DISEASES VIRAL/BACTERIAL/PROTOZOAN

chicks 1

DISEASES THAT ARE LINKED:

There are some diseases that characteristically “pal up” together, and the poultryman must be aware of this as he makes up his vaccination programme.

It is no use for example vaccinating against Newcastle, and not doing the other typically respiratory diseases such as Infectious Bronchitis, Coryza and MG.

Typically the following diseases are linked, in that as the bird contracts the one, his immune system is then compromised and he is likely to come down with the others as well:

VIRUSES ARE HIGHLIGHTED IN RED, BACTERIAL INFECTIONS IN GREEN

 OTHER SOURCES APPEAR IN OTHER COLOURS:

DISEASE CONCURRENTSICKNESS/1 CONCURRENT   SICKNESS/2
GUMBORO ILT /CORYZAMG ECOLI INFECTION
CORYZA ILT/ NEWCASTLE/ INFECTIOUS BRONCHITIS MG
ILT CORYZA MG
COCCIDIOSIS ENTERITIS/ECOLI   SEPTICAEMIA GUMBORO/NEWCASTLE
AE NEWCASTLE  
MAREKS LYMPHOID   LEUKOSIS GUMBORO
MG CHRONIC RESPIRATORY   DISEASE CORYZAILTAVIAN INFLUENZA
PARASITES CORYZA  
WOUNDS/INJURY/STRESS CORYZA /MG ECOLI   SEPTICAEMIA

This is a rough guideline to diseases that can be linked. If the birds are affected by one, they may contract the others. Coryza unfortunately in the last 5 years has become a real challenge as there are so many different varieties of this bacterial infection, it is difficult to vaccinate against them all. Ondersterpoort has come up with a TONGAAT strain of Coryza vaccine which a few years ago dealt with the varieties we faced in south Africa. This year I have found the TONGAAT vaccine absolutely useless. Symptoms of the illness were totally different to anything seen before, yet the PM (post mortem) diagnosis came back as Coryza.

Birds became ill very quickly, had nervous tremors, battled to breathe and succumbed very quickly. My younger birds did survive thanks to the regimen of vaccines I have in place but the older birds compromised by their age died.

I did not lose a lot, but one bird is one too many.

I then decided to scratch the Coryza vaccine and concentrate on MG and building a natural immunity to all diseases.

M.G OR MYCOPLASMA GALLISEPTICUM IS A NIGHTMARE FOR MOST POULTRY BREEDERS AS IT LURKS IN THE BACKGROUND AND WILL RESURFACE IN TIMES OF STRESS FROM HEAT, COLD, PREDATORS, VACCINATION OR TRANSPORT OR EXPOSURE TO A DISEASE NOT M.G.

Mycoplasmosis is a combination of MG and MS (mycoplasma synoviae).

It is difficult to treat, although it is bacterial in nature, and often birds relapse. If you have a good vaccination programme in place and vaccinate regularly against MG this should not happen. MS tends to add several symptoms to the already well known list, respiratory distress, rales, discharge from nose and eyes, coughing. MS adds the added distress of infection in the joints, swelling, lameness.

One must beware when dosing for mycoplasmosis that you do not go into overkill. Do not be tempted to dose with very heavy antibiotics from day one, do not exceed the dosage recommended and do not exceed the timeline of treatment. If there is no improvement, stop with the medication, put the birds on added vitamin and mineral complex, and wait a week, then restart the antibiotics.

In times of high stress I put them onto PROBIOTICS such as maas, milk products, high content vitamin C, Green Lipped Mussel extract and a Probiotic called PROTEXIN, which basically contains most of these anyway.

Probiotics are usually herbal or non chemical in nature, and are prophylactic rather than a treatment for symptoms .

Antibiotics treat a problem, probiotics prevent a problem from developing.

I found this worked a charm. I have discovered that building a good immunity is not an overnight thing, it takes generations of birds. However in the long run, how much better it is for the birds.

I also found I needed very little in the way of antibiotics. Most infections were due to injury from hawks or cats, and the very few illnesses we had were virtually handled by the birds themselves with a little disprin.

I found that wild birds carry a lot of these viruses and bacteria, and the immunity my birds have prevents contamination by outside carriers.

This of course is not a cure all…it is only a general management programme that works for me.

