 |
Interview with Hugh Duffin! Read now Vet Vacancy - Apply now The Vet Animal House Polo Team - Winners on the Midsummer tournament at RLS 2009! Learn more Work Experience & Student Nurse Placements... Learn more Our Opening Times Rugby Surgery Warwick Surgery Opening hours: |
Topic of the Month
Every month we discuss a topical issue - this month "Canine Herpes Virus":
CANINE HERPES VIRUS
- Canine Herpes Virus is generally known as CHV1
- Herpesviridae. Varicellovirus genus
It is the leading cause of puppy deaths
- 80% mortality of pups less than 1 week old (2006)
- 40%+ of European dogs have CHV1
- It has an incubation period of 6-10 days (2004)
It is spread by mating and contact with vaginal secretions, male semen and nasal secretions of infected dogs. It cab be transmitted to puppies in utero, through contact with vaginal secretions during birth and through nasal secretions after birth. The adult herpes virus carrier may have no symptoms, or they could present with painful vaginal or penile lesions. Where lesions are not apparent, on internal examination of the bitch blister-like vaginal wall lesions may be found. As a normal adult dog body temperature is 101-102oF, and the herpes virus is unsuccessful at manifesting at these temperatures, it mostly does not present a problem in the adult canine.
CHV1 is also one of the causes of kennel cough. When not apparent the herpes virus is able to hide in the ganglia of the nervous system. CHV1 causes infertility, re-absorption of litters, abortion, still birth and fading puppy syndrome. It does this by attacking the placenta starving the puppies of nutrients. Fading puppy syndrome is characterised by a new born puppy failing to suckle, crying, weight loss, and literally ‘fading’ despite intensive care. The pups can also have soft greenish yellow faeces, sometimes mistaken for parvovirus or coronavirus. They can have a painful abdomen, a rash on the belly and bleeding under the skin. These puppies usually die within a few hours. Where puppies contract this virus and survive, they are often left with cardiac and/or brain damage.
Blindness and staggering are common presentations. As new born puppies are not able to regulate their body temperature the CHV1 virus can thrive. CHV1 it also over-burdens puppies’ immune systems leaving them prey to other infections and diseases. Small litter sizes and low birth weights can also be a sign of CHV1.
CHV1 can be tested for by blood sampling and on post mortem examination. Serum samples should be taken 2-3 weeks apart from the pregnant bitch near the time of whelping. This should show a rise in anti body titre if she is manifesting CHV1 There is also a PCR test which detects the genetic material of the virus. It is taken from cells or fluids.
Post mortem examination on a puppy will show multiple subcapsular haemorrhages and discolouration of the cortical parenchyma of the kidneys. The spleen and liver will have dark red areas and a frail parenchyma. The lungs will be oedematous with heterogenous appearance with grey and reddish areas. There will be haemorrhagic lesions in the myocardium. There will be evidence of bleeding under the skin and around the abdomen. On fresh post mortem sampling CHV1 can be isolated from the lungs and kidneys but false negative results are common.
Since April 2003 there has been a vaccine to protect against CHV1. this should be given to the bitch during heat or in early pregnancy and again 1-2 weeks before her whelping due date. (The gestation period is around 63 days) If it is an accidental mating with no pre-planning and it is too late to give the vaccine in heat or during early pregnancy it is beneficial to still give 1 x vaccine rather than having none. The vaccine is an emulsion to be given sub cutaneously. It has no contraindications. It must be stored away from light and at between 2 and 8 oC. It is dangerous if injected into a human as it could cause swelling and necrosis. The vaccine protects the puppies from CHV1 infection. It should be given during each pregnancy. There is no cure for canine herpes virus, so a canine that already has it will have it for life.
We have written a help sheet on how to plan a successful whelping inspired by our up-date on CHV1.