Pigeon Rota Virus

 Current disease outbreak in Victoria.Update 5th May 2017The RSPCA released today a statement on Rota virus and racing for 2117. Please see below    RSPCA NSW WARNING: PROPOSED PIGEON RACING WILL SPREAD DEADLY ROTAVIRUS Nation NnnnnnNnnNational Rota Virus Update

1 November 2017

24 October 2017

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An Investigation into the effect of Rota virus on this year’s racing

Many federations around the country have experienced very poor returns this year. Suggestions have been made that this could at least be partially due to the fact that most birds racing this year have recovered from an earlier Rota virus infection. Could the Rota virus be compromising these birds ability to race competitively and return ? A successful fancier contacted the clinic. In one of the federations early club races he had had the fastest velocity in the federation. This had been a short race of 150 miles and had been an easy, high velocity race with a tail wind . But now that the race distances were getting longer and had been head wind flys, he, like the majority of members was experiencing very poor returns. He presented birds to the clinic to have this investigated. As his experiences were typical of many members this was seen as a good opportunity to investigate if Rota was involved or not. Because of this , the Greater Melbourne Pigeon Federation partially funded the investigation.

The following tests were done.

 

1/ Clinical examination   Birds that had returned late on Saturday and on Sunday from the weekend’s race were presented at the clinic  on Monday for examination. The birds had the typical appearance of birds that had recently raced. There were no outstanding clinical features apart from the fact that some birds had yellow plaques at the beak margins, which looked like pigeon pox vesicles

 

2/ Microscopic examination of the droppings—low levels of coccidia eggs were detected

 

3/ Microscopic examination of a crop flush – large numbers of trichomonads were detected, ie the birds had wet canker

 

4/ Blood was collected for a Chlamydia Immunocomb test – this test detects the presence of Chlamydia antibodies in the blood. These antibodies are formed in response to a current or recent Chlamydia infection. The test was negative

 

5/ Blood was drawn for complete biochemistry and haematology. This blood was drawn on Tuesday morning from a bird that had returned late on Sunday. Biochemistry tests among other things evaluate organ function while haematology tests count and compare red blood cells and the various types of white blood cells. We were particularly interested in the liver and kidney results because it is these organs that Rota particularly  targets. The results are below.

HAEMATOLOGY                                                    
                                                                
Test                              Result   Units    
                                                                
*PCV                              0.56           L/L                     
*THROMBOCYTES           Clumped and adequate                   
*WBC                              8.0            x10^9/L                 
*HETEROPHILS%           58             %                                                           
*HETEROPHILS              4.6            x10^9/L                 
*LYMPHOCYTES%          41             %                       
*LYMPHOCYTES            3.3            x10^9/L                 
*MONOCYTES%               1              %                       
*MONOCYTES                 0.1            x10^9/L                 
*EOSINOPHILS%             0              %                                                                
*EOSINOPHILS               0.0            x10^9/L                 
*BASOPHILS%                0              %                       
*BASOPHILS                  0.0            x10^9/L                 
*BLOOD SMEAR            Red cell and white cell morphology     
EXAMINATION             normal.                                
                                                                                           
                                                                
BIOCHEMISTRY                                                   
                                                                
Test                                 Result          Units  
                                                                
*GLUCOSE, SERUM         19.0           mmol/L                  
*UREA                                 1.5            mmol/L                  
*CALCIUM                           2.0            mmol/L                  
*PROTEIN, TOTAL              26             g/L                                                                
*ALBUMIN                            9              g/L                     
*GLOBULIN                         17             g/L                     
*A:G RATIO                         0.5                                    
*AST                                    329            IU/L                    
*CK                                      634            IU/L                    
*CHOLESTEROL                 5.5            mmol/L                                                     
*AMYLASE                         1500           IU/L                    
*GLDH                                    8              IU/L                    
*URIC ACID                        0.56           mmol/L                  
*BILE ACIDS FASTING       32             umol/L                  
*SAMPLE APPEARANCE      Mild haemolysis                        
      Haemolysis may falsely decrease Bilirubin, Glucose and    
      T4, and may affect GGT in an unpredictable manner.         
                             

The principal changes were

  a/ elevated GLDH – GLDH is what we call a hepatocellular leakage enzyme. When liver cells are damaged this enzyme leaks from inside liver cells into the bloodstream. An elevation in the blood is a direct indicator of liver damage. In health the reading should be less than 1. Anything over 3 is regarded as serious . This bird had a value of 8.

  b/ elevated urea – urea is a body waste . It is excreted from the body by healthy kidneys. When the kidneys are working normally the urea level should be between 0.4 and 0.7. This bird’s value was 1.5. Body wastes that should have been excreted in the urine were accumulating in the blood

  c/ elevated PCV  -- PCV stands for Packed Cell Volume. This is the concentration of red blood cells in the circulation. A number of factors affect this but the most common cause of an elevation is dehydration. Normal is about 0.42. This bird’s value was 0.56.The interesting thing is that this bird had been home for 48 hours with free access to water before the blood was drawn and yet it was still dehydrated. The kidneys have 2 main jobs. Namely to excrete body wastes and to maintain a normal level of hydration . When kidneys are not working properly , not only do wastes accumulate in the blood but the kidneys lose the ability to concentrate urine and therefore conserve body fluid and maintain a normal level of hydration  Because of this, unless the pigeon can drink regularly, dehydration occurs

  d/ the total number of white blood cells was low and the actual type of white blood cell that was low was a lymphocyte. This suggested that an inflammatory process was going on in the body that was using these white blood cells up

