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.
