Herd Immunity

[Rob Rixon]

Defination - Herd immunity (or community immunity) describes a type of immunity that occurs when the vaccination of a portion of the population (or herd) provides protection to unvaccinated individuals. Herd immunity theory proposes that, in diseases passed from person-to-person (or dog to dog), it is more difficult to maintain a chain of infection when large numbers of a population are immune. The more immune individuals present in a population, the lower the likelihood that a susceptible person (or dog) will come into contact with an infected individual.

Vaccination acts as a sort of "firebreak" in the spread of the disease, slowing or preventing further transmission of the disease to others. If all whippets had KC jabs and had to show they had had the jab before they got their WCRA sticker would this eliminate KC in racing dogs?

Although no vaccine offers 100% protection, the spread of disease from person to person (or dog to dog) is much higher in those who remain un-vaccinated. Virologists have found that when a certain percentage of a population is vaccinated, the spread of the disease is effectively stopped. This critical percentage, called the herd immunity threshold, depends on the disease and the vaccine. It is the general aim of those involved in public health to establish herd immunity in most populations. However complications arise when wide spread vaccination is not possible, and when vaccines fail.

What do you think? :lol:

 

[wild whippies]

I think it wouldn't be effective as Kennel Cough is caused by several viruses and bacterias.

I suspect it's very much like the flu vaccine in humans, the most likely variant at that period in time is identified and vaccine created for it but it certainly isn't a guarantee that you won't fall ill to another flu virus doing the rounds.

 

[sue greenwood]

Herd immunity is fine if the herd stays in one place and they dont have members of other herds visiting. Each herd has it's own immunity against local strains.However when they visit other herds they secombe to alien strains. Then vaccines step in to try and keep the strains under control. This they do in the short term until the strains evolve.

However:

The questions should be......

1. Do we stop travelling around?

2. Do we vaccinate and hope the strains don't evolve?

3. Do we take our dogs to every possible place were dogs frequent and let them build their own immunity to several strains?

4. Just accept we will get KC what ever we do?

 

[Judy]

Its certainly worked for Parvo, distemper etc. There's not nearly as many cases as before we all started vaccinating for it. If the sub section of racing whippets were treated as a "herd" then it might help but I take the point about KC being like the flu virus.

 

[masta]

whenever kc is about it seems to be the racing fraternity that gets it is this because

a the dogs are stressed and more subsceptable

b the racers are more open re reporting

c less racers are vaccinated

it seems that showing is unaffected no shows cancelled etc

 

[wild whippies]

Bigger means of cross contamination in racing, especially where dogs may be carriers but are not actively coughing.

With regards to parvo, I'm sure it's been alleged that all dogs are now immune to CPV1 -the first strain of parvo. It is the mutated strains which dogs are vaccinated for. Personally I recon even if every dog in the UK was vaccinated against KC tomorrow there would still be outbbreaks.

 

[Joanna]

Kennel Cough is like the common cold, there are many viruses producing similar symptoms. I personally feel it is some-thing we just have to put up with and some years it will be worse than others. On the whole, the virus isn't dangerous unless you have extremely young, old or immune suppressed animals. The very fact that dogs travel from place to place, and are in close proximity to each other at events is going to ensure it is spread throughout the racing fraternity. I think cancelling racing for a few weeks nips it in the bud and it is more nuisance factor than any-thing else. I doubt there is ever going to be a cure as there probably won't be for the common cold, too many strains! I am not worried if my dogs go down with a dose, I would just keep them well away from other animals until they were over it. Anti-bodies to that particular strain would be produced in the dog, and you wouldn't go down with that particualr virus again. Can't see any point in immunising at all. It is possiblyquite telling in a way that Julie's young dogs have caught the virus and we haven'y heard of others that attended Andover going down with it. I wonder if this strain was the one a lot of us got last year and the older and previously affected dogs have developed immunity?

 

[wild whippies]

Snap!! Exactly what I'm thinking Joanna.

