Adenovirus in poultry

Fowl Adenovirus (FAdV) is a group of viruses that mainly affect broiler, breeding and turkey poultry. The virus is present almost worldwide, and in recent years has caused significant outbreaks even in modern poultry houses due to high density, stress and weakened immune systems.

What diseases does it cause?

The virus can cause several main syndromes:

1. Inclusion Body Hepatitis (IBH)

The most common disease in young broiler poultry.

Signs:

* Sudden death

* Apathetic birds

* Decreased eating

* Enlarged and pale liver

* Sometimes jaundice and bleeding

Common age:

3–7 weeks.

2. Hydropericardium Syndrome (HHS)

Also called “Angra disease”.

Signs:

* Fluid accumulation around the heart

* Very high mortality

* Edema and respiratory failure

* Blue/weak birds

Especially common in certain strains of adenovirus.

3. Chronic immunodeficiency

Even if there is no abnormal mortality, adenovirus can:

* weaken the immune system

* make vaccines work less well

* increase sensitivity to coli, clostridia and coccidia

* impair FCR and growth rate

How is the virus transmitted?

Vertical transmission

From mother to chick via the egg — the most problematic route.

Horizontal transmission

Through:

* feces

* water

* equipment

* workers

* dust

* poultry house beetles

The virus is very resistant to the environment and can remain active for a long time.

Key risk factors

* Heat stress

* High density

* Poor ventilation

* Mycotoxins in feed

* Coccidiosis

* Gumboro / IBD

* Insufficient disinfection between cycles

Diagnosis

Diagnosis is made by:

* PCR

* Liver pathology

* Histology

* Virus isolation

At autopsy, the following are usually seen:

* A pale, fragile liver

* Bleeding

* Sometimes fluid around the heart

Treatment

There is no direct antiviral treatment for adenovirus.

What is actually done:

* Stress reduction

* Improved ventilation

* Vitamin support

* Secondary treatment against bacteria

* Reducing environmental load

Prevention — The Most Important Part

Parental Vaccination

This is the most important tool today.

When the parent flock is vaccinated — the chicks receive maternal antibodies.

Biosecurity

* Thorough disinfection

* Pressure washing

* Removal of organic matter

* Complete drying between cycles

House management

* Air quality

* Stable temperature

* Clean water

* Stress reduction

Economic damage

Adeno can cause:

* 5%–30% mortality

* Final weight loss

* Increased feed intake

* Slaughterhouse rejections

* Decreased profitability of the house

Signs that turn on a “red light” in a coop

If you see:

* Sudden jump in mortality at 20–35 days of age

* Pale liver at necropsy

* Sharp decrease in water/feed consumption

* Weak birds with no clear signs of breathing

You should also suspect adenovirus, not just coli or gumboro.

*It is always advisable to consult a qualified veterinarian.