Avian immune system & clinical exam Flashcards
Describe Bird lymph nodes
Psyche! Birds don’t have lymph nodes! Haha!
The Bursa of Fabricius is an organ that is unique to birds and is the only site for B cell differentiation and maturation.
Active immunity is divided: (2)
o Humoral immune response
o Cellular immune response
Primary lymphoid organs of birds: (3)
Bone marrow, thymus, cloacal bursa
o For lymphocyte production and maturation
Secondary lymphoid organs of birds: (3)
Spleen, Harderian gland, lymphoid tissue
assemblies
o For lymphocyte collection, storage, and controlled release
What is the Harderian gland?
The Harderian gland is a gland found within the eye’s orbit that occurs in tetrapods (reptiles, amphibians, birds and mammals) that possess a nictitating membrane.
Research has proposed that the gland has several functions, including that of a location for immune response among others.
Lymphoid tissue assemblies in birds do what:
o Replace lymph nodes
o Bronchi (BALT), intestines (GALT) (gut-associated), eyes (CALT) (conjunctiva-associated)
Stages of avian clinical examination (5)
- Collection of medical history data
- Observation of the bird/birds
- External clinical examination and sampling of the bird/birds, preceded
by capture and restraining of the bird/birds - Euthanasia, necropsy and sample collection from dead bird/birds (if necessary)
- Laboratory diagnosis, further studies
Anamnesis about Bird/flock identifiers:
Species and breed, age, sex, weight, diet, appetite, water consumption,
vaccination data, previous diseases and treatment data, morbidity and mortality,
basis of grouping, production.
Current situation anamnesis:
o Bird/flock health records, disease case data - general clinical features, farm recorded data
Housing conditions anamnesis should include:
Temperature, humidity, environmental
cleanliness, floor area, ventilation,
feeding, watering, biosecurity, etc.
observation, registered farm data
Observation of a flock or groups of birds should last
10-20 minutes at least in order for them to grow accustomed to your presence and be calm
Body condition scoring birds
Your focus is on the Keel area. Should be easily palpated.
Uropygial gland exam
Uropygial or Preen Gland
Gland function is assessed at physical examination by wiping a finger across the tip. An oily secretion should be present. If not, blockage is likely, which may lead to impaction and abscess.
The uropygial gland is located on top of the base of the tail, on the lower back, just in front of the tail feathers. This area is generally featherless except for a tuft of down at the tip called the uropygial wick.
How do you assess Dehydration in birds?
CRT – pressure test (basilic wing vein)
o Instant refill – normal
o Refilling is visible – 5%
o Refill time ca. 1 sec. – 10% or in shock
(Other source: If it takes > 2 seconds it means dehydration of over 7%.)
o Pressure test of comb and wattles can be used
Medication groups used in birds (7)
Vitamins: ration balancing
Probiotics: gut microflora
NSAIDs: pain and inflammation
Anesthetics: inhaled, injectable
Antiparasitic drugs
Antimicrobials
Human medicines - if the use is justified
Avian epiglottis.
Unlike mammals, birds lack a distinct epiglottis, which is a cartilaginous structure that covers the opening of the trachea during swallowing to prevent food from entering the airway.
Instead, birds have a small, flexible fold of tissue called the operculum, which helps to protect the glottis during swallowing.
Note that term “operculum” can indeed refer to different structures depending on the context. Birds also have a structure called an operculum, that is on the outside of the beak.
The avian glottis, which serves as the entrance to the respiratory system in birds.
The avian esophageal opening is located…
In birds, the esophageal opening is located at the base of the tongue, within the pharynx. This differs from mammals, where the esophagus opens into the posterior part of the oral cavity or the pharynx.
Note: Birds have a muscular sphincter known as the esophageal sphincter or the upper esophageal sphincter (UES) surrounding the opening of the esophagus. This sphincter helps regulate the passage of food and prevents the entry of air into the esophagus during breathing. It also aids in preventing the regurgitation of food from the crop back into the mouth.
Describe the avian crop.
A crop is a specialized pouch-like structure located at the base of the esophagus.
The crop serves as a temporary storage organ for food before it enters the stomach for digestion. The esophageal opening often leads directly into the crop, allowing food to be transported efficiently for storage and subsequent digestion.
Birds that commonly have a crop include seed-eating birds like sparrows and pigeons, as well as birds of prey such as falcons and owls.
For example, birds that primarily consume insects or fish, such as swallows or herons, typically do not have a crop because they do not need to store food before digestion. Similarly, many species of birds that consume nectar, such as hummingbirds, also lack a crop.
Describe the avian stomach.
Divided into two parts: the proventriculus (glandular stomach) and the ventriculus (muscular stomach or gizzard).
The proventriculus secretes digestive enzymes, while the ventriculus grinds food with the help of swallowed grit or stones.
The three parts of the cloaca:
the coprodeum (receives waste from the digestive tract),
the urodeum (receives waste from the urinary tract),
and the proctodeum (receives reproductive products).
Administering vaccines to birds.
Live vaccines:
o Eye and/or nose drops
o Coarse mist – aerosol
o Fine mist – spray
o Drinking water
o Injection
Inactivated vaccines:
o Injection: intramuscular, subcutaneous or intradermal, wing web puncture, in ovo.
A good vaccination program includes:
Mandatory vaccination in poultry.
Finland:
* Marek’s disease: on the first day of life
- Avian infectious encephalomyelitis:
10-16 week old laying and breeding hens - Infectious bursal disease: at 8 weeks and at 16-20 weeks
- Chicken infectious anemia: at 6 and
10 weeks
