Porcine Neurology Flashcards
What history do we need to get when called out to a pig farm?
- Type of farm, location of sick pigs in farm
- Age and number of affected pigs
- Number of deaths
- Length of time with clinical signs
- Response to treatment (farmer might have had a go at treating)
- Conditions of shed – water, To, ventilation
- Additives in feed
What nervous signs are seen in pigs?
- Paddling, twitching
- Head tilting, un-coordinated, circling, staggering, goose-stepping
- Change in squeak!
- Pigs depressed, lying down
- Pigs stop eating
How would we approach to pigs being presented with nervous signs?
•Walk-through of farm
–Disease prevalence, assessment of staff, check on pen equipment, feed, water etc
- Clinical examination of pigs
- PM of 2 or 3 pigs
–On-farm or at VIC
–Often no gross lesions
–Swab brain stem for strep
–Culture half brains for virus
•Serum from 10 pigs
How would you conduct a neuro exam of a pig?
- Observation from far
- What are the pigs doing? - Examination of head and eyes
–Head tilt, pus in ear, nystagmus, ocular reflexes
3.Determine likely point of origin
–Specific cranial nerve lesions rare
What is seen with cerebral lesions?
Altered mental state
–Depression, stupor, hyperaesthesia
What is seen with cerebellar lesions?
–Intention tremor, dysmetria, high stepping gate
What is seen with vestibular lesions?
•otitis media
–Head tilt (ipsilateral), circling, rolling
What is seen with UMN lesions?
–Spatial positioning limbs, exaggerated reflexes, weakened/increased extensor tone
What is seen with LMN lesions?
–Reduced local muscle tine and muscle atrophy, reflexes reduced/absent
What is seen with spinal cord lesions?
•tail bite injuries
–Located by evaluating reflexes above and below lesion
What is seen with a skin sensitivty test?
–Conscious response indicates spinal cord and peripheral sensory nerve are intact
Where is panniculus not a good test?
Older
Pedal withdrawal test, what if there is a:
A) Exaggerated response?
B) Reduced response?
A) UMN lesion
B) LMN lesion
Where do we do a patellar refelx?
Sedated ppigs
How can we evaluate gait and posture?
- Difficult in the pig
- Encourage pig to move at different paces and different directions
- Ability to negotiate steps between pens
- Abnormal gait e.g. hypermetria may be visible (cerebellar lesions)
What neuro tests can we do?
•Proprioception
–Usually only possible in piglets – UMN lesions
–Wheelbarrow test
•CSF
–lumbar puncture at lumbosacral space
- Serology
- PM
- Notifiable disease! (Aujeszky’s disease, CSF, Teschen’s disease)
Name differentials for neuro signs in piglets
•Bacterial meningitis – streptococcus
•Viral infections – Aujeszky’s, CSF, Teschen, others
•Congenital tremors
–Common outbreaks – new genetics and viral
–Shaking piglets
–Many recover with nursing
•Carbon monoxide poisoning
–Heating devices for piglets
Name differentials for growing pigs with neuro signs. Highlight the most common
Streptococal meningitis
Water deprivation
Oedema disease
Aujeszky’s disease
Teschen disease (enteroviruses)
Poisonings
Streptococcal meningitis:
A) Which types affect?
B) What else other than neuro does it cause?
C) What is the risk?
A) Streptococcus suis types 1, 2 and 14
B) Arthiritis and serositis
C) Zoonosis
Streptococcus suis type 1:
A) Where is it carried?
B) Where is it common?
C) Name clincial signs
A) Organism is carried in the tonsils of carrier sows and enters piglets body through the tonsilar crypts
B) In piglets aged 10-14 days
C) pyrexia, sudden death, swollen joints, recumbency, convulsions, nystagmus
Streptococcus suis type 1:
A) How is it diagnosed?
B) How do you treat?
C) How can you can control?
A) CS and culture from PM
B) 3-5d penicillin, TMS plus NSAID. Prognosis poor if meningitis (consider euthanasia)
C) hygiene farrowing accomodation, prophylactic antibiotics, depop if severe
Discuss this
How could we confirm?
Streptococcus suis type 1
- Small amounts of pus in meninges esp. at brain stem
- No other lesions
- Histology and bacteriology confirm Dx
Strep Suis type 2 and 14:
A) How is it zoonotic?
B) Where is it usually seen?
C) What are the clinical signs?
