Diseases of the skin Flashcards
Inherited skin diseases of pigs
Epitheliogenesis imperfecta
Hypotrichosis
Dermatosis vegetans
Congental porphyria
Pityriasis rosea
Parasitic skin diseases of pigs
Lice
Sarcoptic mange
Demodectic mange
Fly worry
Viral skin diseases of pigs
Pig pox
Foot and mouth disease*
Swine vesicular disease*
Seneca Valley Virus
Classical swine fever*
PDNS
Bacterial skin diseases of pigs
Septicaemias
Ear necrosis
Greasy pig disease
Fungal skin diseases of pigs
Ringworm
Nutritional skin diseases of pigs
Vitamin A deficiency
Vitamin B definciency
Zn parakeratosis
Toxic skin diseases of pigs
Selenium toxicity
Mycotoxin (ergot)
Photosensitisation
Physical skin diseases of pigs
Tail / ear biting
Fighting
Sunburn / heat stroke
Burns
Electrocution
Aural haematoma
Pressure injury
Epitheliogenesis imperfecta
Large White & Saddleback breeds.
autosomal recessive gene.
Piglet born with an area of skin - especially on the flank - missing.
Treatment: Self resolution, or if severe euthanasia.
Hypotrichosis - hairless piglets
Autosomal dominant gene
Occasionally also caused by Iodine deficiency.
One or more piglets in litter born with no hair or very little hair.
Treatment: None. May have to euthanase very weak piglets.
Louse infestation
now uncommon in commercial production
Haematopinus suis.
brown dorsoventrally flattened sucking louse
Life cycle complete in 30 days.
The pig is the only host.
Lice can survive for 3 days away from pig.
Lice can transmit pig pox and Eperythrozoon (Mycoplasma) suis.
Heavy infestation causes skin irritation, rubbing, hair loss, weight loss and occasionally anaemia.
Treatment: Avermectin based products typically used. These include Doramectin and , Ivermectin
Pityriasis rosea
Quite common on many farms. Usually only one or two pigs in group are affected but occasionally larger numbers.
Autosomal dominant trait with incomplete penetrance; boar dependent
Mostly seen in individual pigs aged 2 - 16 weeks.
Outbreaks affect 2/3 pigs/litter around weaning period over a 2-3 month period.
Skin lesions (pustular dermatitis) seen chiefly on ventral surface of the abdomen and the medial aspect of the thighs.
Lesions are initially small red nodules which develop into larger raised plaques with thin crusty covering.
Lesions expand centrifugally leaving normal skin within the irregularly circular lesions.
Usually no systemic signs.
Looks very like ringworm. No fungal hyphae seen
Treatment: None. Emollient cream may speed spontaneous resolution. Complete recovery within 6 weeks is usually seen.
Sarcoptic mange
Sarcoptes scabei var suis, a small (0.5 mm) burrowing mite
Mites live on the pig and burrow into the skin where they may produce an allergic reaction.
Spread is mainly by direct pig to pig contact.
Skin is thickened and there is a proliferation of underlying connective tissue.
The head, flank and legs are all affected.
The skin is dry and crusty and pruritis continues and may cause reduction in appetite and growth rates.
Hair loss may follow rubbing and chronic head shaking can cause the development of aural haematomas.
Treatment: avermectins (treat whole herd to eradicate and deep clean buildings two weeks in
Demodectic mange
Rare.
Small (3 mm) nodules and pustules may be seen on the skin.
Abscesses may develop later.
Mites (D. phylloides) found in purulent material.
Controlled as part of sarcoptic mange control plan.
Fly worry
Stomoxys calcitrans
Blow fly strike can occur but is less common than in sheep. Very sick pigs with wounds and open abscesses may be at risk from strike.
Impact:
* May disturb sows and piglets and reduce suckling.
* Downgrading of carcases at slaughter (bite lesion hypersensitivity).
* Fomite in pig dense areas: PRRSV, PEDV, ASFV.
Treatment - clean up and treat original lesion. Local application of a fly spray or deltamethrin may help prevent re - infestation.
Pig pox
Suipox virus from the Poxviridae family.
Direct pig to pig spread but also transmitted by lice and flies.
Skin lesions seen on the face, flanks and belly of affected pigs.
Small (1cm) papules develop with vesicles which rupture to produce dark red scabs.