SUMMARY TABLE:

BACTERIAL INFECTIONS MOST COMMON:

INFECTIOUS CORYZA

COLIBACILLOSIS

MYCOPLASMOSIS (CRD, AIR SAC SINUSITIS)

MYCOPLASMA GALLISEPTICUM

MYCOPLASMA SYNOVIAE

FOWL CHOLERA

NECROTIC ENTERITIS

ULCERATIVE ENTERITIS

PULLORUM DISEASE

SALMONELLA AND PARACOLON INFECTIONS

OMPHALITIS

FOWL TYPHOID

BOTULISM

OMPHALITIS

ERYSIPELAS

VIRAL DISEASES

INFECTIOUS LARYNGOTRACHEITIS (IL)

NEWCASTLE DISEASE (ND)

INFECTIOUS BRONCHITIS (IB)

AVIAN POX ( DRY POX OR WET POX)

AVIAN LEUKOSIS

EPIDEMIC TREMORS (AVIAN ENCEPHALOMYELITIS)

INFECTIOUS BURSAL DISEASE (GUMBORO)

INCLUSION BODY HEPATITIS (I.B.H.)

VIRAL HYDROPERICARDIUM

MAREKS DISEASE

FUNGAL DISEASES

ASPERGILLOSIS (BROODER PNEUMONIA)

MYCOTOXICOSIS

MONILIASIS (CROP MYCOSIS, THRUSH) CANDIDA ALBICANS

PROTOZOAN DISEASES

COCCIDIOSIS  (  CAN LEAD TO NECROTIC ENTERITIS IF NOT TREATED)SEE SECTION ON COCCIDIOSIS ON THIS SITE.

BLACKHEAD

HEXAMITIASIS (INFECTIOUS CATARRHAL ENTERITIS)

BACTERIAL DISEASES:

Bacteria are microscopic living organisms. They are grouped into  spherical forms, straight rods, curved or spiral rods and filamentous forms. Most can be grown in artificial media. Bacteria like all living organisms have certain requirements as to environmental temperature, moisture, nutrition for propagation.

Some bacteria are necessary for the survival of poultry and indeed all life. The good bacteria that lives in the gut of all mammals and birds help to break down food to energy, so as the food can be absorbed by the body.

These good bacteria need to be protected, and this is why it is never a good idea to dose your birds continuously with strong antibiotics which, by their very nature destroy all bacteria including the good ones.

The bad bacteria that cause illness, are the ones we need to target, and by denying them the necessary conditions for them to thrive, we inhibit their propagation and limit the damage they can do. For example, if Coryza thrives in wet conditions, dirty bedding, overcrowding and underfed birds, if we give the birds dry clean bedding, don’t overcrowd the flock, and feed properly, we may not completely eradicate Coryza in the flock but we will definitely see it a lot less.

It is imperative that whatever system you have in place, it needs to promote the good bacteria and discourage the bad.

THE INCLUSION OF MEDICATED FEEDS WITH ADDED ANTIBIOTIC OR COCCIDIOSTATS SUCH AS AMPROLIUM  ARE NOT THE ANSWER.

Amprolium is counterproductive as far as I am concerned, and I have observed its detrimental effect on birds. Birds raised on Amprolium  are weaker, tend to fall ill a lot more and a lot quicker than their counterparts, and if they really fall ill with something serious, good luck finding an antibiotic that will work.

Amprolium destroys all vitamins all minerals in the body, weakens the birds, and destroys their immune system at the same time. It will ensure that if a serious illness occurs, the birds will have strong resistance to ANY medication. Quite apart from this, AMPROLIUM will kill ducklings outright.

Far better to have good biosecurity in place, vaccinate wisely, and keep the birds in clean healthy condition so as to avoid serious infections.

Try to keep the conditions in your runs and pens aerobic, that is with plenty of oxygen and fresh air. Anaerobic conditions, that is conditions with no oxygen, wet, full of faeces lead to many diseases, one of which is coccidiosis ( see coccidiosis article on this site).

VIRAL DISEASES

A virus is not the same as a bacterium.

You cannot treat a virus with antibiotics, you can only treat the symptoms as they appear and let the virus run its course. In poultry, it will depends largely on the immune system of the bird whether the bird survives or not. A flock with a good immune system will be able to fight against field challenges of the various viruses, and birds may succumb to some form of infection but will be able to survive and be stronger in the long run.

