Poultry

Question 1

How can history be established when investigating lameness?

Answer 1

Be methodical

FOR BROILERS

• Site identification details
• Age…many conditions are age related
• Age range on site
• Number of birds on farm, in each house, in the affected group
• Nature of the problem i.e. the producer’s concern
• Mortality rates
• Cull rates (separating out leg culls)
• Vaccination/medical history
• Previous crop health and performance figures
• Recent production changes (e.g. New equipment, change in feed ration, breed used)

Question 2

What should be documented when documenting the normal?

Answer 2

• Number of birds
• Age
• Breed
• Egg production
• Egg quality
• Fertility
• Hatchability
• Daily liveweight gain
• Water consumption
• Mortality
• Cull rate
• Evenness
• Food conversion ratio
• European production efficiency factor
• Performance recording underpins FHP

Question 3

What tests can be done on PM investigation?

Answer 3

• Bloods
• Histology
• Faecal microscopy
• Gut content microscopy
• Electron microscopy
• Virus Isolation
• PCR

Question 4

Discuss PM examination of poultry?

Answer 4

• Because of the large numbers of birds kept, mortalities are inevitable
• Post mortem examination of fresh dead allows a unique opportunity to examine the internal organs of the birds
• It is the mainstay of our examinations, but is complemented by other testing
• Sample selection can impact on findings
• Culls vs. Dead
• Average batch size ~ 6 birds

Question 5

What are the recognised methods of culling?

Answer 5

The Humane Slaughter Association’s guidelines advise neck dislocation

Refer to WATOK (welfare at time of killing)

Question 6

What is necropsy procedure?

Answer 6

• Weigh the submissions
• Superficial examination
• Systematic approach, don’t forget spinal pathology

Follow up tests

• Bacteriology
• Parasitology

Question 7

When blood sampling broilers is a snap shot useful?

Answer 7

• The answer is “ yes ” but we must realise what it represents
• Are antibodies increasing or decreasing?
• Serial samples are much more useful (2 week interval)
• Base line samples on a site can be very useful to establish the “ normal ” level

Question 8

What is the blood sampling technique in poultry?

Answer 8

• Good restraint is very important
• Brachial vein exposed by plucking feathers
• Use 21 –23 gauge needle or nick vein with sharp blade
• Half fill blood tube
• Bleeding will usually stop once wing is lowered
• Put cap on tube and lie on side to clot
• Send to laboratory asap (with paperwork)
• DO NOT FREEZE

Question 9

What are your differential Diagnoses for poultry lameness?

Answer 9

Think:

• Viral
• Bacterial
• Parasitic
• Nutritional
• Genetic
• Metabolic

Question 10

What is lameness?

Answer 10

Lameness is the consequence of biomechanical or neural dysfunction or pain and is usually a welfare concern.

Question 11

What do you do if lameness is evident?

Answer 11

In severe cases of lameness the patient should be culled

Question 12

What is a synsacrum?

Answer 12

Like mammals the pelvis consists of the ischium, ilium and pubis. As previously mentioned it is fused to the synsacrum at the ilium.

Question 13

The trochanter of the femur articulates with the antitrochanter of the pelvis. This articulation ensures that?

Answer 13

when the leg is in a normal position, abduction is prevented

Question 14

The more the bird has to run?

Answer 14

The wider the pelvis

Question 15

Femoral condyles are attached by ligaments to, and articulate with the?

Answer 15

tibiotarsus and the head of the fibula.

Question 16

The tibiotarsus is formed by the fusion of ?

Answer 16

The tibia and the proximal row of tarsal bones

Question 17

The fibula is attached to the tibiotarsus by a tight fibrinous union at the fibular crest and extends 2/3 the way down, therefore there is?

Answer 17

little rotation of the leg

Question 18

The hock is?

Answer 18

The hock is an intertarsal joint between the tibiotarsus and tarsometatarsus. It has a single meniscus and a single cruciate

Question 19

The tarsometatarsus is a fusion of the?

Answer 19

distal tarsal bones to the 3 main metatarsal bones and extends to the ground. It can be a very long bone in waders

Question 20

Most birds have digits?

Answer 20

I to IV and they have 2, 3, 4 & 5 phalanges

Question 21

Anisodactyl birds have?

Answer 21

3 forward facing toes and a single hind toe

Question 22

Zygodactyl birds have?

Answer 22

digit II and III facing forward and digits I and IV facing backwards

Question 23

Label the digits in this anisodactyl bird?

Answer 23

Question 24

Why do ducks waddle?

