Tuesday , 2 September 2014
Home > Health Care > Canine Herpesvirus: How Canine Herpesvirus Affects Pregnancy
Canine Herpesvirus: How Canine Herpesvirus Affects Pregnancy

Canine Herpesvirus: How Canine Herpesvirus Affects Pregnancy

Canine herpesvirus (CHV) is a widespread viral infection, similar to the herpes virus found in other mammals such as ourselves. Canine herpesvirus has an extremely high prevalence (particularly in Europe), with rough estimates putting the total number of infected dogs anywhere between 40-90%!

The virus lies dormant in the nerve cells of an infected dog for the majority of its life, causing little, if any issues; however, the virus can be reactivated from time-to-time. Stress is a common cause of reactivation (much like cold sores in humans).

An infected adult dog is unlikely to suffer as a result of canine herpesvirus infection, however, they may experience respiratory distress when first infected and reactivation may lead to the onset of sores or the return of respiratory problems. Canine herpesvirus becomes a much bigger problem during pregnancy, as a connection between the virus and major reproductive disturbances has been identified. The first litter from an infected female is likely to have a low survival rate.

About Canine Herpesvirus

Canine Herpesvirus Infections in Adult Dogs

Compared to human herpesviruses, little has been established about canine herpes virus, despite its extremely high prevalence rate in both males and females. The consequences of being infected with canine herpesvirus remain largely unknown.

A dog becomes infected when they come in to contact with bodily fluids of a dog that is shedding the virus. The virus is mainly shed through discharge from the eyes, nose and genitalia. Canine herpesvirus is not airborne and cannot survive for long in the open environment, meaning close contact is required to become infected.

Once infected, a dog will usually suffer from mild respiratory distress, similar to a typical cold. Even after symptoms clear however, the virus remains as a latent infection i.e. the virus is still present, but hidden away from the immune system. Canine herpesvirus causes a latent infection of certain nerve cells and will remain dormant in those cells until reactivated.

Reactivation of canine herpesvirus usually arises as a result of stress. Examples include; pregnancy, lactation, immunosuppressant therapy or environmental stress such as moving house.

The primary site of infection is the reproductive tract, as a result, the disease can be sexually transmitted, but as mentioned earlier, the virus can also be spread by discharge from the eyes and nose. When the virus becomes reactivated, it may be possible to detect raised sores around the genitalia. Lesions have also be known to occur within the body, but these cannot be detected from the outside and require a necropsy.

Canine Herpesvirus Infections in Puppies

Whilst the virus has typically mild consequences in an adult dog, the same cannot be said for puppies. Puppies that are infected with canine herpesvirus typically have a low survival rate.

Puppies can become infected either during whelping as they leave the birthing canal or through being in close contact with the mother when she is shedding the virus.

The virus is known to cause fatal haemorrhagic disease in pups less than 3 weeks old. Pups that survive go on to become latently infected or may even develop neurological diseases at a later date.

Treating Canine Herpesvirus

There is currently only one available vaccine for canine herpesvirus, which is only available in Europe. The vaccine, Eurican Herpes 205, contains tiny amounts of viral protein, which is enough to stimulate the mother’s immune system in to producing antibodies.

The female should be vaccinated once during heat and again 1-2 weeks before whelping. The second injection ensures that antibodies are transferred to the newborn pups via colostrum. This greatly increases their chance of survival.

Canine Herpesvirus and Pregnancy

There are strong indications that canine herpesvirus causes mortality in newborn pups, especially if female is infected during late pregnancy. Unfortunately, there is little that can be done to treat an infected newborn. Mortalities at 3 weeks or earlier are usually attributable to the virus.

The mother may appear well before pregnancy, but the stress caused by oestrus (heat), pregnancy or lactation can be enough to reactivate the latent virus. Reactivation can cause shedding of the virus, which is usually responsible for infection of newborn puppies.

The clinical effects of viral reactivation have not yet been fully clarified, however, reproductive disturbances and lower pup weights have been suggested. Other investigations of the virus show an apparent association between reactivation and reproduction hormone concentrations.

Kennels with a high prevalence rate of canine herpesvirus note increased reproductive disturbances, including:

  • Resorption
  • Mummification
  • Abortion
  • Low conception rate
  • Embryonic losses
  • Still borns

There is usually little that can be done to save infected newborn puppies during a mother’s first pregnancy, however, subsequent pregnancies are unlikely to be as badly affected, as the mother will produce sufficient antibodies to protect her pups.

Recent Study Findings

Investigation of the canine herpesvirus is not as widespread as investigation of the human herpesvirus for example, however, research does continue to be performed. A recent study looked at a small group of 12 dogs, all of which had canine herpesvirus antibodies (suggesting infection, and also highlighting the high prevalence rate).

The bitches were monitored during their pregnancies to see if canine herpesvirus caused any reproductive disturbances. Even though an increase of canine herpesvirus antibodies was detected in a couple of the study participants (indicating reactivation of a latent infection), no reproductive disturbances as a result of canine herpesvirus were found.

