Symptoms

Weaners & Growers

• Y. enterocolitica causes inflammation of the small and large intestines with diarrhoea and
• Y. pseudotuberculosis causes small tiny abscesses throughout the carcass.
• Inappetence.
• Mild fever.

Sows

• N/A

Piglets

• Rare

Causes / Contributing factors

• This is a faeces spread disease.

Diagnosis

The main significance of the organisms is cross reactions that occur when blood tests are carried out for brucellosis. Pigs carrying the organism are likely to react positively. If this is the case it is necessary to determine the point in the rearing system when exposure takes place and break the cycle by management control. Yersinia are easily grown in the laboratory.

Symptoms

Piglets, Weaners & Growers

• N/A

Sows

• The vulva fills with blood and becomes swollen and dark blue.
• When this occurs the tissues become very fragile and if they are crushed the vulva splits with severe haemorrhage which may not stop.
• The animal becomes anaemic and may bleed to death.
• Pale pigs.

Causes / Contributing factors

• Trauma.
• Assisted farrowings.

Diagnosis

A blood filled vulva at farrowing.

A discharge from the vulva post-service does not automatically mean there has been a pregnancy failure, but it will in most cases indicate infection. Discharges can arise from the rectum, the vulva, the vagina, the cervix and the uterus. Discharges can also arise from infection of the kidneys (pyelonephritis) or the bladder (cystitis) with pus being passed in the urine. It is important to record the time when discharges are first seen, their colour and composition and effects on the sow.

Vulval discharges are common within 3-4 days of farrowing when a thick viscous material may be excreted. If the sow is healthy, the udder is normal and there is no mastitis, ignore it.

A heavy smelling bloody discharge may indicate a retained piglet or afterbirth.

Discharges are important between 14-21 days post-service. The lips of the vulva of each sow should be parted daily and any tackiness or small discharge noted. The sow should be marked and if she repeats a problem may be developing. Discharging sows may be pregnant and always pregnancy test before culling.

Discharges in healthy sows are normal up to 5 days post farrowing at mating and 3 – 5 days post mating – only if slight.

Symptoms

Piglets, Weaners & Growers

• N/A

Sows

• Vulval discharges are common within 3-4 days of farrowing when a thick viscous material may be excreted. This is normal.
• If the sow is healthy, the udder is normal and there is no mastitis, ignore it. It is common practice to inject such sows, but this is not necessary under these circumstances.
• A heavy smelling bloody discharge may be from a retained piglet or afterbirth.
• Sow may be ill.
• Mastitis.
• Increases in returns at 18 – 23 days post service with discharge.
• Increases in returns >23 days post service with discharge.
• Increases in sows not in pig.
• Reduced farrowing rates by 10 – 20%.
• Increased negative or doubtful pregnancy tests at 30 days post service.
• Litter size normal.
• Embryo death.
• Abortion.
• Anoestrus.

The table below gives the times discharges might be seen and their likely significance.

INSERT TABLE

Causes / contributing factors

Infection can be caused in a number of ways:

• Vulval discharges arise from opportunist bacteria in the anterior vagina that cause a womb infection or endometritis. These include:

- Actinomyces pyogenes
- Chlamydia
- E. coli *
- A. suis
- Erysipelothrix
- Klebsiella *
- Leptospira bratislava / muenchen
- Pasteurella
- Proteus
- Pseudomonas
- Staphylococci *
- Streptococci * (* Common causes)

• Herds with high numbers of old sows.
• A short lactation length (14-21 days).
• Multiple matings. Cross mating boars.
• Handling the prepuce at mating and squeezing the preputial sac.
• No supervision at mating.
• Matings towards the end of the oestrus period.
• Wet, dirty boar pens. Poor drainage. Continual use.
• Dirty, wet sow mating pens and continual use without cleaning.
• Small stalls where the sow adopts a dog sitting posture with heavy contamination of the vulva.
• Housing maiden gilts in stalls.
• Heavy vulval contamination, for example in maiden gilts housed on slats where slurry spills over.
• Early embryo mortality.
• Re-mating discharging sows.
• Using old boars on young sows.
• Using young boars on older sows.

