Diseases of Cage Birds

05-14-2007, 05:05 AM

Diseases of Cage Birds

Most popular species are:

AFRICAN GREY Parrots (Psittacus erithicus)

AMAZON Parrots (Amazona spp)

BUDGERIGARS (Melopsittacus undulatus)

CANARIES (Serinus carinus domesticus)

COCKATIELS

COCKATOOS (Cacatua spp)

MACAWS (Ara spp)

Physical examination limited by small size of most species (7-25g). Observe respiratory rate and effort, state of moult, activity. Handle gently in dim light, check pectoral muscle mass (acute/chronic problem), the abdomen (blow feathers apart and look for enlarged liver, dilated GIT, check the skin for pox

lesions and parasites. Do Faecal examination. Helminth infections are rare. Coccidia, yeasts, protozoal cysts may be seen. Passerines are not considered to have a normal gut flora, thus stained faecal smears are useful. Crop swabs for the diagnosis of trichomoniasis and crop candidiasis. Blood samples into

heparinised capillary tube after puncturing the medial metatarsal vein or brachial vein where it crosses the medial elbow. Blood smear (parasites, type of anaemia) and PCV (normal=40-55%), total protein (<35g/l= guarded prognosis, buffy coat (>1mm = leucocytosis) Postmortem always PM birds which die from unknown causes to alter management or control disease outbreaks.

Begin examination with distance observation of bird. Advise owners to bring bird in cage, not carry box, where possible to allow assessment of housing conditions and to be able to examine the brid at rest. The

owners should be instructed not to clean the cage for 24 hours to allow examination of the volume and quality of the droppings - examine within cage or on perch, not on owners shoulder or in your hand (initially) . can bird perch, is it ruffled, assess respiratory rate, is it bright alert and responsive? ,evidence of feather loss, change colour (fret marks) . quality of feathers, beak, nails

Tame birds may allow examination and auscultation with minimal restraint, but it is wise to restrain the head. All the pssitacines are able to inflict a painful bite and the claws of the larger parrots can pierce the skin. Adequate restraint of the head and feet is therefore essential. Birds have no functional diaphragm, air is drawn into and out of the airsacs primarily by sternal movements. Consequently any prevention of these movements will lead to suffocation. Thus when handling a bird, never place the hands around the upper body of the animal. Dim the lights and make calm purposeful movements to avoid excess stress to the bird avoid chasing the bird as the heat generated will not be dissipated when restrained, leading to panting, hyperthermia and collapse .

Smaller birds (budgerigars, cockatiels) may be held by the examiner, but a separate handler is required for the larger birds to enable a complete examination to be carried out. Remove as much cage furniture as possible without stressing the bird.

Small birds may be picked up from a perch. Bare hands or a cloth enable the tightness of grip to be accurately gauged, gloves are not recommended. The use of a small towel or cloth may be used to cover the bird whilst the head is located. This reduces the chance of being bitten and restrains the bird more

adequately as the cloth can be lightly wrapped around the bird to prevent the wings flapping. The birds head is grasped between first and second fingers, the thumb and little fingers used to restrain the feet. Wings can then be extended and held between the thumb and forefinger or using the free hand. . the larger pssitacines require a two handed approach. Tilt the cage to the side (having first removed all cage furniture), allowing the bird to grip the bars with his beak. Using a towel, grasp the bird around the mandible and neck. The towel can then be wrapped around the bird to prevent wing injury and to restrain the feet. A piece of paper or towel will give the bird something to chew on during the examination. Teasing the bird with such a object often allows visualisation of the oral cavity.

Feeding, housing plus the owners description of the birds species indicates the owners knowledge of the pet. Taken with an examination of the cage and contents, a diagnosis may be reached without needing to handle a very sick bird. The history enables an assessment of environemntal stressors (cigarette smoke, long days), poor nutrition (sunflower seeds only) and management problms (poor hygiene, sandpaper perches) . examine cage for evidence of regurgitation, check feed containers to see if bird is eating feed or merely dehusking it. Consider age, sex (if known) when and where bird obtained, plus previous medical problems. Also diet offered including `treats' and supplementation, other pets, photoperiod electric/ gas heatingaccess to fresh air/natural sunlight;provision of bath/ water spray; duration and chronicity of

problem; illness in other pets/ family members; change in appetite, drinking, droppings; coughing, sneezing, diarrhoea, vomiting; change in behaviour/ voice; change in body posturedrowsinessreproductive status . assess quality and quantity of droppings. A stressful journey may have produced some diarrhoea - discount these.