A) Abrasions/oropharynx
B) 3-7 days after stressed in growing pigs
C) •sudden death, pyrexia, acute arthritis, meningitis
Strep Suis 2 and 14:
A) How do we diagnose?
B) How do we control?
A) CS ad PM
B) Hygiene, prophylactic AB, depop
What should we check for with water deprivation?
•Problems with water supply common
–Also suspect if many cystitis cases
–“discharges”
•Check function of all parts of water systems
–Header tanks, lines (scale, rust etc), drinkers
–Frozen pipes
Oedema disease:
A) When does it occur?
B) Name clinical signs
A) 7-10 days
B)
- Sudden death, swollen eyelids, ataxia, recumbency, depression,
- Change in squeak – laryngeal oedema
What causes oedema disease?
- an intestinal infection with E. coli – F18 fimbriae
- These E. coli attach and produce shiga-like = vero toxins – VTe or STe
- These cause a vasoactive toxaemia
- Vascular damage causes gelatinous oedema
How can we diagnose oedema disease?
- Culture VTEC from intestine
- Look for other distinctive signs
- Eyelid oedema
- Stomach wall oedema (greater curvature)
How can we treat oedema disease?
- Use antibiotics such as neomycin in feed and water after weaning – limited effect
- Zinc oxide in feed controls E. coli toxins
(EU now banned)
What virus causes Aujeszkys disease?
Herpes
What are the signs of Aujeskys disease. (include those in older)
- Usually encephalitis in baby pigs
- Incoordination, spasms, paddling
- High mortality common
- But outbreaks may involve pigs up to 14 weeks old
- Older pigs can show locomotor changes – goose stepping, run nose on floor, rabid biting, odd posture
Aujesky’s disease:
A) What else can they show?
B) How do we diagnose?
C) How can we prevent?
A) Rhinitis, tonsilitis and pneumonia
B) Serology, histology and virology
C) Vaccine
Porcine Teschen virus disease:
A) Which virus?
B) Where is it common?
C) What happens inthe UK?
D) What causes subclinical?
A) Teschovirus
B) Eat EU
C) Notify
D) Enterovirus
A) What is seen with Porcine Teschen virus disease?
B) How do we diagnose?
A) Baby pigs <2wks old
- Ataxia, paralysis
- Paddling, tremors, deaths
- No gross lesions
B) Brain histology and virology
•Serology – paired samples
A) What is a congenital tremor?
B) When do signs devvelop?
C) Why might they die?
A)
- Sporadic disease seen in newborn pigs, evident by tremors and shaking of the muscles, of the head and body
- Hypomyelinogenesis and muscle tremor
B) 3 days
C) Can’t suckle
What are the 4 groups of congenital tremors based on histology?
Group 1 - associated with a classical swine fever.
Group 2 - possibly associated with a recently recognised circovirus and involving both circoviruses types 1 and 2 simultaneously. Most of the problems in the field are found in this group.
Groups 3 and 4 - associated with either hereditary disorders seen in the Landrace or Saddleback breeds or with organophosphorus poisoning.
Group 4 - includes aujeszky’s disease and Japanese encephalomyelitis virus
Hypoglycaemia:
A) Where is it a common cause of mortality?
B) How does it come about?
A) Newborns
B) Low blood glucose due to inadequate milk intake
•Little fat reserves at birth so quickly become hypoglycaemic if don’t suckle
What are the signs of hypoglycaemia?
Weakness, ataxia, hypothermia, fitting opisthotonus, champing of jaws
Hypoglycaemia:
A) How can we diagnose?
B) How can we treat?
A) CS, blood glucose <2.8mmol/L
B) 15ml 20% Glucose solution IP q4-6hrs
Name two of the rarer causes of neuro problems in pigs (3)
How does water deprivation/salt poisoning come about?
- High salt diets (rare) or rapid rehydration following water deprivation (common)
- Localised to area of farm affected by water delivery issue – one side of a shed !
- When water becomes available, it enters the brain causing cerebral oedema and raised intracranial pressure.
What are the clinical signs of Water deprivation/salt poisoning?
•Variable, recumbency, convulsions, ataxia, dog sitting, pigs very agitated
Water deprivation/salt poisoning:
A) How do we treat?
B) How do we control?
A) SLOW rehydration, poor prognosis if severe
B) Adequate water supplies and warning systems for failure.
