Porcine Neurology Flashcards
1
Q
You go to a farm where a pig is having fits? What do you ask?
A
- Type of farrm, location of sick pigs on farm
- Age and number of affected pigs
- Number of deaths
- Length of time with clinical signs
- Response to treatment
- Conditions of shed - water, temperature, ventilation
- Additives in feed
- Walk-through of the farm - assess staff, pen equipment, feed, water - get a feel of the farm
- Clinical exam of pigs - neuro eam (depending on conciousness of pig)
- PM of 2 or 3 pigs - on farm, often no gross lesions, swab brain stem for strep, culture half brain for virus
- Serum from 10 pigs
2
Q
Neuro exam continued…
A
- cerebral lesions - altered metnal state, depression, hyperaesthesia
- cerebellar lesions - intention tremors, dysmetria, high stepping gait
- vestibular lesions - otitis media, head tilt, circling, rolling
- UMN lesions - spatial positoning limbs, exaggerated reflexes, increased extensor tone
- LMN lesions - reduced muscle tone and muscle atrophy, reflex absent
- spinal cord lesion - tail bite injury
- Skin sensitivity test - conscious response indicates spinal cord and peripheral sensory nerves intact
- panniculus test - not useful in older pigs
- pedal withdrawal - exaggerated response - UMN, reduced response - LMN
- patellar reflex - sedated pigs only!
3
Q
Other diagnostic tests:
A
Proprioception:
- usually only possible in piglets - UMN lesions
- wheelbarrow test
CSF:
- lumbar puncture (lumbosacral space) - under GA, complex!
Serology
PM
NOTIFIABLE DISEASES? Aujesky’s, Teschen’s dx, Classical Swine Fever (CSF) - consider particularly if there are a lot of dead pigs.
4
Q
PIGLETS - differentials
A
- Bacterial meningitis - streptococcus
- Viral infections - Aujesky’s, Techen, CSF
- Congenital tremors - may recover with nursing
- Carbon monoxide poisoning - heating devices
5
Q
Differential Diagnosis - GROWING PIGS
A
- Streptococcal meningitis*
- Water deprivation *
- Oedema dx
- Aujesky’s dx
- Teschen dx (eneroviruses)
- Poisonings
* most common
6
Q
Streptococcal Meningitis
A
- Universal problem
- Streptococcs suis types 1, 2 and 14
- strep also causes arthritis, serositis
- Most common diagnosis on PM (70%)
- Survives on surfaces
- ZOONOTIC
7
Q
A
8
Q
Streptococcus suis type 1
A
- carried in tonsils of carrier sows and enters piglets through tonsilar crypts
- most common in piglets 10-14 days
- clinical signs - pyrexia, sudden death, swollen joints, convulsions, nystagmus
- diagnosis
- culture from PME and CS
Treatment:
- 3-5 days penicillin, TMS
- NSAIDs
- poor prognosis if meningitis - consider euthanasia
Prevention:
- hygiene farrowing
- prophylactic antibiotics?
- depop-repop if severe
9
Q
Streptococcus suis type II and 14
A
- ZOONOTIC (abrasions/oropharynx)
- can survive in environment for several days
- usually seen in growing pigs 3-7 days after stresses e.g. moving groups
- sudden death, pyrexia, acute arthritis, meningitis
- Diagnosis - CS and PME
- Treatment - same as type I
- Control - hygiene, prophylactic ABs, depop, repop
10
Q
Water deprivation/ salt poisoning
A
- Common
- high salt diets (rare) or rapid rehydration following water deprivation (common)
- when water becomes available, enters the brain causing cerebral oedema and raised ICP
- Clinical signs
- recumbency, convulsions, atazxia, DOG SITTING, agitated
- Diagnosis:
- CS and PME (eosinophilic meningitis)
- Treatment:
- slow rehydration, poor prognosis
- Control:
- adequate water supplies and warning systems for failure
- frozen pipes!
- water in medication - might put too many chemicals in affecting palatability
*suspect if lots of cystitis cases!
11
Q
Oedema Disease
A
- Re-emerging, global
- E. coli VT (verotoxigenic) - O138, O139, O141
- 7-10 days after weaning
- Sudden death, swollen eyelids, ataxia, recumbency, depression
- change in Squeak! - laryngeal oedema - high pitched
- Not a brain infection - intestinal infection
- E.coli - F18 fimbriae - produce shiga-like vero toxins - VTe or STe
- Vasoactive toxaemia and vascular damage causes gelatinous oedema
Diagnosis:
- culture VTEC from intestine
- Look for eyelid oedema
- stomach wall oedema (greater curvature)
- diarrhoea post-wean colibacillosis is more common
Prevention:
- Abs (neomycin) in feed and water after weaning
- zinc oxide in feed controls E.coli toxins
- govenment have stopped the use of zinc oxide but oedema dx on the rise again
12
Q
Aujeszky’s Disease - pseudorabies
A
- Herpes virus
- Eradicated from Britain, 2010 in Ireland
- Globally common, but excellent vaccines
- Many sick pigs, rapid spread around farm
- NOT confied to pigs - cattle, dogs, sheep
- NOTIFIABLE
- Encephalitis in piglets - incoordination, spasms, paddling
- High mortality
- outbreaks may involve pigs up to 14 weeks old
- Older pigs - locomotion changes e.g. goose stepping, run nose on floor, rabid biting, odd posture
- Also might see rhinitis and tonsillitis (PME), pneumonia common
-
Diagnosis:
- serology, histology, virology
- Excellent vaccine now available
*see tonsillar necrosis attached.
13
Q
Porcine Teschen Virus Disease
A
- Common in eastern EU
- Rare in UK
- NOTIFIABLE
- Enterovirus - mostly subclinical
- Proliferate in intestine, viral encephalitis
- Piglets <2weeks old
- Ataxia, paralysis, paddling, tremors, deaths
- NO GROSS LESIONS
-
Diagnosis:
- brain histology and virology
- serology - paired samples
14
Q
Congenital Tremor
A
- Sporadic dx seen in piglets, tremors and shaking of the muscles
- might die from not being able to suckle
- Hypomyelinogenesis and muscle tremor
- Piglets may appear normal, clinical signs by 3 days
- Classified into 4 groups depending on brain histology
15
Q
Group 1
A
- Associated with a classical swine fever