Normal droppings consist of white urates/uric acid with dark faeces. Smaller Pssitacines have compact droppings, larger species it is more bulky. Abnormal amount of urates (more than 50%)can indicate renal problems or increased catabolism (wasting)

Housing

Cages for pet psittacines should be regarded as an unfortunate necessity for housing the bird at night or when unsupervised. These are social animals and so the owner should be encouraged to tame the bird

and treat it as a member of the family as one would a dog. This greatly enhances the owner's enjoyment of the pet and the bird's quality of life.Many of these species live for 20+years and should not be condemned to a cage for this long period. The cage should be large enough for the bird to stretch out fully horizontally and vertically at the very least. Perches of varying diameters (without sandpaper) will help to exercise the feet. The cage construction should be strong enough to withstand the parrots bite, made of easily cleaned, non toxic material, and provide easy access to the bird. Cage furniture should not be provided at the expense of room for the bird. Ropes to secure toys should be used inpreference to chains to avoid leg and foot injuries. Many parrots enjoy destroying toys, so dog chews, wood to strip, etc. are more beneficial than mirrors and bells. Position the food and water bowls above perches to avoid soiling and change the contents daily.

Avian Feeding Recommendations

A lot of clients come in and really have no idea what to feed. The correct diet is crucially important to the health and longevity of the pet bird. Unfortunately, malnutrition is very common in the majority of patients. It is a vital part of the veterinary care of birds to ensure a correct diet is fed. The basic staple diet will be, unfortunately, seed (mixture of seeds: millets, canary seed, sunflower seed, also added will be wheat, oats, and safflower). One must be aware that seed alone is high in fat and low in total protein, and that the protein seed does contain is low in the amino acid lysine and methionine. Another draw-back on feeding seed alone is that it is also deficient in several important vitamins: A, B2, B12, and D3,E and K as well as some minerals like sodium, iodine, choline, copper, calcium, iron, manganese, selenium, and zinc.

Supplementation of the diet is important for the non-breeding bird but becomes essential for those used for breeding. Many commercial pelleted feeds are available, but it can be somewhat difficult converting birds that have been raised on seed. Use a proprietary product such as ACE-High (VetArk)

Cuttle bones and calcium blocks will provide other essential vitamins and minerals. Fruits and vegetables offer a wide variety of nutrients as well as being an added treat for the bird. Leafy green lettuce and chopped apples and oranges are commonly offered, but try a wide variety to find which ones your

bird likes.

Another widely used feeding technique is to soak a portion of seed in a closed jar for 24 hours. Then the seed should be aired out for another 24 hours and allowed to sprout. This meal is fed in addition to the recommended diets above.

It is hard sometimes to change birds over from a strict seed diet to one that is more nutritious and well balanced. Always refer to feeding seed like feeding chocolate cake. It would be best to acquire your birds from a breeder or pet store that weaned the fledglings onto pelleted diets right from formula. At feeding time, place in a new desired food like chopped vegetables and fruits. Leave this in for several hours and then replace it with the regular seed diet. Most birds will at least become curious and might even play with the new foods. Increase the time you leave in the new food as the days go by and make adjustments

depending on whether the bird eats the food or not.

Ideal diets for psittacines: Budgerigars - a proprietary feed (Trill: Pedigree) provides a balanced diet with iodine.

Parrots - a mix of 3 fruits, 3 vegetables, 5 nuts and seeds should be fed daily from one bowl mixed in with a supplement (Avimix; Vetark). This provides a balanced diet and prevents the bird choosing to eat only the `favourite' foods. Tastes change with time so encourage the feeding of such a varied diet constantly and mix so that bird has difficulty selecting out ingredients. Avoid chocolate, avocado, salt, alcohol, tobacco smoke, access to lead or zinc, pesticides, overheated Teflon pans (poisonous). Most pet bird species are opportunistic omnivores. Seed only diets contain excessive amounts of fat and the multiple deficiencies noted in the table below.

Continued

05-14-2007, 05:10 AM

NUTRITIONAL DISEASES

VITAMIN A DEFICIENCY Hyperkeratosis and squamous metaplasia of epithelium, white plaques in oral mucosa, and blunting or loss of the choanal papillae.Also rhinitis and blepharitis are commonly associated with vitamin A deficiency.

