Poultry / PetBirds Flashcards
Highly pathogenic avian influenza (HPAI) has become endemic in some domestic ducks in Asia. Wild ducks and geese can move the virus, often without showing clinical illness. What is the human health concern?
- The HPAI can transfer genes from pig or human influenza strains, which allow the avian flu to become infectious to humans
- Some human genotypes are inherently susceptible to the avian influenza strains and, thus, a portion of the population could die from exposure to the HPAI
- The HPAl can spontaneously mutate or rearrange and become highly pathogenic for humans as well as birds
- The avian influenza strains are not pathogenic to humans, but the porcine (pig) strains are.
- Humans exposed to live pigs carrying pig flu in a market could start a major pandemic
Answer: The HPAI can transfer genes from pig or human influenza strains, which allow the avian flu to become infectious to humans
Explanation
While the highly pathogenic avian influenza strains can kill domestic ducks and poultry, they do not normally cause major public health issues unless they acquire the genes that allow them to attach to human respiratory mucosa and become pathogenic for humans. This is how a worldwide influenza pandemic could occur.
HPAI’s concern for human health lies in its potential to acquire genes from pig or human influenza strains, making it infectious to humans. This genetic shift can enable the avian flu to attach to human respiratory mucosa, potentially leading to a worldwide influenza pandemic. Wild ducks and geese can spread HPAI asymptomatically.
CGPT: Avian Influenza in Poultry and Wild Birds
Which of the following is a feature of avian anatomy or physiology?
- Neutrophils are the predominant type of circulating white blood cell
- A 4-chambered heart
- Incomplete tracheal rings
- 18 air sacs
Answer: A 4-chambered heart
Explanation
The correct answer is 4-chambered heart. Birds have heterophils instead of neutrophils, which essentially serve the same function as neutrophils. Remember, birds will always have complete tracheal rings, which makes them unique compared to most other species. As a general rule of thumb, birds have 9 air sacs.
The correct answer is a 4-chambered heart. Birds have a 4-chambered heart similar to mammals. Additionally, they have heterophils instead of neutrophils, complete tracheal rings, and typically have 9 air sacs, which are key features distinguishing them from many other species.
Several young 2-week old turkeys in a flock have died suddenly after showing signs of labored, gasping breathing. Other young turkeys show signs of ruffled feathers and an unkempt appearance in addition to labored breathing. You are concerned that these may be cases of round heart disease (also known as spontaneous cardiomyopathy). Which of the following tests would be most helpful in confirming the diagnosis?
- Measure selenium levels in feed or from serum of affected animals
- Histopathology of heart muscle of affected turkeys
- Measure taurine levels in feed or from serum of affected animals
- Gross necropsy
- Electrocardiogram on turkeys showing clinical signs
- Test for mutation in cardiac troponin gene
Answer: Gross necropsy
Explanation
Spontaneous cardiomyopathy, also known as round heart disease of turkeys, is a disease that manifests as sudden death due to cardiac arrest in young (less than 3-4 week old) turkeys. While the precise etiology is unknown, it is thought that ischemia, particularly during the brooding period, plays an important role.
The characteristic finding is an affected animal less than 4-weeks old that has a markedly enlarged heart with dilatation of the ventricles, congested lungs, and an enlarged liver. In some cases, ascites and other signs of congestive heart failure may be present.
The diagnosis is usually based on history and gross necropsy findings. Electrocardiogram findings are not considered useful and histologic lesions are nonspecific. They include lymphocytic infiltration and damage of the myofibrils in the cardiac muscle tissue. The disease is not thought to be related to nutritional deficiencies such as taurine or selenium.
If you chose selenium, you may have been thinking of mulberry heart disease of pigs which is related to Vitamin E and selenium deficiency. If you chose taurine, you may have been thinking of dilated cardiomyopathy in cats which can be caused by taurine deficiency.
The most helpful test in confirming the diagnosis of round heart disease (spontaneous cardiomyopathy) in the young turkeys is a gross necropsy. This disease manifests as sudden death with characteristic findings such as an enlarged heart with dilated ventricles, congested lungs, and an enlarged liver. Diagnosis is typically based on history and gross necropsy findings, as other tests like electrocardiograms or histology are not as useful or specific for this condition.
Comprehensive Veterinary Information on Spontaneous Cardiomyopathy in Turkeys
Definition & Etiology:
• Spontaneous Cardiomyopathy (Round Heart Disease): Affects turkeys, especially poults <4 weeks old, leading to sudden death. The etiology is unknown, though hypoxia and environmental factors during incubation or brooding may contribute.
Pathophysiology:
• Biochemical Changes: Decreased CK activity, glycogen concentration, and mitochondrial function, suggesting ischemia-induced myocardial failure. • Gross Lesions: Dilated ventricles, congested lungs, swollen liver, ascites, and edema.
Clinical Signs:
• Sudden death, ruffled feathers, dyspnea, unthrifty appearance, enlarged hearts, and decreased growth rates.
Diagnosis:
• Based on clinical history and necropsy findings.
Treatment & Prevention:
• No treatment available. • Prevention focuses on improving ventilation during incubation, transport, and brooding to prevent hypoxia.
[https://www.merckvetmanual.com/poultry/spontaneous-cardiomyopathy-of-turkeys/spontaneous-cardiomyopathy-of-turkeys?query=spontaneous cardiomyopathy of turkeys]
Previously healthy three-week-old broiler chickens that were fed ad libitum are now dying suddenly with purple heads (cyanosis) and swollen abdomens. The abdominal cavities contain abundant, clear yellow fluid with clear, fibrin clots that cover the liver. The hearts are enlarged and rounded, and the lungs are edematous. What is your initial diagnosis?
-Vitamin E deficiency
-Rickets
-Ascites/heart failure syndrome
-Visceral gout
-Fatty liver disease
Answer: Ascites/heart failure syndrome
Explanation
This is a common metabolic condition of small backyard broiler flocks that have constant access to feed.
