The VRPB – a further veterinary investigation Last month the VRPB successfully completed the trial into the development of immunity in nestlings following PMV vaccination . These results were made available to fanciers in the March ARPJ. With the trial showing that vaccination at 4 weeks of age is not reliable the results are likely to alter the way that PMV is managed in a significant number of Australian lofts . The VRPB has now embarked on another veterinary investigation. The VRPB has gratefully received donations from fanciers, clubs and federations to establish a Health/ Disease Management Fund. Although these funds are extremely limited the VRPB believes that they there is no point in simply having these funds sitting in a bank account. The VRPB feels that they should be actively accessed for the benefit of fanciers . The hope is that information and knowledge can be gained which fanciers can use to better manage their birds. The current investigation involves “Fat Eye”. All we know about “Fat Eye” is that in this condition the tissues around the eye becomes swollen , that the condition usually occurs after Rota virus infection and that the birds appear well otherwise and seem to recover, often without treatment, in a few days. What we don’t know is what causes it and what effect it has , if any , on the birds, in particular its effect on racing.. An ideal opportunity to investigate the problem presented itself this month when a local fancier whose loft had experienced an outbreak of disease now had birds with Fat Eye. The following samples have now been collected and forwarded to the appropriate labs. At the time of writing not all of the results are back. The results to hand are giving us an idea of what is going on. All results will be reported together in next month’s ARPJ. I must thank Dr Madeleine Rowe. Because of the risk to my own birds of me collecting samples I contacted Madeleine . Madeleine worked with me at the Melbourne Bird Veterinary Clinic . She still works there and is a fully qualified avian vet. She was keen to help and has donated all of her time for free .When you are a working vet you have little spare time and Madeleine has literally given hours of this time to the investigation. Her willingness to help and professional expertise are much appreciated. I would also like to thank the fancier involved for making his loft available and for being so willing in helping us collect good quality samples . The following samples have been collected and sent for laboratory testing:- 1/ A swab from the eye , slot ( choana ) and throat from a bird with Fat eye for a Chlamydia PCR ( DNA ) test 2/ A swab from the eye , slot ( choana ) and throat from a bird with Fat eye for a Mycoplasma PCR ( DNA ) test and possibly also Mycoplasma species identification These tests will see whether Chlamydia or Mycoplasma is involved with the Fat Eye Complex 3/ Blood for a complete biochemistry and haematology profile from a bird with Fat Eye - this test will evaluate the general health of a bird with Fat Eye and see if the condition affects any of the internal organs 4/ Droppings for viral PCR ( DNA ) test - in particular Rota and PMV. We are keen to see if Fat Eye is linked to these viruses. 5/ An unwell bird was euthanised and autopsied. A full set of tissue samples was collected and forwarded to the laboratory for microscopic examination. In particular I have asked for the head to be decalcified. In this procedure the decapitated head is soaked in a fluid that leaches the calcium out of the bones of the skull and head. The head, brain , eyes and associated structures can then be sliced finely and a more thorough investigation conducted
So , we have a lot of results to come back and be interpreted. Together they should shed much light on the Fat Eye condition. Results will be reported in next month’s Journal
At what age should pigeons be sent to OLRs – changing ideas After running the recent trial ,where nestlings were vaccinated against PMV ,we now know that vaccinating pigeons at a younger age , in order to give them more protection against PMV before going to a OLR, does not enable them to form the same immunity as that if they were vaccinated older. I contacted my long term friend Dr Rob Conradie to see how he gets around this problem. Rob was the original vet for the South African Million Dollar Race at Sun City and is currently the vet for the Afrika Pro OLR. He explained that SA fanciers have been exposed to OLR for a longer period of time than most other fanciers purely because Sun City was one of the first OLR. Over the years they have learnt that they must send birds about 4 weeks after the second PMV vaccination. Originally everyone thought that they must send the birds to the race as young as possible . They have now learnt that the mortality is much lower if they are sent as older birds .