A congenital form of pig pox has been reported - piglets born with pox lesions sometimes from a clinically unaffected sow.
A high mortality is seen in congenital cases.
In young pigs a conjunctivitis and keratitis may be seen.
No specific treatment. Antibiotics for conjunctivitis may help avoid secondary infection. Topical liquid paraffin may help skin condition improve.
Skin lesions of classical swine fever
patchy purple discolouration of the abdominal skin. Cyanotic necrosis of the ear tips also seen.
Skin lesions of
Porcine Dermatitis & Nephropathy Syndrome (PDNS)
extensive dermatitis may be seen over the chest, abdomen, thighs and forelegs.
Affected areas show numerous and coalescing purple - red papules and macules of varying size and shape.
Skin lesions of Swine Vesicular Disease (notifiable
vesicles seen on the skin of the coronary band. Vesicles and ulcerated areas also seen on the snout, lips and tongue.
Skin lesions of Foot & Mouth Disease (notifiable)
vesicles on the coronary band, tongue and snout.
Skin lesions of Seneca Valley Virus A (SVV)
a non-notifiable but emerging cause of vesicular disease.
No significant disease, aside from transient lameness and transient mortality in neonates.
Needs to be differentiated from notifiable diseases.
Skin lesions in swine erysipelas
Skin lesions are an important sign of this disease.
In peracute erysipelas may see a generalised purple discolouration of the skin.
Other signs include severe depression, pyrexia and sudden death.
In acute erysipelas red, diamond shaped elevated skin lesions are seen and palpable especially over the shoulders and back.
As the lesions get older they become darker and in rare cases sloughing of large areas of the skin of the back occur
Skin lesions of Salmonellosis in pigs
Salmonella cholerae suis is probably the most important serotype associated with skin lesions.
Skin lesions including purple cyanotic discolouration and necrosis of the ears are seen.
Purple discolouration also seen on the flanks, behind the elbows and on the caudal aspect of the thighs.
These are signs of septicaemia and may also be seen in cases of severe mastitis caused by Klebsiella spp
Ear tip necrosis
may be found in pigs affected by septicaemia
Damage to the tips of the ears of healthy growing pig as a result of bacterial infection
Staph hyicus – the cause of Greasy Pig Disease – is the most common isolate
primary cause of the problem is damage to the tip of the ear either from fighting, knocking on feeders or abrasion
Over-stocking is a key risk factor, as is a failure to properly de-grease
earliest lesions are normally visible on the tips of the ears of pigs at 6-7 weeks old and are usually no more that a black greasy deposit, ear tip slowly erodes
At some point, usually above 14 weeks of age, the erosion will halt and the eroded surface will heal over
Individual cases may often not warrant treatment
antimicrobials to which the causative bacteria is shown to be sensitive and which penetrate well into the skin (such as Lincomycin or Florfenicol) can be effective. Reduction in stocking rates is effective.
Greasy pig disease
common
Staphylococcus hyicus. This organism has virulent and non – virulent strains. Dermatophilus spp may be involved in some cases.
Mostly seen in pigs < 6 weeks of age and especially < 2 weeks. Infection is carried by the sow or gilt on her skin or within her vagina
Sudden onset of facial skin lesions with suppressed suckling in affected piglets.
The skin is initially reddened and then becomes thickened and covered with a greasy brown exudate that spreads over the body. The lesions are non - pruritic. Infection occasionally spreads to the mouth and tongue.
Secondary infection with other bacteria may also affect the skin.
Death may occur in untreated piglets.
Treatment: Parenteral penicillin or ampicillin can be effective unless piglets are moribund in which case euthanasia
Washes with chlorhexidine can also be used.
Ringworm
uncommon.
Zoonotic
Mostly Trichophyton mentagrophytes. T. verrucosum and M. canis seen occasionally.
Spread by pig to pig contact
Round or ovoid lesions are seen on the shoulders, back and flanks. Lesions are light brown in colour and the skin may be flaky.
Treatment: Topical enilconazole
Vitamin A deficiency
Skin lesions are a relatively minor sign of this condition.
The coat is dry and has a ‘shaggy’ appearance with splits at the end of the bristles.
A non specific seborrhoeic dermatitis is sometimes seen.
More serious signs of Vitamin A deficiency include CNS lesions - posterior paralysis, night blindness and congenital defects.
Not all are Vit A responsive.
Food should contain 3 - 9 million IU / tonne. Serum 25 - 60 g/dl.