Treatment: Injectable Vitamin A (0.1 ml/100g once), feed carrots, cod liver oil.

CALCIUM/VITAMIN D3 DEFICIENCY Seeds are high in phosphorus content. Phosphorus binds calcium resulting in a deficiency. Vitamin D3 is low in seed diets. Egg laying hens may have an episode of acute hypocalcemia which can result in partial paresis and perhaps egg binding. African Grey Parrots appear unique in being unable to mobilise skeletal calcium reserves in the face of hypocalcaemia. Such birds often present with a hypocalcaemic tetany - wings fluttering violently in apparent "fits". Birds, especially the young, with bone and joint deformities might be deficient in both calcium and vitamin D3. Sources of calcium: spinich, broccoli, cuttlebone, and mineral blocks.

Treatment: Vitamin D3 at 0.1 ml/100g once

VITAMIN E DEFICIENCY Bird becomes lethargic and appears to have coordination defecits. This progresses to equilibrium dysfunction which might present as the bird constantly turning his/her head to one side or move it up and down along the abdomen. Terminally, complete paralysis is observed. Wheat germ oil is an excellant source of vitamin E and should be used as a supplement.

VITAMIN K DEFICIENCY Leads to blood clotting problems and may be exhibited as excessive hemorraging.

Treat with vitamin K1 injections.

IODONE DEFICIENCY Leads to hyperplasia of the thyroid gland (iodine deficiency leads to a decreased production of T3 which is sensed by the body and the response is an increase in the release of Thyroid Stimulating Hormone (TSH) which results in the hyperplasia of the gland). The bird might present with dyspnea due to pressure on the trachea from the oversized gland. Surgical removal may be tried. Thyroid hyperplasia associated with iodone deficiency used to be very common in budgerigars until Trill incoroporated iodine into their seed preparations. It is still occasionally seen in birds given "loose seed" from pet shops if no alternative source of iodine is given. Such birds are presented with markwed dyspnea and a "clicking" noise as they breathe caused by pressure of the hyperplastic thyroid on the syrinx/trachea. Treatment generally consists of a drop of iodine put into the drinking water daily for two weeks, then once a week thereafter. This should continue for at least eight weeks.

Hepatic Lipidosis ( Fatty Liver Syndrome) Due to poor nutrition

Predisposing Factors: genetics, obesity, metabolic disorders.

Pathology: abnormal accumulation of lipid in the liver.

Clinical Signs: Birds are obese; owner reports that the bird is on an all seed diet (seeds are high in fat). Patient might exhibit signs compatible with hepatic encephalopathy: lethargy, depression, anorexia, neurological signs. Urates may be yellow or green.

Clinical Pathology: increased LDH, AST, triglycerides, and bile acids.

Diagnosis: Radiography: hepatomegaly, elevated liver enzymes, and clinical signs. A definitive diagnosis can only be made by liver biopsy.

Treatment: When presented for treatment the condition is usually too far advanced and carries a poor prognosis; Interosseous fluids (Hartmann's), diet high in nutrients (include fructose, biotin, choline, and lactulose), and broad spectrum antimicrobial therapy may be of some benefit.

Skin Conditions

ECTOPARASITES:

Skin scrapings are recommended for diagnosis. This may be difficult in the avian patient due to the thin epidermis which may tear easily. Clear tape on several areas is an effective alternative.

SCALY FACE AND LEG MITE: Knemidocoptes pilae.

Clinical Signs: proliferate hyperkeratotic lesions especially on the beak and legs.

Diagnosis: Skin scrapings

Treatment: Ivermectin at 0.2 mg/kg PO, SQ, or IM. A small drop may be applied topically over the jugular vein and seems to work well. Injection is not recommended in birds weighing less than 500 grams due to problems with toxicity.

RED BIRD MITE Dermanyssus avium and other sp.

Clinical Signs: Intense pruritis; Owner usually reports that the bird has "fits" during the night. This is due to the nocturnal activity of the mite.

Diagnosis: Visualization of the mite on skin scrapings. The mite is red in

color, especially after a feeding, although identification is difficult because

the mite hides in feather follicles during the day and feeds at night.

