Fading Puppy Syndrome

What is Fading Puppy Syndrome?

Fading Puppy Syndrome is the name given to a collection of illnesses in puppies, each of which can lead to death within a few days of birth. Such puppies become progressively weaker until they are unable to suckle; they may have an abnormally low body temperature. Fading Puppy Syndrome may be caused by infection with many agents. The main ones are: (1) Canine Adenovirus (2) Canine Herpes Virus (3) Bordetella bronchiseptica (4) E.coli (5) Salmonella

Canine adenovirus

Canine adenovirus, also known as Canine Infectious Hepatitis Virus, causes sudden death in newborn puppies. They can be infected whilst still in the uterus if the bitch has not been vaccinated and becomes infected, or can be infected after birth by exposure to infected dogs. The virus causes the puppies to have a high temperature, and they are depressed with extreme pallor. They vomit and have diarrhoea, both of which can contain blood. Puppies collapse due to shock and die within 1-3 days.

Canine Herpes Virus

This virus occasionally causes Fading Puppy Syndrome. Puppies are infected by exposure to nasal or vaginal secretions of adult carriers. The virus spreads rapidly in kennels but only causes disease in very young puppies (under 3 weeks old). In these puppies the virus spreads throughout the body via the bloodstream and it is capable of replicating within many organs including the bra.

The signs of Canine Herpes Virus infection include inappetance, diarrhoea, a painful abdomen (tummy) and vomiting. Puppies usually die within 1-2 days of showing signs. No vaccine is available. Since the virus survives best at lower temperatures, keeping young puppies warm will help to prevent infection.


This is a bacterium which contributes to kennel cough in adult dogs. An intranasal vaccine is available which can be given to puppies from 2 weeks of age, but by this time the puppies are more likely to get respiratory disease than fading puppy syndrome if infected. The main means of prevention are adopting good hygiene practices. As with most infections, the bitch is often the source of infection event though she may well not show any signs of disease herself.

E.coli (Escherichia coli)

This bacterium is often found in the blood of fading puppies, but its role in the syndrome is unknown. It is likely that it contributes the syndrome, and control is by adopting good hygiene practices.


This bacterium can be carried without symptoms by the bitch or other adult dogs. Once again it is important to adopt good sanitation practices, and avoid intermingling animals of different ages.


Other causes of neonatal death include Canine Parvovirus and Canine Distemper Virus. Both of these have become less common since the advent of vaccination programmes, but unvaccinated litters are still predisposed. This highlights the importance of vaccinating bitches prior to pregnancy and puppies as soon as they are old enough.


This pet health article is for reference only.

If your pet is showing any symptoms or distress, and you suspect your pet is ill CONTACT YOUR VET IMMEDIATELY.