Canine Herpesvirus

Canine herpesvirus can cause fading puppy syndrome and is a particularly serious infection in newborn puppies.

A sick newborn puppy is an emergency A puppy that stops feeding, cries persistently, becomes weak, cold or has difficulty breathing needs immediate veterinary attention. Do not wait to see whether the puppy improves.

What is canine herpesvirus?

Canine herpesvirus, usually abbreviated to CHV or CHV-1, is a virus that infects dogs. It is widespread within the canine population and many infected adult dogs show no signs of illness.

Once infected, a dog can carry the virus in a latent or inactive form. The virus may become active again during periods of stress, illness or pregnancy, allowing it to be shed and passed to other dogs.

How is it spread?

The virus is primarily spread through direct contact with infected oral, nasal or vaginal secretions. Transmission may occur:

During mating or close contact between adult dogs
Across the placenta before birth
During the birth process
Through contact with the mother’s secretions after birth
Through contact with another dog shedding the virus

An apparently healthy dog may still shed the virus, making complete avoidance of exposure difficult.

How dogs are affected

Pregnant bitches

A bitch infected for the first time during pregnancy may abort, produce stillborn puppies or give birth to weak puppies. The bitch herself may show few or no signs.

Newborn puppies

Puppies infected during their first weeks of life can develop rapidly progressive, widespread disease with a high risk of death.

Older puppies and adults

Older dogs usually develop much milder disease, which may include respiratory, eye or genital symptoms.

Signs in newborn puppies

The signs can be nonspecific and may develop very quickly. Possible symptoms include:

Failure to suckle or reduced interest in feeding
Persistent crying
Weakness and lethargy
Becoming cold
Difficulty breathing
Nasal discharge
Diarrhoea
Abdominal discomfort
Red spots or small areas of bleeding on the gums or skin
Sudden deterioration or death

A notable feature is that severely affected puppies may not develop a fever. Their body temperature may instead be lower than normal.

Puppies that survive a severe infection may be left with neurological, kidney, eye or other permanent damage. Their long-term outlook is therefore guarded.

Diagnosis

The symptoms can resemble those caused by bacterial infection, other viruses, congenital abnormalities and problems associated with birth or inadequate milk intake.

Diagnosis may involve examination of the bitch and puppies, blood tests and PCR testing of suitable samples. If a puppy dies, prompt post-mortem examination and laboratory testing may provide the quickest way to identify the cause and protect the remaining litter.

Arrange testing promptly If your vet recommends a post-mortem examination, ask how the puppy should be stored and transported. Suitable tissues for CHV investigation generally need to be refrigerated rather than frozen.

Treatment

Treatment of a severely affected newborn puppy is difficult and the prognosis is often poor. Treatment must be directed by a veterinary surgeon and may include:

Careful, controlled warming
Intravenous or other fluid therapy
Glucose support when necessary
Oxygen
Nutritional support
Treatment for possible secondary bacterial infection
Intensive monitoring and nursing care

Evidence for antiviral treatment in newborn puppies is limited and inconclusive. Any possibility of success depends on recognising the problem and beginning veterinary treatment immediately.

Do not attempt intensive heating at home A temperature of 35°C or 95°F sometimes quoted in veterinary literature refers to carefully controlled incubator care for exposed puppies before signs develop. It is not a recommended room or whelping-box temperature. Excessive or rapid heating can cause dehydration, burns, overheating and further distress.

Protecting a litter

The following precautions can help reduce the risk:

Separate the pregnant bitch from unfamiliar dogs during the final three weeks of pregnancy.
Keep the bitch and puppies away from other dogs during the first three weeks after birth.
Wash hands before handling the bitch or puppies.
Use clean clothing and footwear when moving between different litters.
Clean and disinfect the whelping area and equipment thoroughly.
Do not share bedding, bowls or equipment between litters.
Ensure that every puppy receives colostrum as soon as possible after birth.
Contact your vet immediately if one puppy becomes ill or dies unexpectedly.

Because clinically normal adult dogs can carry and shed CHV, good hygiene and sensible isolation are more practical than attempting to eliminate every possible exposure.

Canine herpesvirus vaccination

A prescription-only vaccine for use in pregnant bitches is available in the UK. It is intended to stimulate antibodies in the bitch so that her puppies receive passive protection through colostrum.

The licensed schedule for Eurican Herpes 205 consists of two subcutaneous injections:

First injection Either during the bitch’s season or 7–10 days after the presumed date of mating.

Second injection One to two weeks before the expected date of whelping.

The same two-dose course is required during each pregnancy. Vaccinate only on the advice of your veterinary surgeon and follow the current product information supplied by the practice.

Availability can vary, so speak to your veterinary practice early—preferably before mating—to allow time for the vaccine to be obtained and the appointments arranged.

If CHV is suspected

Telephone your veterinary practice immediately.
Keep the bitch and litter isolated from other dogs.
Do not move puppies between litters.
Keep the puppies comfortably warm while following veterinary instructions.
Record each puppy’s weight, feeding and symptoms.
Discuss laboratory testing and post-mortem examination promptly if a puppy dies.

Sources and further information

This page provides general information only and is not a substitute for examination, diagnosis or treatment by a qualified veterinary surgeon. Vaccine schedules and product availability may change, so always follow current veterinary advice.

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