Treatment: Ivermectin at 0.2 mg/kg PO, SQ, or IM. Light pyrethrin powder

FEATHER MUTILATION

Perhaps one of the most common presenting complaints of the avian patient to the vet. One must first discern whether the problem is from a nutritional deficiency, infectious cause (PBFD), parasitic (mites or Giardia), or a behavioral problem.

After the first three have been ruled out you can treat the problem by behavior modification. Lone birds can sometimes be cured by providing a cage mate, adding more toys to the cage, or by simply having the owner spend more quality time with the pet. Sometimes it may be necessary to use an Elizabethan collar

(E-collar) to alleviate the condition. Currently doxepin (0.5-1.0 mg/kg Bid PO) and clomipramine (1.0 mg/kg Bid PO) have been used to prevent feather picking. Prolonged usage of these drugs is not recommended. There have been clinical studies of the use of the human anti psychotic drug haloperidol (0.05-0.2 mg/kg PO Sid or Bid) in chronic feather pickers and the results appear promising.

Diseases of the Respiratory System

AMAZON TRACHEITIS: unclassified herpesvirus

Host range: Amazona genus

Pathology: hemorrhagic necrotic tissue damage to the trachea.

Clinical Signs: may persist for up to nine months and consist of: nasal encrustation with exudation, increased respiratory effort with rales and coughing, oral mucus discharge.

Diagnosis: pharyngeal swab- presence of intranuclear inclusion bodies Cowdry type A (may not be seen); tentative diagnosis may be based on length of illness and clinical signs.

Treatment: Nonspecific- fluid therapy, vitamin A, and methionine. Antibiotics may be given to combat secondary bacterial infections.

Diseases of the GI Tract

PACHECO'S DISEASE: Herpesvirus, serotype 4

Host range: ALL psitticines are susceptible

Clinical Signs: Acute course with nonspecific signs- "sick bird syndrome" with or without diarrhea and respiratory involvement. History usually reveals a stressor in environment (like shipping and transporation). The virus usually attacks the liver; this involvement may be noted by yellowish feces and urates.

Diagnosis: Presence of intranuclear inclusion bodies Cowdry type A indicate a herpesvirus but viral isolation needs to be performed to classify it as Pacheco's (serotype 4).

Treatment: Nonspecific- fluid therapy, vitamin A, and methionine. Antibiotics may be given to combat secondary bacterial infections, but be aware of the selected antibiotics' hepatotoxicity.

Prevention: No vaccine available; strict quarantine of new birds.

MACAW WASTING DISEASE: Unknown- possibly viral

Host range: Macaws under stress, predilection for blue and golds.

Pathology: proventricular dilitation

Clinical Signs: Mouth may be foul smelling, regurgitation, diarrhea (bird may pass undigested seed in the feces), and neurologic manifestations. Bird will eat and eat, but continues to lose weight.

Diagnosis: Radiography will show and enlarged proventriculus, this and clinical signs is enough for a diagnosis. Histopathology will reveal a multifocal lymphocytic leiomyositis and absence of normal myenteric plexus.

Treatment: none, usually fatal. Investigational therapy: surgical evacuation of the proventricular contents and soft food diet.

CANDIDIASIS Candida albicans

Clinical Signs: most common in the young; may see whitish plaques in the oral cavity, under the tongue, and in the crop. Vomiting and regurgitation as well as crop stasis (sour crop) may be symptoms.

Differential Diagnosis: trichomonas and vitamin A deficiency

Diagnosis: Cultures and slide stains on samples obtained from crop and cloaca (use New Methylene Blue).

Note the dark purple staining oval organisms on this Gram's stain of crop swab taken from a three month old Umbrella Cockatoo that was presented for regurgitation of formula immediately after hand feeding.

Treatment: Nystatin oral suspension at a dose of 1ml/300 grams PO Bid works well. Young birds that regurgitate after feeding most likely have Candida. I reccomend treatment to start with nystatin oral suspension. If there is no improvement after 3 days, a cloacal sample should be stained. If large numbers of yeast are identified, treatment should change to Ketoconazole (Nizoral- crush the 200mg tablet and mix with 10 ml of water to a concentration of 20mg/ml; keep refridgerated, shake before each use) dosage is 10-30 mg/kg PO Bid.

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05-14-2007, 05:14 AM

ENDOPARASITES:

Fecal flotation and direct fecal wet mounts aid in diagnosis.