Australian fanciers should note that Dr Conradie’s recommendation are based on the use of Nobilus Paramyxovirus vaccine. This is made from a killed pigeon origin strain of PPMV. This vaccine is sold in South Africa but is made in Europe by MSD/ Intervet
In summary, Rob’s current advice to fanciers sending birds to the Afrika Pro race is :- 1/ The greatest challenge to loft management is keeping the birds healthy during the first few weeks after arrival at the loft 2/ On arrival at the loft birds are kept in quarantine for 30 days 3/ Fanciers entering birds make the task of looking after the birds easier if they adhere to the following guidelines: a/ Breed only from healthy stock birds that are free of canker, worms, coccidia and Salmonella. All stock birds must be fully vaccinated against PMV b/ The youngsters in the nest must be allowed to develop maximum natural immunity with the use of immune boosters such as vitamins, probiotics , herbs and teas. c/ The first PMV vaccine must be given at 3 weeks of age d/ The second PMV vaccination is given 3 to 4 weeks later when the birds are 7 weeks old e/ The development of a complete immunity to PMV takes a few weeks from the time of the second vaccination . For this reason birds should not be sent to a OLR until they are about 12 weeks old f/ Do not send birds younger than this as it is much more difficult to keep very young birds healthy. In particular they are more susceptible to Young Bird Disease g/ Do not send older birds , including birds that have raced. They are much harder to settle and many are lost h/ Do not send birds that are showing signs of ill health to make up the number. They generally do not do well and are a danger to your other birds and the birds in the OLR loft i/ Treat for canker just before shipping. The stress of shipping can lead to a flare up of canker. Canker treatment is repeated on arrival at the OLR to prevent this from happening in South Africa
Dr Conradie goes on to explain that some fanciers do not vaccinate for PMV because they know that the vaccine is going to be repeated when the birds arrive in South Africa. In cases where a fancier has lost a number of birds it is often the result of the PMV vaccine not being given. Rob also stresses the important role that shipping agents have to play, in ensuring that the above criteria have been addressed as best possible. He explains that the last period the birds spend in the country of origin and the initial period at the OLR is vitally important .
In summary then for PMV control, Dr Conradie recommends for international entries into OLRS, vaccination for PMV at 3 weeks and 7 weeks at the loft by the fancier or during quarantine in the shipping country. Birds are then sent to the OLR at about 12 weeks . They are vaccinated again on arrival and then go into quarantine for 30 days .After completing quarantine they are 16 weeks old .They are then placed in OLR loft and start to get let out and “homed”. He explains that in the AfrikaPro OLR the loft staff only want the South African entries 4 weeks after they have had their second PMV vaccination. Dr Conradie explains that what generally happens is that the SA birds only come in after the quarantine of the international entries has lifted. This does generally means that the South African birds are as old as 12 to 16 weeks when they arrive . He advises that they stay healthier this way.
I think the way that OLRs are being managed in Australia is now changing to come more in line with the way that OLRs are conducted overseas. When the first OLRs were organised in Australia PMV did not occur here. The severe impact that this disease can have is now being increasingly realised each year. When OLRs started in Australia the thought was that it was best to get the young pigeons to the OLR when they were about 28 days old. After all, that is what we do at home when we wean babies from the stock loft into our own racing lofts. We are now increasingly realising that sending them as older birds makes little difference as far as subsequent settling and racing but makes a huge difference as far as subsequent disease control and mortality.
An interesting story – 700 miles on the day but in the wrong direction About 20 years ago the VHA had a race from Mildura back into Melbourne. Mildura is 300 miles north west of Melbourne. On the day of the race there was an incredibly strong , 50km/hour NW wind blowing. That night one of my birds from the race was reported in Hobart. Hobart is 400 miles south of Melbourne. The fancier in Hobart who had reported my bird also had another VHA fancier’s bird from the race. These 2 birds had flown from Mildura south and when they reached the Victorian coast had kept going . They had then flown across Bass Strait and then the full depth of Tasmania. It was only when they reached the southern coast of Tasmania and were at risk of heading off over the Southern Ocean on their way to Antarctica that they pulled up. The birds had flown a total of 700 miles but for 400 of those miles they had been flying away from their lofts. The fancier who owned the other bird organized for both birds to be returned and my bird was released at his property , about 20 km south of my loft. I found the bird in my loft that night when I got home from work. The interesting thing is that in the following year in the VHA 600 mile race there were only about 35 birds on the day , from about 1,500 sent , all clocked late on the day. I was placed 24th and the bird I clocked, yes, it was the “Hobart Hen” from the year before. Fortunately this time she had kept her line and scored a good result in the 600. As an aside, the nestmate to the Hobart Hen flew two 600s and a 700 mile for me in 12 months. She flew the VHA 600 one year and the next year flew the Victorian statewide 700mile race and then the 600 again. I guess some of these distance hens with their stamina genes have the potential to keep flying and cover enormous distances.