If you vaccinate against all the worst viruses, such as Newcastle, IB, IBD, Pox, the chances are you will not get any of the accompanying bacterial infections often seen in tandem with the virus.

In many cases viruses are misdiagnosed because a bacterial infection such as MG or Coryza may be masking the real culprit, such as Newcastle. The farmer will dose for the bacterial infection and be none the wiser, and the symptoms will abate, but there will be a relapse at some stage and by then it will be too late to use your antibiotics. By vaccinating you avoid the entire circus.

For example, if you vaccinate diligently against Newcastle Disease, (ND) and your neighbour has an outbreak, your birds may sniffle a bit or come down with mild symptoms but they will survive. They will also be stronger for having survived an outbreak.

Viral infections debilitate the birds, and other infections may then have a field day.

Be careful how you handle each flock, do not interfere too much with the natural immunity by over medicating or over vaccinating. (See article on vaccination versus non vaccination on this site).

In January 2016, because of drought conditions in south Africa, we saw a widespread infection of fowl pox, more so than other years. Pox is a virus transmitted by mosquitoes and spread from bird to bird as the sores on the face break, and when birds infect the drinkers and feeders with fowl pox infected mucus. The infection worsens when mosquitoes bite more infected birds and spread the virus to all uninfected birds. Added to this because the birds’ immune system is compromised by the pox, you are very likely to have an outbreak of secondary infections such as MG or Coryza. Adult birds may recover, youngsters will not. it is imperative you vaccinate your youngsters and avoid further infections. One immunisation covers the bird for life and it is a cheap vaccine to administer. See section on vaccination.

Poultry Production in Mississippi

Viral diseases

Avian Pox

Avian pox is a relatively slow-spreading viral disease in birds, characterized by wart-like nodules on the skin and diphtheritic necrotic membranes lining the mouth and upper respiratory system. It has been present in birds since the earliest history. Mortality is not usually significant unless the respiratory involvement is marked. The disease may occur in any age of bird, at any time.

Avian pox is caused by a virus of which there are at least three different strains or types; fowl pox virus, pigeon pox virus and canary pox virus. Although some workers include turkey pox virus as a distinct strain, many feel that is identical to fowl pox virus.

Each virus strain is infective for a number of species of birds. Natural occurring pox in chickens, turkeys and other domestic fowl is considered to be caused by fowl pox virus.

Fowl pox can be transmitted by direct or indirect contact. The virus is highly resistant in dried scabs and under certain conditions may survive for months on contaminated premises. The disease may be transmitted by a number of species of mosquitoes. Mosquitoes can harbor infective virus for a month or more after feeding on affected birds. After the infection is introduced, it spreads within the flock by mosquitoes as well as direct and indirect contact. Recovered birds do not remain carriers.

Since fowl pox usually spreads slowly, a flock may be affected for several months. The course of the disease in the individual bird takes three to five weeks. Affected young birds are retarded in growth. Laying birds experience a drop in egg production. Birds of all ages that have oral or respiratory system involvement have difficulty eating and breathing. The disease manifests itself in one or two ways, cutaneous pox (dry form) or diphtheritic pox (wet form).

This year we have seen a widespread infection of dry pox in South Africa.

Dry pox starts as small whitish foci that develop into wart-like nodules. The nodules eventually are sloughed and scab formation precedes final healing. Lesions are most commonly seen on the featherless parts of the body (comb, wattles, ear lobes, eyes, and sometimes the feet).

Wet pox is associated with the oral cavity and the upper respiratory tract, particularly the larynx and trachea. The lesions are diphtheritic in character and involve the mucous membranes to such a degree that when removed, an ulcerated or eroded area is left.

Fowl pox is readily diagnosed on the basis of flock history and presence of typical lesions. In some cases, laboratory diagnosis by tissue or transmission studies is necessary.

There is no treatment for fowl pox. Disease control is accomplished best by preventative vaccination since ordinary management and sanitation practices will not prevent it. Several kinds of vaccines are available and are effective if used properly.

fowlpox                               pox

 

AVIAN LEUKOSIS

The diseases that make up the avian leukosis group are transmissible virus diseases of birds. They are usually mis diagnosed, but present with various forms of tumours, internal and external. The disease are devastating and affect mostly adult laying birds.

In this grouping you can include: Lymphoid Leukosis, LL.