GIARDIA:Causes a malodorous and/or mucoid diarrhea, weight loss, and feather picking (especially in cockatiels).

Treatment: metronidazole at 25 mg/kg PO BID for 5 to 10 days.

In this fecal Gram's stain note the larger Gram negative staining Giardia organisms.

TRICHOMONIASIS: Presents with white plaques in the oral cavity and esophagus. Bird may exhibit anorexia, dyspnea, and regurgiation.

Treatment: metronidazole at 25 mg/kg PO SID for 5 days.

Tapeworms, hookworms, and roundworms are rare in the avian patient. When found, they are best treated with the common dewormers: Fenbendazole for tapeworms and roundworms at 25-50 mg/kg PO with a second dose 2 weeks later.Ivermectin for hookworms and roundworms at 0.2-0.4 mg/kg PO. Praziquantel for tapeworms at 10 mg/kg PO.

CROP DISORDERS

CROP STASIS (SOUR CROP) Crop disorders are more common in young birds and usually present as delayed crop emptying or complete crop stasis. The first thing one must do when faced with this condition is empty the crop by gavage (if the crop does not empty by gavage therapy an ingluviotomy may be indicated). A soft crop tube (or foley catheter) may be used to instill a small amount of sterile saline to facilitate removal. If a foriegn body is present (detected by palpation or radiography) an ingluviotomy should be performed. In cases of prolonged stasis a culture and sensitivity followed by appropriate antimicrobial therapy should be instituted. Soft liquid food should be hand-fed or tube-fed until normal motility returns.

Crop burn should be handled the same way except that a culture and sensitivity is necessary. If a fistula is present surgical debridement of necrotic tissue and primary closure should be attempted. Crop lacerations may occur from foreign bodies with subsequent pooling of food subcutaneously and resultant toxemia.

Surgical correction, sterile flushing, fluid and antimicrobial therapy is indicated. With any of these conditions supportive nutritional and intravenous/intraosseous fluid therapy may be required.

In neonates draining crop fistulas can be sutured without anaesthesia. In all procedures involving primary surgical closure of the crop, an inverting (Lembert) interrupted suture pattern should be used. If the subcutaneous tissue has been exposed for a long duration (over 6 hours), only the crop should be

closed, and a drain put in place before skin closure.

Diseases of Uro-Genital System

EGG BINDING Exact mechanism has not been fully elucidated. However, nutritional imbalances seem to be a critical factor.

Clinical Signs: Abdominal swelling, fluffed bird syndrome, anorexia, and depression. Depending on where the egg is impacted, one might be able to visualize it through the dilated cloaca.

Treatment: Medical treatment consists of increasing temperature and humidity of the environment, injectable calcium (for primary uterine inertia), and oxytocin.If palpation reveals the egg to be soft-shelled it may be manually crushed and massaged out. Never crush a hard-shelled egg as uterine lacerations may occur. Needle aspiration of the egg contents via the cloaca or abdominal paracentesis and massage of the uterus may be of some benefit. Lubrication of the cloaca may help if the egg is just beyond the vent, but the benefit of this is controversial If all else fails surgical removal via a ventral laporotomy and hysterotomy is indicated. If the egg is ectopic or has ruptured the uterus, surgical intervention is the only mode of treatment. There has been some debate as to when outside intervention is required to

alleviate this problem. In general, with the smaller birds a time frame of several hours is the normal while the larger species one can wait up to 2 days. This is not to say that each individual case is unique in that if the bird is obviously on a downward spiral health wise, one should act quickly.

Paediatrics care: Chicks - Baby to Juvenile

Chicks will hatch in the order the eggs were laid (@ 2 days apart for the smaller breeds; may go up to 3 days in the larger breeds). Eyes open at 7-9 days post hatching. Chicks may be close-rung when their eyes start to open.