The stages of a PMV outbreak When PMV gets into a loft of non- vaccinated birds the resultant disease doesn’t look identical in every loft but the outbreaks do share some similarities. Typically several stages are seen :- Stage One Birds in good condition get sick and die in 1 to 2 days. These are the birds with no immunity. The virus quickly overwhelms them with these birds not living long enough to lose condition. When these bodies are presented for veterinary examination they look normal except that they are dead. Stage Two More drawn out. Larger numbers of birds become unwell with some living for over a week. These birds become thin and weak and show a variety of symptoms including a thirst, decreased appetite , wet droppings , fluid filled crops, vomiting and general depression. These birds have some immunity which “fights” the disease . Unfortunately many eventually die and those that survive suffer permanent damage that compromises long term health and racing ability. Large numbers of extremely watery droppings start to appear on the floor. Sometimes the birds appear to literally just squirt water from their vents. This is due to the virus damaging the kidneys and interfering with their ability to conserve body fluid and concentrate urine. Stage Three Birds with “twisted necks” start to appear. These birds have survived the acute stage of the disease. Late in the disease the virus invades the brain causing a viral encephalitis ( brain inflammation ) leading to “twisted necks” and sometimes loss of balance and unusual behaviour. Most of these birds survive and with time as the brain heals and accommodates become more normal . If they have genetic potential they can be used for breeding but when such birds are subsequently raced they are almost invariably lost. Because PMV is only carried for up to 60 days they do not represent a source of infection after this time.
Responsibility of a fancier with a PMV outbreak So if a flier has an outbreak of PMV in his loft what are his official responsibilities. There are none. Neither any federations, the VRPB or ANRPB have outlined any guidelines in this regards. There are however actions that are considerate of other fanciers that help to reduce the spread of the disease. 1/ If an outbreak occurs in a loft at a time of year when fanciers are still weaning babies and there has not been sufficient time to complete vaccination programs then continuing to let young birds out puts racing neighbours birds at risk. Youngsters that are still settling and have the potential to stray can potentially spread the disease to the lofts of neighbouring fanciers . Some fanciers might choose to just keep quiet and continue to let their birds out. It would be responsible however for a PMV affected fancier to notify his neighbours and to confine his birds, at least until his neighbours have had a chance to vaccinate their birds. Obviously any fancier does not want to lock up his developing youngsters for any longer than necessary but 4 weeks should allow his neighbours birds to form sufficient immunity from one shot to protect them from PMV’s worst effects. 2/ A fancier with PMV in his loft should not visit lofts with unvaccinated birds or birds that have not completed their vaccination program . Similarly fanciers with birds that are not fully protected should not visit him. 3/ A fancier with PMV in his loft should not enter birds in a OLR or a squeaker sale for up to 60 days after the last of his birds recovers 4/ A fancier with PMV in his loft should not offer birds for sale for up to 60 days after the last of his birds recovers
PMV Vaccine Failures Some fanciers have come up with some novel vaccination alternatives . Examples include :- 1/ One vaccination is sufficient --- no, this is incorrect. Earlier testing has shown that one shot provides full immunity in 70% of birds. For 100% of birds to develop complete protection from PMV viral damage two vaccinations are required 2/ Freeze half the vaccine and keep it for next year – there is no guarantee that the vaccine will still work after freezing. The label specifically warns –do not freeze 3/ Give a double dose as just one shot – although this means that each bird gets the same amount of vaccine (ie in one shot rather than two ), the boostering effect is lost so this is just like giving a single shot. To me this is a bit like cooking two evening meals and then telling someone to eat both now – that way they won’t need to eat tomorrow night. The boostering effect is important . More information can be found on the VRPB website
Amicide poisoning in pigeons Amicide is a commonly used herbicide . It kills flatweeds such as dandelion and capeweed but does not kill grass. Recently a very successful Melbourne fancier sprayed the lawn around his loft to eliminate weeds with Amicide. At this time of year the pigeons have significant periods of “open loft” and often spend this time foraging around the loft. He contacted me when some of his birds became quiet, fluffed and unsteady on their feet. About 5 of his large team of 300 were affected and 1 died. The manufacturer of Amicide recommends that stock such as sheep and cattle do not graze pasture for a week after spraying. Amicide contains 2,4-D 625g/L present as dimethylamine and diethanolamine salts and although primarily a plant toxin it appears that it can do pigeons harm if ingested in sufficient quantities . There is no mention of potential harm to birds on the label. This situation is perhaps a timely reminder of the risks of herbicide spraying near a loft.