 

These values were all regarded as significant. The blood results indicated the presence of liver inflammation and impaired kidney function. The results also told us that the bird was dehydrated and  that there was a focus of inflammation somewhere in the body that was involving lymphocytes. Racing pigeons are not like parrots sitting in an aviary. They are athletic birds that are usually not just healthy but also fit.  It takes quite a bit to cause changes in blood values such as these

 

  e/ Autopsy and histopathology – Without histopathology we would not know what was the actual cause of the liver and kidney problems. A different bird that had also been late from the race was selected. It was euthanized and a full set of tissue samples collected and forwarded to the specialist pathologists at AgriBio for microscopic examination. Click here for the results. The pathologists confirmed the presence of coccidia and determined the ulcers in the mouth to be pigeon pox. The pattern of inflammation in the liver was described as lymphocytic and heterophilic. What this means is that it is these 2 types of white blood cell that were primarily involved in the inflammatory response. The pathologist states, “This type of inflammatory response is not consistent with clinical Rota virus infection (at least not the fatal infection) as there is no necrosis (ie  tissue death ) or phagocytic macrophages present ( ie the type of white blood cells involved are different ). I would presume that the hepatitis ( ie liver inflammation) is associated with Rota virus though “. The final diagnosis by the pathologist is a presumed Sub Fatal Rota virus infection.

 

  f/ A Rota virus PCR test that detects DNA was done on the liver and this was positive. This loft was exposed to “Poovac “ mid- June. Now in late October the pigeon was still carrying Rota virus .

 

At this stage in our understanding of Rota virus the diagnosis can only be presumed. No other cause of the hepatitis was detected and Rota virus was present. To date, however, this is the only case that has been investigated and so there is no point of reference. We just don’t know if this is the typical pattern of inflammation and liver damage seen with chronic Rota virus infection. This type of investigation needs to be done on more birds from different lofts. However at this stage it does seem as if the changes in the blood and identified on histopathology are due to Rota virus. If this is indeed the case, it does mean that at least some recovered pigeons previously infected with Rota virus do suffer long term damage. This damage involves active liver inflammation and impaired kidney function. It does  therefore appear that being infected with Rota virus does subsequently interfere with a pigeons ability to race. Because of the damage to the kidneys and resultant impaired ability to excrete body wastes and prevent dehydration it is logical that this effect will be more marked in races where birds need to spend longer on the wing and  in races that are conducted during hot weather

 

I would like to thank The Greater Melbourne Pigeon Federation  in Melbourne, Victoria for partially funding this investigation. I would also like to thank Stevan Gazzola for making these results available and also for letting us do this investigation. The results are useful to us all.

 

Vaccine availability.

I had an email from Dr Mark White yesterday. He has explained that with ongoing uncertainty about the contract, incomplete R&D and the Christmas slow-down period coming up , that it is going to be challenging to have the vaccine available before racing next year.  Mark is certainly doing as much as he can to have the vaccine available as quickly as possible. I must say that I am frustrated, disappointed and annoyed that the contract negotiations have taken so long . This has led to a delay in Latrobe releasing manufacturing details to Mark so that he can get on with production.

October 16

What is happening with  the vaccine?

I am extremely disappointed to report to fanciers that since my last Update 6 weeks ago that there has been no advance in developing the vaccine. The whole process has been bogged down in ongoing contract negotiations. Anyone would understand that after all our efforts to expedite the process and get the diagnosis, explore cross immunity with available vaccines here and overseas, realise we had to make a vaccine and then make an experimental vaccine it has been very hard to watch the weeks go buy with negotiations when we are right on the cusp of moving to commercial production. In an effort to prevent further delays I have personally offered to act as guarantor for he Latrobe invoice both through the ANRPB and also directly. For reasons that have not been explained to me except “ that it was more prestigious for the University to deal with a national Board rather than a private individual”. I saw my offer to pay Latrobe while the contract was being sorted as a lifeline to the pigeon industry to avoid delays. Frustratingly this has not happened. I rang the Vice chancellors office today. At this stage the contract negotiations appear to be hopefully coming to a conclusion. A friend has advised me

 “as a general comment I would say that usually universities are not easy to deal with. There is often a disconnect between the researchers doing the science work and the back-office staff dealing with commercial issues. There tends to be wheels within wheels going on in the background that we don’t fully understand, not uncommonly related to their longer term funding plans and the politics of the university. They sometimes have unrealistic notions about the practical and commercial value of the IP. Plus all the vagaries of a public sector governance system. Nebulous is the word that comes to mind to describe their style. It’s like trying to tie down a cloud.”

