first recognized as a disease in pigeons in 1975.1 It spread through Europe by 1983
and by 1984, was present on the east coast and in Canada. It is now present in pigeon
flocks throughout the US. It is not yet present in Australia, probably due to stringent
import and export laws. Paramyxovirus (PMV-1) is related to another type of Paramyxovirus
known as Newcastle's Disease. Newcastle's Disease is a highly infectious viral disease
of poultry and other birds but seldom is a disease of pigeons. Newcastle's Disease
mainly causes upper respiratory signs, neurologic signs and death. Since the incidence
of this disease in the US. is low, it will not be discussed here further.
PMV-1, however, is present in show pigeons, flying breeds and wild pigeons. We will
stick to the information about this virus that is pertinent to the pigeon fancier.
Transmission- PMV-1 is transmitted by direct contact1,2,3 This may occur in crowded
lofts, shipping containers or even by social contact such as territorial aggression
between cocks. More importantly, transmission can occur between show cages. Indirect
transmission may also take place from contaminated food and water sources. Fecal
dust can become airborne and further transmit the disease between lofts and pens.
Vectors such as rodents and humans can transport infected dust on fur and clothing,
respectively. Last, insect vectors; pigeon flies and mosquitoes, may infect birds
with PMV-1 and thus should be controlled in the loft.
Route- The route of infection is predominately through inhaled or ingested particles.
Occasionally, the virus may enter through membranes around the eye. The virus leaves
the pigeon's body in the feces and in the respiratory discharges.
Stability- The virus is sensitive to the usual disinfectants.1 Diluted bleach,
quaternary ammoniums (Roccal), chlorhexidine (Nolvalsan), phenolics (Environ) and
aldehydes (Wavicide) should be effective in disinfecting the premises.
Incubation- The incubation period (the time when first exposed to the virus until
signs from disease occurs) is typically one to two weeks, may be as long as four
weeks, but is not usually over six weeks. This variable time period can allow the
disease to spread slowly throughout the loft. Carriers may exist that are shedding
the virus in their feces but not show any signs.
Severity- Different strains exist which may cause mild to severe disease. Young,
unvaccinated, unexposed pigeons are at an increased risk. If left untreated and
the virus allowed to run its course, 20-80% of the flock may develop signs. Up to
90% of the birds showing neurologic signs may die.1,2 Infected pigeons will form
antibodies to fight off PMV-1 within 2-3 weeks; a percentage of these birds will
Diagnosis- A test on an infected bird's blood serum will confirm exposure to PMV-1.
Unfortunately, this test is reliable only in unvaccinated pigeons or 8-10 months
after vaccination. It tells the veterinarian that the bird tested has been exposed
but gives little information on the present state of the disease. More involved
tests may include isolating the virus or identifying the virus in tissues of an affected
bird. These tests are performed by veterinary laboratories.
Signs- Initially, infected pigeons will consume more water and have watery, greenish
droppings. They will often go off feed, act depressed, rest fluffed-up and lose
weight. Later in the course of the disease, birds may develop neurologic signs.
The first being incoordination and inability to fly. Head and neck twisting is
easily recognized and often leads to circling or head and neck tremors. Paralysis
or weakness of wings and legs can also occur. Nine out of 10 birds with prominent
neurologic signs will die and unvaccinated squab mortality may reach 100%.
It is important to confirm that PMV-1 is the cause of a suspected outbreak since
other diseases may manifest signs similar to PMV-1. Salmonella (Paratyphoid), Herpes
(Pigeon Herpes Encephalomyelitis Virus, PHEV), Newcastle's Disease and intoxications
(lead, zinc, and organophosphates) also cause neurologic signs and should be ruled-out
as potential causes. Necropsies (autopsy) of dead and ill birds will provide information
in determining the true cause.
Treatment- Once PMV-1 enters a loft, it may persist in the flock in asymptomatic
carriers. Flying breeds with obvious neurologic signs should be culled as they may
remain carriers, cannot usually be safely flown and are often unthrifty breeding
birds. Show breeds can be strictly isolated from the flock and bred but may produce
infected, carrier offspring. Most fanciers elect to depopulate birds with severe
neurologic signs. Isolation of affected birds should be done immediately and performed
on a daily basis as more affected birds are identified. Due to the long incubation
period, disposal of all affected birds seldom controls the spread of the disease.
Supportive care is recommended for the lightly affected and non-affected remaining
birds. Sulfa drugs such as Vetasulid (sulfachlorpyridazine) and Bactrim (sulfamethoxazole/trimethoprim)
in the water are effective at controlling secondary infections. Cleaning and disinfecting
watering devices, food dishes and surface areas will help control dissemination of
the virus through fecal contamination. Providing warmth, good feed and fresh water
will also help.
The most effective method to control the disease is to immediately vaccinate all
apparently healthy birds in the face of the outbreak. Vaccinating already infected
birds does little good and is not recommended. Maine Biological Laboratories' killed
PMV-1 vaccine has proven to be very effective in stimulating an immune response and
thus prevent disease. The vaccine does not, however, prevent infection; it merely
limits the deleterious effects of the natural disease. Vaccinated birds, therefore,
may carry a PMV-1 infection but not show signs.
Prevention- The pigeon fancy, through intermingling of multiple birds from multiple
sources during shows and races, predisposes pigeons to contracting PMV-1 and other
infectious diseases. Preventing introduction of the virus into the loft is the key
to protecting your flock. Feral pigeons should be excluded, show birds should be
isolated or kept in a separate loft when returning from shows, and racing birds need
to be trained to enter a separate loft after flight. Preferably, this racing loft
or isolation area should be across the yard but a solid barrier (preventing contact
through wire or mesh) is usually effective. Do not allow potentially infected birds
access to the main part of your flock.
Crowding in the loft should be dealt with as this leads to more rapid spreading of
the virus and the other problems that often accompany overpopulation. All birds
should be dusted with insecticide powders to eliminate the common insect vectors,
pigeon flies and lice. The loft should always be kept in a clean state.
As stated already, vaccinating for PMV-1 is the best means to establish and maintain
a healthy paramyxovirus protected loft. The vaccine manufacturer recommends vaccination
at 4 weeks of age and a booster 4-8 weeks later. Older, unvaccinated birds are also
vaccinated and boostered 4-8 weeks later and then re- vaccinated annually. Vaccinate
all young birds 4 weeks prior to the start of the young bird racing and show seasons.
Vaccinate all birds in the loft about 2 weeks before the breeding season.
Paramyxovirus can be a devastating disease in an unprotected, large flock. Protect
your birds through understanding, good management and vaccination. The day will
probably come when all pigeons flown in races or exhibited at local, state and national
shows will require vaccination for PMV-1.
1. Tudor DC: Viral diseases. In Pigeon Health and Disease. Ames, Iowa
State University Press, 1991, pp 19-53.
2. Dorrestein GM: Viral infections in racing pigeons. Proc Assoc Avian Vets, 1992,
3. Schrag L: Healthy Pigeons. Hengersberg, West Germany, Shober Verlags-BmbH, 1989,