Infectious Diseases of Pigs Flashcards Preview

Veterinary Year 3 > Infectious Diseases of Pigs > Flashcards

Flashcards in Infectious Diseases of Pigs Deck (31)
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1
Q

What are the causes of porcine skin disease

A
  • vices - biting
  • vector driven
  • infection
  • congenital
  • toxic
  • physical
2
Q

What are the consequences of skin disease

A
  • unwanted culling
  • welfare problems
  • unexpected death
  • treatment costs
  • carcass condemnation
3
Q

What are the non-infectious causes of skin disease

A
  • sunburn - common in outdoor systems, ensure shade is provided
  • transient erythema - scald from urine or chemicals - usually occurs during long transport
  • hyperkeratosis - flaking of the dorsal skin due to stagnant humidity from overhead water systems
  • biting - common in testosterone driven males due to boredom, competition or to show dominance
    secondary infections common
    in females bites to the vulva can affect parturition
4
Q

What are the Vector driven skin diseases

A

flies - irritant, sometimes biting species, can spread disease

pig louse - haematopinous suis
causes pruritis
large lice seen more commonly in backyard pigs

5
Q

briefly describe the general features of sarcoptic mange

A
  • most common parasitic disease
  • pruritis
  • encrusted lesions on legs, ears and body
  • diagnosis via deep skin scraping
6
Q

briefly describe the general features of septicaemia

A
  • skin discolouration or necrosis
  • other causes include swine fever (notifiable), PRRSV, Erysipelas (raised skin blemishes), glasser’s disease (haemophilus species, attacks smooth surfaces of the heart, brain and intestines resulting in pericarditis, peritonitis, pneumonia and pleurisy. Spread via respiratory secretions and inhalation)
7
Q

briefly describe the general features of greasy pig - exudative epidermitis

A
  • most common skin disease
  • staph hyicus
  • chronic and acute forms
  • typically non-pruritic
  • can be fatal
  • increases the gap between cells causing oozing of greasy fluid which breaks down the skin’s protective barrier leaving it open to secondary infections
  • toxins are produced and absorbed into the system damaging the liver and kidneys
  • common in piglets over 5 days old and weaners
  • infected pigs have a greasy feel and are grey looking
  • bacteria can manifest and multiply in the sow’s vagina so piglets can be infected at birth
  • lesions caused by exfoliatetive toxin which results in the loss of keratinocytecell to cell adhesion
  • treatment = systemic antibiotics - amoxycillin or lincomycin, sudocream works well in mild cases
8
Q

briefly describe the general features of swine pox

A
  • rare
  • can be congenital
  • diagnosis via virus isolation
  • limited clinical significance unless associated with greasy pig
9
Q

briefly describe the general features of ringworm

A
  • often due to contact with rodents, cattle or cats
  • look like dirty marks on the skin
  • minimal pruritis
  • highly contagious
  • no treatment necessary , clears up in a few weeks
10
Q

briefly describe the general features of false ringworm

A
  • pityriasis rosea
  • seen mainly on the underside
  • non-infectious - inherited condition
  • develops at about 6-8 weeks and clears up spontaneously by about 20 weeks
11
Q

briefly describe the general features of epithliogenesis imperfecta

A
  • congenital
  • commonly seen on legs and flanks
  • absence of the epidermis or mucosal epithelium
  • will slowly heal may need sutures
  • severe cases require euthanasia
12
Q

briefly describe the general features of PDNS - Porcine dermatitis and neuropathy syndrome

A
  • can be fatal
  • can be confused with swine fever
  • mainly seen in growers and finishers
  • pigs are depressed anorexic, have a fever and are reluctant to move
  • have extensive greasy brown/ purple raised blotches of various shapes and sizes over their bodies
  • can affect the kidneys - see white lesions on PM
13
Q

briefly describe the general features of treponema

A
  • bacteria
  • causes syphylis, digital dermatitis and dental disease
  • found in skin lesions that prevents healing
  • found in a number of other species
14
Q

what are the clinical signs of dysentery

A

piglets:

  • severe, acute
  • sloppy light brown faeces +/- blood and mucous
  • loss of condition

weaners and growers:

  • tail twitching
  • partial appetite loss
  • slight reddening of the skin
  • sunken eyes
  • dehydration
  • sudden death
  • loss of condition - hollowing of the flanks
  • sloppy diarrhoea - stains skin under the anus +/- blood initially contains jelly like mucous then turns watery
15
Q

briefly describe the general features of porcine dysentery

A
  • bacteria invades intestinal epithelium in the caecum and colon
  • treat drinking water with lincomycin tiamulin or tylosin for at least 7 days
  • inject those badly infected for 4 days
16
Q

