PDD: What it means to YOU

[Graehstone]

HELP STOP PROVENTRICULAR DILATATION DISEASE!

A recently recognized infectious agent is killing companion, aviary, and free-ranging birds throughout the world. At present, no birds or aviaries are known to be protected. This dreaded affliction is called Proventricular Dilatation Disease (PDD).

What Species are susceptible to PDD?

In the order Psittaciformes, PDD has been reported in more than 50 species, including the families Cacatuidae (Cockatoos and Cockatiels) and Psittacidae (Lovebirds, Macaws, Parakeets, Parrots, Amazon Parrots, Conures). Pacific, South American and Afro-Asian species have been described with characteristic lesions. Suggestive lesions also have been reported in free-ranging Canada Geese (Branta canadensis, Order Anseriformes), and Spoonbills, Toucans and Weavers. Other non-psittacine birds also may prove to be susceptible to this disease as improved tests are developed to accurately diagnose affected individuals. Clinical reports suggest that adults are more commonly affected than neonates.

When was PDD first recognized and what synonyms have been used?

Proventricular Dilatation Disease has been recognized since the late 1970's. Initially, the disease seemed to be limited to macaws. This fact, in conjunction with an unknown cause, gave rise to the terms macaw wasting or fading syndrome, wasting macaw syndrome, and gastric distension of macaws. As it became apparent that the disease occurred in psittacines other than macaws, a more general terminology was used to describe the disease, including psittacine wasting syndrome, proventricular hypertrophy, or proventricular dilatation syndrome. Various terminology also has been used to describe the pathological features of this disease, including neuropathic gastric dilatation, myenteric ganglioneuritis, proventricular and ventricular myositis, psittacine encephalomyelitis and infiltrative splanchnic neuropathy.

What are the signs of PDD?

The most common clinical signs of PDD include depression, weight loss, constant or intermittent regurgitation, and/or passage of undigested food in the feces indicating a malabsorptive or maldigestive disorder. Proventricular impaction, muscle atrophy, abdominal enlargement, lethargy, weakness, polyuria, diarrhea, scant feces or hypotension also have been reported in some birds. When the central nervous system is involved, signs may include ataxia, abnormal head movements or seizures. Some affected birds may develop central nervous system signs in the absence of gastrointestinal abnormalities.

How is PDD diagnosed?

A presumptive diagnosis of PDD is based on historical information, clinical signs, and radiographic evidence of proventricular dilatation or dysfunction. Confirming that a living bird has PDD is difficult. Biopsy of the ventriculus or proventriculus can be used to diagnose the disease. However, obtaining a biopsy sample from these organs is invasive and dangerous. In some birds, biopsy of the crop can be used to diagnose the disease. At necropsy, emaciation, pectoral muscle atrophy, and dilatation of the esophagus, proventriculus, ventriculus, or small intestine are observed commonly. The proventriculus may appear thin-walled and friable. Microbial infections, parasitism, gastrointestinal obstructions, neoplasms, trauma, malassimilation disorders, toxin ingestion or malnutrition may cause similar changes and also must be considered. A definitive diagnosis is often made after death when microscopic examination of the tissues reveals the characteristic lymphoplasmacytic inflammatory infiltrates in central and peripheral nervous tissues.

What causes PDD?

The etiologic agent of PDD remains unconfirmed, although recent research conducted by the Psittacine Disease Research Group at the University of Georgia implicates an infectious agent. The disease apparently has subacute, acute and chronic stages; however, the majority of diseased birds die within several months to a year after developing clinical signs. Interestingly, disease does not develop in all exposed birds, which suggests that some birds have an innate resistance, develop a protective immune response, lack factors that are required for inducing the disease, possess factors which prevent development of the disease, or develop a carrier state. The fact that some exposed birds remain normal is good news for the avicultural community. This suggest that continued research efforts could provide effective control measures to prevent disease.

What can be done for birds with PDD?

Unfortunately, all birds with confirmed PDD have died. Until further information is available about the virus that is causing this disease, preventative measures such as quarantine of new birds, avoidance of direct or indirect contact between isolated groups of psittacine birds and appropriate hygiene are the only available methods to reduce exposure.