The initial diagnosis is ascites/heart failure syndrome. This condition is common in small backyard broiler flocks, particularly those with constant access to feed. The sudden deaths, cyanosis, swollen abdomens, and associated findings like fibrin clots and enlarged hearts support this diagnosis.
Key Information on Ascites Syndrome in Poultry
Etiology and Pathogenesis
• Causative Factors: Pulmonary hypertension, right heart failure, genetic predisposition. • Triggers: High altitude, rapid growth, cold stress, increased oxygen demand, high sodium intake.
Clinical Findings
• Signs: Cyanosis, red abdominal skin, congested peripheral vessels, increased respiratory rate, decreased growth. • Lesions: Ascites, hydropericardium, liver congestion, right ventricular hypertrophy.
Diagnosis
• Necropsy Findings: Clear, yellow fluid in body cavities, swollen liver, right ventricular enlargement.
Control
• Prevention: Control growth rate, maintain optimal environmental conditions, avoid etiologic agents. • Management: Genetic selection for resistance, appropriate altitude management, and prevention of chilling in neonates.
[https://www.merckvetmanual.com/poultry/miscellaneous-conditions-of-poultry/ascites-syndrome-in-poultry]
On physical exam of a budgerigar with a history of voice change and regurgitation, you note a gross enlargement in the neck region that palpates like soft tissue. What is your most likely diagnosis?
- Thyroid carcinoma
- Neck trauma
- Crop stasis
- lodine deficiency
Answer: lodine deficiency
Explanation
The correct answer is iodine deficiency which results in goiter. The clinical signs along with physical exam findings are consistent with the diagnosis. Thyroid carcinoma is highly unlikely in birds. Neck trauma and crop stasis are good differentials but given that you are palpating a soft tissue mass, goiter is more likely.
The most likely diagnosis for a budgerigar with voice change, regurgitation, and a palpable soft tissue enlargement in the neck is iodine deficiency, leading to goiter. Thyroid carcinoma is rare in birds, and while neck trauma and crop stasis are differential diagnoses, goiter is more consistent with these findings.
An Amazon parrot presents to your clinic with the history of being polyuric and polydypsic (PU/PD), overweight, lethargic and recently inappetant. What is the most likely diagnosis?
- Adrenal tumor
- Renal gout
- Viral pyelonephritis
- Diabetes mellitus
Answer: Diabetes mellitus
Explanation
Birds with diabetes mellitus have clinical signs and blood results similar to other animals including hyperglycemia, glucosuria and increased thirst and urine production. This is not an uncommon disease in captive birds and is likely due to poor diet, lack of exercise, poor condition and obesity. Treatment options include insulin injections and oral medications such as glipizide.
The most likely diagnosis for an Amazon parrot with polyuria, polydipsia, overweight, lethargy, and inappetence is diabetes mellitus. This condition in birds shows similar signs to other animals, including hyperglycemia and glucosuria, often due to poor diet, lack of exercise, and obesity. Treatment includes insulin injections or oral medications like glipizide.
The goose shown in the image below was found weak on the shore of a local pond where oil had been dumped. The goose was covered in oil, dehydrated and weak but responsive. Which of the following is an important acute clinical effect of oil on affected birds?
- Nephrotoxicity
- Contact dermatitis
- Hepatotoxicity
- Lead toxicity
- Disruption of function of the plumage
Answer: Disruption of function of the plumage
Explanation
Feathers serve a critical waterproofing and insulatory function which is disrupted by oil and can rapidly result in hypothermia. Other concerns for oiled birds include Gl irritation from ingestion of oil during preening, hemolytic anemia, and pneumonia due to inhalation of oil.
Treatments include heat, supportive care, and activated charcoal. Once stabilized, frequent high pressure, warm, mild detergent baths and clean warm water rinses until water beads freely off of the feathers is important. Birds should be placed in warm air flow until dry and they should be maintained on self-skimming ponds for several days after washing to ensure full waterproofing.
During the summer, a number of waterfowl have been found dead or not moving (see image) on the shore of a lake at the city park. The lake is shallow and heavily overgrown with foliage. You perform a necropsy and find no gross lesions. What is your preliminary diagnosis?
- Blackhead
- Psittacosis
- Pacheco’s disease
- Botulism
- Polyoma virus
Answer: Botulism
Explanation
Outbreaks of botulism often occur in hot weather due to alkali and anaerobic conditions arising, often in stagnant water. As the water temperature rises, oxygen levels fall. Fish and invertebrate carcasses act as a substrate for clostridial spores and toxin production.
Diagnosis of avian botulism can be confirmed by identification of Clostridium botulinum type C toxin by serum toxin analysis or from maggots found on carcasses because the toxin becomes concentrated in the maggots.
Affected birds can be treated with nursing and supportive care if they are still at least able to walk (but not fly). If unable to walk, the prognosis is poor. Prevention relies on improved water flow and oxygenation, removal of any carcasses from the water, and yearly vaccination with type C toxoid.
What is the most common method for a bird to contract Staphylococcus aureus infection?
- Previous infection with coccidiosis
- Dirty litter
- Skin trauma
- Contaminated drinking water
- Exposure to oculonasal secretions
Answer: Skin trauma
Explanation
Staphylococcus aureus is a normal flora of the skin and mucosa and is most commonly transmitted through trauma to these areas.
Immunocompromised individuals are more susceptible to illness.
A breeding pair of blue and gold macaws (Ara ararauna) are laying eggs that are being taken for artificial incubation. As seen in the image below, several of the eggs have died near hatch (between 21-24 days of incubation). Egg necropsy, combined with microbiology, demonstrates a bacterial infection with Pseudomonas aeruginosa. Which of the following could be performed to try to salvage the remaining eggs in the incubator?
- Inject eggs with nystatin
- Decrease incubation temperature
- In-ovo vaccination with Pseudomonas bacterin
- Increase incubation temperature
- Inject eggs with piperacillin
Answer: Inject eggs with piperacillin
Explanation
A normal, healthy egg should hatch sterile. Occasionally, eggs may be infected by low level bacterial contamination. Infection may occur as a result of ovarian, oviductal or cloacal infection. Contamination is by minute cracks or pin-holes in the shell at the time of handling or egg collection.
