chapter 10 of managing pigs health

8/19/2019 Chapter 10 of Managing Pigs Health

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Cptr 10. Skin ConditionsStructure and Appearance of the Skin

Structure and Appearance of the Skin

How to Recognise Skin Conditions

How to Recognise Skin ConditionsSkin Conditions

Abscesses

AnaemiaAujeszkys disease (AD) - Pseudorabies virus (PRV)

Bursitis

CyanosisEpitheliogenesis Imperfecta or Defective Skin

Erythema

Erysipelas

Flank BitingGranuloma

Greasy Pig Disease (Exudative Epidermitis)

Greasy Skin

HaematomaHaemorrhage

Hyperkeratinization

Insect BitesJaundice

Lice

Mange (Sarcoptic)

Necrosis of the SkinParakeratosis

Photosensitisation

Pityriasis Rosea

Porcine Reproductive and Respiratory Syndrome - (PRRS)Preputial Ulcers

Pustular DermatitisRingworm

Shoulder Sores

Swine PoxSunburn

Tail Biting

Thrombocytopaenic Purpura - Bleeding

Ulcerative Spirochaetosis (Ulcerative Granuloma)Vesicular Diseases

Vulval Oedema

Chapter 10 Skin Conditions

Structure and Appearance of the Skin

(450) At birth the skin and subcutaneous tissues account for up to 10% of body weight but by the time the animal hasmatured this has dropped to around 6%. The boar's skin over the shoulder blade is thickened by a mat of fibroustissue. This protects the shoulder when fighting occurs.

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The structure of the skin consists of three parts; an outer epidermis, which is the scaly surface of the skin, the dermiswhich is the main thick part and the sub dermis which consists of fat and connective tissue. The clinical appearance ofthe skin particularly in white breeds can be a useful guide to the health or disease state of the pig. When anexamination is carried out the following should be noted.

Colour - In white skinned breeds, this may range from very pale, suggesting anaemia possibly from intestinalhaemorrhage or iron deficiency, to red which may be generalised suggesting possible fever or sunburn, or localised orpimple sized suggesting insect bites or mange. Blue/black extremities (ears, feet, tail, snout) may suggest septicaemiae.g. salmonellosis, toxaemia, or circulatory failures.

Eczema - This describes dermatitis, where serum oozes to the surface giving rise to a wet lesion. It is often seen intraumatic lesions to the ears and flanks as a result of viceHair growth - If this is excessive it may be related to low environmental temperatures, poor nutrition, or general illhealth resulting from diseases such as pneumonia, swine dysentery or mange.Inflammation - Infection and inflammation of the superficial layers is called epidermitis and in the deeper parts,dermatitis. Epidermitis is seen typically in greasy pig disease and dermatitis is associated with bacterial infections suchas staphylococci, streptococci and erysipelas. The areas of inflammation may coalesce into large patches or remain asdiscrete small areas or pimples.Jaundice - The skin is a slight to moderate yellow colour but these changes are more easily observed in the mucousmembranes in the eye. Jaundice may be associated with the blood parasite Eperythrozoon suis, leptospirosis, orwhere there is damage to the liver due to toxins such as aflatoxin, migrating ascarid larvae, or poisons such aswarfarin.Necrosis - When there is restriction of blood supply to an area of the skin the surface tissue dies (called necrosis)

leaving a dark area. Such changes are often seen on the teats, tails and knees of piglets as a result of trauma and inskin lesions of erysipelas diamonds, where the causal organisms block the tiny blood vessels supplying small areas ofthe skin.Pustules or papules - These are small areas of inflammation usually from 1-3mm in size that have red raised centresthat may show evidence of pus, dead black tissue or initially appear as small vesicles (see below). They arise afterinfection with viruses, streptococci or staphylococci, or allergic reactions to the mange mite.Vesicles - These are blisters containing clear fluid which are small (< 1mm) in the case of PRRS virus infection, or upto 10mm in pox virus infections. Large confluent vesicles occur around the skin horn junctions and the mouth andtongue in the vesicular diseases such as swine vesicular disease, foot-and-mouth disease, or vesicular exanthema incountries where these occur.

