EN 
NL 
PL 
RO 
DE 
FR 
ES 
AR 
ZH 
JA 
ZH_TW About Vaccines for Viral Diseases and Paratyphoid (Bacterial)
When writing an article about pigeon diseases these days, it’s impossible to avoid discussing Paratyphoid, which has been one of my focal points for over 50 years. During that time, I’ve witnessed countless cases of this disease, not only in Europe but in all continents where I practiced and was affiliated with pigeon clinics, often as a partner.
Chronologically, this was in the Netherlands, then in Germany (Oberhausen), Taiwan (Taipei), England (Colchester), and Poland (Katowice), and also in China (Beijing).
As you can imagine, dear readers, this involved extensive traveling by plane and car. Just in cars, I’ve traveled 3 million kilometers, not to mention all the flying. My father was already known as the “Flying Dutchman,” but I’ve definitely followed in his footsteps. In terms of kilometers, I’ve far surpassed him, though in terms of selection techniques, he was unbeatable.
In the field of veterinary medicine, pigeon sports haven’t changed spectacularly. Okay, a few new diseases have emerged over the last 50 years, such as Herpes type 2 and Paramyxo. Circoviruses are relatively new, while Adenoviruses types 1 and 2 have been around for longer.
The most recent addition to the “pigeon virus tree” is Rotavirus, which is somewhat connected to the so-called “Adeno-Coli Syndrome,” a name coined by Dr. Lemahieu and myself in the late 1970s. So, there has been some novelty in viral diseases.
For some of these newer viral diseases, effective vaccines have been developed, such as those for Paramyxo and a reasonably effective vaccine for Rota. But that’s about it! After extensive practical research with large numbers of pigeons, I found that vaccines against Herpes are worthless. They are an illusion—they don’t work at all!
The same applies to vaccines against Adeno and Circovirus, the latter ironically being a pig vaccine. Circovirus was once considered by scientists and veterinarians as the primary cause of “Adeno-Coli Syndrome,” but based on my experiences and observations of the disease’s progression, I never believed that. After years of scientific research and advancing insights, it was discovered that during infections, particularly in the intestines, there is a rapid increase in the number of Circoviruses normally residing in young pigeons’ Bursa of Fabricius, an organ located at the top of the cloaca. Essentially, it is a relatively normal inhabitant of the pigeon cloaca and is hardly found in older pigeons.
Older pigeons also rarely harbor Rotaviruses, at least in Europe. However, in Australia about eight years ago, the situation was different. Rotavirus outbreaks there affected mostly older pigeons, often resulting in high mortality rates.
Here in Western Europe, I’ve encountered only one case of Rota in yearlings. However, these pigeons were less than 12 months old and had no contact with other pigeons, which is an important observation! In simple terms, limited exposure to a virus can build immunity, while excessive exposure can lead to illness, especially if immunity levels are low—a principle that applies to all infectious diseases.
Recently, I experienced problems with a “white” Paratyphoid vaccine. As you may know, I dislike “white” (oil-adjuvant) vaccines, especially for older pigeons, due to the potential harm they can cause. This is not necessarily the fault of the person administering the vaccine; some pigeons are simply more sensitive to it. Interestingly, young pigeons seem to have fewer issues with it.
A client came to me complaining about one of his hens suddenly appearing lethargic, refusing to eat, and producing greenish droppings. I asked three questions:
- Have you introduced new hens? Answer: No.
- Is she pairing with a partner? Answer: No.
- Were they vaccinated, and if so, when and for what? Answer: Yes, against Paratyphoid.
One more question: Was it a white vaccine, like Salmovac, about two weeks ago? Answer: Yes.
Bingo: a lump in her neck, painful and pressing on vital nerves above the spinal column. The hen was clearly in pain and felt weak. She was admitted, put on an IV, given painkillers and antibiotics, and recovered quickly. I asked the owner to check the necks of his other vaccinated pigeons, and sure enough, multiple vaccine lumps (granulomas) were found.
Feeling for these lumps requires some skill—deep palpation with an empty crop, on both sides of the crop. Some lumps disappear after months, while others may ulcerate or remain, potentially hindering the pigeon. Many fanciers don’t notice this, and unfortunately, neither do many veterinarians.
There is far more vaccination against Paratyphoid than in the past, yet I’m seeing more cases of Paratyphoid now. Sometimes, I suspect that vaccination can lead to chronic forms of the disease.
On our lofts, we house many pigeons, but we do not vaccinate against Paratyphoid, nor against Adeno, Herpes, or Circo, and we rarely encounter issues with these diseases.
We do, however, conduct preventive treatments against Paratyphoid, knowing that in September, Salmonella (Paratyphoid) can be cultured from 70% of transport crates. This was confirmed by scientific research conducted by Dr. R. Haesendonck, a renowned pigeon veterinarian and scientist, director of the esteemed Zoolyx laboratory in Aalst (B).
Latent Paratyphoid remains a persistent issue for over 50 years, but with proper monitoring, it can be well controlled.
I wish you happy holidays and a healthy and prosperous 2025.
Breda, 5 december 2024
Drs. H.J.M. de Weerd
Veterinarian for Homing Pigeons
Leave a Reply