All eggs should be candled so that any non-viable eggs may be removed from the incubator prior to possible contamination of healthy eggs. The incubator should be sanitized.
Pseudomonas infection in eggs can be treated by injection of an appropriate antibiotic such as piperacillin. A small hole is drilled, using a sterile 27 gauge needle over the air cell, and the antibiotic is injected into the air cell.
The hole is sealed with white, water-soluble glue (being careful not to cover additional areas of the shell as this would reduce water loss from the egg during incubation). Any chick that hatches should be cultured for bacteria immediately upon breaking open the shell, and antibiotic therapy should be commenced depending on the culture results. Nystatin should be given concurrently at 100,000 U per 400 g of body weight to prevent secondary infections with Candida spp.
You have confirmed the diagnosis of Chlamydophila psittaci in a group of birds. What is your treatment of choice?
- Doxycycline
- Nystatin
- Acyclovir
- Itraconazole
Answer: Doxyxycline
Explanation
The correct answer is doxycycline. Nystatin is used to treat candidiasis. Acyclovir is an anti-viral agent and would be ineffective in this situation. Itraconazole is used to treat avian aspergillosis. VetPrep Note: Other antibiotics such as enrofloxacin and azithromycin are showing promise in the treatment of Chlamydophila but the classic treatment has been doxycycline. This may change to one of the other drugs in the future but public health officials may request the use of doxycycline in an outbreak situation because of its long time use and success.
**PowerPage: Avian Chlamydiosis
**PowerLecture: Reportable Respiratory Diseases, Part 3: Laryngotracheitis And Chlamydiosis
The 11-week old handfeeding male Solomon Island eclectus has suddenly become a fussy eater and is refusing handfeeding formula despite being fed at the correct temperature and consistency. On your examination, an oropharyngeal lesion is seen (see image below). You swab the lesion with a sterile, saline-moistened cotton-tipped applicator and make a cytologic slide which shows large numbers of budding yeast. Which of the following is an appropriate treatment?
- There is no specific therapy
- Amoxicillin
- Metronidazole
- Fluconazole
- Ivermectin
Answer: Fluconazole
Explanation
This is an example of oral candidiasis. Oral and gastrointestinal candidiasis often occur secondary to a predisposing factor such as antibiotic therapy, poor hygiene, environmental stress, vitamin A deficiency, malnutrition, oropharyngeal trauma, or concurrent infection. It is appropriate to try to ascertain the presence of any such predisposing factors and to correct them.
In addition, treatment with nystatin topically or an -azole antifungal systemically is usually effective although some strains of Candida are resistant to ketoconazole. It is sometimes advocated to administer the drug in an acidic liquid such as orange juice to aid absorption and acidify the microenvironment to make it less hospitable to Candida.
Which of the following foods is considered toxic to parrots?
- Chicken
- Habanero peppers
- Avocado
- Cheese
- Blueberries
Answer: Avocado
Explanation
A toxin, known as persin, is a phytochemical found in the Guatemalan type of avocado which causes myocardial necrosis in the budgerigar, parrot and possibly other pet bird species. Blueberries and peppers (even “hot” peppers) are not toxic to psittacines. Chicken and cheese are high in fats and are not appropriate to feed parrots, but there is no toxicity associated with them.
***PowerPage: Toxicities of Pet Birds
An avid bird breeder is concerned that one of his prized budgerigars is sick. You recommend trying tube feeding over the next few days. Which of the following is true regarding the bird esophagus?
- Lies ventral to the trachea
- Contains complete cartilage rings
- Made up of skeletal muscle
- Lies on the right side of the neck
Answer: Lies on the right side of the neck
Explanation
The correct answer is lies on the right side of the neck. This is important to know when tube feeding birds, since you want to be 100% certain not to inject your food material into the trachea. The trachea contains complete cartilage rings, not the esophagus.
A 10-yr old, 825 gram, male, Moluccan cockatoo named “Ira” is presented to your clinic with a complaint of feather loss on the distal end of the right wing. A feather cyst had been removed from this area three months earlier. Physical examination reveals a thickened, yellow, friable skin lesion on the dorsal aspect of the right metacarpus. You make a contact smear of the area and cytology reveals macrophagic inflammation with multi-nucleated giant cells and cholesterol clefts as seen in the image below. What condition is this most compatible with?
- Cutaneous lymphoma
- Cutaneous xanthomatosis
- Cutaneous gout
- Bacterial dermatitis
- Avian poxvirus
Answer: Cutaneous xanthomatosis
Explanation
Cutaneous xanthomatosis is a unique condition of birds caused by excessive accumulation of lipids in the skin. It is a macrophagic inflammatory response, with multinucleated giant cells and cholesterol crystals observed cytologically. A xanthoma is a benign growth and is most prevalent in cockatiels, budgies and cockatoos. They are typically non-aggressive, but at times can become locally invasive causing irritation and self-mutilation of the site. The etiology is unknown but a high fat diet and inactivity may contribute.
Gout is a build-up of uric acid, and typically causes swollen painful joints. Bacterial dermatitis is usually associated with a heterophilic or mixed inflammation. Poxvirus lesions have clusters of squamous epithelial cells with eosinophilic cytoplasmic vacuoles. Cutaneous lymphoma yields highly cellular samples of immature lymphocytes.
A proliferative honeycomb beak (as seen in the image below) along with scaly crusty lesions on the legs and feet of a bird can be a sign of_________
- Cnemidocoptes pilae
- Mycobacterium avium
- Avian pox
- Chlamydophila psittaci
Answer: Cnemidocoptes pilae
Explanation
The correct answer is Cnemidocoptes pilae. Cnemidocoptes pilae, is also known as “scaly face” or “scaly leg.” This mite can be treated with topical or oral ivermectin. It is more common in birds that are immunocompromised, and beak deformity may be permanent even after the mite is cleared.
