds resond to medical management while others will require removal of yolk material and lavage, others may die. Prognosis is guarded. Lethargy and respiratory problems may be seen. Egg yolk peritonitis is commonly seen in birds with chronic egg laying. Diagnosis can be made by aspiration and cytology of coelomic fluid or by endoscopic examination.
85
What is the treatment for heavy metal toxicity?
Stabilise with warmth, fluids, diazepam, start injectable CaEDTA if radiographs are indicative.
86
What should you NEVER give to parrots?
DO NOTGive itraconazole to a grey parrotInject enrofloxacin IM or SC or atleast not for more than 1-2 injections.Clip the wing of a birdAdd mineral/vitamins to a balanced dietGive avacado to parrotsGive chocolateGive intracoelomic fluids
87
Describe the basic husbandry requirements for chickens
Should be kept outside. Must provide the basics of shelter from wind and rain, protection against predation, a dry safe area to roost an asleep in and a secluded area to lay. Ability to roam freely and forage during teh day is also important but may not be an option over the winter, in which case floor space is very important - 30cmx30cm per bird for large chicken and 20cmx20cm for bantams. Dust free wood shavings make good litter and should be spot cleaned daily or changed entirely every 1-2 weeks depending on stocking density. Virkon or F10 make good disinfectants for cleaning. Alternatively a deep litter system can be used, removed once a year but nest boxes should be cleaned weekly still. Straw and hay can harbour fungal spores. Perches for roosting should be broad, and should be above nestbox height but easy to get up on to and not too high as handling heavily can cause bruising and bumble foot. Perches should allow about 15cm length for bantams and 23-25cms for large chickens. Lighting in winter is necessary if laying is to continue. Nestboxes should be in the lowest and darkest part of the housing. light breeds come into lay at about 18-20 weeks old and heavy breeds at about 26 weeks or later. A hen will become broody and incubate the eggs when she has laid a clutch or if the eggs are not removed. Incubation period for fertile eggs is 21 days. Vaccination not commonly carried out.
88
What nutrition should chickens be given?
Should be age appropriate and many commercial formulated diets are available - crumbs up to 5 weeks, grower pellet up to 16 weeks and then layer pellets or mash. Whole grain can also be given after the age of 12 weeks to supplement the diet and provide enrichment if scatter fed. common advice is to feed pellets in the morning and grain in the afternoon. NNote that some commerical feeds contain coccidiostats which can be toxic ffor turkeys. Grit is important for gizzard function and egg shell formation. Household scraps, grass and garden plants are also enjoyed. Should be kept away from poisonous plants such as yew, deadly nightshade and potato sprouts. A constant supply of clean drinking water is essential.
89
Where can a blood sample be taken from a chicken?
Either from the right jugular vein, medial metatarsal vein or basillic vein.
90
What anaesthetic should be used for chickens?
Gaseous anaesthesia using isoflurane is recommended.
91
What is mycoplasmosis?
Poor ventilation, high ammonia and high dust levels will predipose to respiratory problems. Mycopasmosis most common due to M gallisepticum or M synovia which causes swollen joints in addition to mild respiratory signs. typical signs of mycoplasmosis are nasal discharge, foamy eyes, swollen eyelids and sinuses, sneezing and gasping. Treatment options include enrofloxacin, tylosin, tiamulin and tetracyclines. Antibiotics will control clinical signs and reduce incidence within a flock but not eliminate infection and it may recur.
92
What is aspergillosis?
from a high burden of fungal spores in mouldy hay or straw or rotting vegetation. prognosis usually poor. Treatment may be attempted with systemic itraconazole and nebulisation with F10.
93
What is infectious bronchitis?
Caused by a coronavirus. It can also lead to renal damage and oviduct infection. clinical signs are similar to mycoplasmosis but the disease spreads rapidly in 1-3 days and is generally mild and often self limiting. Concurrent mycoplasmosis predisposes to IB and commercial flocks can be vaccinated. Diagnosis is usually on clinical signs but serology and viral PCR are available.
94
Why may egg binding occur?