How to Recognise Skin Conditions

(451) Skin diseases in the pig can be broadly divided into two groups. Those conditions or specific infections that onlyinfect the skin and have minimal effect on the pig and those that are signs of more generalised disease.

Figure 10-1 lists the conditions that may be observed and the times when they are likely to occur, from birth through tothe adult animal and indicates whether or not there is a generalised effect on the pig. Note that there are only fivemajor diseases that have any economic significance; greasy pig disease, mange, necrosis, sunburn and the vesiculardiseases.

Recognition commences by clinical observations across the herd. The following need to be considered:

What proportion of pigs are affected?

What age group is affected (refer to Fig.10-1).

Is there a generalised illness associated with the condition and can this be related to a specific disease?Has the condition appeared suddenly or is it one that has been present in the herd for some time?

Have you seen the condition before and can you recognise it? If not it may be advisable to consult yourveterinarian or refer to the photographs.

Do the pigs recover without treatment?

Use the progression pathway shown in Fig.10-2 together with Fig.10-3 which outlines diseases that may beresponsible for the symptoms observed.


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Abscesses

(453) Abscesses, Fig.10-4, are pockets of pus that contain dead cell material and large numbers of bacteria. Thebacteria normally enter the body through damage to the skin or via the external orifices. They become walled off from

the body tissues, or the bacteria are disseminated by the blood stream to develop abscesses elsewhere in the body.Near the skin surface they may become painful with an inflamed appearance.

Clinical signs

They commonly arise from fighting particularly when sows are grouped at weaning. Initially there is a break in the skinwhich leaves a scar followed by swellings beneath. Abscesses can also arise as secondary infection to otherconditions such as swine pox, PRRS, pneumonia or tail biting and if they become widespread throughout the body, theresult may be emaciation followed by death or condemnation of the carcase at slaughter.

ABSCESS ON THE NECK

This abscess has resulted following faulty vaccination.


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Diagnosis

This is based on the clinical signs of abnormal swellings under the skin especially with overlying scars. To confirm thediagnosis, feel and press the swelling to ascertain if the contents are fluid or solid and whether they are beneath theskin or deep seated. To examine the swelling more closely, restrain the pig by a wire noose or by heavy sedation(stresnil 1ml/10kg), and sample the contents. This is carried out using a 10ml syringe with a 18mm 16 gauge needleattached. The needle is inserted at the lowest soft point of the swelling and fluid withdrawn. If it is an abscess a white,

yellow or green substance of either a watery or a cheesy consistency will appear.

Similar diseases

Haemorrhage into the tissues from a recently ruptured blood vessel or a haemorrhage of long standing is the onlycondition likely to be confused with an abscess. In such cases either pure blood or a very thin blood stained liquid willbe withdrawn. Such pockets of blood are called haematoma and if they have been present for a long time a clot willhave formed, in which case only serum or a clear liquid will be withdrawn.

Treatment

This is aimed at draining the pus. Sometimes it will occur naturally after the abscess bursts but most require

lancing or opening surgically. To do this make an incision approximately 15-20mm long at the lowest pointparticularly where it is soft and fluctuating. A sharp scalpel blade with only 15mm exposed is inserted into theabscess in a downward movement to open it up. Carry this out only when the sow is restrained. A quickcontrolled movement of the blade will cause little pain, far less than trying to infiltrate a local anaesthetic. Thepus should be squeezed out and the interior washed using a syringe and sterile saline solution. Such asolution is made by adding 5 grams of salt to 1 litre of previously boiled water. The wound must be kept openfor at least 3 or 4 days or until all the pus has drained out, otherwise the abscess may reform.