PMV vaccination and fertility I had a fancier contact me this month who had spent $50,000 on stock birds but would not vaccinate them against PMV . He believed that the vaccine would reduce their fertility. To me this seemed very risky. This thought in Australia originated because some of the killed and live pigeon origin PMV vaccines used overseas carry this warning. We don’t use these vaccines in Australia – we use a killed chicken origin vaccine. Common sense says that if this vaccine did this then all lofts who used it would be affected. This however is not the case. Many many lofts use this vaccine and experience excellent fertility. I think some fanciers are a bit quick to reach the conclusion that any reduction in fertility must be due to the vaccine . The vaccine is an easy target . There is no scientific evidence to support that the killed chicken origin PMV vaccine used in Australia compromises fertility. So, don’t put your valuable stock birds at risk – vaccinate them
Vet Questions 1/ In the March ARPJ there was a short article that stated that sweat from mammals contains toxins. The article went onto say that because pigeons don’t sweat they get rid of the same toxins in the form of dust , is this true? No, it is not true. The feathers that cover a pigeons body are several different types of, what are called, covert feathers . These are all lost and replaced during the annual moult. In addition, pigeons are one of the birds species, that have specialized feathers called powder down feathers . These feathers occur in 2 bands over the top of each leg and extend across the side of the abdomen. They are not replaced in the annual moult but grow continuously . As they do this the ends become fragile and disintegrate to produce the powder ( or dust or bloom ) that spreads throughout the feathers. The powder down feathers grow particularly when the birds are well. This leads to the production of more feather powder . This is why fanciers correlate a lot of bloom on the birds feathers with good health. The feather powder is essentially keratin and does not contain toxins. Feather dust , however, if allowed to accumulate in the loft, either through inadequate cleaning or poor ventilation can adversely affect the pigeons health in the same way that breathing in any dust would. It is worth mentioning that mammalian sweat also does not contain toxins. The skin is not an excretory organ. It is the liver and kidneys that eliminate toxins from the body. Sweat is made up primarily of water and electrolytes. Toxins do not accumulate in or are excreted from the body in sweat. Occasionally there may be traces of a potential toxin in the sweat but this is incidental and the levels at which they are found would not be regarded as toxic.
2/ How vital is it to give the second vaccination exactly 4 weeks after the first one? When numerous batches of youngsters are going into the race loft, it can be difficult to monitor. That’s a good question. Vaccinating weaned young birds of different ages at the right time is a hard situation . I can’t give you an exact answer. When I did the long 18 month trial in 2012 the CCEAD ( the Consultative Committee on Emergency Animal Disease) suggested a number of vaccination protocols but in all of the protocols they suggested that the booster be given 4 weeks after the primary shot. This suggestion was made as an extrapolation based on the use of other vaccines where giving the second shot 4 weeks after the first provided a good boostering affect . We did not trial any other intervals primarily because of financial restraints – I were running the trial on funds donated by fanciers . What is known is that boostering is essential (this is detailed with appropriate graphs on the VRPB website ) and that if the booster is given at 4 weeks it works well. In reality being exactly 4 weeks is probably not that critical .Anything between 3 and 5 weeks would probably be OK. Too early and the immunity from the first shot is still rising, too late and the immunity from the first shot has become too low to respond to the booster
3/If a pigeon has been vaccinated against PMV , it is protected from death, but is it still able to catch the disease and potentially pass it on to another bird? The vaccine confers enough immunity to stop birds dying and to prevent the development of illness. It does, however, not provide enough immunity to prevent the birds becoming infected with the virus. Once infected, pigeons carry PMV virus for up to 60 days. The long term carrier state does not exist with PMV (as it does with other viruses like Herpes virus ). So, vaccinated birds can carry the virus and spread the disease for up to 60 days, if they are exposed to it , even though they are perfectly well themselves.