Can occur in hens with low calcium levels. Warm fluid therapy, calcium supplementation and gentle lubrication of the cloaca may enable passage of the egg if it is within the cloaca, but if it is within the ovidcut the prognosis is more guarded. Breakage of the shell and removal per cloaca may be possible but oviductal trauma may occur. Egg coelomitis Is probably the most common systemic problem seen in backyard poultry. It is caused by the release of an ovum free into the abdomen or as a result of bacterial infection of the oviduct via the cloaca. Both scenarios usually lead to an overwhelming systemic toxic bacterial infection and a severe chronic salpingitis. Affected hens are depressed and lethargic with a swollen painful abdomen and cessation of laying. supportive care and antibiotic treatment may be effective but generally prognosis is poor. Surgery also an option.
95
What is sour crop?
Crop stasis due to candida albicans can be secondary to antbiotic therapy , or often occurs in association with crop stasis secondary to underlying GI or reproductive disease.
96
Why may crop impactions occur in chickens
Crop impactions are frequently to due ingestion of long grass which forms a ball and cannot be passed further down the GI tract. In mild cases softening with liquid paraffin and gentle massage/milking out of the mouth with the head held down may be possible, monitoring carefully for any respiratory distress. Severe impactions will require general anaesthesia and ingluviotomy to remove impacted material. An impacted crop frequently becomes pendulous and the muscles stretch and weaken. Pendulous crop and impaction may also occur secondary to heavy metal toxicity and hypocalcaemia.
97
What endoparasites are common in birds?
Coccidiosis is an important poultry disease and is common in rearing birds of 4-6 weeks of age. seven species of Eimeria are specific to chickens and affect different parts of the GI tract with differing severity. all have direct life cycles, short prepatent periods and sporulation in the environment is rapid in warm moist environments so rapid reinfection can occur and escalation of disease levels with mortality. Affected birds will have poor growth and wet watery diarrhoea. Diagnosis is confirmed by oocyst counts and treatment is with toltrazuril. Prevention is with good biosecurity and hygiene. the use of coccidiostatis in feed until 6 weks used to be common however vaccinaiton is now available given orally to day old chicks. Nematodes also common in back yard chickens including roundworms (ascardia) hairworms (capillaria) and caecal orms (heterakis). all my be associated with weight loss. Flubendazole is the only wormer licensed in the UK usually given in feed as a powder and prophylactic use is advised when birds are kept on the same area of ground which cannot be rotated.
98
What may cause bacterial diarrhoea?
May be due to salmonella pullorum, S gallinarum, S typhimurium and S enteriditis. E coli and campylobacter jejuni may also cause diarrhoea especially in chicks. General hygiene and vermin control is important and vaccination is available for salmonella and E coli. Treatment of individuals with amoxicillin is possible.
99
Which ectoparasites may effect chickens?
Red mites - dermanyssus gallinae - lvie in the environment and feed on the birds at night and cause anaemia and lethargy. These have survival off the host for 6 months and meticulous cleaning and treatment is essential. Permethrin or pyrethrum powders can be used. Northern fowl mite has its life cycle entirely on the bird and causes dirty moist patches on the feathers. Pyrethrum powders or spot on ivermectin is effective. (ornithonyssus silvarum). Scaly leg mides (cnemidocoptes mutans) very common and cause intense irritation and a build up of yellowish musty smelling debris s. Ivermectin is effective. Depluming mites (cnemidocoptes gallinae) an occasionaly cause feather loss around head and neck and fipronil can be effective. Chicken louse menopon gallinae is flat fast moving about 2mm long. Eggs clump together and have the appearance of granulated sugar at the base of the feathers. treatment with fipronil, ivermectin or pyrethrum powder
100
What is mareks disease?
Caused by an alphaherpesvirus - that causes lymphoid tumours and demyelination of peripheral nerves leading to wing droop and leg paralysis. Tumours develop in a variety of organs as well as the brachial and sciatic nerve plexi and affected birds will be immunosuppressed, lose condition and may die. if the vagus nerve is affected, difficulty breathing or dilation of the crop may occur. no treatment is possible and control is by vaccination at one day old.
101
What is newcastle disease
A notifiable disease caused by a paramyxovirus and can cause both respiratory and neurological signs. other signs include reduced egg production and greenish diarrhoea. disease in backyard chickens is not common in the uk but may occur via feral pigeons and vaccination in the face of an outbreak is possible.
