PSITTACOSIS and ORNITHOSIS (Parrot Fever)
More info on these diseases and other Viral Diseases can be found here.
The two most dangerous illnesses of Budgies and parrots--especially from the viewpoint of transmissibility to humans--are psittacosis and ornithosis. The two diseases are closely related to each other, with psittacosis the most dangerous for handlers. Budgies are basically healthy birds with good natural resistance. Given good care, the birds generally don't suffer much from disease. But psittacosis when it occurs, is a serious problem that should not be taken lightly. Psittacosis is a communicable disease of birds. Birds with psittacosis may exhibit typical symptoms or be silent carriers that look healthy while shedding germs and infecting other birds. The method of transmission is through the droppings or nasal secretions. Humans can be carriers to. Humans infected with psittacosis have symptoms reminiscent of pneumonia or typhus, with high fever and frequently spots on the abdomen. Not all cases reach this dangerous stage, often, symptoms are mild and disappear quickly. The disease almost always is picked up from birds, there are practically no known cases of transmission between humans. Few people die from psittacosis, and fear of bird diseases should not keep people from the hobby. The best lesson to draw from the human risk is to promote cleanliness.
It seems reasonable that people generally get infected by breathing in dust containing dried droppings. So clean the cage bottom regularly and cover it with clean sand to minimize this problem. The birds themselves exhibit serious symptoms in the respiratory organs. Nasal secretions are common. So is a type of diarrhoea that is green, slimy, and sticky---generally causing the feathers around the cloaca to stick together. The remedy of choice since 1959 has been aureomycin. American research proved this antibiotic effective for treating psittacosis at that time. Aureomycin can be purchased premixed into seed, or it can be bought in powder form for use in the drinking water. The yellow powder is available at drug stores, quantities no larger than the head of a matchstick should be mixed into about a pint of water. Furnish medicated water for several weeks when psittacosis is suspected. Within that time, infected birds should have recovered and carriers should no longer pose a danger. More recently a newer antibiotic, chlortetracycline, has proven even more effective than aureomycin. Ask your veterinarian for instructions for use. Any bird exhibiting symptoms of psittacosis should immediately be placed in isolation. Don't try to save it, even if it is from your most valuable stock. The dangers inherent in keeping the sick bird around far outweigh the value that any one bird represents. Don't assume that every bird with a runny nose and diarrhoea has psittacosis. A number of other illnesses could cause the same symptoms. Enteritis is a prime example.
It will be appreciated from what has been said that clinical signs are far from specific or diagnostic, although in typical cases the post-mortem lesions are fairly characteristic. The disease may be suspected from the pattern of infection in an area or premises. Confirmation, however, requires highly specialised laboratory techniques. One method is serological testing for antibodies of the disease. This is the usual method when human beings are involved. It is merely a method of measuring the amount of resistance the man or bird has developed in response to meeting the disease. If this happened a long time ago, the antibody level will be low. When the disease is being actively fought, however, the level rises rapidly. A fairly recent infection produces a high level of antibodies which only falls slowly over months or years. Other stages such as complete recovery, the carrier state, or lack of adequate antibody response to infection all give inconclusive results. An old way of detecting the presence of the infection in a bird can be demonstrated with certainty after death by infecting a susceptible host, such as a mouse. This involves inoculating an extract of a piece of diseased liver, spleen or other internal organ into the brain or peritoneal cavity. Death of a proportion of inoculated mice showing certain characteristic lesions confirms the diagnosis. The disease can also be diagnosed by inoculation of the extracts into the yolk sacs of living embryonated eggs.
Most books recommend that infected birds should be destroyed. It is unwise to attempt treatment unless the dangers of the situation are appreciated and the premises and stock are self-contained. Treatment should be carried out only under the strict supervision of a veterinarian. The owner should not underestimate the considerable danger to himself, his family and others who may come into close contact with his birds or himself. The tetracycline’s are the best drugs where treatment is thought prudent. They check, but do not necessarily kill the causal organism. Symptomatic treatment and careful nursing should accompany the specific antibiotic therapy.
