Porcine neurology Flashcards
What are the most common signs of neuropathy seen in pigs?
- Paddling, twitching
- Head tilting, uncoordinated, circling, staggering, goose stepping
- Change in squeak
- Pigs depressed, lying down
- Anorexia
Outline a generic approach to neurological cases in pigs
- Thorough history
- Walk through farm and assess disease prevalence, assess staff, chek pen equipment, feed, water
- Clinical examination of pigs
- PM of 2 or 3 pigs
- Serum from 10 pigs
- Clinical assessment involving full clinical and neurological exam and lesion localisation
How will cerebral lesions present in pigs?
- Altered mental state
- Depression
- Stupor
- Hyperaesthesia
How will cerebeller lesions present in pigs?
- Intention tremor
- Dysmetria
- High stepping gait
In pigs, what is a common cause of spinal cord lesions?
Tail bite injuries
What do conscious responses on skin sensitivity tests indicate?
Spinal cord and peripheral sensory nerves are in tact
Discuss the use of the panniculus, pedal withdrawal and patellar reflex in neurological examination of pigs
- Panniculus: not very useful in older pigs
- Pedal withdrawal: exaggerated responses = UMN, reduced respond = LMN
- Patellar: only in sedated pigs
What are the main differentials for neurological disease in piglets?
- Bacterial meningitis (strep)
- Viral infections (Aujesky’s, CSF, Teschen etc.)
- Congenital tumours
- Carbon monoxide poisoning from heating devices
Outline the cause and presentation of congenital tumours in pigs
- Common as outbreaks, viral or genetic cause
- Shaking piglets
- Many recover with nursing
List the differentials for neurological disease in growing pigs
- Streptococcal meningitis
- Water deprivation
- Oedema disease
- Aujesky’s disease
- Teschen disease
- Poisonings e.g. lead, organophosphates
List rare causes for neurological disease in pigs
- Spinal abscesses
- Toxicities e.g. selenium
- Nutritional deficiency e.g. vit A, pantothenic acid
Describe the epidemiology of porcine streptococcal meninigitis
- Universal problem in pig farms
- Strep suis types 1, 2, 14 most associated with neurological presentation
- Strep also causes arthritis, serositis
- Most common diagnosis at PM
- Survives in farm surfaces
- Zoonotic (risk at PM)
Describe the transmission and prevalence of Streptococcus suis type 1
- Carried in tonsils of carrier sows and enters piglet’s body through tonsilar crypts
- Most common in piglets aged 10-14 days
Describe the clinical signs of Streptpcoccus suis type 1 meningitis
- Pyrexia
- Sudden death
- Swollen joints
- Recumbency
- Convulsions
- Nystagmus
Outline the diagnosis of Streptococcus suis type 1
- Clinical signs and culture from PM
- If joints affected can culture from joint fluid
- On PM, may see small amounts of pus in meninges but few other lesions, confirm diagnosis by histology and bacteriology
Describe the treatment of Streptococcus suis type 1, 2, 14
- 3-5d penicillin or TMS
- NSAIDs
- Prognosis poor if meningitis, consider euthanasia
Describe the control of Streptococcus suis type 1
- Hygiene of farrowign accomodation (all in all out management, cleaning between litters)
- Prophylactic antibiotics poor choice
- Depopulation in severe outbreaks
How can Streptococcus suis type 2 and 14 spread to humans?
Via abrasions/oropharynx
Outline the occurrence of Streptococcus suis type 2 and 14
Usually growing pigs 3-7 days after stresses e.g. moving groups
Describe the clinical signs of Strep suis type 2 and 14
- Sudden death
- Pyrexia
- Acute arthritis
- Meningitis
Outline the control of Strep suis type 2 and 14
- Hygiene (survive in environment for several days)
- Prophylactic antibiotic (short term to gain control)
- Depopulation
What are the common causes of water deprivation/salt poisoning in pigs?
- Occasional outbreaks depending on cause e.g. water system failure
- High salt diets (rare)
- rapid rehydration following water deprivation (common)
How does rapid rehydration following water deprivation cause neurological signs in pigs?