Avian pox can cause skin lesions, diptheric membranes, or septicemia. Mycobacterium avium causes granulomatous disease throughout the liver and Gl tract. Chlamydophila psittaci is the causative agent of psittacosis, and causes lethargy, respiratory, and Gl signs.
Which of the following is not a unique adaptation of avian species?
- Countercurrent air flow
- Incomplete tracheal rings
- No diaphragm
- Pneumatized bones
Answer: Incomplete tracheal rings
Explanation
The correct answer is incomplete tracheal rings. Birds have complete tracheal rings. Additionally, they have pneumatized bones (femur and humerus), countercurrent air flow exchange at the level of the lungs, and no diaphragm.
What are the genotypes of male and female birds?
- Male ZZ, Female WW
- Female ZZ, Male WW
- Female ZZ, Male ZW
- Male ZZ, Female ZW
Answer: Male ZZ, Female ZW
Explanation
The correct answer is Male ZZ, Female ZW. Females are the heterogametic sex in birds while males are the homogametic sex. This is in contrast to mammals where males are heterogametic (XY) and females are homogametic (XX).
A budgerigar is showing signs of squamous metaplasia of the oral mucosa, conjunctiva, and upper airways. It has developed associated bacterial sinusitis (see image). In a pet bird, what are these clinical signs most suggestive of?
- Hypovitaminosis D
- Hypovitaminosis A
- lodine deficiency
- Hypervitaminosis D
- Hypocalcemia
Answer: Hypovitaminosis A
Explanation
The correct answer is hypovitaminosis A. The functions of vitamin A are related to epithelial maintenance, vision, and skeletal development. In birds, problems with the skeleton or vision are rarely seen with vitamin A deficiency. Vitamin A deficiency can manifest as squamous metaplasia of the oral mucous membranes or glands. Glands may be entirely converted to squamous epithelium with keratin material and can look like abscesses or pustules but are essentially keratin cysts. They should be differentiated from lesions of pox, Candida, and Trichomonas. Lesions of the conjunctiva, nasolacrimal duct, upper Gl tract, and upper respiratory tract can occur. Presenting signs may include severe dyspnea or respiratory signs.
***PowerPage: Nutritional Diseases of Pet Birds
A Cockatiel hen, one of the owner’s prize egg layers, was found on the bottom of its cage and brought to your clinic on emergency. You check your records and see that the bird has had one previous reproductive problem with metabolic exhaustion but has always laid the egg successfully. On physical exam, you note the cloaca to be pink and dilated and abdominal palpation reveals a firm, round mass in the caudal abdomen. Your tentative diagnosis is that the bird is egg bound. Which of the following is the best treatment option?
- Medical treatment including analgesics, subcutaneous fluids, calcium administration, placing the bird in a warm, moist environment and reassess in 24 hours
- Prepare the bird for immediate surgery to remove the egg and perform an ovariohysterectomy
- Provide the owner with a poor prognosis since unfortunately there is no viable treatment option for birds with this condition.
- Female Cockatiels are prone to adrenal tumors which prevents the normal release of prostaglandin during egg laying so immediate surgical removal of the egg should also include adrenalectomy
Answer: Medical treatment including analgesics, subcutaneous fluids, calcium administration, placing the bird in a warm, moist environment and reassess in 24 hours
Explanation
This is the best answer because taking a debilitated bird to immediate surgery will be extremely risky. Since the bird is a proven layer, it is best to stabilize this dystocia patient for its metabolic needs during the first 24 hours while monitoring its response. In many cases, the egg will be produced with medical treatment alone - especially since she has laid eggs successfully in the past. If the bird does not produce the egg within 24 hours, then surgical and non-surgical options for removal can be discussed. Cockatiels are not prone to anti-prostaglandin producing adrenal tumors.
What are the genotypes of male and female birds?
- Male ZZ, Female WW
- Female ZZ, Male ZW
- Male ZZ, Female ZW
- Female ZZ, Male WW
Answer: Male ZZ, Female ZW
Explanation
The correct answer is Male ZZ, Female ZW. Females are the heterogametic sex in birds while males are the homogametic sex. This is in contrast to mammals where males are heterogametic (XY) and females are homogametic (XX).
A fluffed cockatiel with a recent history of anorexia and dyspnea presents to your clinic. You place the bird in oxygen for approximately an hour and then perform a physical exam. On physical exam you note coelomic distention. Blood work shows a heterophilia, increased AST, CK, and fibrinogen. What is the most likely diagnosis?
- Egg binding
- Gout
- Aspergillosis
- Egg yolk peritonitis
Answer: Egg yolk peritonitis
Explanation
The correct answer is egg yolk peritonitis. Egg yolk peritonitis can be life-threatening. Clinical signs include anorexia, fluffed feathers, coelomic distention, and dyspnea. Blood work findings are consistent with egg yolk peritonitis. If gout was the diagnosis, we would expect to see painful joints. We would not expect to see coelomic distention with aspergillosis. With egg binding you would not expect to see hyperfibrinogenemia.
Additionally, cloacal straining could potentially be present. Treatment for egg yolk peritonitis involves antibiotic therapy, surgery, and anti-inflammatories.
An adult conure presents to you for progressive right sided lameness. On physical exam, you palpate an abdominal mass. What diagnostic test do you recommend?
- Complete blood count
- Abdominal radiograph
- Right leg radiographs
- Urinalysis
- Serum biochemistry
Answer: Abdominal radiograph
Explanation
The correct answer is abdominal radiograph. Based on the description, you should suspect a renal mass (carcinoma) causing progressive compression of the ischiatic nerve. A radiograph would be the best test of these choices to confirm that diagnosis. Radiographs of the right leg would rule out orthopedic disease, but would not show the primary mass. Urinalysis would most likely not show evidence of neoplastic cells.
Which of the following is not a possible sequela of calcium, phosphorus, and vitamin D3 imbalance in a pet bird?
