Topic 112 - Salmonella diseases of swine (RED) Flashcards
Name the diseases of salmonellosis of swine
1. Swine typhoid
2. Swine paratyphoid
3. Typhocolitis of swine
What is swine typhoid?
A chronic infectious necrotic enteritis of growers and finishing pigs
Occurrence of swine typhoid
Formerly common ⭢ nowadays rare due to better hygiene and higher level of agriculture
Causative agent of swine typhoid
Salmonella typhisuis
Susceptible species of swine typhoid
ONLY swine
Is causative agent for swine typhoid obligate or facultaitve?
Obligate
How is swine typhoid introduced and spread?
Introduced by infected asymptomatic animals and faecal contamination
Spread by oral infection
Age susceptible for swine typhoid:
Growers and finishing pigs above 5-6 weeks of age
Pathogenesis of swine typhoid:
1. Infection by oral route
2. Replication in the large intestines in the lymphoid patches causing an inflammation
3. As a result, the mucus membrane above the lymphoid patches will be elevated and circulation is decreased.
4. There will be necrosis of the mucus membrane, and ulcers are formed.
5. The bacteria gets into the gut wall and mesenterial lymph nodes in not too high numbers ⭢ only bacteraemia is seen
6. The bacteria reaches the parenchymal organs and we see a focal inflammation and necrosis which are the typhomas and they help us diagnose the bacteria
Clinical signs of swine typhoid:
Due to it being chronic, the clinical signs appear slowly and the severity is influenced by the management
- Diarrhoea: Watery, yellow
- Increasing cough in later phase when the typhomas have reached the lung
- Retardation
- Weight loss ⭢ Very common !!
PM lesions of swine typhoid
1. In the large intestines we see enlarged lymhpoid patches and ulcers
2. We see focal inflammation and necrosis on the organs and the tonsils
How to diagnose swine typhoid:
As PM lesions are very informative, we can have a good diagnosis already.
But for lab.diagnostics we use:
- Bacterium isolation
Treatment of swine typhoid:
1. Movement restrictions - To prevent the spread
2. Not keeping animals for breeding, due to them being life-time carriers
3. Use AB to reach a better general state, complete healing CANNOT be expected
What is swine paratyphoid?
An acute, generalised disease seen most frequently in animals of 2-5 months of age
Occurrence of swine paratyphoid:
Worldwide
Causative agent of swine paratyphoid:
Salmonella cholerasuis and Salmonella typhimurium
Is swine paratyphoid a obligate or facultative pathogen?
Facultative
Pathogenesis of swine paratyphoid:
- Per os infection
- Replication in the small intestines, causing an inflammation
- The bacteria reaches the blood and we have a septicaemia
- The bacteria reaches the parenchymal organs and paratyphomas are developed
Incubation time for swine paratyphoid:
2-3 days
Clinical signs of swine paratyphoid:
1. Fever, causing anorexia and depression
2. Cyanosis
3. Diarrhoea is typical, seen as yellow, watery and creamy
(4. Chronic cases: Pneumonia, cough, arthritis, tenosynovitis)
PM lesions of swine paratyphoid:
Acute cases
1. Cyanosis
2. Haemorrhages
3. Hyperplasic spleen
4. Enlarged lymph nodes
5. inflammation of small intestines
6. Focal inflammation and necrosis in the liver
Chronic cases
1. Necrosis of the mucus memrbane of the small intestines
2. SOMETIMES ulcers in the large intestines can be seen
How to diagnose swine paratyphoid:
Bacterium isolation
- Organs = direct isolation
- Faeces = selective medium
Treatment of swine paratyphoid:
1. AB for septicaemia
Prevention of swine paratyphoid:
- Prevention of predisposing factors
- General epidemiological measures
- Hygiene
- Vaccines
Which type of vaccines is used against swine paratyphoid:
Inactivated and attenuated
BUT, since all serotypes cannot be included they cannot give a complete protection
What is typhocolitis of swine?
A frequent disease, similar to paratyphoid, with low mortality in growers and finishing pigs
Causative agent of typhocolitis of swine:
Salmonella typhimurium
Pathogenesis of typhocolitis of swine:
1. Infection per os
2. Replication in the large intestines, causing inflammation and sometimes we see haemorrhagic enteritis
Clinical signs of typhocolitis of swine:
1. Yellow, watery diarrhoea
2. Bloody diarrhoea
3. Sometimes we see mucous in the faeces
PM lesions of typhocolitis of swine:
Large intestines
We see necrotic enterocolitis and typhlitis
Treatment of typhocolitis of swine:
Per os AB, be carefull of the resistance
Prevention methods for typhocolitis of swine:
1. Elimination of predisposing factors
2. Isolation from birds
3. Rodent control
