Alok Kumar Singh1#, Amit Singh2, Deepali Tiwari3, Snigdha Shrivastava4and Pallabi Pathak5
Poultry is commonly affected by external parasite, causing economic loss in poultry industry globally. Ectoparasite is usually blood feeder in nature and causes clinical signs depending upon the level of infestation and may lead to heavy mortality in flock. Ectoparasite or external parasites are group of arthropods which usually live outside the host body. Depending upon duration of time spend on host body it can be classified as; continuous parasite which live in host for its lifetime while,temporary only feed on host for its requirement. External parasites also transmit several pathogens such as; bacteria, virus, and fungal diseases to other birds hence proper external examination should be done before introduction to new flock to reduce the economic losses. The external parasites are categorizedinto two groups.
1). Continuous parasite
Northern fowl mite(Ornithonyssussylviarum):
- Ornithonyssussylviarum commonly known as northern fowl mite is the most common external parasite in poultry (i.e. chickens, game birds, pigeons,turkeys, etc.), especially in winter season.
- It transmits directly through bird to bird contact.
- It is blood feeder depending upon severity of infestation and it causes various clinical signs such as anaemia due to blood loss, reduction in egg production,carcass weight, feed intake further it increases flock susceptibility for various diseases.
- It usually seen around the vent area and presence may be indicated by mite eggs and faecal material.
- Mites are often seen as tiny white or dark specks move quickly on the surface of skin.
- The mites are also seen in many species of wild bird mainly English sparrow and usually prevalent in poultry flocks during the winter and cooler months of fall and spring season.
- The synthetic pyrethroids i.e. cypermethin, deltamethin etc. used to control mites. Dust of insecticides is effective treatment as the bird touches the strip the insecticide transfers directly from the surface of the strip to the birds. It provideslonger time of protection against northern fowl mites.
- Some other powdered insecticides used are cypermethrin 10%,malathion 50% and carbaryl dust 0.5% gives good protection.
- A natural insect control powder such as diatomaceous earth,obtained from deposits of diatomite, which are the fossilized sedimentary layers of tiny phytoplankton called diatoms. Amorphous silica in the form of diatomaceous earth absorbs oily or waxy cuticles, producing desiccations when the thin waterproof layer is removed and the rupture of an insect’s cuticle resulting in the death of parasite.
- Some other such as Pyrethrum is a botanical insecticide derived from chrysanthemums and appliesa weekand treatment is required if infection persist.
Stick tight flea (Echidnophagagallinacea):
- Echidnophagagallinacea commonly called as stick tight flea, another common external parasite of poultry. It is a burrowing type flea, female attached and lays eggs around face and wattles usually stick tight fleas are stationary in nature as compared to others.
- It causes aggravation and ulceration near affected area when, area around eye affected it may cause blindness and also may lead to heavy mortality in young ones.
- It isalso transmitted to other i.e. dogs, cats, horses and human beings.
- Its larvae develop in the soil generally near chicken cages and pupate in about two weeks and later, adult fleas emerge from the pupae and are free-living until breeding time.
- The skin around the face and wattles of birdsis the most prevalent attachment site where female it lays their eggs to continue the life cycle.
- The birds are raised in wire cages three or more feet above from the ground are less susceptible with particular flea infestation.
- The sevin dust is a common treatment and applied to the fleas as well as litter.
- Also adult birds may be coated with petroleum jelly which kills flea in short time and removal ofdead flea from the body.
Scaly leg mite(Cnemidokoptesmutans):
- Cnemidokoptesmutanscommonly called as scaly leg mites are generally found in the skin under the scales of the feet of birds, may leads to lifting of the scales and deformity of the feet.
- Birds raised in wire cages three feet or more above the ground do not usually become infested with this mite.
- Prevention is easier and economical than treatment hence proper inspection should be done of birds before adding into flock. Transmission is direct from bird to bird.
- Treatment includes dipping the legs in linseed oil or petroleum jelly (Vaseline) at weekly interval for three weeks.
