There have been many posts recently about CHV (Canine Herpes Virus).  With much research, with my own and other Vets, including Royal Dick Veterinary College, Edinburgh, I have tried to, in Laymans terms, produce a small synopsis, in the hope that everyone can gain a better understanding of it.

Herpes virus infection in the last three weeks of pregnancy or the first three weeks post-whelping is most likely to result in infection of the puppies. This happens because the mother passes on the virus to the puppies but does not give them antibodies against the disease, so they are susceptible to infection. In most cases, a bitch who has been infected with herpes virus prior to being bred will pass on adequate antibody protection to her puppies to keep them from being infected at a time when they are likely to become severely ill or die. This includes bitches that are unlucky enough to become infected during the critical time in a prior pregnancy. Even though their first litter was infected, their subsequent ones are unlikely to be infected. Trying to shelter a bitch from herpes virus prior to breeding her is probably a mistake. It is better to allow her to be exposed to situations in which other dogs are around so that she will become infected with the herpes virus, develop antibodies and pass them on to her puppies. Once she is bred, though, it may be better to assume that she has not been exposed and to try to protect her from contact with dogs that may have herpes virus. Herpes virus is very common and it would be surprising if the male had not been exposed previously, so there isn't much reason to worry about him. There is a lot of conflicting information on canine herpes virus and I don't know if I am just missing something or if a lot of poor information is out there. As far as Iknow, based on the books I have here, this is the situation with canine herpes virus: This virus is a common inhabitant of the upper respiratory tract of dogs, which means that many dogs should have a positive titre. If a bitch is first exposed to this virus during a pregnancy, it can affect the litter, leading to foetal death or early death of the puppies after birth. If the litter is exposed in the first few weeks of life, they may also show severe signs of illness. Once the bitch is exposed to the virus, it is very unlikely that any further litters will be affected. The virus is common enough that if the male dog is being shown or being used for breeding on a regular basis it is very likely that he will have been exposed to the virus already and that he will have a titre. If he doesn't, I suppose he could be infected by the female. The risk to the male dog seems to be pretty small, though. Based on how I understand this situation, I would think it would be a good thing if the bitch had a titre to herpes virus prior to breeding, since that would infer that she could protect the puppies from infection during the pregnancy. Since this isn't the way the situation seems to be understood by dog breeders, I have to wonder if I am missing something -- but that is how I currently interpret the situation with canine herpes virus. Your vet should have some references that discuss this virus.
Canine herpes virus (CHV-1) is a virus that has been largely forgotten for many years, due in part to the difficulty in making a definitive diagnosis. However, it is becoming increasingly clear that the virus causes many more problems than was first thought.
Like all herpes viruses, CHV is highly infectious, and a recent study showed that more than 80% of the dogs tested had been exposed to the virus at some time in their lives. Other studies have shown infection rates of 40-100% in kennels around Europe. In kennels not previously exposed to the virus, CHV can cause massive losses, sometimes of entire litters. Death occurs in the first few days and weeks of life, with the classic pathological changes described in Diagnosis Once the virus becomesestablished in kennels, periods of high mortality are interspersed with a general fall in the average birth weight of the litter, and increased pre-weaning losses. In kennels with long-established disease the breeder may well have become accustomed to the poor results, and the existence of a problem only becomes apparent once a vaccination programme is put in place. A number of signs may suggest that CHV is causing problems, but many of these signs are multifactoral and therefore it is important to try and make a definitive diagnosis.
CHV can be a significant cause of death in young puppies, and also smaller litter size and weight. A number of problems have also been identified in adult dogs, such as infertility and abortion
The unborn puppy: CHV attacks the placenta of the mother, starving the foetus of nutrients. This can lead to abortion, stillbirth or resorption of the foetus (seen by the breeder as infertility.
The newborn puppy: If the puppy is infected before birth and survives, it may be underweight at birth and have a weakened immune system, making it vulnerable to early puppyhood infections. If the puppy is infected at or soon after birth, CHV is known to be one of the factors in fading puppy syndrome in which the pup fails to suckle, cries constantly, loses weight and fades away despite intensive care, sometimes in a matter of a few hours. Another sign is soft, yellow-green faeces, sometimes mistaken for parvovirus or coronavirus. The abdomen is painful and there may be bleeding under the skin, or a rash on the belly. Some puppies may show signs of brain damage, such as blindness or staggering.
The adult dog: in the dog, CHV can cause painful lesions on the genitals. In the bitch, there may not be any external signs, but the bitch seems infertile or gives birth to undersize and weak litters. Careful examination may sometimes reveal small blister-like lesions on the vaginal wall. In both males and females, CHV is also known to be one of the causes of kennel cough.
Pathology. Gross pathology consists most notably of kidney changes - multiple subcapsular haemorrhages, and mottling and discoloration of the cortical parenchyma. Spleen and liver will contain discoloured and dark red areas, with a frail parenchyma. The lungs will be oedematous and have a heterogonous appearance with both reddish and grey areas. Haemorrhagic lesions are occasionally observed in the myocardium (heart). There is often bleeding under the skin, especially around the abdomen
Treatment. There is no cure for an animal that has CHV.  infection is probably lifelong and can flare up repeatedly during periods of stress. Antiviral drugs such as acyclovir have shown very limited efficacy and are expensive
The disease is most clinically significant in unborn and newborn puppies. Infection takes place transplancentally, during birth and soon after birth. Therefore caesarean birth cannot guarantee freedom from infection. It can also be transmitted from mother to pup as an aerosol (droplet infection). However, good hygiene and quarantine measures between breeding units will reduce the viral burden within the environment and reduce the incidence of secondary bacterial infections.
CHV multiplies rapidly when body temperature falls below 37C (99F). This explains why puppies in the first three weeks of life are worst affected, as they have poor ability to regulate body temperature. The ideal body temperature of 39C (101.5F) can be maintained with the use of infra-red heat lamps, though it is important not to overheat the mother. As the greatest amounts of virus are shed in the first hours post partum, colostral antibody is the most important factor in reducing disease incidence in the puppy. Even seropositive (previously exposed) bitches do not produce significant amounts of neutralising antibody, and therefore it is necessary to boost the immune system prior to whelping. Previous exposure to CHV will not confer lasting immunity. The virus becomes latent until the circulating antibody levels fall, which can occur in as little as three months. It will then reappear during periods of stress, particularly whelping and overcrowding. High levels of maternal circulating antibody are required to provide protective levels in colostrum.
An inactivated vaccine is now available. The vaccine has been shown to significantly improve weaning rates, increase puppy birth weights and reduce early puppy death. There even appears to be a trend to larger litter sizes, indicating a protective effect on the unborn pup. Even bitches that already have the virus can be vaccinated.
Two doses of the vaccine are given to the bitch, the first dose at or soon after mating and the second dose two weeks before due whelping date. This stimulates the bitch to produce high levels of protective antibody to CHV, which she then passes to the puppies in their first feed of colostrum.
The vaccination schedule must be repeated at each pregnancy, i.e. two injections.
The vaccine will not interfere with PCR or virus isolation tests.