Hand rearing: Allow the parents to feed the young until they are roughly 2-2 1/2 weeks old (slightly older for the larger breeds). Chicks should then be hand fed about every five hours (never let the crop stay empty for too long). Start with a watery mixture of formula and increase its consistency as the chick grows

(which will also increase the feeding interval and decrease the burden on the owner). ALWAYS make sure the formula is not too hot or serious injuries like crop burn will occur

Disorders of the Sensory Organs and Nervous System

PARAMYXOVIRUS INFECTION: Host range: Amazons and poultry

Clinical Signs: Torticollis, circling, seizures, and dyspnea

NOTE: Most important disease caused by this virus is Newcastle's Disease (Notifiable in UK) which is usually seen in smuggled Amazons. Poultry vaccine available, but efficacy in other species not proven

Systemic Diseases

BIRD POX: Avipoxvirus

Host range: most common in canaries

Transmission/Pathogenesis: Carriers; mosquitoes may be vectors. Virus cannot penetrate intact epithelium- entry gained from traumatic lesions (like a mosquitoe bite) resulting in hematogenous spread.

Clinical Presentations: several recognized forms-

-Skin Pox: presence of wart like lesions in the skin. Course tends to be chronic: yellow nodules form on the beak, eyelids, and other areas of the skin. The nodules disintegrate and discharge a serosanguinous fluid. The areas then scab over. When these lesions are present on the feet they may occlude blood

vessels resulting in tissue necrosis of the lower extremities.

-Diphthertic form: presence of plaque-like lesions on mucous membranes. This form may appear alone or in conjunction with skin pox. When membranes (especially in the oral and nasal cavities) they may bleed profusely. Scabs may be inspired and lodge at the carina causing asphyxiation. Birds infected with

these forms may recover but are believed to be persistent shedders (carriers) of the virus for life. Worth mentioning, older literature describes a form of pox referred to as the "gasping form" where it is believed that the virus causes cardiovascular compromise resulting in an increased respiratory effort. The bird

may appear to have "something caught in its throat" due to the persistent head shaking. Clinical course was said to be roughly 3 days from onset of clinical signs to death. Some believe that this was actually the diphthertic form where death was caused by the aforementioned lodging of scab material at the carina

and the resultant asphyxiation.

-Septicemic form: acute onset with death several hours after infection. Diagnosis: Biopsy- presence of Bollinger bodies (intracytoplasmic lipophilic inclusion bodies) Treatment: unsatisfactory: one may try a mixture of glycerol and tinture of iodine to paint the skin lesions, vitamins A and C in feed or by

intramuscular injection.

Prevention: vaccination

POLYOMAVIRUS INFECTION ( = Papovavirus):

Host range: Broad- Budgies, Amazons, Macaws, Conures, Cockatoos, and more.

Pathogenesis: Carried by adults and passed on to the chicks at feeding time. The virus propagates under stressful conditions. For chicks the most stressful event is feather development.Clinical Signs: Distended abdomen, lack of or malformed down feathers, retarded growth of tail and contour feathers, urate soaked vent- usually involves the liver and the kidneys, reduced weight gain, slow emptying crop, and vomiting.

Diagnosis: Serology; Inclusion bodies on impression smears of liver and spleen.

Treatment: none

Prevention: Do not allow adults to breed for at least 6 months such that the immune system can clear the virus.

NOTE: This virus is responsible for Budgerigar Fledgling Disease which usually is rapidly fatal. Disease may take a more chronic course in other birds. Also causes papilloma like skin lesions in African Grey's which can be treated by an autogenous vaccine 2 weeks apart.

AVIAN SEROSITIS VIRUS (ASV): Virus suspected

Clinical Signs: affects chicks- distended abdomen leading to generalized edema,

lethargy, depression, respiratory difficulty due to impingement on the tract, and signs of massive hepatic damage.

Treatment: none

NOTE: There has been an association made between ASV and MWD.

Continued

05-14-2007, 05:16 AM

PSITTACINE BEAK AND FEATHER DISEASE (PBFD): circovirus with a broad host range.

Clinical Signs: Loss of feathers, decrease in down feathers on flanks, retained pin feathers, short clubbed feathers, deformed feathers. Differentiated from self-inflicted trauma in single birds as feathers on head also affected - normaly bird cannot reach these to self-damage. Beak may change in color, grow abnormally and become necrotic beginning with a palatine crust in the maxillary beak. Secondary bacterial infections makes the condition worse.

Diagnosis: Biopsy and Serology

Treatment: Usually a fatal disease so treatment may be unrewarding. Investigational therapy: gamma globulins and antibiotics.

