By Dr. L. Dwight Schwartz, DVM
Avicon, Inc.

 

There is an aura of mystique about diseases and illnesses that are common to ornamental birds, hobby birds, zoo and exotic birds.  The peafowl would certainly be included in this group of birds.

The peafowl, Pavo cristatus, is a bird the size of a turkey, Meleagridis gallopavo.  The peafowl is an Old World Bird originating in India and Sri-Lanka while the turkey is a New World bird being a native of North America.  Other than being continents apart, the two species are quite similar and actually somewhat related.  However the diet of the peafowl in the wild (Asia) is snails, frogs, insects, grains, juicy grasses, and bulbs which is somewhat different from the birds in this country (US).

The peafowl is the showiest of all birds because of its size and the beauty of its train.  The male bird, peacock, is the showy bird of the species while the peahen is smaller with less varied colors and lacks the long train.  The peafowl has been treasured for its great beauty since Biblical times (I Kings 10:22).  About 400 B.C., royalty in Rome considered peafowl a great delicacy as a roast and served in its own feathers.  The best known of this bird family is the Indian peafowl, India’s national bird, and is also the primary peafowl in America.

The diseases of peafowl are almost identical to those of its New World counterpart, the turkey.  Likewise, peafowl will respond to medications that are known to be effective for the turkey.  This is to say that anyone experiencing illness in peafowl can consider it a turkey in seeking diagnosis and establishing a treatment.

Infectious diseases of peafowl cross the whole spectrum of etiological or causative agents including virus, virus-like bacteria, fungi, protozoan, worms, and external parasites.  Similarly, all systems of the bird are affected by these infections.  The approaches to study diseases are to consider specific infections, regardless of causative agent by systems such as the respiratory, digestive, immune, reproductive, circulatory, renal, and nervous systems.  The more common approach is to study the disease agent by its manifestations, clinical signs, systems affected and control.  One soon learns by disease name what system(s) will be affected.

The Poultry Health Handbook uses both of these approaches.  Section II covers the respiratory diseases while subsequent sections cover diseases by category of causative agent such as virus, bacteria, protozoa, internal and external parasites.  The experienced peafowl and poultry breeder become familiar with diseases endemic on their farm, locality or state.  All bird fanciers are encouraged to familiarize themselves with necropsy (post-mortem) procedures and should routinely necropsy freshly dead or sick birds at the onset of a disease outbreak.  Even if you contact your veterinarian or birds are submitted to a diagnostic laboratory, you need to be in position to describe the lesions you found in the birds.  Important points to observe are the attitude of the bird, feathering, fleshing, color of flesh, scaly legs, crusts on beak or eyelids, internal lesions by organ, i.e. heart liver, lungs, spleen, intestine, gonads, and kidney.

There are approximately 80 infectious diseases that are somewhat regularly diagnosed in peafowl.  Luckily only a few of these are found in any given flock; therefore the producers should be familiar with the diseases in his or her own flock.  This further emphasizes the importance of early recognition of the common problems in your flock.  Every acute disease episode should be confirmed with a laboratory diagnosis.

A common question that I am often asked is, “What tests should I do on my birds?”  A relevant answer is the tests that are  outlines in the National Poultry Improvement Program (NPIP).  The program focuses on diseases that should be eradicated:  Salmonella Pullorum (Pullorum) and S. gallinarum (Fowl Typhoid).  Since there is no cure for these diseases, the program requires an annual blood test.  The producer can be trained to conduct this simple test on the farm.  I recommend that each fall as you select breeding stock for the coming year that you pullorum test the birds.  Keep the tested birds separate from the birds that you do not plan to keep.  The annual test of flocks participating in the NPIP program qualifies the birds for exhibition and interstate travel without further tests at the time of show or export.  Keep the forms that show the birds are negative as proof of the tests as well as the bird being negative for pullorum and fowl typhoid.  The one test, Whole Blood Plate Agglutination, detects both diseases.  Every peafowl breeder should be a participant in the NPIP Program.

Now a brief dissertation on the most common diseases in the peafowl divided into categories.

VIRUS AND VIRUS-LIKE DISEASES

Newcastle Disease (ND) is an acute rapid-spreading respiratory disease that is caused by a virus.  ND can cause high mortality depending on the virulence or pathogenicity of the virus.  The duration of ND is about 14 days.  Since there is no effective medication against ND, it must be prevented or controlled by vaccination accompanied by excellent husbandry at all times.