See lancing an abscess or haematoma chapter 15.

Most of the organisms that cause abscesses in the pig are either penicillin or oxytetracycline sensitive.

If the area is badly inflamed, squeeze into the hole an antibiotic cream (a cow mastitis tube is ideal) containingpenicillin/streptomycin, oxytetracycline, amoxycillin or ampicillin.

Treatment should be given by intramuscular injection - if the area is inflamed or the sow is ill. Medicines thatcould be used include:

- Penicillin/streptomycin daily for 3-4 days.- Amoxycillin long-acting (LA) every other day.

- Oxytetracycline (LA) every other day

- Penicillin (LA) every other day.

Management control and prevention

Identify various projections and sharp objects in the environment. A typical example would be a neck abscessassociated with worn and jagged metal on feeders. Long-acting antibiotic injections given at the time ofdamage will often prevent infection.


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Reduce fighting.

Prevent tail biting. See vice chapter 9.

Check injection procedures.

Anaemia

See chapter 8 for further information.

(454) Anaemia arises in the sucking piglet due to iron deficiency because the sow's milk is deficient in iron and thepiglet has minimal reserves. Iron forms an essential part of haemoglobin in the red blood cells and this is responsiblefor carrying oxygen. The piglet becomes rapidly anaemic and susceptible to other diseases such as scours, unless ironis supplied either orally or by injection. The skin is very pale particularly if there has been a severe haemorrhage bothinternal and external and there may also be respiratory embarrassment. Gastric ulcers with internal haemorrhages area common cause in the growing pig. Porcine enteropathy resulting in massive loss of blood into the gut is seen ingrowing pigs and gilts.

Aujeszkys disease (AD) - Pseudorabies virus (PRV)

For the main information on this disease see chapter 12.

(455) Aujeszky's disease (Fig.10-5) is not normally regarded as a cause of skin changes, but in acute outbreaks smallvesicles of approximately 1mm in diameter may be seen on the skin around the nose and the mouth. Similar lesionsare occasionally seen in PRRS.

AUJESZKY'S DISEASE Vesicles on the nose of a 2 day old piglet

Bursitis


(456) Bursitis (Fig.10-6) arises due to constant trauma of the skin particularly where it covers the bony prominences.The skin reacts, becomes thickened and small soft fluctuating swellings may be formed (false bursae).

BURSITIS Swellings are evident on both legs below the hocks.

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Cyanosis

(457) Cyanosis (Fig.10-7) is the name used to describe a blue or red discoloration of the skin which may or may not belocalised to small areas, mainly the extremities. It is not a specific skin condition but a symptom of generaliseddisease.

CYANOSIS

There is a clear line of demarcation on the left ear from the normal skin. This picture is typical of PRRS or blue eardisease or toxaemias.


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The colour changes are associated either with poor circulation due to heart disease, toxic conditions, thrombosis ofblood vessels or poisoning, particularly by carbon monoxide.

Epitheliogenesis Imperfecta or Defective Skin

(458) This is a condition where the piglet is born devoid of an area of skin. (Fig.10-8). It usually occurs on the legs orflanks. Provided the area is not too large, the skin will gradually heal. If it involves an area of loose skin such as overthe flank, local anaesthetic can be injected, the skin edge separated and the two edges sutured using mattress orinterrupted sutures. In severe cases however the piglet should be destroyed.

EPITHELIOGENESIS IMPERFECTA The front leg is a common site.

Erythema

(459) This describes a reddening or blue discoloration of the skin, often transient, and commonly seen duringtransport. The pigs skin is sensitive to irritants such as urine, sawdust and disinfectants. Generalised discolorationparticularly the extremities is seen in toxic conditions, bacterial septicaemias and viraemias and where there arecirculatory problems. Occasionally when sows are bedded on urine soaked shavings in farrowing crates their completebody turns blue, the sow appearing quite normal. This is usually of no consequence.

