Practical 1 Broilers

Question 1

Enteric disease complex in chickens Clinical symptoms?

Answer 1

» Huddling, litter ingestion
» Diarrhoea consequences
» Poor production, fail to grow
» Heterogenous flock

Question 2

Runting stunting syndrom causes?

Answer 2

Astroviridae
Coronaviridae
Reoviridae
Rotaviridae
PARVOVIRIDAE

Question 3

pododermatitis causes?

Answer 3

standing on wet litter

Question 4

Pathogenesis of enteric diseases ?

Answer 4

Dilation of the intestinal loops → Changes of content quality

Villus degeneration > Destruction of the epithelial layer → Villus denudation, atropy or fusion .
Cause : Parvovirus
May lead to : Maldigestion - malabsortion syndrome

Question 5

General pathogenesis of viral enteritis

Answer 5

Replication of the virus
• villus-atrophy – shortening due to the regeneration of the enterocytes
• viraemia
• Other lesions
– feathering problems
– ricketts
– other lesions in the skeletal system
• dyschondroplasia, epiphysiolisis
– vitamin-E deficiency
– atrophy of the immun organs

runting stunting as birds will remain small

Question 6

other enteric diseases

Answer 6

Necrotic enteritis
– Clostridium perfringens
– 2-5 weeks (4 weeks – 6 months)
– Coccidiosis
– Eimeria sp.

Question 7

Respiratory diseases in Broilers?

Answer 7

– Metapneumovirus, Paramyxoviridae
• Pathogenesis
– Infection – via inhalation
» Few days incubation period!
– If secondary bacterial infection occurs
» Swollen head syndrome
• Clinical symptoms
– sneezing, nasal discharge, head shaking
• Pathology
– Air sacculitis
– Tracheitis
– Peritonitis – secondary E. coli infection

Question 8

Differential diagnosis in respiratory diseases in Broilers?

Answer 8

–Avian influenza (bird flu)
»Increased mortality
»hemorrhages!
–Newcastle disease
»Increased mortality
»Central nervous symptoms!
–infectious bronchitis
»Kidney lesions also occur

Question 9

Infectious Bronchitis?

Answer 9

– Coronavirus • Pathogenesis – Infection via inhalation » Replication (Harderian gland – trachea epithel – oviduct and kidney) • Clinical symptoms – High morbidity – mortality 0-20 % – In young flocks » Respiratory symptoms – In layer flock » Uricosis, egg laying problems

Question 10

Respiratory disease Mycoplasmosis?

Answer 10

Mycoplasma gallisepticum, M. synoviae
• Pathogenesis
– Predisposing factors needed
– M. meleagridis
• Clinical symptoms
– M. gallisepticum
» Respiratory signs
– M. synoviae
» Arthritis and tenosynovitis

Question 11

colibacillosis?

Answer 11

Escherichia coli
• Forms
– Omphalitis
– Septicaemia
– Swollen head syndrome
• Chronic Respiratory Diseases (CRD)
– Predisposing factors
» Non infectious (ammonia – alkaline pH)
» Infectious causes (Mycoplasma sp.)
– Clinical symptoms
» Depends on the predisposing factor!
– Pathology
» Conjunctivitis – tracheitis – air sacculitis

Question 12

Respiratory symptoms?Ornithobacteriosis - ORT?

Answer 12

Ornithobacterium rhinotracheale
• Pathogenesis
– Facultative pathogen bacterium
» Chicken anaemia virus (CAV)
» Gumboro disease
» infectious bronchitis virus (IBV)
» Feed containing mycotoxin
» environment
• Clinical symptoms
» Lack of appetite, thirsting
» Respiratory syndromes
• Pathology
– Mucoid discharge in the airways
– Foamy content in the air sacs