Riboflavin (vit B2 deficiency)
skin lesions include a roughened skin and matting of the hairs by a heavy sebaceous exudate.
May resemble Greasy pig disease
May also see poor growth, limb and eye abnormalities, scouring and irregularities of the oestrous cycle in sows.
Nicotinic acid (vit B3) deficiency
can occur in pigs fed on high levels of maize.
The skin may be yellow in colour and show alopecia or irregular hair growth.
At post mortem lesions similar to necrotic enteritis may be seen.
Pantothenic acid (vit B5) deficiency
risk of low levels if fat content of food is high or when Copper supplementation used.
Skin lesions include dermatitis, patchy alopecia and a dark exudate around the eyes.
Additional signs include goose stepping gait and diarrhoea.
Demyelination - especially of the peroneal nerve - is seen at PM.
Treatment is by including 10 - 12g Calcium pantothenate per tonne of food.
Biotin (Vit B7) deficiency
the diet should include 180 mg biotin per tonne of food.
Levels may fall in diets with high wheat or barley content.
Skin lesions include alopecia, broken hairs, brown crusty lesions and petechial haemorrhages.
May also see signs of lameness caused by cracks in the solar horn which readily become infected.
The response to biotin therapy is often very slow.
Parakeratosis
Zn deficiency in diet or malabsorption of Zn from gut in animals with diarrhoea
High levels of soya and bran and also high levels of Ca++ in the diet can predispose.
Signs seen especially in 7 - 10 week piglets
Less likely in outdoor pigs
Poor growth and weight loss.
May see poor herd fertility and breeding results.
Skin lesions - symmetrical erythema with crusty lesions on the flank, back, belly and ears.
Deep fissures are seen between areas of hyper - keratinisation. There is no greasiness and no pruritis.
Some secondary abscessation of the skin may be seen.
Treatment: 200g Zinc Carbonate or sulphate per tonne of food.
Tail biting, ear biting
Mainly the result of environmental stress through poor husbandry and inadequate accommodation and nutrition
Severe damage can occur rapidly - the whole tail can be removed and deeper biting damage into the perineal tissues can occur.
Infection can enter the damaged tail and spread upwards through local invasion or by haematogenous means.
Vertebral body abscesses are a common sequel and can result in posterior ataxia or paresis.
Minor injuries are left untreated
Infection should be treated with parenteral and local antibiotics.
Identify and if possible remove individuals who start the biting cycle.
Tail docking
has some benefits in reducing the incidence of the problem of tail biting (Welfare (Farmed Animal) Regulations require docking to be done only where managemental correction has not resolved the problem. Docking must be done before 7d of age otherwise anaesthesia is required.
FIghting injuries
severe problem in pigs who naturally fight when mixed with animals from another group
Minor lacerations usually heal by primary intention.
Deep wounds must be sutured under sedation and local anaesthetic.
Infected wounds must be cleaned with antiseptic solutions such as chlorhexidine.
Abscesses must be opened and checked to make sure that premature closure and re - formation of further abscesses does not occur.
Antibiotic cover and tetanus antitoxin must be used when necessary.
If groups have to be mixed sedation of all the pigs involved with azaperone before mixing may help but results can be disappointing.
Heat stroke
The pig is very susceptible to overheating- perspiration minimal and thick layer of s/c fat insulates the body
progressive distress. Panting - open mouthed gasping respiration. T > 42 C. Membranes may become cyanotic. Tachycardia. Death follows.
cool pig immediately - cold water hosing - increase ventilation.
Electrocution
Usually the result of an electrical fault such as poor wiring.
Pigs involved are usually found dead.
Superficial burn marks may be found on the skin.
Signs of a violent death are present.
Fractures of bone especially of the neck of the scapulae or the humerus are common - caused by violent incoordinated muscle contraction.
Blood stained froth may appear at the nose and premature decomposition may occur.
Must treat suspected cases with care in terms of electrical safety and also check that there is no infectious cause of sudden death such as anthrax.
Ergot poisoning
An uncommon condition.
Pigs may occasionaly gain access to ergot from contaminated grain or at pasture.
Skin lesions - gangrene of the extremities.
May also see high levels of stillbirth, agalactia and abnormalities of the oestrous cycle.
Treatment of gangrenous extremities - may require surgical aid, local antibiotic therapy or euthanasia.