Erysipelas


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See Chapter 7 for further information.

(460) This disease, caused by the tiny bacterium Erysipelothrixrhusiopathiae (insidiosa), produces very characteristic skin lesions oftendescribed as diamond markings. The organism enters the blood streamcausing a septicaemia. In the process it forms small clumps which block orthrombose tiny blood vessels supplying the skin. Affected areas appear as

raised diamond shaped patches several centimetres across, scatteredover the back, flanks and abdomen. Fig.10-9. They are usually pink incolour and in clean white skinned pigs are readily seen but in coloured ordirty pigs they may not be so evident. In such cases run the palm of yourhand over the pig's back and sides and they can be felt as raised areas.The affected pigs may or may not be depressed and running a fever. If thethrombosis is complete and treatment is not given these areas can turnblack as tissue dies and eventually slough off. The organism is verysensitive to penicillin and effective vaccines are available.

ERYSIPELAS Diamond shaped skin lesions and others on the neck and flank.

Flank Biting

See chapter 9; Vice for further information.

(461) This is a relatively new condition in intensive pig producing systems but also occasionally it is seen in pigshoused in straw yards. It is often associated with ear and tail biting and usually commences as a small dark scab nomore than 5-10mm in diameter. (Fig.10-10).

If the scab is removed a wet eczema or dermatitis is evident from which large numbers of Staphylococcus hyicus canbe isolated. The condition at this stage is of no consequence until the scab is removed either mechanically or by otherpigs that traumatise the area. This rapidly progresses into vice and in extreme cases severe cannibalism. It isimportant to remove the infected pig into a hospital pen and identify the offending pigs that are responsible for the viceand isolate them too.

FLANK BITING This is a developing lesion with cannibalism just commencing.

Diamond shaped lesions tyipical of Erysipelas


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Granuloma

( 462) A granuloma (Fig.10-11) is a large mass of fibrous tissue that has been produced in response to persistenttrauma and irritation to the skin and underlying tissues. Granuloma can also arise due to low grade bacterial infections. A typical example would be the large lumps seen in cases of chronic mastitis. The most common sites are over thelateral aspects of the front legs, particularly the knee, hock and elbow joints and on the hind legs over the lateralaspects of the hock and the posterior parts of the legs and feet. Occasionally the granuloma will burst to the skinsurface and ulcerate. Animals showing large granuloma, particularly if they are starting to ulcerate, should beslaughtered. It is also possible to amputate large ones and you are advised to discuss this with your veterinarian.

GRANULOMA These are common on the legs. This one is starting to ulcerate.


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Greasy Pig Disease (Exudative Epidermitis)


(463) Trauma and subsequent infection of the skin by the bacterium Staphylococcus hyicus causes a wet eczema ordermatitis. The lesions often develop to cover the whole of the piglet, the skin becomes flaky and greasy and the bodyturns a dark brown to black colour. (Fig.10-12).

GREASY PIG DISEASE The generalised form.

These changes often start around the face and ears or along the abdomen. Mortality can be quite high in thegeneralised form due the absorption of toxins from the organism and from dehydration. A more localised form (Fig.10-13) is seen in pigs from five weeks onwards as small discrete patchy areas of wet inflammation 10-30mm in diameter,often covered over by a black scabs. The organism can also cause eczema of the tail and tips of the ears which leadsto vice.

GREASY PIG DISEASE A localised lesion of greasy pig disease. This may be cannibalised.


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Greasy Skin

(464) This is a condition that in the initial stages can look like greasy pig disease but is seen only in the growing pig orthe sow. The skin, particularly behind the ears, eyes (Fig.10-14) between the elbow and body and the inner parts of

the legs, contains a thick brown greasy material. It occasionally may involve the whole of the pig. Unlike greasy pigdisease it has little if any generalised affect. It is usually of no consequence.

GREASY SKIN Note the thick brown waxy deposits behind the sow's ear and beneath the eye.


