Canary pox (CNPV) is in the Papiloma family of viruses. This is the same group of viruses that cause common (sometimes genital) warts in people. The human form of this virus does not seem to be transmitted from people to birds. It, like the canary pox virus, is equally harmless to us.
The incidence of canary pox is higher during summer and also in humid, mosquito-prone regions of the country. Canary pox is transmitted exclusively by mosquitoes, which presumably contract it from the blood of wild birds. As many of us know, mosquitoes get indoors quite often and, while annoying to us, they can be potentially dangerous to our birds.
Because canaries are a highly-domesticated species, they have lost much of their resistance to the diseases carried by wild birds, including CNPV. Wild birds are sometimes affected by the virus, but, in most cases, seem to be impervious to it. The virus was named “Canary Pox,” because the incidence of infection after exposure is extremely high in canaries.
For this reason, canaries are not a good choice for outdoor bird keeping. The only reasonable option would be to place a layer of window screen or shade cloth all around an outside enclosure. The dangers of keeping canaries outside outweigh the benefits. Their winter breeding habits can also present problems if canaries are kept outside in mild areas. It is also possible that CNPV can be transmitted by physical contact with other birds and/or feeding babies (not only from mosquito bites).
There are many diseases that can affect canaries but do not seem to be problematic for finches, which are closer genetically to their wild cousins, or parrots. Air sac mites, Paratyphoid, as well as CNPV and avian tuberculosis are among the potential problems for outdoor canaries.
This is not to say that your canary should not have regular exposure to sunlight. The amount of time needed for maximum health benefits is around 20 minutes, twice a week.
Bringing your bird outdoors in the midday is the safest time of day, as mosquitoes are most active at dusk and at dawn. There is still a risk of an insect bite, but the chances are lower. Always stay directly with your bird and be sure it has the option of getting out of the sunlight if it wants to. Use twist ties to secure every opening on the cage before going outside.
Canaries are not the only birds affected by the pox. Any bird in the Serin family, which includes grey singers, green singers and European goldfinches, is prone to this virus.
Two Forms Of Canary Pox Virus
Canary pox occurs in two forms: wet (dyptheric) or dry. The wet form is more serious, as it often results in internal lesions in the airway, which can lead to suffocation. The wet form of pox sometimes shows externally as open, weeping sores or lesions, usually around the eyes or on the feet. (These are the areas most likely to be bitten by mosquitoes.) Sadly, the wet form of the pox nearly always ends in eventual death.
The dry form of the disease is less destructive. Wart-like extrusions develop on the skin of the feet or eye (normally). This form tends to run its course without really harming the bird. The dry lesions tend to simply fall off at a certain point. There is controversy over whether the dry form of the virus can become “wet” and also if/how it transmits from a surviving bird that no longer shows symptoms.
Most birds can survive the dry form of the pox, though it is probably not a good idea to let them breed until more is known about this disease.
New Birds & Canary Pox Virus
Inspect new birds very carefully, including listening to their breathing. Breathing sounds should be free of watery or clicking sounds. There should never be any nasal or oral discharge on the bird. Watery or clicking respiratory sounds can also be indicative of general respiratory infection or air sac mites.
Examine the skin around the eyes, and also the legs and toes. There should be no reddish bumps or any type of growth or sore. Quarantine new birds for at least a month, and disinfect your hands between groups of birds. It is a very good idea to have a different pair of shoes to wear in each bird area. Some illnesses are known to be physically carried from one place to another, and others are too poorly understood to justify a risk.
Canary pox is one of many avian pox viruses, though all but CNPV are not common. The CNPV virus can be transmitted to people, but it appears to have no effect once entering the system. It is always extremely unlikely to become sick from handling or being around captive birds.
There is a canary pox virus vaccine that has been proven effective (with canaries). Check with your avian veterinarian for more information.