COMMON BACTERIAL INFECTIONS

Many different bacterial organisms are responsible for most clinical presentations of avian illnesses. Respiratory and gastrointestinal problems are the most frequently encountered. Culture of the choana and cloaca help in antibiotic selection in combating disease. A Gram's stain should also be performed to determine the ration of Gram positive to Gram negative bacteria. Mostly Gram positive organisms should be present although one should expect some Gram negatives to be found as well. An abundance of the Gram negative bacteria in a clinically normal bird may indicate a subclinical infection that may be treated with antibiotics in the water (some birds will be able to tell the water has been spiked depending on

what drug is used, and may not drink the water. If the number of Gram negative bacteria is substantial, a

complete culture and sensitivity (C&S) should be performed and the bird placed on subcutaneous or intramuscular injections. Obviously, a clinically ill bird should be treated. Below is a list of the most common avian bacterial infections with a brief description of their clinical presentations.

CAMPYLOBACTER -causes hepatopathies; clinical signs include wasting, diarrhea, anorexia, emaciation

Treatment: Erythromycin or tetracycline

CLOSTRIDIAL DISEASE

-necrotic/ulcerative enteritis, diarrhea with or without blood.

-gangrenous dermatitis: bluish-black emphysematous skin lesions

-botulism: flaccid paralysis of skeletal musculature (limber neck)

Treatment: antitoxin, penicillin.

ERYSIPELOTHRIX

acute infection- sudden death; red coloration of the skin.

chronic infection- thickened dermis, arthritis, endocarditis

Treatment- penicillin, tetracyclines.

COLIBACILLOSIS : E. coli

-may cause enteritis, respiratory disease (rhinitis and air sacculitis)

Treatment: always perform a C&S, Enrofloxacin (Baytril)

HAEMOPHILUS

-rhinitis, conjunctivitis

Treatment: sulfonimides

KLEBSIELLA

-nephritis, pneumonia, hepatitis

Treatment: Gentamicin or Polymyxin B

LISTERIA

acute infection- acute deaths

chronic infection- tremors, stupor, paresis, and paralysis

Treatment- tetracyclines

MYCOBACTERIUM

-chronic wasting with a good appetite, recurrent diarrhea, polyuria, anemia,

shifting leg lameness, and arthritis.

*Zoonotic- euthanasia reccomended

PASTEURELLA

-respiratory and GI signs

Treatment: sulfonimides, chloramphenicol, tetracyclines.

PSEUDOMONAS

-diarrhea with or without blood, labored breathing, necrotozing dermatitis

Treatment: Gentamicin

SALMONELLOSIS

-nonspecific signs accompanied by gastrointestinal signs (diarrhea- watery,

slimy feces)

-infection has been associated with stressed African Greys

Treatment: C&S, chlorampehicol and tetracyclines

STAPHYLOCOCCUS

-embryonic mortality

-navel/yolk sac inflammation

-septicemia

-arthritis/synovitis (toe necrosis)

-osteomyelitis

-dermatitis

-secondary invader in bumblefoot

Treatment: Carbenicillin or gentamicin

STREPTOCOCCUS

acute infection- diarrhea, dyspnea, paresis, conjunctivitis, depression leading

to death within 3 days.

chronic infection- joint inflammation, tendonitis, endocarditis

Treatment- combination of ampicillin and erythromycin

YERSINIA pseudotuberculosis-generalized organopathy

ASPERGILLOSIS : Aspergillus fumigatus

Clinical Signs: Respiratory difficulty with or without discharges, Chronic debilitation, Acute infection may result in sudden death. Diagnosed on PM, endoscopy of eg air sacs, or serology.

Treatment: difficult and usually unrewarding; may try: Amphotericin B, 5-fluorocytosine, Rifampin.

PSITTACOSIS

Once considered a virus, many consider it a bacteria, causal agent is Chlamydia psittaci. One of the most important disease conditions due to its' zoonotic potential (meaning humans can catch this disease from an infected bird; the condition in humans is referred to as Ornithosis). All newly acquired birds should be quarantined/segregated and tested before allowed to mix with an aviary population.

Clinical Signs: lime green loose stool, weight loss, depression, splenomegaly, and air sacculitis. Bird should be suspect even if urates are yellowish (indicates liver involvement)

Diagnosis: Cloacal swabs and blood for an ELISA

Treatment: doxycycline (50 mg/kg PO Sid) for individual treatments or chlortetracycline in the feed for flock situations, both for at least 45 days. Enrofloxacin at 5-10mg/kg for 10 days.