- Seizures
- Proventricular dilatation
- Egg binding
- Osteoporosis
- Rickets
Answer: Proventricular dilatation
Explanation
The correct answer is proventricular dilatation. Birds on all seed diets often have problems with calcium and phosphorus metabolism. Inadequacies in these minerals result in osteoporosis, acute hypocalcemia (weakness, tremors, seizures), rickets and splayleg in young birds, and egg binding. Excess vitamin D3 can cause mineralization in tissues, particularly the kidneys.
When comparing Marek’s disease (MD) and Lymphoid leukosis (LL), which of the following statements is CORRECT?
- Both MD and LL are classified as wet and dry forms.
- Both MD and LL viruses are transmitted only in feather follicle epithelium.
- Both MD and LL cause paralysis in 4-week-old chickens.
- Both MD and LL both cause neoplastic transformation of lymphocytes
- Both MD and LL are controlled by vaccination in the hatchery.
Answer: Both MD and LL both cause neoplastic transformation of lymphocytes
Explanation
MD and LL are caused by viruses that initiate lymphoma.
You are examining a flock of chickens that has recently had a 10-20% drop in egg production. You note that chickens are displaying signs of varying severity including watery eyes, nasal discharge, dyspnea with extension of the neck during inspiration, coughing of mucus and blood, and decreased food intake. There has been low mortality from this condition and you perform a necropsy on a deceased chicken and find caseous exudate and blood in the trachea. You suspect that this may be an outbreak of infectious laryngotracheitis. **Which of these findings would confirm your diagnosis?*
- Intranuclear inclusion bodies in tracheal epithelium
- Multifocal necrosis in the liver with large, granular basophilic intracytoplasmic inclusions
- A positive tracheal wash culture for beta-hemolytic Streptococcus
- Isolation of Heterakis gallinarum from cecal walls
- Intracytoplasmic inclusion bodies in the chorioallantoic membrane of inoculated chick embryos
- A positive tracheal wash culture for mycoplasma
Answer: Intranuclear inclusion bodies in tracheal epithelium
Explanation
Infectious laryngotracheitis (ILT) is caused by a herpesvirus. Intranuclear inclusion bodies in the tracheal epithelium help distinguish this condition from the diphtheritic form of fowlpox. Fowlpox virus produces intracytoplasmic inclusions. Liver necrosis with large, granular basophilic intracytoplasmic inclusions is consistent with avian chlamydiosis.
**PowerLecture: Reportable Respiratory Diseases, Part 3: Laryngotracheitis And Chlamydiosis
Your client’s turkey developed nasal and ocular discharge, weight loss, inappetence, and then died. You performed a necropsy and found pneumonia, multifocal necrosis in the liver and spleen, and severe pericarditis. Histopathologic findings included many basophilic intracytoplasmic inclusions found in the affected organs. What is the most likely cause of death?
- Aspergillus fumigatus
- Newcastle disease
- Chlamydia psittaci
- Fowl cholera
- Mycoplasma gallisepticum
Answer: Chlamydia psittaci
Explanation
The correct answer is Chlamydia psittaci. The intracytoplasmic inclusions, along with involvement of multiple organs and supportive clinical findings, are indicative of this disease. Chlamydia psittaci is known as ornithosis in turkeys.
***PowerLecture: Reportable Respiratory Diseases, Part 3: Laryngotracheitis And Chlamydiosis
A small scale rearer of pheasant chicks reports that several birds from a group had developed abnormalities of the legs around 5-weeks of age (see image) resulting in mild lameness. You perform a microscopic evaluation on the underside of some of the crusts and see the mites shown in the images below. What is the best interpretation?
- This is a mixed infestation of Knemidocoptes and Sarcoptes
- This is a mixed infestation of Cheyletiella and Knemidocoptes
- This is a Sarcoptes infestation
- This is a Knemidocoptes (also can be spelled Cnemidocoptes) mutans infestation
- This is a mixed infestation of Sarcoptes and Cheyletiella
Answer: This is a Knemidocoptes (also can be spelled Cnemidocoptes) mutans infestation
Explanation
The location and appearance of these lesions is most suggestive of a Knemidocoptes mite infestation, also known as scaly leg mite. White-grey powdery debris forms between and on the surface of the scale resulting in the honeycomb crusts. The legs may become thickened and distorted. Diagnosis can usually be made by skin scraping or examination of the underside of a crust microscopically to detect the mite. The microscopic evaluation reveals two mites that look substantially different. These are the male and female Cnemidocoptes mites. The adult female, seen on the left, is almost round with short legs and devoid of suckers. The adult male is smaller with longer legs and suckers on long stalks. Treatment of choice is ivermectin.
Several turkeys recently moved to new housing, which previously housed chickens, have died. One is brought to you for necropsy and you find marked inflammatory changes, cecal wall thickening and ulcerations. There are also rounded necrotic lesions present on the liver. What is the most likely diagnosis?
- Histomonas meleagridis
- Coronavirus
- Heterakis gallinarum
- Aspergillus fumigatus
- Mycoplasma gallisepticum
Answer: ** Histomonas meleagridis**
Explanation
The correct answer is Histomonas meleagridis. Heterakis gallinarum is the parasite which hosts the protozoan Histomonas meleagridis which causes clinical disease. Clinical signs include drooping wings, unkempt feathers, sulfur colored droppings, listlessness, and death. The liver and cecal lesions are considered pathognomonic for Histomonas meleagridis. This is must know information for boards.
You have been called to evaluate a flock of approximately 6 week old chicks who have been showing signs of respiratory disease. You notice that the hatchery equipment and facilities are run down. You perform a necropsy on one of the affected chicks and find cream-colored plaques throughout the lungs. What is your recommendation to the owner?
- Cull affected birds
- Begin aggressive broad spectrum antibiotic therapy
- Separate affected birds
- Start all birds on appropriate antifungal therapy
Answer: Cull affected birds
Explanation
The correct answer is cull affected birds. The clinical signs and necropsy findings are consistent with an Aspergillus infection (aka brooder pneumonia, mycotic pneumonia, or pneumomycosis). The best thing to do is kill affected birds as treatment is considered useless. Additionally, the facilities should be thoroughly disinfected.