 

[peppermint lady]

thats right in the most part jo :thumbsup:

but maybe im the only one to be upfront and honest in the fact that my dogs had it :- "

after speaking with many racing folk over the last few weeks....we all find it very hard to believe out off 140 racing dogs plus dogs that had travelled to the track but maybe not racing...ie puppies/older dogs...that mine have been the only dogs effected by kc.. :unsure: :- "

for example for mine to catch it they would of had to have contact with either

a dog carrying kc but was not showing the signs untill after the open (hence the owner probaly ran the dog but would not have known it was carrying kc untill after racing when coughing started)...this cant be helped

or....a dog had kc..had stopped coughing but was not in the clear to be exposed to other dogs at the time of the open :unsure:

im glad all mine got it at the same time and now no longer are a threat to anyone elses dogs......i just hope this is the end of it for this year at least :thumbsup:

 

[peppermint lady]

also

all my dogs have had their jabs, and my dogs are by no means stressed.

im 100% sure that work/ show dogs of any breed also catch kc...its just do people own up or not :- "

 

[masta]

Kennel Cough is like the common cold, there are many viruses producing similar symptoms. I personally feel it is some-thing we just have to put up with and some years it will be worse than others. On the whole, the virus isn't dangerous unless you have extremely young, old or immune suppressed animals. The very fact that dogs travel from place to place, and are in close proximity to each other at events is going to ensure it is spread throughout the racing fraternity. I think cancelling racing for a few weeks nips it in the bud and it is more nuisance factor than any-thing else. I doubt there is ever going to be a cure as there probably won't be for the common cold, too many strains! I am not worried if my dogs go down with a dose, I would just keep them well away from other animals until they were over it. Anti-bodies to that particular strain would be produced in the dog, and you wouldn't go down with that particualr virus again. Can't see any point in immunising at all. It is possiblyquite telling in a way that Julie's young dogs have caught the virus and we haven'y heard of others that attended Andover going down with it. I wonder if this strain was the one a lot of us got last year and the older and previously affected dogs have developed immunity?

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i understand why it is spread in racing, but why is it not as prevelant with showers they travel to shows in different parts of the UK the dogs are mixing many more dogs than the racers how many dog shows + game fairs were cancelled this year?

 

[masta]

also all my dogs have had their jabs, and my dogs are by no means stressed.

im 100% sure that work/ show dogs of any breed also catch kc...its just do people own up or not :- "

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when i said "stressed" i ment due to racing /adrenaline etc lowering immunity

 

[Judy]

I don't think it has anything to do with immunity. Probably it's passed on more easily at racing because at the end of a race on the lure, carrier dogs are breathing hard in the other dogs faces and they in turn are breathing in deeply too and its passed by droplets in the air. This seems to mean that unlike in the normal population, affected dogs can pass it on before they are actually coughing.

They do get Kennel cough at shows etc but they don't tend to get cancelled, I assume because of the much higher difficulty and cost of putting on a show (hiring venues/ benching etc.)

 

[midlanderkeith]

I don't think it has anything to do with immunity. Probably it's passed on more easily at racing because at the end of a race on the lure, carrier dogs are breathing hard in the other dogs faces and they in turn are breathing in deeply too. Its passed by droplets in the air. This doesn't happen at shows.
They do get Kennel cough at shows etc but they don't tend to get cancelled, I assume because of the much higher difficulty and cost of putting on a show (hiring venues/ benching etc.)