Probably more has been written about ornithosis than any other avian disease. It was first recognised and named in 1879. Because the disease is infectious and sometimes even fatal to human beings, the importation of psittacine species or parrot-like birds has been controlled in several countries as these species are especially susceptible to the infection. It was originally thought that a virus caused the infection, but it has now been established that the agent is a rickettsia-like organism, which is usually referred to as Redsonia and more recently called Chlamydia. Ornithosis, which literally means "bird disease" started its recognised life with the names psittacosis and parrot fever, because it was originally believed that only parrots were affected. When the seriousness of human infection was realised and cases arose in people not in contact with parrots or budgerigars, investigations were carried out on numerous other species. It is now known that many species in a variety of families of birds and small mammals also carry the disease, often with little or no clinical signs in the creatures themselves. Although psittacine birds still appear to account for the greatest number of cases, ornithosis also occurs occasionally in domestic poultry, (especially in turkeys, ducks and pigeons), certain seabirds and some other species. The virulence of the disease varies from species to species and from outbreak to outbreak. Investigations in England, have shown that a high percentage of pigeons develop an immunity to the disease, while a smaller number harbour the ornithosis agent with little clinical effect. Human infections derived from pigeons appear to be less serious and less common than those contracted from parrots. It is possible that birds in the parrot family have the power of increasing the disease's virulence for man. Alternatively, more virulent strains may survive best in psittacines.
The ornithosis agent is susceptible to some antibiotics, especially tetracyclines. It is of world-wide occurrence and is endemic in the bird population of many countries, as is shown by the detection of antibodies in the sera of many species. Only quite brief contact may be necessary for one bird to infect another or a human being. Transmission is by inspiration of the organism in water droplets or dust. A less common method of infection is via the mouth. Although showing no clinical signs of disease, many birds excrete the organism in the droppings or nasal discharges, while the feather dust and debris may also be contaminated. Repeated passages through a succession of individuals occasionally results in an intensification of the virulence for that species, until some birds show obvious signs of the disease and even die. The most commonly infected cage, aviary and ornamental birds are the psittacines, including the entire range of parrots, parrotlets, parakeets, budgerigars, macaws, cockatoos, cockatiels, lories, lorikeets and lovebirds, as well as all types of pigeons and doves. Gamebirds, including pheasants, partridges, certain ducks and also species of hummingbirds, magpies, tits, thrushes, various finches including the Java sparrow, canaries and cardinals, and some members of the troupial famiIy are occasionally infected. No list can be complete because new host species are frequently being found.
Clinical signs of the disease include green or grey diarrhoea, listlessness, huddling, closing of the eyes and conjunctivitis, droopiness, occasionally a watery or pus-like discharge from the nostrils and/or beak, rattling respiratory sounds, rapid laboured breathing, lack of appetite, loss of weight, prostration and death. Flight is inhibited in older birds due to weakness and listlessness. Young stock are particularly susceptible. Intensively kept birds, such as those kept in large numbers in an aviary and bred collectively are most vulnerable to serious outbreaks. As with all diseases, the infection is less likely to occur in collections of birds where the hygiene is good and a balanced diet is fed. It is important to realise that birds which survive the disease may carry the causal organism for long periods, excreting it continuously or intermittently. These dangerous birds are called carriers, and may never show signs of illness. Although it is still not certain, it appears possible that some species can transmit the infection to the embryo by laying infected eggs. The shell may also become contaminated and infect the chick on hatching if the parent does its own brooding, or alternatively the adult may directly infect the nestlings. When transported long distances, birds are often subjected to stresses such as change of diet, fluctuating temperatures and restricted activity caused by overcrowding in cramped containers. Adverse conditions of this nature frequently lower the birds resistance to disease and especially to ornithosis. The survivors, however, reach the dealers and pet shops, where, when weak and therefore tame, they may be sold by unscrupulous people to unsuspecting members of the public. Under such circumstances the disease often becomes virulent for man and other avian species. The isolated parrot imported by a person for his family and kept under good conditions usually becomes acclimatised by the time he gets it home, and if by then it is still healthy, it is likely to remain so. It may still, however, be a carrier and a potential source of infection to its owner or any other birds with which it comes into contact.
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Hamilton & District Budgerigar Society Inc. 1996