Answer 24

The hip can be extended and flexed but there is also rotation in the recovery phase. This is pronounced in ducks: hence their waddle. There is very little abduction or adduction

Question 25

What are the extensors and flexors in the poultry limb?

Answer 25

**Extensors**= pubo-ischio-femoralis & iliofemoralis (shock absorbers when landing) **Flexors**=iliotibialis cranialis

Question 26

The stifle is flexed and extended by?

Answer 26

flexed by the iliofibularis and extended by the femorotibialis

Question 27

The hock joint is flexed and extended by what?

Answer 27

flexed by tibialis cranialis and extended by gastrocnemius. The palpable gastrocnemius tendon passes through a sleeve connected to the caudal surface of the cartilage and ends on the plantar aspect of the tarsometatarsus. (Heavy birds can often develop a “slipped tendon”.)

Question 28

What allows a bird to perch?

Answer 28

When birds crouch slightly the flexor tendons tense thus allowing perching. There is also a locking mechanism in the digits where the flexor tendons have a ratchet that prevents them moving when the muscle is tensed and the toes are flexed and gripping. Thus when getting a bird of a perch it is made easier if you lift it slightly

Question 29

What would be you d/dx for this clinical presentation: ## Footnote Sitting on hocks, no obvious lesion in the legs, no obvious pain?

Answer 29

**1.** Spondylolisthesis (kinky back)...can feel the deformity at the level of the free vertebra **2.**Osteomyelitis of the thoracic spine.

Question 30

Illustrate a chicken and a turkey vertebral column?

Answer 30

Question 31

Birds appear to be uncomfortable walking, with bilateral lameness. The bones of the hock joint may appear thickened, and a lot of mild bone deformities may be present. Bones and beak are more malleable than normal. Bone deformity-bowing of the proximal tibiotarsus, with thickened tibiotarsal growth plates What are your 2 differentials?

Answer 31

Rickets Tibial Dyschondroplasia

Question 32

What is Rickets?

Answer 32

* Thickening of all long bone growth plates * confirm with histopathology * This is an osteodystrophy due to a lack of vitamin D3 or a Ca/P imbalance resulting in a lack of mineralisation. Long bones are soft and pliable and there may also be rickets rosaries

Question 33

What is tibial dyschondroplasia?

Answer 33

* TD...thickening of the growth plate of the tibiotarsal bone * The zone of hypertrophied cartilage cells in the proximal end of the tibiotarsal bone fails to become calcified because its blood supply is absent (Chondrodystrophy-insufficient bone is produced at the cartilaginous growth zone resulting in short bowed bones. Appositional growth is normal, therefore joints can appear swollen. It may be a precursor to slipped tendons. Aetiology maybe nutritional or secondary following a congenital infection...NOT VERY COMMON)

Question 34

What are these clinical signs likley cause: Severely lame, difficulty in rising, wings used for support, possible pain on palpation of medial aspect of femur. Severely lame-hot swollen joints and /or tendons?

Answer 34

Femoral head necrosis

Question 35

What is the cause of femoral head necrosis?

Answer 35

Immunosuppression Bacteria, especially Staphylococcus aureus, Reovirus

Question 37

Discuss hock infections?

Answer 37

* Typically larger birds affected * Just prior to slaughter * Birds go lame first * Poor hygiene can be to blame * Swollen hock joint * Culture –e.g. Staphylococcus aureus Escherichia coli Ornithobacteriumrhinotracheale and Mycoplasma synoviae * Antibiotics useful in early lesions

Question 39

What do these clinical signs suggest: ## Footnote Hopping lame with a palpable thickening of the gastrocnemius tendon above the hock joint

Answer 39

TENDON RUPTURE Associated with rapid growth and insufficient exercise

Question 40

How can welfare be assessed?

Answer 40

Five Freedoms * Freedom from **hunger and thirst** * Freedom from **discomfort** * Freedom from **pain, injury or disease** * Freedom from **fear and distress** * Freedom to **perform most normal behaviour**

Question 41

Our poultry legal responsibility is outlined in which legislation?

Answer 41

Our legal responsibility is defined by: * Animal Welfare Act 2006 * Welfare of Farmed Animals (England/Wales) Regulations 2007 * Welfare of Animals (Transport) England Order 2006 * The Welfare of Animals at the Time of Killing (England) Regulations 2015

Question 42

Name common causes of poultry lameness?

Answer 42

Common causes of poultry lameness: * Femoral head necrosis * Hock joint infection * Osteomyelitis * Tibial dyschondroplasia * Rickets * Pododermatitis * Spondylolisthesis (Kinky back) * Spinal abscesses