Diagnosis

Diagnosis is considered in three parts:

1. Studying records.
2. Observations on vulvas 14 – 21 days post service.
3. Bacteriological examinations of swabs from the prepuce and vagina from all boars and 10 problem sows and post mortem examinations on the uteri of affected sows.

Cultures are carried out on the swabs and the predominating bacteria determined. Sensitivity tests identify antibiotics that could be used.

The main organisms associated with endometritis and vulval discharges are opportunist invaders. In some herds no specific organism can be identified, although bacteriological tests may show one or more bacteria predominating either in the prepuce or vagina. A precise diagnosis can be difficult.

Sows bite at the vulva, which has become swollen with advancing pregnancy, particularly when access to food fed on the floor is poor. A sow bites the vulva to gain access to feed. The trauma causes haemorrhage, infection and the development of scar tissue which may inhibit the farrowing process.

Symptoms

Sows

Acute:

• Blood on the noses of sows.
• Blood around the vulva of the affected sow.
• Haemorrhage.
• Swollen red torn infected vulva.
• Occasionally inappetence.

Chronic:

• Scar tissue.
• Abscesses.
• Low grade infections.
• Ascending womb infections discharges.
• Repeats in some badly affected sows.

Piglets, Weaners & Growers

• N/A

Causes / Contributing factors

• Group behavioural abnormalities.
• Vulval biting is much more common in pens that are long and narrow rather than those that are wide. There is less competition at feeding time in a wide pen.
• Vulva biting is also common when electronic feeder systems are used. It requires careful stockmanship and good pen design to prevent it.
• There is a relationship between vulva biting and feed intake, the size of the feed pellet, the type of floor surface and the bedding used. Many cases occur in the last 3 – 4 weeks of pregnancy.
• High stocking densities predispose.

Diagnosis

Made from the symptoms, examine the vulva for trauma.

May be confused with cystitis.

There is a variation in virulence between strains resulting in two different disease syndromes. Both start at around 4 days of age, are sudden in onset and affect whole litters

Symptoms

Sows, Weaners & Growers

• N/A

Piglets

• Huddled.
• Hairy.
• Vomit bright green-yellow vomitus.
• Constipated.
• In the typical vomiting and wasting disease syndrome piglets lose their ability to suck or swallow, become very thirsty and stand with their heads over water but are unable to drink.
• They waste away, become severely emaciated and die.

In the typical encephalitis or brain infected syndrome they:

• Froth and champ at the mouth.
• Develop blueing of their extremities.
• Abdomens become bloated.
• Tremble.
• Stilted gait which rapidly progresses to partial paralysis of the legs.
• They lie down.
• Go into convulsions.
• Roll their eyes.
• Die within four days of onset.

Causes / Contributing factors

• Lack of immunity from sows to piglets via colostrum.

Diagnosis

The clinical and pathological picture is diagnostic of the disease. If you open up their abdomens you will find gas in the stomach and intestine but no food, only some brightly coloured liquid. You will also see brightly coloured crystals in the kidneys. A blood test is available. There is no treatment.

Vice in the dry sow is confined to vulval biting particularly in the last 3 to 4 weeks of pregnancy. This can be a major problem in loose-housed sows and in badly managed systems there may be 80% of all sows in a herd with the vulva completely bitten off. Severely traumatised vulvas heal with scar tissue and this can cause constrictions and difficulties at farrowing.

Types of Vice

The weaned pig

• Penis / navel sucking..
• Prepuce sucking.
• Ear sucking..
• Tail biting.

Growers

• Tail biting.
• Ear necrosis.
• Chewing feet.
• Flank biting.

Sows

• Vulval biting See disease listing

Piglets

• Prepuce sucking

Symptoms

Weaners & Growers

• Evident by trauma and infection of the skin – Dermatitis.
• Lameness.
• Mortality.

Piglets

• N/A

Sows (See Vulval Biting)

• Swollen / torn vulva.
• Evidence of blood on the skin and noses of the sows highlight the possibility of this condition.
• Severe haemorrhage with loss of life in a few animals.
• Low grade infections.
• Ascending womb infections.
• Increased repeats.
• Scar tissue.