PDD Summary:

Proventricular Dilatation Disease is a deadly infection that can kill many species of parrots and other birds. There is no effective treatment. Recent findings confirmed that this disease is infectious. Suspicion of PDD is based upon historical information, clinical signs and radiographic evidence of proventricular enlargement or dysfunction. Definitive diagnosis of PDD requires the microscopic demonstration of characteristic lymphoplasmacytic infiltrates within nervous tissue. The disease cannot be diagnosed by clinical abnormalities or gross necropsy findings.Microscopic examination of the ventriculus, proventriculus, crop or brain of affected birds is currently the only way to confirm the disease.

Here is a very good article from Parrot Chronicles: http://www.parrotchronicles.com/septoct2004/quilt.htm
Too many of our Fids have passed from this most horrible of illness' and only we (the Parronts) are in a position to change history and ensure that these beautiful creatures will still be there for our grandchildren to enjoy as much as we do.
If you do nothing of import for the rest of your lives, this one deed (your donation) will ensure your spot in history as a Hero for the cause.
Thank you from the bottom of my heart in the name of all the countless families that have had personal experience with this scourge.

info garnered from here: http://www.mecca.org/~rporter/PARROTS/no_pds.html

[greyburd]

Mike, thanks for posting this!!! (as always..... YOU ROCK!!)

Kev's or Mods, is there any way we can keep this post as a sticky or keep it toward the top of the page so it doesn't get lost in all of the other posts?

[Graehstone]

In order to perhaps better understand the above information I would like to add that PDD is to the avian community what AIDS is to humanity.
I am sure that there are folks that are better suited to explain just what this disease is and does.

Proventricular Dilatation Disease (PDD) is also known as Macaw Wasting Disease is a viral infection causing destruction of the nerves in the digestive system. This destruction to the nerve supply to the stomach, gizzard, and small intestine makes it difficult for the bird to digest food, causing malnutrition and "wasting". The bird actually begins to starve to death.

The disease first started showing up in the late 1970's and was believed to have been passed to tropical birds shipped with chickens. Macaws were the first birds to show signs of the disease - thus the name "Macaw Wasting Disease". Since then, the disease has moved to other members of the parrot family.

Symptoms of the disease are:

* Weight loss over a weeks or months (despite eating well)
* Passing undigested food in the stool
* Vomiting
* Distention
* Food impaction in the crop

The tragic part of PDD is that there is no cure.

It is almost always fatal. It is also easily transmitted to other birds in the house. If a bird starts to show signs of the disease it should be quarantined immediately and then taken to an avian veterinarian for testing and diagnosis. Unfortunately, it is not known how long it takes for the bird to show signs of the illness. It could lie dormant for years before showing up in clinical signs. At this time, there is no test to determine if a bird has the disease in the early stages. A contrast x-ray test can determine how long it takes food to move through the digestive tract - if it takes hours, it can be a sign of nerve damage.

Currently, research is being done at the Emerging Disease Research Group (EDRG) at the University of Georgia's College of Veterinary Medicine to find a cure for PDD, but at this time there is little that can be done to fight this killer.

If interested, here is more information on Proventricular Dilatation Disease.
http://snipurl.com/kssu

I hope that helped a bit in making it more understandable for those of you that are truely interested. Thanks again for your time.

[fatma]

Thanks alot for this great informations!

[Tiki]

Just stickied! Thanks for an excellent article, Mike! I will be highlighting this topic in next month's newsletter.

For those of you wishing to donate to the reasearch team headed by Dr Branson Ritchie who are trying to find a cure for PDD, please visit his website:

www.stoppdd.org

You can send checks or use Paypal, Paypal is the easiest option for overseas people.

[Alyce Johnson]

PDD is clearly viral, and sounds like it might be in the herpes family, because of the affinity for the nervous system. If so, AIDS may be an all too accurate analogy, and a cure may be a very long time in coming (sadly).

Human varieties of herpes viruses have been implicated as a possible cause of MS and as a possible co-factor in the development of full blown AIDS in HIV positive folks. There are many members of this family of viruses. Human chicken pox - and it's adult "relapse" called shingles - are also in this family. Genital & oral herpes are in many ways the least nasty of the bunch, although well known.

All that said, I would think that a general program to boost viral immunity might be a really good thing, especially if you think your fid might have been exposed.