A geriatric Amazon parrot had a 1 cm diameter raised ulcerated mass on its left wing surgically removed at your clinic six months earlier. Histology found the mass to be an aggressive squamous cell carcinoma. The same bird returns due to severe weight loss, lethargy and a return of the mass. The owners wish to euthanize the bird. What is the most humane method to euthanize this parrot?
- Manually restrain the bird using gloves, intubate and administer inhalant carbon dioxide
- Administer isoflurane gas via facemask and when adequately anesthetized, administer intravenous pentobarbital
- Manually restrain the bird in a towel, intubate and provide intravenous ketamine
- Manually restrain the bird in a towel and administer intravenous potassium chloride
Answer: Administer isoflurane gas via facemask and when adequately anesthetized, administer intravenous pentobarbital
Explanation
Gas anesthesia via facemask is recommended before performing euthanasia to allow patient relaxation and easy access to the veins. Pentobarbital is a satisfactory euthanasia agent in birds.
Which of these avian blood cells does NOT contain a nucleus?
- Red blood cell
- None of the above (all of the cells listed contains a nucleus)
- Heterophil
- Thrombocytes
Answer: None of the above (all of the cells listed contains a nucleus)
Explanation
All blood cells are nucleated in avian species.
A cockatiel presents with a large yellow-orange mass on the tip of its wing and also on its breast. You perform a fine needle aspirate and cytology reveals macrophagic inflammation with multi-nucleated giant cells and cholesterol clefts. What is your diagnosis?
- Xanthoma
- Squamous cell carcinoma
- Triglyceroma
- Feather cyst
Answer: Xanthoma
Explanation
A xanthoma is a benign growth composed of lipids and cholesterol accumulations and is most prevalent in cockatiels, budgies and cockatoos. They are typically non-aggressive, but at times can become locally invasive causing irritation and self-mutilation of the site. The etiology is unknown but a high fat diet and inactivity may contribute.
An Amazon parrot presents to your clinic with the history of being polyuric and polydypsic (PU/PD), overweight, lethargic and recently inappetant. What is the most likely diagnosis?
- Diabetes mellitus
- Viral pyelonephritis
- Adrenal tumor
- Renal gout
Answer: Diabetes mellitus
Explanation
Birds with diabetes mellitus have clinical signs and blood results similar to other animals including hyperglycemia, glucosuria and increased thirst and urine production. This is not an uncommon disease in captive birds and is likely due to poor diet, lack of exercise, poor condition and obesity. Treatment options include insulin injections and oral medications such as glipizide.
A newly acquired Cockatiel with an unknown history presents for increased respiratory effort. Which of the following is the least likely differential diagnosis for this bird?
- Chlamydiosis
- Mycoplasma infection
- Polyomavirus infection
- Bordetella infection
Answer: Polyomavirus infection
Explanation
The correct answer is Polyoma virus infection. The avian Polyoma virus causes delayed feathering, diarrhea, gastrointestinal stasis, ascites, and death. Respiratory difficulty is not a classic clinical sign for Polyoma virus.
Mycoplasma infection, chlamydiosis, and Bordetella infection are all respiratory infections in birds that can cause head shaking, sneezing, and rhinitis.
A 6-year old Sun Conure presents for evaluation of a skin lesion. The owner reports that the bird is very sensitive on the wing near the lesion. On your exam, you note an oval swelling involving the feather follicle as seen in the image below. What is the best treatment for feather cysts?
- Surgical removal of the feather cyst and follicle
- Lance and drain the feather cyst, flush with saline
- Treat with systemic antibiotics for 4-6 weeks
- Squeeze and express the material out of the feather cyst
- No treatment is necessary as feather cysts typically resolve spontaneously
Answer: Surgical removal of the feather cyst and follicle
Explanation
Feather cysts are the avian equivalent of an ingrown hair. A growing feather is unable to protrude through the skin and curls within the follicle. Since feathers are much larger than hairs, cysts can be quite large and painful.
They commonly are found in the primary feathers of the wing. The cysts contain keratinized feather material that can be expressed or excised but commonly recur. Treatment of choice is surgical removal of the involved feather follicle.
On physical examination of a cockatoo, you notice that on both sides of the neck there appears to be a discreet line of feathers, and when parted, you can see the underlying skin, trachea, and jugular vein. You tell the owner:
- The bird is showing early signs of hypothyroidism
- This is a normal featherless tract known as the aptera
- This bird has a pathognomonic sign of Psittacine Beak and Feather Disease (PBFD)
- This bird has a genetic feather defect
Answer: This is a normal featherless tract known as the aptera
Explanation
There are numerous featherless areas or tracts, known as aptera, distributed over the body of most parrot species. They usually go unnoticed unless the feathered areas, called pterylae, are wet or physically parted. The aptera along the lateral neck is a good site to visualize the trachea, muscles and blood vessels of the neck.
This 3-year old female Budgerigar presents on emergency for a 3-day history of being fluffed at the bottom of the cage with a decreased appetite. The owners noticed red tissue protruding from the vent today. Her diet is seed only with a cuttle bone, and she is housed with a male. She has no previous medical history, but did lay a clutch of eggs last year. They appeared normal to the owner. What is a common predisposing factor for this condition in seed-eating birds?
- Calcium deficiency
- Calcium excess
- Hypercholesterolemia
- Vitamin A deficiency
Answer: Calcium deficiency
Explanation
With seeds as a primary diet, many reproductively active females do not maintain adequate calcium levels to be able to lay eggs normally. This leads to weakened contractions of the reproductive tract and an inability to pass eggs through the oviduct.
Initial therapy should consist of fluid support and calcium prior to attempt to reduce the prolapse.
While vitamin A deficiency is often present in seed-eating birds, the clinical syndromes associated with this are more commonly squamous metaplasia affecting the oral mucosa, respiratory and renal systems.
Hypercholesterolemia is often associated with seed-diets, but does not generally result in egg-binding or prolapse, as reproductively active birds will normally have elevated levels of cholesterol for egg production.