Fowl Pox (FP) is a relatively slow spreading disease caused by a virus that is transmitted primarily via the bite of infected mosquitoes.  The pox virus replicates or reproduces in the epithelial tissue; hence lesions are confined to unfeathered areas of the skin, conjunctiva of the eye and throat area.  FP is a true pox in that the lesions are raised, scabby and crater-like with the scab firmly attached until the lesion is healed.  Treatment would include vaccination of flock before or during an outbreak, mosquito control, and topical treatment of pox lesions with a skin antiseptic.

Hemorrhagic Enteritis (HE) is an acute and often fatal disorder caused by an adenovirus.  The disease is characterized by extensive inflammation and hemorrhage of the intestines.  The birds are most susceptible between 4 and 13 weeks of age.  The disease is not spread bird to bird but from the ingestion of infected material such as fecal droppings in the feed, water, or litter.  Prevention by sound management and vaccination is the best policy since there is no specific treatment. However; antibiotics in the feed or water are a good therapy to prevent a secondary infection which would shorten the recovery period.

M. gallisepticum (MG), M. synoviae (MS), and M. meleagridis (MM) are micoplasma diseases with MG and MM being the most serious and prevalent.  Both MG and MM produce respiratory illness often diagnosed or reported as “Sinusitis”, swelling of the eye sinuses, and “Air Sacculitis”, air sacs or air reservoirs of the respiratory system are enflamed and contain exudates or pus.  MS infections are seen as arthritic and joint infections.  There are no absolute cures for micoplasma infections but several antibiotics are effective as treatment and control of the infections.  Recovered peafowl remain carriers and the disease is transmitted from the hen to the chick in the egg.  Therefore; it is best not to save any micoplasma postive birds for breeding purpose since this would be perpetuating the disease year after year.

BACTERIAL DISEASES

Pullorum and Fowl typhoid are acute diseases caused by bacteria of the genus Salmonella — S. pullorum and S. gallinarum, respectively.  These two bacteria are antigenically related.  Both are spread from infected breeder birds to the progeny in the egg.  To control these diseases, blood test the parent birds before the breeding season and eliminate the Pullorum-positive birds.  If all Pullorum-positive birds are destroyed, all progeny would be pullorum and typhoid free.

Paratyphoid is an acute septicemic and intestinal disease caused by a bacterium of the genus Salmonella.  There are at least 2000 serotypes in this bacterial group which makes control by testing of the parent bird unfeasible.  Paratyphoid causes high mortality in young birds from 8 to 28 days.  After that, infected birds are chronically ill with many becoming stunned and unthrifty.  Like pullorum and fowl typhoid, paratyphoid is spread from the infected hen to the chick.  Chicks become infected at hatching as they come in contact with bacterial on contaminated egg shells.  Losses from paratyphoid can be reduced by medication, neomycin or nitrofuran, in the chick starter feed.

Arizona (paracolon) infection is an acute septicemic and intestinal infections in young birds.  Arizona infections parallels paratyphoid in seriousness, losses and disease symptoms.  The Arizona bacterium is closely related to Salmonella;  therefore, isolation and identification procedures are identical.  Differentiation between Arizona and paratyphoid should be made in any outbreak because of the close relationship between the two pathogens.  Arizona is sensitive to drugs used for paratyphoid.  Neomycin and/or nitrofuran drugs are recommended for treatment and control.

Staphylococcus is an infectious non-contagious disease caused by a bacterium Staphylococcus aureus.  The disease is characterized by septicemia, bumble foot and/or arthritis.  Staphylococci are ubiquitous with most infections contracted by birds individually from the environment.  Outbreaks do respond to antibiotic therapy that can be administered to birds individually or to the flock in the feed or water.  Improved sanitation of the housing environment and better flock management will help control staphylococcosis.

Fowl Cholera (FC) is an acute septicemic infection caused by the bacterium Pasteurella multocida.  The disease is characterized by a rather sudden onset, high mortality with extensive hemorrhages in affected birds.  The best control is prevention of the introduction of Pasteurella into the flock from new birds, sick birds, or contaminated materials and equipment.  Vaccines are commercially available but are only marginally successful.  Outbreaks can be brought under control by flock medication with sulfa drugs and antibiotics.  Premises will remain infected following a FC outbreak unless a thorough decontamination program is conducted.