This is one of the leukoses most prevalent in poultry concerns. It affects adult chickens, turkeys and pheasants. The lymphoid tumour is most common, although there may sometimes be bone malformation, (osteopetrosis) .

LL is caused by a group of RNA viruses. Simplified, the agent causing the infection is transmitted via faeces and in the eggs. It can also be transmitted via blood sucking parasites, and if there are infected birds in the flock, via injectable vaccinations. Most infections occur in the early weeks of life. Affected birds may die with no symptoms at all, and it is only on post mortem examination that the tumours are discovered on liver and spleen.

Basically what the poultryman must look for are the following signs:

  1. Emaciation in young birds. Pale colour in comb and skin. Small and non thriving chicks.
  2. Lack of appetite, progressive emaciation and diarrhea which may be constant and pale in colour.
  3. In older birds which may have survived, there may be tumours visible under wings and on the body.
  4. There may be lameness, and weak legs if the variety of the disease is the bone (osteopetrosis) type. The leg bones will thicken and be deformed.

The clinical diagnosis of LL is difficult, and can be confused with Mareks Disease.

YOU CANNOT TREAT FOR LL OR MAREKS OR ANY OF THE LEUKOSES.

You can however:

  1. Buy resistant strains from reputable people who vaccinate their birds against Mareks and have worked to make their flock resistant to LL.
  2. Brood in isolation. Most LL is acquired early, before 6 weeks. If you keep the young flock away from the older birds you are less likely to encounter LL or its family of horrors.
  3. Keep incubator very clean, disinfect with reputable disinfectants between batches.
  4. Control blood sucking parasites.
  5. Have a solid vaccination programme in place, and do not fall for “gimmicks” or old wives tales that try to lead you astray.

MAREKS DISEASE.

This is another of the leukoses.

Mareks infects young chicks but has been known to allow the birds to survive until 6 months. Unlike LL the tumours can be visible externally, although sometimes you see nothing at all until the bird dies. The birds die in the hurdle position, one leg before one leg behind.

Mareks is caused by a type of HERPES virus. The virus is concentrated in the feather follicles and is shed in the dander. The survival time is long sometimes up to 3 years in the dander.

Tumours may be ocular (eyes), or lymphoid in nature,neural or skin. Lesions may be visible on the gonads, ovaries, liver or spleen or kidneys. Massive internal tumours are typical. Tumours may be seen at the base of feather follicles.

You will always know when you have Mareks in your flock, or LL or any other type of leucosis. The birds are usually very thin, not thriving and pale. They will not be eating well and the keel will be very pronounced. Most farmers will actually slaughter these birds as being sub standard without going to the trouble of a diagnosis.

It has been proven that birds with acute coccidiosis are more prone to getting Mareks as well.

(courtesy of MSU Mississippi university extension offices)

PROTOZOAN DISEASES

These are the easiest to control, since you are dealing with organisms and not bacteria. You need to make sure your flocks are dewormed regularly, that you have a clean and healthy environment where protozoa do not thrive, and control rats, flies, mosquitoes and beetles in your runs.

Do not overcrowd your birds, as this leads to many problems (see article on overcrowding on this site)

It is wise never to breed your turkeys and chickens or ducks in the same pens and in the same areas. There is a common protozoan disease known as blackhead that affects mainly turkeys but can affect chickens as well. Turkeys raised on soil previously used to raise chickens are seriously at risk of contracting blackhead. Chickens are rarely affected but ducklings may be seriously at risk if raised in an area infested with blackhead, which remains active for months.

The clinical name is Histomoniasis, caused by a protozoan parasite called Histomonas meleagridis.

The blackhead organism is passed in the fecal material of infected birds.Usually the organism hides within other parasitic infestations such as the eggs of Heterakis Gallinae, the cecal worm most common in chickens. In this case the free form organism may not last in the open by itself, but those contained within worm eggs can survive for YEARS. Turkeys are susceptible to this as they eat the worm eggs. Chickens seem to be immune up to a point. Chickens may even be infected without showing any signs of being infected. These birds however shed enormous amounts of blackhead organisms, many protected by cecal worm eggs.

Symptoms are loss of appetite, mainly in six to sixteen week old turkey poults. Increased thirst is also a symptom as is droopiness, drowsiness, a darkening of the head and facial regions,and sulphur coloured droppings which will be watery.

 

lifecycle

 

 

 

 

 

 

 

 

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