4/ I am an avian vet . I would appreciate your help with a case. A pigeon fancier had an outbreak of disease in his young birds . Only a small number got sick and only a small number died. A bird was autopsied and tissue samples were sent to the lab for testing. The results have come back as suggestive for:
Pigeon paramyxovirus-1 (PPMV-1)
Pigeon circovirus
Pigeon adenovirus
Mycoplasma sinusitis or high ammonia in the environment
The principle microscopic tissue changes were an interstitial nephritis and pancreatic necrosis. I'm wondering if the pigeons only experienced low morbidity/mortality in this PMV outbreak because they have partial immunity transferred from their parents? But my recommendation would be to maintain a regular annual PMV vaccinating schedule to try and prevent future outbreaks. Do you have any additional thoughts? With the interstitial nephritis ( a type of inflammation in the kidneys ) and pancreatic necrosis ( death of pancreatic tissue )it is very likely ( almost certain ) that these birds have had a PMV exposure. The level of immunity , either passively acquired from vaccinated parents or from active vaccination programs ( complete or otherwise ) very much modifies the pattern of clinical disease. It is not unusual in partially immune flocks for birds to become unwell ( quiet, fluffed, decreased appetite, PU/PD) and then recover and for the overall mortality rate to be quite low. Circo virus is very common – almost ubiquitous and is commonly also identified in young pigeons with PMV. Being immunosuppressive it exacerbates the severity of the disease outbreak compromising the birds ability to mount an effective immune response against PMV and making it more likely for opportunistic pathogens to become involved The inclusions in the liver and bowel are consistent with Adeno. In young birds Adeno normally affects the bowel, has a high morbidity but low mortality. It is often accompanied by secondary enteric E coli infections and the birds often respond well to treatment ( such as Trimethoprim/ sulphadiazine ) in the drinker for 5 days . Adeno in the liver is not so common in young birds . Here it is more a mature bird problem with a low morbidity but high mortality. All pigeons have one or more Mycoplasma species in there resp tracts. In well managed lofts they usually don’t cause much of a problem but ammonia and dust can trigger them to cause clinical disease. Management suggestions 1/ Consider PMV vaccination 2/ Owner to review loft ventilation and cleaning method/frequency 3/ Consider treatment of enteric gram neg infection 4/ If the owner is willing it would be great to do the Adeno, PMV and Circo PCRs
The PMV vaccine is cheap, readily available and very safe. If you are sure that it is PMV and all birds have been exposed to “wild” virus then no need to vaccinate this year. If there is any doubt there is no harm in vaccinating them all now. Certainly continue with annual boosters
5/I have PMV diagnosed in my birds but I am a little confused by the results. Apparently from the fact I have over 400 unvaccinated young birds in the loft which are from stock birds not vaccinated for over 2 years i also have several fantail pigeons that have never been vaccinated and have not fallen ill. Many of the older young birds( bred from September- December) have shown very little signs of any problems other than the odd bird reluctant to eat or fly for a few days . The majority of the birds are enjoying their loft flying for approximately an hour and a half each day. My main concern would be will there racing/ homing ability be compromised if PMV has gone through them? Also with racing due to start here on the 7th of April will my birds still be infectious being its only approximately 6 weeks away? Recovered PMV birds continue to shed the virus ie are infectious for up to 60 days. This means that if you have unwell birds in the loft now that the loft would still be infectious for 60 days after the last of these recover Most birds fully recover from PMV but not all of them. The 2 main organs damaged by PMV are the pancreas and the kidneys. The pancreas is involved in energy release ( by making sugar available to the cell ) and the kidneys, in health , amongst other things, maintain a normal level of hydration. Damaged kidneys lose the ability to concentrate urine and conserve fluid which can lead to dehydration if the birds don’t drink regularly. Dehydrated pigeons with impaired energy release are unlikely to perform. There are veterinary tests to see which birds have failed to recover fully but these are not practical for financial reasons . Usually, however, the damaged birds start to identify themselves. Those that start to come consistently late or appear overly tired or exhibit prolonged recovery should be viewed as potentially damaged birds . If these birds have genetic potential they can be used at stock but not as long term race birds. Your loft is an interesting case. Earlier testing has shown that youngsters bred from birds vaccinated in the previous 3 years have about 1/3 rd the immunity necessary to fully protect them from disease. This immunity is enough ,usually, to stop them from dying and decrease the severity of disease if exposed. If exposed during this time symptoms may be mild but this natural exposure stimulates strong immunity. This may explain why PMV has had less of a clinical impact on your loft.
