Topic 123 - Atrophic rhinitis of swine (RED)

Question 1

Occurrence of atrophic rhinitis of swine

Answer 1

The infection is widespread, but the clinical form is getting rare

Question 2

Host range of atrophic rhinitis of swine

Answer 2

Only in swine

Question 3

Causative agent of atrophic rhinitis of swine:

Answer 3

1. Toxin producing Bordetella bronchispetica
= Widespread carriage
2. Toxin producing Pasteurella multocida D or A
= Carriage in infected herds

Question 4

Both Bordetella bronchispetica and Pasteurella multocida D or A produce a virulence factor, name it:

Answer 4

Dermonecrotoxin
= a protein

Question 5

Predisposing factors in case of atrophic rhinitis of swine

Answer 5

Transporation
Mixing of animals
Overcrowding
Qualtity of the stable: humidity, ammonia, dust, temp.

Question 6

Clinical forms of atrophic rhinitis of swine, and their causative agent

Answer 6

Non-progressive form = Bordetella bronchispetica

Progressive form = Pasteurella multocida

Question 7

Age susceptibility in case of atrophic rhinitis of swine:

Answer 7

1. Clinical form is seen when the animal is infected at an Early age

2. In older pigs, the infection is asymptomatic, but they can be infected.

Question 8

Pathogenesis of the non-progressive form of atrophic rhinitis of swine:

Answer 8

1. Bacteria is inhaled
2. Bacteria is colonised in the upper respiratory tract, where they replicate and produce an inflammation = arthritis
3. The inflammation causes necrosis
4. The dermonecrotoxin will damage the turbinate bones in the nasal cavity
5. The process is reversible, unless it continues to become a progressive form

Question 9

Pathogenesis of the progressive form of atrophic rhinitis of swine:

Answer 9

1. P.multocida colonises in the mucus membrane, because it is already damaged by B.bronchoseptica
2. The inflammation of the mucus membrane continues
3. P.multocida produces dermonecrotixin, which is more toxic then the dermonecrotixin of B.bronchoseptica, meaning the lesions become more severe
4. The primary target of the dermonecrotixins are the osteoblasts, which are responsible for the building of the bones
(Osteoclast cells are responsible for the decomposition)
5. The osteoblast cells will be inhibited and the osteoclast cells will be doing its work without any interference - resulting in: decomposition of the bones.
6. Due to the turbinate bones being thin, we see atrophy of the septum
7. Depending if the bone absoprtion is one sided or both sided we see atrophy, shortened maxilla, bended nasal bones
8. Complications with other infections can happen, due to the protection being lost

Question 10

Clinical signs of the non-progressive form if atrophic rhinitis of swine

Answer 10

Seen in piglets 1-4 weeks of age

1. Nasal discharge
2. Sneezing
3. See drop of blood from the nose

Question 11

Clinical signs of the progressive form if atrophic rhinitis of swine

Answer 11

Seen in growers, above 3 month of age, the signs appear one by one:

1. Occlusion of lacrimal duct and the tears are collected around the eye and we see the dust gathering there
2. Deformation of the nose, can be bent to one direction
3. Wrinkles on the nose due to the maxilla being shortened

Question 12

PM lesions of atrophic rhinitis of swine

Answer 12

Does not cause death, but can be found at slaugher:

Progressive form:
1. Inflammation and erosions of mucus membrane
2. We saw behind the first premolar tooth and make a cross section: we see atrophy of turbinates, nasal septum is bent, absoprtion of turbinates
3. Shortening of the maxilla

Question 13

Diagnostic methods of atrophic rhinitis of swine

Answer 13

We detect the toxin production by using PCR, ELISA, cell culture with nasal discharge

Question 14

Treatment of atrophic rhinitis of swine:

Answer 14

Only done in suckling piglets !!!

1. We give AB in feed, or as a spray or parenteral
2. The pigs will remain carriers !!!!!

3. Adult pigs cannot heal

Question 15

Prevention methods of atrophic rhinitis of swine

Answer 15

1. Keeping older sows in breeding to provide good maternal protection
2. Optimal environment
3. Breeding of infected animals - AVOID !!
4. Vaccine

Question 16

Type of vaccine used for atrophic rhinitis of swine

Answer 16

1. Inactivated bacterium
2. Toxoid vaccine

⭢ Vaccinate the sow in the 3rd term of pregnancy and the can vaccinated only once