Excessive amounts of oral calcium are generally not absorbed by the gastrointestinal tract and are excreted, making it difficult to over-supplement with oral calcium.
A woman purchased two 4-month old budgerigars recently. She is concerned about their appearance which is shown in the photos below. Which of the following should you tell the owner?
- Her birds have a nutritional disorder and require vitamin supplementation
- Her birds have signs of toxicity and the toxic source should be identified and removed
- Her birds have an infectious disease that should be treated with appropriate antimicriobials
- Her birds have a genetic disorder and she should inform the breeder
- This is a normal appearance for budgerigars of this age
Answer: Her birds have a genetic disorder and she should inform the breeder
Explanation
This is the striking appearance of a genetic condition in budgerigars known as
“Chrysanthemum disease.” They are colloquially referred to as “feather dusters.” This is an autosomal recessive disorder that results in continuous growth of feathers all over the body.
Initially, these birds stand out in the nest as the largest and best feathered of the group. But over the first days or weeks, the classic appearance becomes obvious. This frequently results in obscured eyesight, inability to fly, and difficulty preening. Conventionally, it has been stated that birds with this condition only live 3-6 months but with care taken to provide adequate nutrition and supportive care, they can live several years.
An owner presents with his sulphur crested cockatoo and his main complaints are “powder loss” and an irregular beak (see image). What disease should you test for?
- Papillomatosis
- Parrot fever
- Pacheco virus
- Psittacine beak and feather virus
Answer: Psittacine beak and feather virus
Explanation
The correct answer is psittacine beak and feather virus. Powder loss in cockatoos is a common finding with this disease that you should be aware of. The beak and nails will also be affected. On physical exam, you can also expect feather dystrophy.
Pacheco’s virus does not cause the same clinical signs. Usually you will observe anorexia, depression, and it may cause death. With papillomatosis you will expect to find papillomatous lesions, which are not described in the question. Parrot fever is another name for Chlamydophila psittaci, which has non-specific clinical signs such as lethargy, respiratory signs, diarrhea, and decreased activity.
***PowerPage: Psittacine Viral Diseases
A 26-year-old female Double-Yellow Head Amazon presents with a 1-day history of profuse polydipsia, polyuria, lethargy and anorexia. The owners noticed today that the droppings were bright red (see image) and brought the bird for evaluation. On physical exam, the bird is severely depressed, approximately 12-15% dehydrated based on eyelid turgor and basilic vein refill. There are no other significant physical exam findings. The bird immediately drinks when placed in front of a water bowl. You are able to obtain a small amount of blood from the medial metatarsal vein. You run a PCV/TS on the blood sample. The PCV is 19% with total solids of 5.2gm/dl, and you note the plasma is red following centrifugation. The bird has no previous medical history and is housed alone in a wrought-iron cage. She is indoor-only and is allowed supervised time out around the house. The owners noticed her chewing on the windowsill behind her cage. What is the most likely differential for a bird with this presentation and what should be your next diagnostic step?
- Chlamydophila psittaci; obtain conjunctival/choanal/cloacal swab for PCR
- Liver disease; obtain bile acids
- Leukocytozoon infection; evaluate blood smear for presence of parasites
- Heavy metal toxicosis; perform 1-view radiograph to confirm presence of metal in gastrointestinal tract
Answer: Heavy metal toxicosis; perform 1-view radiograph to confirm presence of metal in gastrointestinal tract
Explanation
These signs (acute onset severe lethargy, polyuria, polydipsia, and hemolysis) are all consistent with heavy metal toxicosis; however, it is difficult to differentiate lead vs. zinc toxicosis without a heavy metal panel.
Hemoglobinuria is sometimes seen in Amazon parrots with lead toxicosis. Positioned radiographs are not required to diagnose heavy metal toxicosis, and it is important not to stress ill birds to obtain positioned radiographs. The history of chewing on a windowsill or other household objects is common for birds with metal toxicosis, especially in older houses with lead-based paint.
Liver disease may present similarly; however, the urates are generally more green-yellow, and the feces may also have a greenish tinge. Some animals with metal toxicosis will present with bright green feces, so this remains an important differential. In this bird, the red-tinged urates help to differentiate this presentation from that of liver disease.
Chlamydophila psittaci is a common cause of hepatosplenomegaly in psittacines and may cause signs similar to those listed for liver disease. The evidence of hemolysis in this patient is not consistent with avian chlamydiosis.
Leukocytozoon is a commonly found blood borne parasite found in birds of prey and may cause anemia in birds that are otherwise immunosuppressed. This is extremely uncommon in household psittacines.
You are presented with a dead 5-year old parrot from a local breeder with a history of chronic weight loss. It was received two months ago from another breeder following shipment across the country. A necropsy is performed and the most notable finding is an enlarged liver with diffuse 1mm white nodules (see image). Histopathology reveals granulomatous inflammation and acid-fast bacilli in the lesions. What is the most likely diagnosis?
- Salmonella
- Polyomavirus
- Clostridium
- Mycobacterium
Answer: Mycobacterium
Explanation
Acid-fast stain (also known as Ziehl-Neelsen) is a special bacteriological stain used to identify acid-fast organisms, mainly Mycobacteria. Birds are susceptible to Mycobacterium avium, the causative organism of avian tuberculosis (or avian TB) and is the diagnosis in this case. Nocardia is also a bacterium that stains acid-fast positive but clinical disease is much less common in avian species. Clostridium and Salmonella are not acid-fast bacteria, and polyomavirus is a virus.
Several grower chickens are found dead in a free-range poultry farm. The carcasses are very pale and have large numbers of mites (see image) present in the feathers. What is the cause of death in the chickens?
- Anemia secondary to severe Ornithonyssus bursae infestation
- Anemia secondary to severe Dermanyssus gallinae infestation
- Anemia secondary to severe Knemidocoptes mutans infestation
- Septicemia secondary to Laminosioptes cysticola infestation
- Septicemia secondary to Ornithonyssus bursae infestation
Answer: Anemia secondary to severe Dermanyssus gallinae infestation
Explanation
Dermanyssus gallinae is known as the poultry red mite. They are nocturnal feeders and severe infestations can cause anemia and even death in severely infested animals. Management of Dermanyssus depends on effective treatment of the environment with residual insecticides. Individual animals can be treated with a variety of topical agents but long term management depends on environmental control.
