Fowl Pox in Broiler And Layer

Fowl Pox

It is common to see fowl Pox in broilers and layers. it is a viral disease in poultry. Fowl pox is also found worldwide and well-known among all poultry producers. It is also known as Avian Pox. In 1998 outbreak of severe fowl pox occurred in Australia.

Etiology

Fowl Pox caused by virus belongs to avipoxvirus genus out of eight genera of subfamily chordopoxvirinae. It is mainly caused by the fowlpox virus (FWPV) in broiler and layers. Avipox viruses are placed under three groups-

FWPV- like viruses- chicken, turkeys, pigeons, dove, and falcon.

CNPV- like viruses- Canaries, pigeons, starlings, and sparrows.

Psittacine pox viruses- only Psittacine birds

Fowlpox virus is a DNA virus of 250 nm diameter. the virus is easily killed by common disinfectants but the scab may protect it from contact with the disinfectant.

Common reasons

  • Standing water for production of mosquitoes
  • Wrong route or long duration of vaccines
  • Reo virus variant in nature combines with fowl pox
  • Multiage groups Broilers having recycled litter
  • Pecking in layers
  • Poor beak trimming
  • Abrasions caused in growers due to flightiness
  • Presence of vegetation around farm
  • 30 PC genetic in nature
  • the disease is known to spread by mosquitoes bite and becomes endemic in some farms where greenery is there like crops cultivation or vegetable cultivation.

Is Male Bird Responsible for Fowl Pox?

majority of farmers retain some .25 to .5 pc males which come from a hatchery as sexing error needs to be destroyed after they show combs at 5 weeks. but labor wishes to retain it for self-consumption.

some times owner has a myth that in presence of males, female birds would lay more it is wrong. in fact keeping males along with females may invite fowl pox . as pox warts are visible on comb, shank, and any soft tissue by the bite of mosquitoes.

so few male birds always pose risk for the entire flock at the early age of 80 t 90 days before birds are given the vaccine for fowl pox. this could be the reason that local birds or desi birds get more fowl pox as they roam in the company of males

Facts About Fowl Pox In Broiler

while talking about fowl pox we never talk about broilers. to the best of my knowledge her broilers have recessive genes against fowl pox and are seen in isolated cases in breeders . have we ever seen thick footpads in layers it is again genetically modified in broilers to sustain higher body weight.

Gene for a better comb in broiler is not very active as it denotes gonadal activity or sex in broiler males it is prominent after 6 months while same is prominent in 5 months in layers .so many genes of layers are made recessive in broilers.

Epidemiology

The disease is more common in summer or spring in broiler and layer. during the viraemic phase, the disease is easily transmitted by blood-sucking insects, particularly mosquitoes.

the poxvirus survives for a very long time of months or years in broiler and layer farms.

Responsibilty of Mosquitoes in Fowl Pox

Mosquitoes transmit viruses from viremic birds to layer and broiler birds. broiler and layer birds with larger coms and males will probably be affected more severely because they provide a good surface for mosquitoes bites. In mosquitoes, the virus persists for days or weeks.

Clinical Symptoms

  • Pink focal lesions occur on the comb and wattles and non-feathered portions of the body.

Nodular lesion at comb

Face area covered by pox

pox lesion in shank

  • These foci enlarge to become 0.5 to 1.0 mm diameter, black scab-like lesions, which persist for up to two weeks followed by desquamation and healing.

diphtheric type pf fowl pox

  • Broilers may show confluent and extensive lesions of the back especially in the slow-feathering males of the autosexing strains.

oral orifice blocked by pox lesion

  • Mild respiratory rales (sounds) may occur in broiler flocks especially with suboptimal ventilation due to tracheitis.

See Also- Fowl Pox Symptoms And Treatment

Pathology

  • Histological examination shows characteristic intracytoplasmic inclusion bodies in infected skin and tracheal mucosa.
  • The diphtheritic form is recognized by the presence of nodular hyperplasia of the mucosa of the pharynx and trachea.
  • Chickens that die of diphtheritic pox may show a plug of desquamated epithelium which lodge in the glottis resulting in asphyxiation.

Diagnosis

Cutaneous lesions are characteristic. Histological examination of affected tissue will confirm the presence of intracytoplasmic inclusions (Bollinger bodies) in the respiratory mucosa and skin.

Prevention

  • Immunization is recommended in endemic areas using a mild-attenuated avipox, chicken-strain virus vaccine administered at approximately 8 weeks of age. In areas where early exposure occurs, the age of vaccination can be advanced.
  • In some areas, broilers are routinely vaccinated against avian pox by subcutaneous injection at day-old. The efficacy of this procedure is questionable based on demonstrated maternal antibody interference.
  • In areas where flocks are affected with vertically transmitted mycoplasmosis, adverse vaccine reaction from avian pox vaccine can be prevented by administration of a pigeon-pox vaccine.

Treatment

There is no treatment for fowl pox. The best way to control the disease is through vaccination. Several pox vaccines are available for use in the backyard as well as commercial flocks.

Types of Fowl Pox Treatment

According to types of lesion of fowl pox, the treatment is divided into two forms-

1) Dry form fowl pox Treatment

This type of lesion is commonly seen on feather lesion areas such as mouth, comb, wattle, ear, shank, vent, eyelid area in chickens.

Treating dry-form lesions with Vetericyn, iodine, or another antiseptic to prevent infection and promote healing.

To provide broad-spectrum Antibiotics to check secondary bacterial infections. If you’re at high risk of complications

If you or your birds are at high risk of complications, your doctor may suggest an antiviral drug such as acyclovir (Zovirax, Sitavig). This medication might lessen the severity of chickenpox when given within 24 hours after the rash first appears.

2) wet form fowl pox Treatment

This type of Fowl Pox lesion commonly affected the internal organ of the chicken. It is started from the mouth to the Intestinal region. But, it is very rare in poultry.

Providing antibiotics in the drinking water to prevent secondary infection in sick birds, in particular in birds affected by the wet form of the disease.