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Haematoma

(465) This is a large swelling caused by haemorrhage beneath the skin into the subcutaneous tissue or muscles.(Fig.10-15). It is caused by fighting or external damage that ruptures a small blood vessel. The common sites are theears and flanks. They can be confused with abscesses and to differentiate between them it is necessary to use aneedle and syringe and sample the fluid contents. Most haematomas stop bleeding and the body defences graduallyremove the serum and the blood clot. Occasionally they become infected to form an abscess, and need to be dealtwith as such.

HAEMATOMA

Haematoma of the ear, note the swelling.

Haemorrhage

(466) Bleeding into the skin is not uncommon in the pig and is associated with trauma, poisons, bacterial or viralinfections.

Hyperkeratinization

(467) This term describes thick layers of surface epithelial cells that become impregnated with black sebaceousmaterial and dust from the environment. It is typically seen in confined sows, particularly over the neck and the back.(Fig.10-16). Occasionally, the condition in its extreme form will involve all the upper skin surfaces. It can be confusedwith mange but there is an easy and simple method of differentiation.

The mange mite burrows into the skin layers causing chronic inflammation and thick scabs. Hyperkeratinization on theother hand only consists of surface debris or scurf which is easily scrubbed away by the hand, leaving a clean smoothnormal skin beneath. The condition is unsightly but of no consequence. It has been associated with a shortage ofessential fatty acids. 4.5 litres of cod liver oil per 50 sows per week, added to the sow ration will improve the skinappearance. Alternatively essential fatty acids from other sources may be added in the diet.

HYPERKERATINIZATION The black dead skin rubs away leaving normal healthy skin.


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Insect Bites

See chapter 11 (Flies) for further information.

(468) Skin damage associated with biting insects is surprisingly common particularly in the summer months and moreso where farrowing house floors are slatted. The lesions appear as small red pimples that can look very similar to theallergic form of mange but tend to be localised behind the shoulders and the flanks where biting flies gain accessthrough slatted floors from the slurry. Sometimes it is necessary to take skin scrapings to eliminate mange particularly

in herds that are monitored and believed free of the mite.

Jaundice

(469) Jaundice is a yellowing of the skin and mucous membranes due to the breakdown of red cells in the blood, theaccumulation of the bye-products in the liver and the production of a substance called bilirubin. The condition may beseen at any age but is usually confined to individual animals or litter mates.

In sucking pigs it is associated with a haemolytic anaemia where the piglets' red cells become sensitised by antibodiesin the colostrum of the sow. (See purpura later in this chapter). Jaundice will follow the breakdown of red cells causedby the blood borne parasite Eperythrozoon suis and be seen in sucking and weaned pigs and occasionally in the sow.Jaundice can also occur in individual pigs under about three months of age, when the blood is infected with bacterium,Leptospira icterohaemorrhagiae, derived from rats' urine.

It produces a toxin that breaks down red blood cells. Jaundice can also be caused by direct damage to the liver byfungal toxins such as aflatoxin or fumonisin which may be present in feed components such as peanuts or corn. It canalso be caused by coal tar toxicity from eating fragments of clay pigeons, builder's tar or by ingesting high levels ofcopper in feed, or by vitamin E and selenium deficiency.

In all of these there are usually other severe clinical signs such as loss of appetite, depression, and respiratorydistress. It can also occur (rarely) from heavy ascarid worm infestations blocking the tube from the gall bladder to theintestine.


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Lice


(470) These insects are visible by the naked eye. Fig.10-17. They are approximately 3mm long and are commonlyfound behind the ears and elbows. They also congregate between the legs. They suck blood and can be responsiblefor anaemia and the transmission of blood borne infections.

LICE These are easily seen by the eye and are often grouped together behind the ears.

Mange (Sarcoptic)

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See chapter 11 for the main section on mange.