- Avoid the use of fuel oil, kerosene, motor oil or other liquid petroleum products to the affected birds.
- Poor management is an indicator forinfestation of mites. The swollen and deformed leg remain even after dead of mites hence prevention is more important than the treatment.
- Menacanthusstramineus is populary known as body louse while,Menopongallinaeis the shaft louseof poultry and these two species are most commonly found on poultry.
- It sucks the blood and other fluids of the host, causing birds to become restless and irritated and due to this this adversely affects cause reduction in feed intake, digestion, growth and egg production.
- Young ones are more seriously affected.
- The population, tend to be more abundant in dirty/unclean,overcrowded conditions.
- The control measure of lice is typically done by the use of some insecticide such as, malathion and sevin dusts applied to the host.
2). Temporary Parasites:
These are the blood sucking external parasites which feeds on bird but do not actually live on them for its lifetime. They leave host after feeding and remain around host premises like cracks, floor and walls. The most common parasites are; fowl ticks, poultry mites and bed bugs.These are nocturnal feeder i.e. active during night, slow moving, and hence may be easily observed on bird’s body so usually examination should be done in night time for detection.
- Argaspersicusis also known as fowl ticksor blue bugs.
- It is light reddish brown to dark brown in colour, with wrinkledskin. The adults are usually 6 to 9 mm in length, classified under soft tick anddifferent from hard tick which is usually found in dogs and cats.
- Female ticks lay eggs in batches generally 30 to 100 eggs per batch, though some batches may contain more than 100 eggs and a female lays an average of 700 to 800 eggs during her lifetime.
- A blood meal is essential to produce each batch of eggs and ticks may completely remain engorge in host body for 30-45 minutes.
- Under favourable conditions, approximately 30 days are required for development of adult from egg. Adults are extremely resistant to starvation and may live more than a year without a blood meal.
Poultry mites (Dermanyssusgallinae):
- Dermanyssusgallinaecommonly known as red mites or roost mites of poultry. It resembles with the northern fowl mite (Ornithonyssussylviarum). So that differential diagnosis is required to avoid confusion. The main difference between these two mites is duration spent on host body. The northern fowl mite spends its entire life on the host while the poultry mites are temporary in nature.
- Poultry mitesmay be seen with the naked eye and usually found in large numbers. Its life cycle is discontinuous between feeding and non-feeding immature stages.
- Hatching of eggs take place in an around three days, and in favourable conditions the life cycle is completed in seven to ten days. Adults are very resistant to starvation and may survive without host for more than a month.
Bed bugs (Cimexlectularius):
- Cimexlectulariuscommonly called bed bugs and adults are reddish brown in colour, while the immature are off-white in colour. They are found large in number and females lay eggs in cracks and crevices in batches of 15 to 60. Generally total 150 to 600 eggs are laid during its lifetime. One to four month is required to the development of an adult from eggs.Nymphal stages may withstand longer periods of starvation i.e. 1 to 5 months and still survive. Although, adults gets completely engorge on hosts in 5 to 10 minutes.
Prevention and control:
- These temporary external parasites causes’ bloody lesions of various sizes depending upon the type of parasite harbor by host and it decides its impact on host. The bird mite also affects wild birds, rodents and other animals, but transmission of ticks and bed bugs between flocks is still unknown.
- Prevention includes;changes in poultry housing system which is very effective in elimination of these parasites from commercial flocks. However, these may be present in small flocks of poultry or otherbirds hence proper external examination for this parasite should be done before introducing to new birds in farm.
- No specific pesticides are available for its control however,parathroidsmay be used to treat the poultry house, cracks and crevices, which arethe common place of hiding of this parasite, should be eliminated, minimized, or sealed.
- Entry of wild birds and rodents should be prohibited and should be prevented with screens and other barriers.
- Regular cleaning and sanitization of poultry house can effectively reduce the prevalence of this parasitic infestation and reduces economic losses.