Causes / Contributing factors

Weaners, Growers & Piglets

• Management factors
• A change in the diet.
• A very humid environment.
• Long tails.
• Aggressive breeds.
• Draughts.
• No bedding.
• Fluctuating temperatures.
• Trauma.
• High air speed
• Uncomfortable conditions.
• High stocking densities.
• Unhappy pigs.
• Shortage of trough space.
• Water shortage.
• Ammonia levels > 20ppm.
• Wet pens.
• Automatic feeding and little human/pig empathy.
• High hydrogen sulphide levels > 10ppm.
• Pigs too small for the environment.
• Bad pen designs – badly sited feeders.
• High carbon dioxide levels > 3000ppm.
• Nutritional factors
• Low salt in the diet.
• Inadequate nutrition.
• Diet changes.
• Poor feed availability.
• Feeding pellets.
• Rations with small particle sizes.
• Disease factors
• Colitis.
• Greasy pig disease.
• New concrete and skin trauma.
• Parasites.
• Pneumonia.
• PRRS skin lesions.
• Skin trauma.
• Swine pox.
• Wet eczema.

Diagnosis

Based on observations and skin lesions.

The VS virus produces a disease in pigs that is clinically indistinguishable FMD, SVD and VES. Most often however infection of pigs is subclinical.

Symptoms

All Pigs

• Drooling saliva.
• Foot lesions and lameness.
• May be a reduction in growth rate.
• Rise in body temperature to 40-41°C (106-107°F).
• Clinical signs are so closely similar to those of FMD, that they need not be repeated in detail here.
• Like FMD, the most striking feature is the appearance of vesicles (blisters) up to 30mm diameter on the nose, lips, and teats and around the coronets of the feet which may make the pigs lame.
• Mortality is usually low and most pigs recover in one to two weeks.
• One difference from FMD is the relatively small proportion of pigs in a herd outbreak that show vesicles. Another difference from FMD is that usually when an outbreak occurs in a pig herd it rarely if ever spreads to cattle and horses on the same farm and vice versa.

Causes / Contributing factors

• The virus is spread mechanically by a variety of insects and has been isolated from face flies, black flies, eye gnats, sand flies, leaf hoppers and mosquitoes.
• The virus may multiply in some of these insects and can pass vertically through the ovaries to the offspring.
• Insects are therefore thought to act as reservoirs, perpetuating the virus in the enzootic regions.
• It is thought that in the spread between pigs in epizootic regions insects get the virus on their mouth parts from feeding on the lesions left after the vesicles have burst and carry it mechanically to other pigs in the same herd or in neighbouring herds. It is unlikely that they get infected from sucking the pigs’ blood.
• The virus can also spread between pigs by direct contact particularly when pigs are tightly packed together, for example, during transport or when pigs fight after mixing
• The virus can also be carried from herd to herd through the movement of pigs.

Diagnosis

VS is notifiable in most epizootic areas, i.e. if you suspect it in the herd you or your veterinarian have to report it to the authorities.

The clinical signs of VS are similar to those of FMD and SVD both of which are subject to government slaughter and eradication policy in Canada, the USA, Mexico, Chile, South Brazil, and Argentina. It is therefore crucial to reach a fast accurate diagnosis. This can only be done by delivering samples to a laboratory equipped and capable of doing the appropriate tests. The aim is to eliminate the possibility of the disease being FMD or SVD (or in California VES).

The best samples to submit are vesicular fluid, if available, which has high concentrations of virus and/or vesicular tissue (e.g. the thin superficial skin layer over the vesicle) which also contains virus. If these samples are from pigs or cattle the authorities will probably only allow you to send them to a designated FMD laboratory in case the disease is FMD. If they are from a horse then they cannot be FMD (horses do not get FMD, SVD, or VES) and you may be allowed send them to other laboratories (e.g. in the USA, the USDA-NVSL at Ames or other State laboratories).