(471) This is caused by the tiny mite Sarcoptes scabiei which invades the skin and causes dermatitis, proliferation ofthe surface cells and asbestos like lesions in chronic cases. (Fig.10-18a).

MANGE Chronic mange. Note the thick crust in the ears.

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These crusts are found within the ear, behind the ears, behind the elbow and on the anterior surface of the hind legs. An allergic skin form of the disease is common when the body is sensitised to the proteins of the mite. This is shownby the appearance of very tiny red pimples throughout the body but particularly over the flanks (Fig.10-18b) thateventually turn black. Intense irritation occurs.

MANGE Acute mange. The skin is covered by minute red pimples.

Necrosis of the Skin

(472) Necrosis means that the cells and surrounding tissues have died. (Fig.10-19) It arises in one of three ways, frompressure on the skin from the environment, trauma causing necrosis of the teats, knees and the tail, or as a sequel toinfectious diseases. It is common in the sucking pig.

KNEE NECROSIS This can cause severe pain and lameness.

TEAT NECROSIS

Note the small black damaged teat ends.


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TEAT NECROSIS The anterior teats protected by cow gum.

EAR NECROSIS This can be so severe that most of the ear is lost.


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Parakeratosis

(473) This is seen in pigs from 5-16 weeks of age associated with a deficiency of zinc and/or an excess of calciumwhich suppresses the availability of zinc in the diet. Up to 50% of pigs may be affected. The major signs are limited tothe skin where gross thickening and roughening occurs over the complete body. It may start initially with small lightbrown spots or papules on the legs and abdomen and in young pigs it can look like greasy pig disease. Treatment andcontrol involve analysing the levels of calcium in the diet (normal 0.6 and 0.7%). Zinc oxide or sulphate can be addedto the ration at a level of 50ppm to prevent the disease. The condition is now uncommon.

Photosensitisation

(474) This occurs in outdoor pigs that have been in contact with substances that make the skin sensitive to ultra violetradiation. These include alfalfa, clover, rape, lucerne and a fungus that grows at the base of grass in dry weather,pythomyces charterum. Certain medicines, in particular tetracyclines and sulphonamides can also have a similar affectfollowing prolonged use. The disease is characterised by a reddening or erythema over the white areas that areexposed to sunlight. The affected surfaces are damaged and become coagulated with serum followed by secondarybacterial infection and eventually a thick crust is formed. These changes cause a considerable amount of pain andaffected animals should be moved indoors and if necessary given broad spectrum long-acting antibiotic treatment byinjections. Amoxycillin could be used. Animals may abort or absorb the embryos.

Pityriasis Rosea

(475) This is a sporadic condition seen in young pigs from 3 to 16 weeks of age. It is characterised by large coalescingringworm like lesions that often start on the abdomen and spread up behind the back legs and ultimately in severecases involve the whole of the body. (Fig.10-20). It is believed to have a hereditary background particular in theLandrace breed. The lesions are characteristic and the condition naturally resolves itself over 6 to 8 weeks. Notreatment is required. It is of no consequence apart from being unsightly but may cause customer reactions if you areselling 25kg weaners to finishers.

PITYRIASIS ROSEA

Note the raised ringworm like lesions.


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Porcine Reproductive and Respiratory Syndrome - (PRRS)


(476) Occasionally skin lesions are seen in PRRS that are characterised by small discrete vesicles anywhere on thebody but particularly around the nose and the shoulders at points of pressure. The vesicles rupture, become infectedand dark coloured and ultimately heal over a three week period.

It is not uncommon where PRRS virus is active in growing pigs to see a generalised form in 1-2% of pigs. (Fig.10-21).The lesions look similar to localised greasy pig disease but close examination will show tiny vesicles covered withblack scabs 1-10mm in diameter.

SKIN LESIONS ASSOCIATED WITH PRRS Note the tiny black lesions and the larger ones beneath the hair.

Preputial Ulcers

(477) These occur as areas of wet eczema around the skin on the end of the prepuce.

