86. Viral and bacterial diseases of the nervous system in swine

Question 1

Viral diseases?

Answer 1

Aujeszky

Rabies

Teschen virus

Question 2

Rabies ethiology?

Answer 2

Rabies

• Extremely rare, Hungary is free, notifiable, zoonosis
• Lyssavirus
• Free range/contact with wild animal(s)

Question 3

Clinical signs Rabies?

Answer 3

Clinical signs

o Fever

o Salivation

o Nervous signs

§ Aggressivity, anorexia, head pressing, ascending paralysis weakness of the hindquarters),

depression, vocalization

Question 4

Rabies lesions?

Answer 4

Lesions

o Cortex < brain stem < spinal cord

§ Non-suppurative encephalomyelitis, perivascular white blood cell (lymphocytes, plasma

cells, macrophages)

§ Diffuse or multifocal gliosis

§ Neuronophagia

§ Haemorrhages and vasculitis in the grey matter

Question 5

Aujeszkys disease ethiology?

Answer 5

Aujeszky’s disease
• Rare, Hungary is free, notifiable
• Herpesvirus (SHV-1)- carriers
• Contact with infected animals (wild boars), aerial spread (3Km), mechanical vectors

Question 6

Clinical signs Aujeszky?

Answer 6

Clinical signs

o First outbreak in naïve herd

§ up to 20% of non-nursing sows: abortions, early farrowing’s, birth of dead or weak piglets,

disruption of the normal cycle (all stages) (diff. diag.: ASF, CSF) (CATS!!)

piglets (<3 weeks): anorexia, vomiting, diarrhoea, respiratory signs, incoordination, seizures

older animals: fever, anorexia, respiratory signs, seizures, blindness

o chronically infected herds

§ decreased reproduction parameters, occasional birth of mummified, dead, or weak piglets

(young sows)

Question 7

Differential diagnosis Aujeszky?

Answer 7

Differential diagnosis

o PRRS

Question 8

Teschen disease ethiology

Answer 8

Teschen disease (Talfan)

• Rare, notifiable in Hungary

Teschovirus (PTV)

Contact with contaminated equipment, vehicles, or infected animals

Question 9

Pathogenesis of teschen virus?

Answer 9

Pathogenesis:

• Intestines - bloodstream - nervous system

Question 10

Clinical signs of teschen virus?

Answer 10

Clinical signs:

• First outbreak in a naive herd:

o In all age groups (most common in weaned piglets and growers) first off-feed, depression, FEVER!!,

then staggering, ascending paralysis (hind hooves, thighs, pelvis, lumbosacral region, …), NO FEVER

AT THIS POINT!!, opisthotonos, nystagmus, complete paralysis is possible. Only motor nerves are

affected, sensory ones are functional (hyperesthesia)!!

• Polioencephalomyeleitis, lymphocytic perivascular infiltration (spinal cord!!)
• Do not halve carcasses in the midline!

Question 11

Bacterial diseases?

Answer 11

Streptococcus suis

Glasser disease

Bowel oedema

Question 12

Streptococcus suis ethiology?

Answer 12

Streptococcus suis

• Zoonosis
• Present in the tonsils, risk factors (regrouping, vaccinations, treatments, PRRS) facilitate the clinical disease
• Haematogenic spread, heart, respiratory system, nervous system, joints are affected

Question 13

Clinical signs of streptococcus suis?

Answer 13

Clinical signs:

• Predominantly weaned piglets

o Sudden death

o Meningitis: anorexia, blotched skin, fever, depression, staggering, lameness, paralysis, swimming,

opisthotonos, tremors, seizures, blindness, deafness

o Pericarditis

• Sows: decrease in reproduction, birth of dead piglets
• 2to4weeks to fattening pigs: respiratory signs, pneumonia (PRRS, B. bronchiseptica, M. hyorhinis

predisposes)

Question 14

Treatment of streptococcus suis?

Answer 14

Treatment:

• Usually not treated
• Individual: piglet-penicillin’s, fluid therapy if nervous signs are present, euthanasia
• Herd: AB before re-grouping, replace herd

Question 15

Haemophilus parasuis ethiology?

Answer 15

Haemophilus parasuis (Glasser’s Disease)

• Lives in the upper respiratory tract
• Appears with the disappearance of maternal immunity, haematogenic spread, attacks serous membranes

Question 16

Clinical signs of haemophillus parasuis?

Answer 16

Clinical signs:

• animals 4 to 8 weeks old
• sudden death (septicaemia)
• high fever, coughing, abdominal breathing
• arthritis
• recumbency, swimming, tremors, seizures
• chronic: adhesions of serous membranes losses at slaughter

Question 17

Lesions and treatment of haemophillus parasuis?

Answer 17

Lesions:

• Septicaemia, pleuritis, peritonitis, pericarditis, arthritis, meningitis

Treatment:

• usually not treated
• penicillin’s, ceftiofur, enrofloxacin, tiamulin, potentiated sulphonamides - whole group, individually
• preventive AB: can be effective, not recommended (EU)

Question 18

Bowel oedema ethiology?

Answer 18

Bowel Oedema (oedema disease)

• Verotoxin producing E. coli
• Rare
• Bacterium attaches itself to the intestinal wall, produces toxin (maternal IgA prevents disease, infection after

it disappears), toxin is absorbed, causes oedema in the gastric and intestinal wall and blood vessels in the

brain

Question 19

Clinical signs of Bowel oedema?

Answer 19

Clinical signs

• 1-4 weeks after weaning
• Sudden death (best piglets)
• Staggering, incoordination, swollen eyelids, high-pitched squealing, anorexia, lameness, partial paralysis, fits,

seizures, difficulty breathing

Question 20

Treatment and prevention of bowel oedema?

Answer 20

Treatment

• Usually not successful

Prevention

• Clean environment, early weaning, restrict feed after weaning or increase fibre content, replace sensitive

herd