The possibility of the disease being FMD or SVD (or in California VES) should be eliminated and an accurate identification of the VS virus made. The first of these, namely, elimination of FMD, SVD and VES can probably only be done in the designated FMD laboratories. Other diagnostic laboratories may be able to do the second, namely, identification of the VS virus in samples from horses. This is done by demonstrating the presence of the VS virus in the vesicular fluid or tissue first by ELISA which is rapid giving an answer in a few hours time.

Paired blood samples (i.e. one sample taken during the early stage of the disease and one 10-14 days later) may also be taken. The authorities will probably allow these to be tested in non FMD-designated laboratories (e.g. in the USA, State laboratories). The tests used are generally ELISAs with back-up neutralisation and complement fixation tests. In horses, rising antibody levels to the VS virus have to be demonstrated in the blood samples to be sure that an active VS infection has taken place. This is because in epizootic regions some old horses may have positive antibodies from the last outbreak. Pigs generally do not live so long so single positive samples would be strongly indicative of active infection.

Unfortunately blood sampling and serology may mean a delay of at least two weeks which is too long.

Symptoms

All Pigs

• VES does not affect cattle, sheep, goats or any species other than the pigs and sea mammals. So, unlike FMD, if you keep other livestock they will not be affected.
• Mortality is low but there may be some deaths in sucking piglets.
• Salivation.
• Inappetance.
• Vesicles around the mouth, nose, tongue and feet.

Causes / Contributing factors

• Feeding uncooked garbage/pork scraps to pigs.

Diagnosis

This is the same as for suspected FMD and SVD and requires laboratory tests to identify it.

Usually there is a history on the farm of poor milking amongst all ages and one or two pigs per litter having to be fostered at around 5 to 7 days of age due to poor growth. Scouring problems can sometimes be related back to udder oedema and a poor intake of colostrum.

Symptoms

Sows

• It is characterised by a clinically normal animal with no fever or loss of appetite.
• The distinguishing features are a firmness and swellings of all the glands, discomfort on high pressure but no actual pain.
• Mastitis may develop.
• Palpitation of the udder shows fluid either just beneath the skin or deep in the gland and often extending between the legs towards the vulva. The vulva is also often involved.
• No milk.
• Constipation.

Piglets, Weaners, Growers

• N/A

Causes / Contributing factors

• High levels of feed 7 to 10 days before farrowing, particularly high energy levels.
• Constipation associated with a reduction in fibre intake
• Breed of sow.
• Lack of exercise.
• Low intake of water.

Diagnosis

This is based on the demonstration of oedema of the udder, by appearance and palpation and the appearance of the litter. Oedema and congestion can lead to mastitis.

The avian/intracellulare complex also causes sub-clinical non-progressive infection in healthy people. The main concern is that it could cause more serious disease in immuno-suppressed people and people with AIDS.

In most countries if lesions are found in the neck at slaughter the whole head is condemned and if they are found in the mesenteric lymph nodes which drain the intestines the offals are condemned. If they are more widespread in the body, which is rare, the whole carcass may be condemned or cooked. If small lesions are missed by the meat inspector normal kitchen cooking destroys the organism.

Symptoms

All Pigs

• It causes small nodules in the lymph nodes of the neck and those that drain the small intestine.
• In the great majority of cases the lesions are non-progressive, they do not spread through the body, do not make the pig ill and are not excreted.
• There are no clinical symptoms and there is no difference in performance between infected and non-infected pigs.

Causes / Contributing factors

• The disease does not spread between pigs and should be regarded as an environmental infection. It is rarely diagnosed in living pigs.
• Paddocks that have been treated with poultry manure up to one year previously, (or, in the case of bovine TB, which have been grazed by infected cattle or badgers).
• Avian TB as the name implies is found in wild birds. The organism is shed in large numbers via droppings and therefore food, grain or bedding contaminated by birds becomes a potent source.
• Peat often contains M. intracellulare. Peat is used both for bedding and gut stimulation in the young piglets. It should only be used if it as been pasteurised.
• Water contaminated by M. avium/intracellulare is often a source.

Diagnosis

In living pigs diagnosis is by the skin tuberculin test but usually it is brought to the farmer’s attention by high condemnation rates at slaughter.