SARCOCYSTSIS:

Etiology: Coccidial parasite (protozoal)

Host range: Cockatoos, cockatiels, and African Parrots.

Pathogenesis: Protozoan enters aviary via infected insects or rodents.

Clinical Signs: Death is acute and sarcocystis must be considered in all sudden deaths. Owner may observe signs of central nervous system disease (posterior or unilateral paresis, intention tremors, and head tilts). Due to replication in the lungs, edema may also be observed as well as dyspnea.

Clinical Pathology: increases in liver and muscle enzymes.

Treatment: Combination therapy of pyrimethamine (0.5 mg/kg PO BID) and trimethoprim sulfadiazine (30 mg/kg IM BID) for at least 2 weeks.

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05-14-2007, 05:18 AM

ROUTINE MEDICAL PROCEDURES

Fluid Administration:

Administration of a small amount of fluid may be given subcutaneously or by crop-tubing. When a patient is presented with a serious debilitating condition or trauma, fluid imbalances and deficits require intravenous fluid therapy. Catheterization of a vessel is difficult due to small vessels that are "blown"

very easily. A technique that is becoming more popular in avian medicine is intraosseous cannulation.

The patient is anesthetized (preferably isoflurane), the distal ulna located, feathers around the area plucked, and the skin aseptically prepared. An 18 guage needle may be used in larger species and a 25 gauge in smaller ones. Position the needle at the center of the distal end of the ulna parallel with the bone

(PALPATE!!!). Hold the wing with one hand and use the other to advance the needle with firm pressure to penetrate the cortex. The needle should then advance easily through the marrow. If you feel resistance a second time then a second cortex is being penetrated: retract the needle slightly and re-direct. Seat the needle hub with one or two subcutaneous sutures. Cut a slit in a 2x2 gauze pad to place around the needle and then place the wing in a figure of eight bandage.

Blood Collection:

Sites: clipped nail, right jugular vein, median ulnar vein (wing web vein- crosses at the elbow), and median tarsal vein. Blood accounts for approximately ten percent (10%) of the birds' weight. The amount that may be safely taken is about ten percent of the total blood volume: Birds' weight in grams X 0.01 =

maximum amount of blood that can be drawn in milliliters (ml).

Injections:

Use an insulin (tuberculin) syringe with a 25 or 27 gauge needle. Intramuscular injections may be given in the pectoral muscles on either side of the keel. The needle should be placed at a 45 degree angle (or less). Intravenous injections may be given in the wing web vein.

Anesthesia:

Ketamine has been widely used, but recovery is rough and may lead to self-injury. Thus, masking the bird down with isoflurane is recomended.

Surgical Sexing:

With the arrival of DNA sexing, this procedure is performed rarely. But for large numbers of birds or if it is necessary to know the sex immediately, this procedure is ideal. The bird should be masked down with Isoflurane and placed in RIGHT lateral recumbency (this is because females usually only have one

functional ovary on the left side). The wings may be held over the back by an assisstant, or crossed over each other by the humerus .Locate the last rib, just caudal to it feel for a depression that is at the mid-femur level. Pluck the feathers and aseptically prepare the area. Make an incision in the depression through the skin and muscle layers. A small rigid endoscope (or even an otoscope with a sterile attachment) is inserted into the incision. Direct the scope craniodorsally (this is done to minimize hemorrhage and organ damage). Then slowly direct the scope caudally until it is nearly perpendicular

to the body wall.

At this point one should be able to visualize the cranial and middle parts of the kidney beneath the air sac wall (The air sac wall is a clear to clear-white with a filmy appearance that has small blood vessles running through it). Puncture the air sac by pushing the scope through it; be sure to choose an area

with few or no blood vessles. Follow the kidney cranially until the "triad" of the kidney, adrenal gland, and gonad is located.

The testicle is oblong to elliptical with a smooth surface (it may be somewhat pigmented and thus appear darker). The ovary appears as a cluster of "grapes" and may exhibit follicles in different stages of development.

It is common practice to tattoo a bird after surgical sexing with a dye that is injected subcutaneously under the wing: males on the right, females on the left.Some vets will place a split ring denoting the bird's sex on the leg.There is no need to suture the incision as the bird in the normal wing and leg position will effectively seal the wound until it is healed.

Diseases of Cage Birds

BrokenWing