Avian tuberculosis (TB) is a slow spreading disease of adult birds, probably 3 to 4 years of age in peafowl.  The disease is caused by the bacterium Mycobacterium avian, an acid-fast organism.  TB is characterized by gradual emaciation with the development of Tubercles (granulomas) in the viscera and is contracted by the bird from the infected environment.  Infected premises remain infected for long periods unless there is a deliberate decontamination program developed.  To confirm a diagnosis, the acid-fast staining technique is used.  There is no treatment against TB.  Improved management, better sanitation of the environment will help to prevent the introduction of the disease.

PROTOZIAN DISEASES

Coccidiosis is an infection caused by one or more species of coccidia.  Avian coccidia protozoan organism belongs to the genus Elmeria.  Coccidia is a disease primarily of young birds 3 to 12 weeks of age.  Coccidia is host specific; that is, coccidia does not cross infect from one bird species to another.  Most bird species are subject to coccidial infection by 2 or more species.  Coccidiosis is best controlled by
reventative medication in the feed during the susceptible age of the birds.  Coccidiostats (preventive drugs) are available commercially with Amprolium and Rofenaid being the most prominent two.  If a coccidiostat cannot be obtained, any good sulfa drug can be substituted in the feed.  When outbreaks occur, birds can be treated with sulfa drug in the drinking water.  All drugs should be used in accordance with the label instructions.

Histomoniasis, commonly called “Blackhead” is an infectious intestinal disease caused by the protozoa Histomonas meleagridis.  Birds are most susceptible between 6 and 14 weeks of age.  Symptoms are watery, sulfur-colored droppings, drowsiness, and weakness.  The causative agent is shed in the feces of the infected birds and then contracted by susceptible birds as they feed from the floor and litter.  Histomoniasis can be controlled by specific medication of a bird or flock at the onset of an outbreak or prevented with the use of a histomonastat, drug specific from Histomoniasis, in the feed.  Presently there are no FDA approved Histomonastats.  Currently, Metronidazole (Flagyl), copper sulfate, and Histostat are the medications used for the treatment of Blackhead.

Trichomoniasis is a disease found especially in young birds.  There are two forms of this disease: (1) Mouth, crop-esophagus infection or upper form caused by Trichomonas gallinae and (2)  intestinal or lower form caused by Trichomonas gallinarum.  Birds with the upper form will be depressed, drool, have a sunken empty crop, swallow frequently and have a fetid odor.  Many affected birds will maintain an upright penguin-like body posture.  Signs of the lower form are depression, unthriftiness, loss of weight, and yellow-watery diarrhea.  The symptoms are similar to Histomoniasis with treatment and control the same as for Histomoniasis.

Leucocytozoonosis is a malaria-like disease caused by a protozoan organism that parasitizes the white blood cells of the bird host.  This disease is world-wide in distribution and occurs regionally in a nation or country where situations are conducive for the vectors to breed.  Birds of any age are susceptible but is the most devastating in the young birds.  The disease is most prevalent in birds on range.  Onset is sudden with severe anemia, fever, weakness, loss of appetite, and lameness.  In the terminal stages of the disease, birds will vomit, excrete green feces, and die.  Leucocytozoonosis is transmitted by infected vectors, blackflies (Simuliuim sp.) and biting midges (Culicoidos sp.).  Both vectors breed in fast flowing streams.  Prevention is by keeping susceptible birds confined to buildings during the vector season.  Neither of these insect vectors will feed inside buildings; hence, confinement prevents exposure.  Treatment of birds during outbreaks will a sulfa drug or clopidol (Coyden) will bring the disease under control.

Haemoproteus infection or pigeon malaria is caused by a protozoan blood parasite of the genus Haemonproteus that invades and destroys the red blood cells.  This results in severe anemia and death of the bird.  Haemoproteus is transmitted by blood sucking insects including the biting midge (Culicoides) as described with Leucocytozoonosis.  The disease onset is sudden with general weakness, lethargy, poor appetite, and death.  Antimalaria drugs are effective against Haemoproteus for treatment of outbreaks.  Prevention can be by a combination of insect control and a low-level continuous medication with an antimalarial drug or Clopidol,

INTERNAL PARASITES

Ascaridia, common round worms, are prevalent in many species of fowl.  Ascarid species are essentially host specific in that each has its preferred bird species.  The ascarid life cycle is egg-larva-adult.  The worm egg is passed in the feces, germinates on the environment, and is then eaten by a susceptible host which provides opportunity to complete the life cycle.  The larva migrates extensively in the intestinal lining causing much tissue damage, blood loss, intestinal lesions with complications.  Adult worms are susceptible to piperazine worm medicine that can be administered in the water or moist feed for a one-day treatment.  Medication can be periodically repeated as needed.