Does anyone have any advice re appropriate doses of things like vitamin C in fids? (For ex. by weight, in mgs per grams of bird?) Any other naturopathic types of flu preventatives known for birds? (Flu being also viral would suggest that a flu preventative might also help protect against PDD.) How about some of the other (human) natural antivirals, like mushroom extracts & so on? Any knowledge of natural medicine for birds where viruses are concerned?

How about antiviral drugs, like acyclovir & Valtrex (it's newer supposedly slicker cousin)? We parronts can easily get access to those drugs, and could give them if we knew appropriate doses, and if we knew it was safe to try it. Has anyone heard of PDD being treated this way? Anybody know if this stuff is toxic to birds? (It's not all that great for humans - has nasty side effects & such, but it's far preferable to the alternative, is all.)

[The Outlaw]

Actually though it acts more viral than anything else, its not CLEARLY viral. Everything that that we thought we knew a year ago, we now know was probably incorrect. It simply defies all of the normal rules for disease.

Its frustrating. Until they can actually isolate it in its active state, all we are sure of is what its destroyed along the way. Trust me, it simpy defies all of the laws of science.

That is why the research is so important. We have to understand the process, isolate the pathogen and then find out what stops it in its tracks. That is the mission and that's why the research is essential. Its similar to AIDs, but its clearly NOT AIDS. Its far more complicated.

[Montys Mommy]

Thanks so much for the article, I've been looking for something as informative as this on PDD for along time.
Once again Thanks alot, and you to mods for stickying it!

[Alyce Johnson]

I should have said "likely" viral, rather than "clearly". Nor did I mean to suggest it was in any way related to AIDS biologically. And I didnt mean to suggest that research wasnt important - it's vital, obvioiusly.

But, to use AIDS *purely as an example* there has been a lot of research money for AIDS and 25 years of some of the best minds working on it. And still no cure. In fact we still arent even sure what causes the disease process, at the most basic level. So yes, research is good, but I wouldnt hold my breath, is all I'm tyring to say. These things are incredibly hard to crack, even given every modern trick.

As far as AIDS goes, your best bet is still a condom. So I'm just wondering what we could do, in the interim, to try to keep our babies safe. Because the science may take awhile yet to pan out, no matter how dilligently we fund it.

Re PDD: I read the research links given here and it seems a variety of viruses are under consideration but none have been consistently found in all victims. Most of what they're describing though (staying latent for long periods of time, for ex) actually isnt unheard of - anthrax does that too, for ex. The prion that causes mad cow disease cant even be "killed" (denatured would be more correct) by very high temperature.

Bottom line, the bugs have been at this a lot longer than we have and all of them have smaller, more mutable genomes than we (or our birds) do, meaning they can usually adapt to their hosts (to keep living inside us) faster than our immune systems can normally adapt to them (to give them the boot).

So regardless of what causes or triggers PDD (bacterial, viral, prion, autoimmune, environmental toxin etc.) I would still think any immune system boosting we could do would be helpful, no? Does anyone have any info, references or resources on that topic?

Or on the topic of antivirals being used in birds?
The drug they were using in the PDD studies referenced in the links was Celebrex -a "cox 2 inhibitor" anti-inflamatory, not an antiviral. Celebrex is used in humans mainly to treat osteoarthritis - it's a close relative of Viox, which was in the news not so long ago. But there was no mention of antivirals, which seemed odd, since they were listing off all of the causitive suspects and all were viruses. This suggests maybe antivirals are too toxic to be used in birds? Does anyone know?

[The Outlaw]

The Celebrex and Mobic only reduce the inflammation in the proventriculus allowing the gut to work longer and more efficiently. As for the anti virals, not sure. I can send an inquiry to Dr. Ritchie. However, common sense tells me its probably been tried.

We have NO hope of controlling or preventing this killer without research. That's simply a fact of life. Whether we do or do not find a cure depends on whether or not we can control its spread. Since we have done a lousy job of that, we really need to understand that EVERY bird is in danger. Even the isolated ones. You just cannot keep their environments contaminent free. Were it so, none of the zoos would have lost any specimens.

There is ongoing research in Canada and England. The University of Pennsylvania also is using Mobic in their studies. I believe they are working with the Canadians.

Still, you have to understand where the bulk of captive parrots now live, and that's right here in the States. Unlike AIDS, we can't control its transmission. We don't even understand how its transmitted. The research MUST go on.