106. Tyzzer disease and gangrenous dermatitis of poultry.

Question 1

Tyzzers disease Aetiology?

Answer 1

Tyzzer’s disease

• Aetiology: C. pilliforme
• Obligate intracellular – culture: mouse fibroblast, liver, egg
• Resistant: spore – in environment more than a year
• Susceptibility: rodents, dogs, cats, foals etc.

Question 2

Epidemiology of Tyzzer disease?

Answer 2

Epidemiology

• Rodents carry asymptomatically
• Predisposing factors
• immune suppression,
• stress,
• coccidiosis,
• feed with high protein content
• Mainly young animals will be ill

Question 3

Pathogenesis of Tyzzer disease?

Answer 3

Pathogenesis:

• PO infection → gut epithelium → liver, heart
• (local inflammation, necrosis)

Question 4

Clinical signs of tyzzers disease?

Answer 4

Clinical signs:

• fever
• anorexia
• diarrhoea
• colic
• jaundice

Question 5

Pathological lesions of tyzzers disease?

Answer 5

• Lesions:

• Gut:
• oedema,
• necrosis of the MM
• Liver, heart:
• haemorrhages,
• hepatitis,
• focal necrosis,
• jaundice

Question 6

Diagnosis of Tyzzers disease?

Answer 6

Diagnosis

• Epidemiology
• clinical signs
• PM lesions (not very typical)
• Detection of the agent: staining (giemsa),
• IF,
• PCR (agent cannot be cultured on artificial media)

Question 7

Treatment of tyzzers disease?

Answer 7

• Treatment:

• tetracyclines
• fluid therapy

Question 8

Gangrenous dermatitis Aetiology?

Answer 8

Gangrenous dermatitis

• Aetiology:

• C. septicum,
• C. perfringens A,
• Staph. aureus (can cause dermatitis on its own, but can help
• clostridia)

Question 9

Gangrenous dermatitis Epidemiology?

Answer 9

Epidemiology:

• Predisposing factors
• Infectious:
• infectious bursitis,
• chicken anaemia,
• adenovirus,
• reovirus
• Non-infections:
• wound,
• cannibalism,
• bumblefoot (sole ulcer)
• Mainly 4 weeks – 5 month old chicken, turkey

Question 10

Clinical signs of gangrenous dermatitis?

Answer 10

Clinical signs:

• Depression;
• clinical signs on wing,
• breast, belly, thigh;
• skin: oedema, haemorrhages,
• crepitating (gas produced);
• muscles: oedema, reddish

Question 11

Pathological lesions of gangrenous dermatitis?

Answer 11

Pathological Lesions:

• muscles – oedema,
• liver – focal necrosis

Question 12

Diagnosis of Gangrenous dermatitis?

Answer 12

Diagnosis

o Epidemiology – clinical signs

o Bacterium isolation

o Identification of predisposing effects

Question 13

Treatment of Gangrenous dermatitis?

Answer 13

Treatment:

• ABs,
• elimination of predisposing factors