Knemidocoptes mutans is also known as the “scaly leg mite” and affects chickens, pheasants, and pigeons. It causes lesions primarily on the legs and unfeathered parts although irritation can lead to feather picking. The lesions progress to appear thickened and encrusted. The adult females are short legged, round, up to 0.5mm in diameter.
Laminosioptes cysticola is the subcutaneous mite and typically causes 1-3 mm nodular subcutaneous lesions.
Ornithonyssus bursae are the tropical fowl mite and often infect the feathered regions around the vent. They spend the entire life cycle on the host.
A 7-year old yellow-naped Amazon presents with a 3-month history of polyphagia, weight loss, and voluminous foul-smelling, light tan droppings (see image). A complete blood count, chemistry panel including amylase and lipase, aerobic cloacal culture, fecal Gram-stain, chlamydia screening, and fecal flotation were all negative or within normal limits. Which of the following treatments would be most likely to cause clinical improvement of the most likely underlying disease?
- Dietary supplementation with vitamin C
- Administration of short-acting insulin initially, followed by longer-acting insulin
- Dietary supplementation with vitamin A
- Addition of thyroxine
- Dietary supplementation with pancreatic enzymes
Answer: Dietary supplementation with pancreatic enzymes
Explanation
Exocrine pancreatic insufficiency in birds may occur due to congenital pancreatic atrophy or due to end-stage chronic pancreatic disease. Clinical signs include weight loss and large, pale, voluminous droppings often referred to as having a “popcorn” appearance as shown in the photo. Polyphagia is variable.
This is treated by identifying and eliminating underlying causes and converting the bird to a formulated diet supplemented with pancreatic enzymes.
Psittacine beak and feather disease, as seen in this lorikeet showing loss of distal primary feathers, mainly affects birds of which age group?
- 10-20 years of age
- 30-40 years of age
- Less than 3 years of age
- Over 50 years of age
Answer: Less than 3 years of age
Explanation
The correct answer is less than 3 years of age. The disease is caused by a circovirus and can affect any psittacine bird, but clinical illness is seen most commonly in those less than 3 years of age. Clinical signs include feather loss, abnormal pin and mature feathers, lack of powder down, and various beak abnormalities. The clinical signs are progressive, and birds may have their feathers, beak, or both affected. Diagnosis is based on appearance of birds and by blood tests using a viral DNA probe.
A spectacled Amazon parrot presented for surgical sexing. During the laparoscopic procedure, black spots were observed on the lungs and air sacs as seen in the image below. No other signs of inflammation were detected. Which of the following is the most appropriate treatment or management recommendation?
- Treat the parrot with metronidazole
- Do not breed the parrot
- Treat the parrot with ivermectin
- Treat the parrot with fluconazole
- No treatment or management change is indicated
Answer: No treatment or management change is indicated
Explanation
This appearance of black spots on the air sacs and lungs in a bird are known as anthracosis. This is considered a routine non-pathologic finding provided there are no other signs of inflammation in those areas and no treatment or management change is needed in birds.
This 3-year old female Budgerigar presents on emergency for a 3-day history of being fluffed at the bottom of the cage with a decreased appetite. The owners noticed red tissue protruding from the vent today. Her diet is seed only with a cuttle bone, and she is housed with a male. She has no previous medical history, but did lay a clutch of eggs last year. They appeared normal to the owner. What is a common predisposing factor for this condition in seed-eating birds?
- Vitamin A deficiency
- Hypercholesterolemia
- Calcium deficiency
- Calcium excess
Answer: Calcium deficiency
Explanation
With seeds as a primary diet, many reproductively active females do not maintain adequate calcium levels to be able to lay eggs normally. This leads to weakened contractions of the reproductive tract and an inability to pass eggs through the oviduct. Initial therapy should consist of fluid support and calcium prior to attempt to reduce the prolapse.
While vitamin A deficiency is often present in seed-eating birds, the clinical syndromes associated with this are more commonly squamous metaplasia affecting the oral mucosa, respiratory and renal systems.
Hypercholesterolemia is often associated with seed-diets, but does not generally result in egg-binding or prolapse, as reproductively active birds will normally have elevated levels of cholesterol for egg production.
Excessive amounts of oral calcium are generally not absorbed by the gastrointestinal tract and are excreted, making it difficult to over-supplement with oral calcium.
Visceral gout, as seen in the image below in a parrot, is the result of crystallization of what compound?
- Ursodeoxycholic acid
- Oxalic acid
- Glycolic acid
- Urea
- Uric acid
Answer: Uric acid
Explanation
The correct answer is uric acid. Gout occurs when urate crystals form and deposit. Urea is soluble and does not crystallize. Ursodeoxycholic acid is the active ingredient of Actigall (ursodiol), which is used in biliary disorders of small animals. Glycolic acid is metabolized to oxalic acid, which may precipitate into calcium oxalate crystals in mammals.
The 18-day duck embryo on the left (see image) is normal while the one on the right of the same age shows cervical lordosis, a shortened axial skeleton, and subcutaneous emphysema. Which management change would be most likely to reduce the incidence of such abnormalities?
- Depopulate the flock and replace with pathogen free ducks
- Reduce or eliminate use of polychlorinated biphenols (PCBs)
- Supplement ducks with iodine
- Supplement ducks with calcium
- Reduce or eliminate organophosphate use
Answer: Reduce or eliminate organophosphate use
Explanation
These deformities are associated with organophosphate insecticides, particularly parathion, which can cause several vertebral and long bone abnormalities as well as generalized stunting of embryonic development.
PCBs are mixtures of compounds released in combustion. They cause reproductive toxicity in avians by binding to estrogen receptors and altering thyroid and adrenal homeostasis. They do not cause specific fetal abnormalities.