Clinical signs

The ventral part of the prepuce near the opening is swollen, oedematous, red and painful. It is only shown in outdoorboars and is sporadic. The lesions are usually quite obvious and may become extensive.

Diagnosis


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The cause of this condition is unknown but the possibility of a virus infection cannot be ruled out. Frost bite may beanother cause. Secondary bacterial infection develops.

Treatment

Isolate the boar until the lesions have healed.

Apply an antiseptic antihistamine cream.

Spray with antibiotic.

If the prepuce is badly infected inject the pig with long-acting amoxycillin.

Consider culling affected animals.

Pustular Dermatitis

(478) This disease is seen in young growing pigs and occasionally in adults. The skin becomes infected withstaphylococci or streptococci bacteria and small circular raised red areas appear. These are similar to acne in thehuman. In some cases the condition can affect large areas of skin. It is usually confined to individual animals andrecovery takes place over two to three weeks. Antibiotic injections will help and lincomycin, amoxycillin or tetracyclinescould be used. It can be confused with mange, localised greasy pig disease and pig pox.

Ringworm

(479) This is an uncommon condition in the pig but where it does exist it is of little economic significance. However it isa condition that can be transmitted to the human. It is caused by a dematophyte fungus. Unlike other animals there isno specific host-adapted species. Trichophyton and Microsporum species are involved. Infected skin shows graduallyincreasing circular areas of light to dark brown discoloration behind the ears and on the back and flanks.

Infection can occur in all classes of stock. The fungi enter the skin through abrasions and diagnosis is made byexamining scrapings from suspicious areas under the microscope to look for fungal spores. Treatment consists ofwashing the area with 1% savlon or hexetadene skin disinfectants or fungicides. In cases where infection iswidespread, which would be rare, the pig can be treated orally with griseofulvin antibiotic at a level of 10mg/kg for aperiod of 7 days.

Shoulder Sores

(480) They arise due to constant trauma over the bony prominences on the shoulder blade. Ultimately the skin breaks,there is an erosion and a large sore develops. It is associated with totally slatted flooring and individual sows that havea prominent spine to the shoulder blade. It is first noticed in the farrowing crates where the floors are slippery and thesow has difficulty in rising, thus constantly bruising her shoulder. Such sows should not be kept for future breeding.

SHOULDER SORES

This has become a large ulcerating granuloma.


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Clinical signs

At the highest point on the spine of the scapula or shoulder blade a reddening of the skin first appears, which graduallyforms into an ulcer. In severe cases the lesion may extend to 40-70mm in diameter with the development of extensivegranulation tissue. Often both sides of the shoulder are affected.

Treatment

As soon as the condition appears move the sow into a well bedded pen. Feed ad lib for 2 to 4 weeks.Cut a hole slightly larger than the sore in a 70mm square piece of foam or thick carpet and place over theshoulder sore. Hold it in place with contact adhesive such as evostik. This pad will then protect the sore andallow it to heal.

Large granuloma that sometimes develop can be surgically removed.

Watch for cannibalism by sucking pigs. If this occurs wean the sow.

Swine Pox

(481) This is a disease caused by the swine pox virus which cansurvive outside the pig for long periods of time and is resistant toenvironmental changes. It is a vesicular disease characterised bysmall circular red areas 10-20mm in diameter that commence witha vesicle containing straw-coloured fluid in the centre. After two tothree days the vesicle ruptures and a scab is formed whichgradually turns black. The lesions may be seen on any part of thebody but are common along the flanks, abdomens andoccasionally the ears. There is no treatment and the conditionusually resolves itself spontaneously over a three week period.

It can be spread by lice or mange mites. It can be confused withlocalised greasy pig disease, pustular dermatitis and the allergic

form of mange.

Sunburn

(482) This is common in the white non pigmented breeds, some ofwhich can be highly susceptible to ultra violet radiation. The symptoms are similar to those in the human with rapidreddening of the skin and considerable pain.

