What is canine herpes virus?
Canine herpes virus is an infectious disease of dogs caused by a virus that belongs to the herpesviridae family and to the same subfamily as that of the human varicella virus and the virus responsible for the disease of 'Aujeszky.
In dogs, the virus is especially dangerous for puppies under 3 weeks old and for pregnant bitches in which it causes embryonic mortality and abortions.
How can a dog get infected?
Contaminants are nasal secretions and sputum, genital secretions and sperm, saliva, tears, stools as well as abortion products (fetuses and fetal envelopes).
Thus, the virus is transmitted mainly by the oral-nasal, transplacental and sexual routes.
After contamination, the virus first replicates in the mucous membranes before reaching the macrophages and spreading throughout the body. In adult dogs, the immune system manages to contain the infection and viral replication so that the virus generally becomes dormant. It can nevertheless be reactivated in the event of stress on the body (illness, immunosuppression, parturition).
In very young puppies, the replication of the virus is not slowed down by their immune system, which is not yet functional, so that the infection is often fatal. The incubation period in puppies is four to six days after which clinical signs of the disease appear.
Is canine herpes virus transmitted to humans?
No, canine herpes virus is not a disease transmissible to humans.
What are the symptoms of canine herpes virus?
In adult dogs, the virus is not very pathogenic but can manifest itself by:
- hyperaemia (accumulation of blood) of the penile mucosa or hemorrhages in the vaginal mucosa,
- respiratory signs similar to those of kennel cough (rhinitis, pharyngitis, conjunctivitis) in older dogs or young dogs.
On the other hand, it is more serious for pregnant females in whom it is the cause of premature births, abortions and fetal mortality.
The most serious clinical signs occur in puppies under 3 weeks old. They include:
- anorexia (puppies don't suck),
- abdominal pain that manifests as crying and complaining,
- gray-yellow soft stools,
- contracture of all the posterior muscles of the body (opisthotonos)
- skin signs.
In 80% of cases, the disease results in the death of the animal within 24 to 48 hours after the appearance of clinical signs.
Canine herpes virus: means of diagnosis
Diagnosis is generally based on clinical signs in affected dogs and by isolation of the virus from an oropharyngeal swab, genital secretions or blood.
Unfortunately, in puppies that die suddenly, the diagnosis is often confirmed by post-mortem examination of the puppies' tissues and/or virus isolation from tissue samples from different organs.
What is the treatment?
Unfortunately, there is no effective antiviral treatment against the canine herpes virus and most infected puppies under 3 weeks of age die from it.
However, a vaccine is now available that has been shown to reduce puppy mortality from canine herpesvirus. It is done on the mother and must be renewed during each pregnancy.
In farms, however, the disease can be avoided:
- by regularly disinfecting the premises,
- by isolating females 4 weeks before and after giving birth,
- by testing animals before mating them.