6/ I have had a recent outbreak of PMV in my loft. I have approximately 140 birds I am due to be selling. These birds have been vaccinated approximately 12 months ago and have not shown any sickness. I plan to vaccinate asap after the recent PMV outbreak. My question is when should I be confident these birds will be clear to sell without putting any other fanciers at risk? Worth noting that there was 3 un vaccinated birds being 1 high flier and 2 modena birds and did become ill approximately 10 days ago. 2 died and one was culled. The sale was scheduled to run over this month however I delayed it until the results came back from the lab for the autopsy bird Studies have shown that after vaccination all birds are protected from clinical disease ( ie from becoming unwell ) for 12 months. After this , with each month , as immunity wanes , an increasing percentage of birds become vulnerable. This means that if your birds were vaccinated 12 months ago and are boostered now they should be protected. The difficulty in this situation however is that although the immunity formed after vaccination is high enough to prevent the birds from becoming unwell, it is not high enough to protect them from becoming infected with the virus. Vaccinated birds that are themselves well but come from an infected loft can therefore spread the virus. This can occur for up to 60 days – PMV is only carried by pigeons for up to 60 days and can only survive in the environment also for up to 60 days. This means that any birds from your loft could be a source of PMV infection for up to 60 days after the last sick bird recovered.
7/ Should old birds be vaccinated against Rota once or twice? Pigeons should have 2 shots the first year that they are vaccinated no matter what their age and then single annual boosters
8/ I have an 8 year old hen which lays eggs but after a day or two they crack. We have jacked her up with calcium but are unsure why she is not correcting. She is a top producing hen so we want to get her right. This year she gave 6 squabs in the start of the breeding but then laid 6 pairs and they all broke. The shell seems hard but it has got a sandy rough texture all around. Are there any products or recommendations for this? It is good that you have given her a calcium supplement as calcium deficiency is one of the two main causes of what you describe. This condition occurs either because there is not enough calcium available for the Shell Gland to secrete a normal shell or alternatively the Shell Gland is diseased and cannot use the available calcium to make a normal shell. The Shell Gland is a diffuse gland imbedded in the wall of the oviduct (the tube that carries the egg to the exterior). It secretes the egg shell on to the expanding egg as it passes down the oviduct. A healthy, functional Shell Gland cannot produce a normal shell if calcium is not available to it. If problems occur despite adequate calcium supplementation, it is likely that the Shell Gland is diseased. If the gland is diseased, the most likely cause is an infection. The usual bacteria that cause these infections are ones that live in the bowel and back-track from the cloaca into the oviduct. If the infection has been there for a long time (several weeks), the gland will respond poorly to treatment. However, if caught early, they can respond quite well. Usually, the hen is separated from her cock, treated with antibiotics ( Baytril 0.25ml once daily for 10 days is a good choice )for an extended time and then, after a further period of convalescence, reintroduced to her mate. If necessary medication can be prescribed by your vet (cabergoline or a GNRH blocker) to reduce or stop egg production for a period of time. Some older hens develop a cystic type of degeneration in the lining of the oviduct as they age. A type of cancer, an adenocarcinoma, is also surprisingly common in the oviduct of older hens.