Cecal Worms, Heterakis gallinea, are tiny worms that live in the ceca (blind pouches) of the birds.  These worms cause little damage or discomfort to the bird but are important because they serve in the perpetuation of histomoniasis.  The dormant histomonad has been shown to exist from one season to the next in the egg of the cecal worm.  The flock can be dewormed effectively with one of several commercially available wormers.

Gapeworms, Syngamus trachea, are worms that localize in the trachea (windpipe) of birds.  Heavy infections cause respiratory distress in young birds with their small trachea being mechanically blocked which plugs the passage of air.  Infective Syngamus eggs apparently winter over in worm-contaminated pens.  It is also thought that earthworms are an intermediate host of this parasite.  Control is treatment of infected birds with Thiabendazole or Tramisol.

Capillaria worms, capillaria sp. are parasites of the gastro-intestinal tract.  At least two capillaria species are known to infect the crop, esophagus, and mouth while other species (4 or 5) localize in the intestine and ceca.  Each species tend to have its preferred location in the digestive tract.  Capillaria cause a general unthriftiness, paleness and rough feather coat in the infected birds.  Capillaria are resistant to most poultry wormers; however, Thiabendazole, Tramisol, Fenbandazole, or Ivermactin would be recommended.

Tapeworms (numerous species) are known to parasitize fowl.  It is assumed that only those species common to the peafowl and/or turkeys would be involved.  Tapeworms have a two-stage lifecycle with the bird being the second stage or the primary host.  The first stage occurs in insects, arthropods, and crustaceans called secondary hosts.  Peafowl become infected from feeding on infected secondary host.  Symptoms usually depend on finding tapeworm segments in the bird feces.  Periodic treatment of the birds will free them of tapeworms but reinfection usually begins again as the peafowl returns to the source of the infected secondary host.

EXTERNAL PARASITES

Lice are common external parasites in outdoor birds and birds in the wild.  Lice are insects that spend their entire life cycle on the host.  Lice feed on skin, scales and feather debris.  Poultry lice have chewing mouth parts.  Lice spread bird to bird asbody contact is made by birds.  Control is established by initiation treatment for all birds in the flock on a periodic basis with an approved safe pesticide.  Treatment is not recommended unless lice are present on the birds.

Mites are common to all avian species.  The Northern mite is the most prevalent and troublesome of the mites in poultry and other birds.  Mites are members of the spider family.  They spend their entire life cycle on the bird and tend to be more resistant than lice to pesticides.  Mites spread from bird to bird as flock members make body contact.  The life cycle is 7 to 14 days so control requires treatment at 10 day intervals for 3 to 4 treatments and monthly thereafter of all birds in the flock with an approved safe pesticide.

Chiggers are mites that live and reproduce in the environment.  The chigger that parasitizes birds and mammals represents the nymphal, or immature stage of the mite.  Chiggers feed in clusters on the thighs, breast, undersides of the wings and the vent.  These chigger clusters result in reddish scabby lesions.  The chiggers feed for about 14 days, then drop off after which the lesion heals.  Control would require the treatment of the pen or range inhabited by the bird.

NUTRITIONAL DISEASES

These diseases result from a deficiency in the diet of essential required vitamins or minerals.  Nutritional disorders most often seen in young birds are:

1.Rickets – Calcium, phosphorus, vitamin D deficiency;

2.Curled Toe Paralysis – Riboflavin deficiency;

3.Nutritional Roup – Vitamin A deficiency;

4.Perosis – Manganese deficiency;

5.Crazy Chick Disease – Vitamin E deficiency; and

6.Gizzard Myopathy (white muscle disease) – Selenium deficiency.

Treatment requires the correction of the deficiency in the feed plus a short period of vitamin-electrolyte supplementation in the water.

SUMMARY

In summary, the diseases and health of peafowl are about the same as those in domestic poultry, especially turkeys.  Any avian pathologist would be a reliable contact for specific health information on peafowl by the enthusiast.  Since many of the avian diseases do cross species line, the mingling of peafowl with other menagerie birds or domestic poultry will increase the chance of becoming infected with diseases that are endemic.  Peafowl owners are encouraged to consult an avian veterinarian or pathologist at the poultry diagnostic laboratory in their region for specific help on diagnosis and treatment.

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