In severe cases oedema and oozing of serum may take place with secondary bacterial infection. One major problemwith sunburn in outdoor or exposed weaned sows is their refusal to stand for the boar at mating.

Example of a pig with swine pox.


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Ultra violet radiation can also cause embryo absorption and abortions in pure white breeds. Outdoor pigs can beprotected by shades and access to good wallows throughout the year. Ensure that the breeds used have pigmentedskins.

Tail Biting

See chapter 9; Vice for further information.

(483) Trauma to the tail and the skin is common under all conditions of management both indoors and outdoors. It ismore common however in intensive conditions particularly where pigs are housed on slatted floors or solid oneswithout bedding.

Fig.10-24 shows a typical case, probably 2-3 days old , with considerable infection around the stump. Infection mayprogress into the spine or be disseminated throughout the pig causing multiple abscesses.

TAIL BITING Note the swelling and infection around the tail.

Thrombocytopaenic Purpura - Bleeding

(484) This is an uncommon condition seen only in young piglets from approximately 7 to 21 days of age. It arises whenthe sows colostrum contains antibodies that destroy the piglets blood platelets (thrombocytes). The immune system ofthe sow during the period of pregnancy recognises the platelets as foreign protein and produces antibodies againstthem. The formation of these antibodies is also related to the boar that is used. Disease commences 7 to 10 days afterthe intake of colostrum.

Clinical signs

These can be sudden and are indicated by good pigs found dead. Look closely at the skin of these and you will seehaemorrhages wherever there has been bruising, teeth marks or trauma. Haemorrhages are evident throughout allbody tissues. The piglet dies through the failure of normal blood clotting mechanisms. The disease is very sporadic but

up to half the litter may be affected. Invariably the pigs die.

Treatment

There is no known treatment other than good nursing. In the early stages of the disease it is worthwhile cross-fosteringlitters to remove exposure to any lingering antibodies in the sows milk.

Management control and prevention


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Where a sow has produced such a litter make sure she is mated with a different boar at the next pregnancy orcull her.

THROMBOCYTOPAENIC PURPURA Note the haemorrhages throughout the carcase, skin and lymph nodes.

Ulcerative Spirochaetosis (Ulcerative Granuloma)

(485) This is caused by a spirochete bacterium called Borrelia suis, together with secondary infections with otherbacteria including streptococci and staphylococci. The disease is seen in pigs from three to ten weeks of age and skindamage is first necessary to allow the organism to enter. It causes considerable irritation in the tissues, severeinflammation and the development of fibrous tissue. Diagnosis requires laboratory examination and isolation of theorganism. Control involves improving hygiene, reducing trauma and identifying the areas within the managementsystem where infection first starts and making changes to these. Infected pigs can be treated with either penicillin,tiamulin or lincomycin. It is not a common disease.

Vesicular Diseases


(486) These include foot-and-mouth disease, vesicular stomatitis, vesicular exanthema and swine vesicular disease. All these viral infections produce blisters or vesicles around the snout, the tongue, on the teats and at the hoof skin junctions or coronary bands. (Fig.10-26a-c). In most countries they are notifiable and if suspected must be reported tothe authorities.

VESICULAR DISEASES Unruptured vesicles are evident at the hoof skin junction.


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VESICULAR DISEASES Ruptured vesicles are evident on the nose.

VESICULAR DISEASES The dark areas on the hoof are due to long standing lesions of SVD.


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Vulval Oedema

See chapter 8: Udder oedema for further information.

(487) Fluid accumulating in the vulva at or near farrowing is a common occurrence and in mild cases is a normalphysiological process and of no consequence. Fig.10-27 shows an extreme case extending into the udder, where itcan interfere with milk let down and production.

VULVAL OEDEMA The fluid extends from the vulva between the legs and into the udder.


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chapter 10 of managing pigs health

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