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Am i reading this right, money afore dogs welfare, tell you summat, as long as theres even a whiff of kennel cough or out else thats going, game fares and the likes are out for me till its shifted, and thats the only way, shut everything right down

 

[Louise_Simon]

I had my three vaccinated and have kept them away from their other activities and other dogs since the outbreak as I didnt want them picking anything up during the break from racing, also 1 of them is elderly and I really dont want to risk her health

 

[Joanna]

but maybe im the only one to be upfront and honest in the fact that my dogs had it 

Very possibly, I do find it difficult to believe yours were the only ones to go down with it. To be fair, not every-one with racing whippets visits this site so I suppose we do need to give the benefit of the doubt 8) Is there an emoticon with a halo, can't find one

 

[wild whippies]

Firstly dogs can be carriers and not suffer from the disease. Mass swabbing of NGRC kennels and the kennels in America clearly demonstarted dogs can be carriers of various viruses and suffer no symptoms.

Masta is quite correct, racings dogs does elevate stress levels - people take offence at this but the term shouldn't be confused with a dog suffering, like he says elevated adrenalin levels, increased thyroxine production and periods of excitability will 'stress' an animal. It's the reason why periods of rest and recouperation are so beneficial to the racing dog.

Dog showing, well firstly I strongly suspect there is nowhere near the likelihood of cross infection as there is within dog racing. Dogs are rarely panting, barking or bouncing all over each other. They're usually benched with partioning between each other and physical contact with each other is low. I agree the dog showing fraternity rarely cancel their events during outbreaks and suspect Judy's hit the nail on the head about costs.

Dog racing, panting and barking all propel saliva into the air. Traps can become heavily infected along with the lure. At the knock off, dogs clamber all over each other and I've got plenty of shots where dogs mid race have saliva trailing off in air.

Non-ped racing has continued in general but recommendations have been put in place to prevent the spread of the virus and I hope they continue to use these regardless of infections doing the rounds. Owners have been very honest about their dogs becoming infected and the vast majority have stayed away from the tracks.

Immunity - there are a few hypothesies on the net supporting a raised immunity level can prevent kennel cough infection. As most of these are regular homeopathic remedies I don't see a disadvantage in trying them and as such have been giving these remedies. I figure at their best they may prevent an infection altogether and at their worse they may prevent a secondary bacterial infection setting in.

If mine do succumb to kennel cough, I'm not going to try and isolate infected dogs here and think it's better to let them all be exposed and succumb rather than delay it spreading within the kennels. My logic behind this is that it minimises the total time period of infection and older dogs with a well established immunity and no history of respiratory illnesses generally recover a lot quicker than the youngsters. Obviously during their period of infectivity, they will not be visiting any tracks and neither will I as a potential source of contamination.

 

[peppermint lady]

but maybe im the only one to be upfront and honest in the fact that my dogs had it 

Very possibly, I do find it difficult to believe yours were the only ones to go down with it. To be fair, not every-one with racing whippets visits this site so I suppose we do need to give the benefit of the doubt 8) Is there an emoticon with a halo, can't find one

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o o here you go jo...have one of mine

 

[Pipco]

Although it is known that Kennel cough can be caused by multiple agents, the two most common culprits are Parainfluenza virus and Bordetella. Since it is possible to vaccinate against both these agents (the first by injection and the second using the nasal spray vaccination) would it not be possible to achieve reasonable herd immunity within the racing community if this was a stipulated requirement?

l understand that antigenic drift can occur and is well documented for human influenza but is there any evidence to show that this also happens with canine parainfluenza virus? If so, is the vaccine updated on a yearly basis to reflect this change?

 

[wild whippies]

Searching for protocols on Kennel Cough vaccination is variable, some stipulate 6 months, others 12. Either being the case, it would appear to me that the frequency of vaccination is indicative of the agents concerned being able to replicate and mutations occuring would enable antigenic drift. Influenza viruses are apparently all susceptible to antigenic drift but it's speed at doing so is variable.

There is another concern, we are all well aware that the older dog with an established immunity generally fairs well when they succumb to the virus. What happens if the dog never receives exposure to milder variants and then encounters something different like adenovirus or canine respiratory coronavirus?

Would a regularly KC vaccinated dog fair better than a dog with naturally acquired immunity or would they both succumb poorly because it is a different agent altogether? I'd of presumed it would be the latter? :unsure: