A-Z of chicken diseases

[OrpingtonManiac]

16. Avian borreliosis (fowl spirochetosis)
This is an acute, fatal septicemic disease of birds caused by the helio spirochete bacterium. Fowl ticks, in the genus argus, are the primary vectors for this bacterium, though mites and mosquitoes can also spread it. The severity depends on the strain of bacteria.
The spleen, kidney, liver and heart can become swollen and pale.

Symptoms:
Fever, weight loss, watery green diarrhoea containing urates and bile in excess, anemia (pale combs and wattles, increased water consumption, paralysis, depression.

Prevention:
Reduce number of ticks on property

 

[OrpingtonManiac]

17. Avian cellulitis
Avian cellulitis is a bacterial infection of the subcutaneous tissues of the muscle and skin. The infection can occur anywhere there is an opening to the skin (when it occurs on the breast it is known as Breast Blister). The area will have fewer feathers, and will be reddened, puffy and warm to the touch. It is caused by Escherichia coli, but several other bacteria may be involved.
Recent trauma allows the bacteria to enter the subcutaneous tissue. As birds have thinner skin epidermis, they are at more of risk of cellulitis than animals.

Symptoms:
Swelling, warm to the touch, lameness

Prevention:
Don't overcrowd birds, keep environment clean, feed a balanced diet, give regular health checks, check (and treat) for ectoparasites: lice, mites etc.

 

[OrpingtonManiac]

18. Avian Chlamydiosis (AC)
AC is a zoonotic disease caused by the bacterium Chlamydia. Clinical signs are often non-specific, and infected birds may not show any signs. It is transmitted primarily by the inhalation of contaminated fecal or feather dust (infected birds shed chlamydia in the feaces). Chlamydia has an incubation period of 3 days to several weeks.

Symptoms:
Greenish diarrhoea, ruffled feathers, sneezing, conjunctivitis, depression, weight loss, loss of appetite, lethargy and nasal or ocular discharge.

Prevention:
Separate exotic birds from chickens, prevent exposure to wild birds, quarantine new birds, reduce stress.

 

[Squawkers]

18. Avian Chlamydiosis (AC)
AC is a zoonotic disease caused by the bacterium Chlamydia. Clinical signs are often non-specific, and infected birds may not show any signs. It is transmitted primarily by the inhalation of contaminated fecal or feather dust (infected birds shed chlamydia in the feaces). Chlamydia has an incubation period of 3 days to several weeks.
Are the symptoms similar in humans?
Symptoms:
Greenish diarrhoea, ruffled feathers, sneezing, conjunctivitis, depression, weight loss, loss of appetite, lethargy and nasal or ocular discharge.

Prevention:
Separate exotic birds from chickens, prevent exposure to wild birds, quarantine new birds, reduce stress.

Are the symptoms similar in humans?

 

[OrpingtonManiac]

Are the symptoms similar in humans?

Not really… Avian chlamydiosis is cause by chlamydia psittaci, whereas in humans its chlamydia trachomatis which is probably why the two are so dissimilar. They are also spread differently. Hope that helps!

 

[OrpingtonManiac]

19. Avian encephalomyelitis
This is an infectious neurological disease caused by a picornavirus. This occurs in poultry, mostly chicks between 1-3 weeks of age. It is usually transmitted from adult breeding hens. Their offspring transmit the virus through their faeces for up to 2 weeks. Chicks older than 6 weeks are usually immune, with exceptions to immunocompromised chickensChicks develop signs anywhere from 1 day to 3 weeks after hatching if it is transmitted vertically. When infected by direct contact, it takes up to 11 days for symptoms to develop.

Symptoms:
Seizure like activity, wry neck, spinning, ataxia (in coordination, stumbling), rapid trembling of head or neck, paralysis, sitting on hocks or shanks, prostration (lying down with legs stretched out on either side), dull expression in eyes, when disturbed may fall on their side.