When water available again, enter brain causing cerebral oedema and raised intracranial pressure
Describe the clinical signs of water deprivation/salt poisoning in pigs
- Variable
- Recumbency
- convulsions
- Ataxia
- Dog sitting
- Pigs agitated
- Cystitis (aka discharges)
Outline the diagnosis of water deprivation/salt poisoning in pigs
- Based on history and clinical signs
- Or PM showing eosinophilic meningitis
Outline the treatment and prevention of water deprivation/salt poisoning in pigs
- Slow rehydration
- Poor prognosis if severe
- Control with adequate water supplies and warning systems for failure
When does oedema disease of pigs occur?
7-10 days after weaning
How does oedema disease of pigs develop?
- E. coli VT required to proliferate in farms
- E coli intestinal infection, produce shiga-like vero toxins VTe or STe
- Cause vasoactive toxaemia
- Vascular damage causes gelatinous oedema in the brain, eyelids, stomach, colon and larynx
Describe the clinical signs of oedema disease in pigs
- Sudden death
- Swollen eyelids
- Ataxia
- Recumbency
- Depression
- Change in squeak due to laryngeal oedema (high pitched)
Outline the diagnosis of oedema disease in pigs
- Culture VTEC from intestine
- Look for other distinctive signs such as eyelid oedema, stomach wall oedema
Which form of post-weaning colibacilliosis in pigs is most common?
Diarrhoeal
Outline the control of oedema disease in pigs
- Antibiotics e.g. neomycin in feed and water after weaning (limited effect, colistin ideal but protected)
- Zinc oxide in feed controls E. coli toxins
Describe the clinical signs of Aujesky’s in piglets
- Encephalitis
- Incoordination
- Spasms
- Paddling
- High mortality
Up to what age of pigs may be involved in Aujesky’s outbreaks?
14 weeks
Describe the clinical signs of Aujesky’s in older pigs
- Locomotor changes
- Goose stepping
- Run nose on floor
- Rabid biting
- Odd posture
- Rhinitis, tonsilitis, pneuomonia also common
What methods are used in the diagnosis of Aujesky’s?
Serology, histology, virology
Outline the prevention of Aujesky’s in pigs
- Stop feeding dogs potentially infected pig meat
- Vaccine available
- Eradication programmes if re-appears
Where does Teschen disease proliferate?
In the intestine
Describe the clinical signs of Teschen virus disease
- Mainly piglets <2 weeks old
- Ataxia, paddling
- Paralysis, tremors, death
- No gross lesions
Outline the diagnosis of Teschen disease virus
- Brain histology and virology
- Serology, paired samples
Describe the presentation of congenital tremor in pigs
- Sporadic disease in new born pigs
- tremors, shaking of muscles of head and body
- Piglets may appear normal at birth, clinical signs from 3 days old
- Death if unable to suckle
What causes the clinical signs of congenital tremor in pigs?
Hypomyelinogenesis
Outline the treatment and prognosis of congenital tremor in pigs
Require good nursing but unlikely to survive
Outline the 4 groups of causes of congenital tremor in pigs
1: Associated with classical swine fever
2: Possibly associated with circovirus and involving circovirus type 1 and 2 simultaneously
3: Associated with hereditary disorders seen in Landrace or saddleback breeds or organophosphate poisoning
4: Aujesky’s disease and Japanese encephalomyelitis virus
Explain the common presentation of hypoglycaemia in pigs
- common cause of mortality in newborn piglets
- Low blood glucose due to inadequate milk intake
- Little fat reserves at birth so quickly become hypoglycaemic if don’t suckle
Describe the clinical signs of hypoglycaemia in pigs
- Weakness
- Ataxia
- Hypothermia
- Fitting opisthotonus
- Champing of jaws
Outline the diagnosis of hypoglycaemia in pigs
- Clinical signs
- Blood glucose <2.8mmol/L
Outline the treatment of hypoglycaemia in pigs
- 15ml 20% glucose solution IP q5-6hrs
- Herds people generally good at sorting this out themselves