Although further study is still needed, particularly as the group size was small in this study, the conclusion was that; good management during pregnancy did not result in canine herpesvirus related disturbances.

Canine Herpesvirus During Pregnancy and Non-Pregnant Luteal Phase, B Stro¨m Holst et al. Reprod Dom Anim 47 (Suppl. 6), 362–365 (2012)

For more information on canine herpesvirus take a look at these guides:

About James Watts

BSc Bioveterinary Science. Editor of PetSci. When I'm not writing, learning, discussing, or reading about animals, you know it's the weekend!

11 comments

  1. Margaret Gardner

    I Have asked my vet about having my Bitch vaccinated as a precaution for herpes.
    She came into season today, someone said she should have a vaccine administered now and then another 7 days before the puppies are born.
    However my vet has said that the first vaccine should be administered 7-10 days after Mating and then again 7 days before whelping.
    Can you assure me that the first is to be done before mating whilst still in season or after the bitch has been mated.
    Look forward to your reply.
    Kind Regards,
    Margaret Gardner

    • Hi Margaret

      As the virus can be sexually transmitted, I’d suggest vaccinating before mating, however, it is the second vaccine that is the most important. The second vaccine ensures high levels of HPV antibodies are transferred to the pups to help them fight off the infection.

      I hope that helps!

  2. Hi James
    I have a bitch that has produced three litters thus far and the last being a disaster loosing 7 of 9 pups to the virus. We’ve bred her again as was told that she would pass on antibodies to the next litter. She is confirmed pregnant again, however only 2 pups have been ultrasounded. I’m aware of the UK vaccine by Merial, however it may be too late for this litter. What is the probable future of this bitch with respect to future litters. She is one of our champions and produces beautiful pups. Should she be spayed or is there future hope. Your knowledge and advise would be appreciated.

    Best Regards
    Bob Clarke
    Birch Hollow Goldens

    • Hi Robert

      Sorry to hear about the recent losses. Once infected, the female is always going to experience issues with pregnancy caused by the virus. As your vet pointed out however, subsequent litters will be less affected.

      You may still get losses, but nothing like the 7/9 from the recent litter.

      It is often recommended not to breed a bitch infected with herpes virus, but it might be worth seeing how the current litter fares and deciding after that.

      Let me know how you get on.

      James

  3. hi i have a six year old staffie ch bitch she has been mated 3 times now with no pups. Could having the herpes jab help her to get pregnant?

  4. Hi I have just lost a full litter on a first time bitch fullterm all born dead from healthy lines where there has never been a problem only lost 3 pups in 25 yrs do you think this could be the cause I used my own stud dog who has only been used once before and produced a normal healthy litter can we test to see if the bitch has herpes also if she has will she have infected my stud boy?

  5. Hi James I bred my bitch Rosie very big healthy girl and her entire litter 9pups died it was heartbreaking :( then I found out about this herpes I bred my other bitch dayna but got her the herpes jab she had 7 pups 2 still born and 1 died at 2 days old I’m worrying about the remaining pups would the jab have affected the still borns and what’s the chances of the remaining puppies surviving worried owner

  6. hi my staffy has had her first litter 2 weeks and 4 days ago by c section as she has a low blood count of 20% and loss of appetite, and lost a lot of weight suddenly, she id doing well now, but im concerned about the pups, as ive now lost 4, the first one (runt) died at 1 week old, symptoms were just crying constantly, and limp, took vets they gave painkillers said it could have been over eating, after an hour she picked up, but a few hours after started again and her tummy was still hard, then blood came out of her nose, and was gasping for air, but sadly passed away on the way to the vets…..second and third pup died 4 days ago, symptoms of the first pup were really sudden, whole body blew up like a balloon, took a gasp in , whole body went hard, and his body suddenly deflated sunken in under ribs, and died, tried to bring him back with no luck, the third puppy did exactly the same three hours after the second pup died, but I managed to bring him back, took him to the vets and he was back to normal, said they weren’t sure what it was, maybe something congenital or intracranial, but was unsure…only back home an hour and it happens again, this time it looked like he was having some sort of fit, with arched back and gasping for air, he did this 6 times one straight after another, with only a minute between each and stopped breathing 6 times, but I managed to bring him back each time, he then had another one, and did the same as the second pup, blew up like a balloon and deflated and passed away, I didn’t make it to the vets in time, happened so quickly….the fourth pup, was sadly put to sleep yesterday, she was gasping for air, but never went limp, was still moving about and strong, took her to emergency vets, and they put her in oxygen tank and was doing really well, but the oxygen tank was helping her breath 80% …wen she was taken out she quickly deteriorated and started gasping again, clear fluid came out of her nose and caused her to go limp, vet said she would not make it and though that the best for her would be to put her to sleep to stop her from suffering….im so heartbroken that this is happening, im also hand feeding the pups every 2 hours as the mother cannot feed them as she had an operation and was on medication that would have killed the pups, as it would have been in the milk, also all the pups have had no symptoms prior to being ill, can anyone please give me any advise on what could be causing this please..x

  7. Hi could you please tell me if it is o.k. To show dogs that are known carriers of CHA ?

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>