Treatment:
Treatment is supportive. Affected chicks should be separated from others and should have easy access to food and water.
Should chicks recover, they may have ongoing coordination issues, and may develop cataracts at 18-20 weeks of age. This presents as bluish lens and impaired vision. If adults are affected, they will show little symptoms, apart from decreased egg production -by 5-10%- (with no change to eggshell quality) which may return to normal after 2 weeks and hatchability - by 5%, due to late embryonic death.

Prevention:
Vaccination

AE can survive in most environmental conditions for long times.

 

[OrpingtonManiac]

20. Avian goiter
This is an abnormal enlargment of the thyroid gland. This can be caused by:

Dietary Iodine deficiency:
The thyroid gland uses iodine to produce thyroid hormomes. When there is not enough iodine in the blood, the brain signals the thyroid to make follicular epithelial cells, causing an enlargement of the thyroid.

Exposure to toxins:
When a bird is exposed to high levels of organophosphates or chlorinated biphenyls, the hyperplasia or enlargement of the thyroid

Genetic defects

Trauma

Septicemic diseases:
These can cause hperplasia and enlargment.

It is most often caused by eating excessive goitrogenic agents such as:
Kale, broccoli, turnips, cabbage, flax rapeseed and soybeans.

Symptoms:
Enlarged masses along the neck, depression, lethargy, easy to develop infections, skin and feather abnormalities, decreased hatchability, increased embryo death, convulsions, vomiting, crop blockage, difficulty swallowing, loss of voice, sudden death, respiratory abnormalities.

Prevention:
Supplemental iodine, limiting goitrogenic agents

Additional info:
Goitrogenic agent interfere with the normal production of thyroxine.

• Convulsions, difficulty swallowing, vomiting, respiratory abnormalities, loss of voice and crop blockages are caused by the thyroid pressing on other organs

 

[OrpingtonManiac]

21. Avian Influenza
This is a highly contagious infection of both wild and domestic birds worldwide. It is classified as two types:

• Low Pathogenic Avian Influenza (LPAI). This causes a milder version of the disease

• Highly Pathogenic Avian Influenza (HPAI) results in severe, multi-systematic infection

AIV is excreted from the nasal and respiratory secretions (nares, mouth, conjunctiva), cloaca and faeces of the bird into the surrounding enviroment. The virus is transmitted directly or indirectly from infected birds.
Wild waterfowl are the primary hosts of Influenza A viruses (IAV). They act as asymptomatic carriers of LPAI and shed high amounts of the virus in their faeces.
The incubation period is between 3-5 days and is dependent on the dose of virus, transmission route and the species exposed.

Symptoms:
Ruffled feather, swollen face, sneezing, red or watery eyes, head or neck tremors, coughing, wry neck, cyanosis, sudden death, depression, decreased egg production, diarrhoea, pale comb and wattles, paresis (muscle weakness), focal ecchymosis.

Prevention:
Biosecurity, regularly test for AIV, keep wild birds away from flock, limit stress.

 

[OrpingtonManiac]

22. Avian intestinal spirochetosis
AIS is caused by contamination of the caeca and colon of anaerobic spirochaete brachyspira.
It is introduced by pigs, wild birds, rodents, insects, dogs, cats, other poultry species, other livestock and humans. Pigs are the main hosts, although ducks cam also be subclinical carriers. It is spread by contaminated soil, water and/or food contaminated with faeces. When chickens are in the same environment with infected hosts, they are at risk of becoming infected. Older chickens are more likely to be infected, and free-range chickens are also more susceptible.

Symptoms:
Delayed onset of laying, reduced egg production, smaller, lighter or poor shell quality eggs, caramel coloured frothy feaces, fecal staining of eggshells, lethargy, depression, chronic diarrhoea in adults

Prevention:
Do not house with pigs, or allow chickens on land where pigs were previously kept. Clean and disinfect waterers and feeders regularly, practise good sanitation and minimise attraction of rodents.

 

[Squawkers]

What exactly is anaerobic spirochaete brachyspira? Is it a type of bacteria?