Personally, I would no longer consider any mating without using the vaccine, including maiden bitches.

Kay

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Many thanks for this post Kayc, It has answered a few of my questions about it. Like you I will not be mating my bitches without the vaccine. It must of taken you ages type this post, as well as reading up on it.
Many thanks
Lynn

Thanks Kayc very informative i have used the vaccine twice now on two of my bitches and well worth the £47.

thanks for the infomation very helpful. i have lost 2 litters now and have given my bitchs the chv jab when in season and  2 weeks before welping,  fingers crossed it works wont know untill the end of jan 2011 when she is due, i have 5 girls and would not breed now without it.   thanks karen.

Could this cause infertility in stud dogs also? I am hearing of tales of stud dogs who are suddenly becoming infertile, with no obvious cause.

it's Brucellosis that is the scary one re infertility and abortions etc. 

It's a notifiable disease as far as I could find out that is not in the UK.

It is one of the things a dog/puppy is tested for before it can go to Australia along with Babesiosis, Leshmaniasis and some other things, though not Herpes.

If's and but's Polly... There is no scientific evidence to prove this either way, but that question has come up many times... without a clear and difinitive titre test, their is no way of knowing... and with Canine Herpes having a tendency to throw more false negatives than any other virus, the doubt will always be there...

We have put another dog to the test over the last week, what a coincidence lol... A bitch that is and has been ovulating over the last 5 years (or to be precise 3 years that we know of), she is now 5yrs old... has been mated 5 times over the 3 years and has either never been in whelp, or has been in whelp and resorped too early to scan for pregnancy....

My Ossie (a virgin dog) had his sperm tested last week and the sperm count was 4.2million  (taking into account a possible 25%wastage) there should be no reason why he could not impregnate a bitch.... We allowed this bitch to be mated with Ossie... We are now on day 8 of possible whelp.  She was never given the vaccine in previous matings, she was given the vaccine this time.... It is highly likely that she does carry the virus, and we will now watch Ossie's sperm count over the next year or so

One of the problems with this random and non scientific research, is that although the dog may be producing viable sperm, she may be producing unviable eggs.  Removing the eggs for testing is far too invasive and really not ethical...

Unfortunately the dog that had been used on 3 previous occassions had the snip because the owner assumed it was his fault, so he was never tested for sterility

watch this space, I may have at least one answer in 3 weeks or so :-)

Amazing how this thread is resurrected after 6 years and yet we are still no further forward.  And still so few people/breeders and even vets know about the Vaccine....

> before it can go to Australia along with Babesiosis, Leshmaniasis and some other things, though not Herpes.

Ehrlichia canis, Brucella canis, Leptospirosis and Leishmaniosis  :)

But more breeders are getting to hear about it :-D

And I've done my bit in educating my vet practice ... they're 100% more knowledgeable than they were :-D

PS Thanks for all your help in both of the above :-)  :-)

Hi this is an old post but I am just wondering if it’s too late to have this vaccination? My bitch is due to whelp in 3 weeks and has missed the first one as I was unaware of it. Should I just get the one done?

Better getting one of them than none. You may need to call your vet to get it ordered in, it’s given 7-10 days before whelping.