Briefly describe the general features of E.coli

A
  • responsible for neonatal scour
  • caused by a range of serotypes
  • high mortality and rapid onset
  • causes post- weaning diarrhoea via enterotoxins
  • diagnosis via culture and serology
  • sow can be vaccinated to prevent transfer to piglets
  • clinical signs:
  • ataxia
  • anorexia
  • stupor
  • unusual vocalisation
  • diarrhoea rarely seen in older pigs
  • oedema of the face and puffy eyes
17
Q

briefly describe the general features of clostridium

A
  • many species - some gut commensals
  • antibiotics no use for type C.perfringens
  • C.perfringens and C.novyi

C.perfringens

  • type A and C most prevelant cause of disease
  • type A causes low grade chronic diarrhoea
  • type C colonises neonatal pigs, high mortality and acute disease

C. Novyi

  • systemic infections in the sow
  • common in outdoor rearing systems - soil is the source
  • bacteria migrates from the gut to liver where toxins result in necrotic lesions (aero chocolate liver)
18
Q

briefly describe the general features of transmissible gastroenteritis TGE

A
  • coronavirus
  • causes vomiting and diarrhoea in older sows
  • rapid spread
  • survives in cold temperatures
  • no known treatment for piglets
  • causes high mortality in piglets via acute diarrhoea
19
Q

briefly describe the general features of porcine circovirus (PCV)

A
  • Non-enveloped DNA virus
  • PCV1 - largely a-virulent
  • PCV2 - related to post weaning multisystemic wasting syndrome
  • occurs at 2-4 months of age
  • lymphocytic depletion
  • wasting, diarrhoea, enteritis and occaisionally skin lesions
20
Q

briefly describe the general features of lawsonia- porcine proliferative enteritis and haemorrhagic bowel syndrome

A
  • intracellular gram -ve curved rod
  • obligate intracellular bacteria
  • common in finisher pigs
  • sub-clinical carriers exist
  • acute disease - bloody diarrhoea and sudden death
  • create a hose-pipe like appearance in the ileum due to enterocyte lesions and thickening of the mucosa
  • haemorrhagic bowel syndrome doesn’t cause diarrhoea
  • treat with antibiotics
  • difficult to culture
  • live attenuated vaccine
  • on PM see ileal wall thinning and haemorrhage
  • infection of enterocytes causes proliferation and hyperplasia of crypt cells leading to characteristic lesions
21
Q

What type of virus causes PRRSV and describe its pathogenesis?

A

Arterivirus – replicates in the perinuclear cytoplasm of alveolar macrophages and infiltrates regional lymph nodes around the body

22
Q

What are the clinical signs of PRRSV?

A

Sows – abortion, still births, weak piglets, red-blue discolouration of ears and vulva, subcut and hindlimb oedema, fever, anorexia, lethargy, agalactica, pneumonia, delayed return to service

Boars – fever, respiratory signs, changes in semen

Neonates – dyspnoea, CNS signs, high mortality

Growers and finishers – anorexia, increased secondary infections, respiratory signs, failure to thrive, fever

23
Q

How is PRRSV transmitted?

A

Transmitted via ingestion, inhalation, coitus and skin penetration

24
Q

Describe the inter-pathogen relationships with PRRSV

A

Mycoplasmas enhance PRRSV’s effects, PRRSV enhances the effects of porcine influenza and predisposes pigs to streptococcus suis

25
Q

What is the vaccination protocol for PRRSV?

A

Vaccinate sows 2-4 weeks before mating and piglets from 2 weeks old

26
Q

Name pathogens associated with respiratory disease in pigs

A
porcine circovirus 2
PRRSV
Swine influenza
Bordetella bronchiseptica
Enzzotic pneumonia / myccoplasma hyopneumoniae
27
Q

What increases the likelihood of pigs contracting infectious disease?

A
poor nutrition
other pig farms nearby 
bringing in new stock 
mixing stock
poor ventilation 
poor biosecurity 
high stocking densities
poor hygiene
stress
28
Q

Describe the general features of swine influenza

A
  • influenza virus type A
  • has H and N surface glycoproteins
  • has a 12-48 hour incubation
  • immunity very short lived
  • clinical signs:
    piglets - fever, pneumonia, coughing
    sows - pyrexia, abortion, coughing, pneumonia
29
Q

Describe the general features of procine circovirus 2

A
  • DNA virus
  • associated with reproductive failure
  • boars shed virus in semen
  • can result in intra-uterine infection
  • stable in the environment and resistant to a number of disinfectants
  • infection causes the depletion of lymphocytes which leave distinct histological lesions
  • vaccination availbable
30
Q

Describe the general features of enzootic pneumonia/ mycoplasma hyopneumoniae

A
  • gram positive
  • dies quickly outside host
  • long incubation - 2-8 weeks
  • mild clinical signs
  • can be more serous in combination with other pathogens
31
Q

Describe the general features of bordetella bronchiseptica

A
  • gram -ve
  • colonises ciliated epithelium resulting in impaired mucocillary apparatus causing pneumonia
  • causes pleuropneumonia in younger pigs and brochopneumonia in older animals
  • can cause rhinitis
  • spontaneous resolution