This helps to put things in perspective. We will continue to advance things as quickly as we can

 

Is Rota virus affecting racing?

Before racing started we drew blood from several recovered Rota virus birds and ran biochemistry and haematology blood profiles. Haematology tests count red blood cells and the various types of white blood cells while biochemistry tests, amongst other things evaluate organ function. We were particularly interested in the liver and kidney values because it is these organs that are particularly damaged by Rota virus. Had the organs healed sufficiently to keep all the blood parameters within normal range? The result was that all the values were normal. These tests were done however several months before racing started. The birds were not in formal training and just flying the roof. Pigeons however are exertional, athletic, competitive animals and I am starting to believe that as the hours on the wing start to climb particularly on warm days that having had  Rota virus may start to affect performance, Whereas a pigeon with say 90-95 % liver or kidney function may be able to look well and keep its blood values within normal range when not under stress, any deficit in organ function would be important during racing. What we really need to do is draw blood and run profiles on some recovered Rota birds after they return from a hard race . One worrying thing is that some fanciers are reporting large wet patches on the loft floor after birds return from a race. These dropping are primarily  made up of dilute urine and are often associated with impaired kidney function. When pigeons are working on a hot day and not drinking , as in a race , healthy kidneys conserve body fluid by making the urine more concentrated. An inability to do this quickly leads to dehydration unless the pigeon can drink regularly. This opportunity may not present itself during return. 5% dehydration leads to mental confusion. 10% dehydration is death. I don’t think that Rota virus is the beginning and end of why many federations are reporting poor returns on harder days but I think it may be a contributing factor. Particularly with the large numbers of pigeons involved it would be surprising if every pigeon had fully recovered with no damage from Rota. I think that it is at least probable that there are a proportion of birds which are left with persistent residual damage to variable extents, and that these birds would struggle on a hard day

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New Zealand

I  have been doing some work for the New Zealand government over the last 2 weeks . I was engaged to review the “Rapid Risk Assessment; Pigeon Rota virus in pigeons from Australia”. The New Zealand government currently has an import ban on racing pigeons from Australia. With Rota virus now in Australia this ban is likely to continue.

Federation Columbophile International ( FCI)

A statement was released the week by the international governing body of pigeon racing regarding Rota virus.

Dear Sirs..... Federations or OLR

 Australia is now facing an epidemic of a new strain of rotavírus that causes a mortality in racing pigeons up to 40% including adults. The epidemic started in May 2016 in West Australia and already spread to the whole country and Tasmania.

The australian government did not declare a ban to export pigeons to other countries. So for containment of the distribution of this new rotavirus the FCI has a duty of information to the member federations and imposes a ban of participation of australian pigeons in all FCI Exhibitions and OLR of the FCI Grand Prix. This measure to be lifted when the disease is erradicated or an effective vaccine is available.

In annex an article about this new epidemic by Dr Lydia Teske et al.

 The President of the Veterinary Commission of the FCI

 Dr David Barros Madeira

Australian fanciers need to be mindful that they should not consider exporting pigeons or taking pigeons with them if they go overseas. No one wants to be the fancier who gives Rota virus to the rest of the world

Is Rota virus going to affect breeding this year?

The answer is probably yes, but hopefully not in a big way.This will be the first full breeding season on the eastern sea board since the outbreak. The majority of stock birds will have had Rota virus and therefore have some immunity and the few that are long term carriers will still be shedding the virus. There was some information that came out of WA last year but reports were mixed. In some instances fanciers seemed to be modifying the         so called facts to match what they wanted the truth to be.

There are a number of possibilities for what might happen and there are a number of precedents with other viruses.

1/ It is likely that in most lofts carrier stock birds will pass the virus to their own youngsters and other youngsters in the loft. It is also likely that they will transfer some of their immunity as well. This will mean that even though the youngsters are exposed to the virus they will not become sick at that time.  This is what happens with Herpes virus.

2/It may be that the level of immunity is not high enough to protect some youngsters and so a small number may develop disease that could be mild to severe depending on the amount of immunity they acquire. This is what happens with Circo virus.

3/ It could be that the level of immunity is low now in some stock lofts, particularly if they had the disease more than 12 months ago . Youngsters bred in these lofts may have quite low immunity. If these youngsters come in contact with the virus once weaned, particularly in hot weather, then severe disease could occur. This happens with PMV.

If the loft has had Rota in the previous 10 to 12 months I think that either of the first 2 options are the most likely.

However protective immunity passively acquired from parents is usually only transient in yougsters. For example, we know that this immunity only lasts about 6 weeks with PMV in youngsters bred from either vaccinated birds or birds that have had the disease in the previous 12 months . At one point the immunity the youngsters have from their parents against Rota will fade and so therefore at some point all of the youngsters bred this year will become vulnerable to catching the disease. This is why large numbers of young pigeons caught the disease the first time they mixed with birds from other lofts (and were exposed to the virus) in the early races in WA this year.It is also why it is so important to get the vaccine as quickly as we can. 


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