As promised, we now start the first in our series of articles written by other canine enthusiasts who are experts in their chosen field. The first such item has been written by Dr Stephanie Cousins BVSc MRCVS and is kindly reproduced here courtesy of Show Dogs Ireland. We do hope these interesting articles are helpful, useful and informative. We welcome your thoughts, whether it be by email, message or directly in person. Happy reading !

Diane Stewart-Ritchie

Illness in Neonatal Puppies

Illness in Neonatal Puppies1

Expecting a litter of puppies can be a time of great anticipation for many people involved in the show ring. We all strive to rear a litter of healthy, happy puppies with a dam that is just as healthy and happy. Unfortunately we can encounter problems and it is important to be prepared for the many issues that may arise when deciding to breed. In this article, I aim to highlight some early warning signs in neonatal puppies, as early recognition and treatment can be vital to the survival of young animals. Reaching a diagnosis in neonatal animals can be very difficult as many symptoms they show are non specific. This is why many sick pups go undiagnosed and are referred to as ‘faders’ even without a cause for the pups illness. About 50% of neonatal deaths have been classified as ‘fading puppy syndrome’ as they have no obvious cause of death. One study has shown that one third of cases described by the owner as fading puppy had a specific predominant cause not picked up by the breeder. In this article, we will look at specific causes of illness in neonatal puppies as well as the mysterious illness known as ‘fading puppy syndrome’.

            Dogs are an altricial species. This means their young are born helpless and are heavily reliant on their parent for food, warmth and protection. In the first 10 days they are the most vulnerable. This is called the neonatal period. However they are dependent on the dam for the first three weeks which is called the perinatal period. They are particularly vulnerable for a variety of reasons. Their thermoregulatory mechanisms are poorly developed and shivering mechanisms do not begin until after the first week. Pups should open their eyelids between day 10-14 but their vision is poor until they reach 4-5 weeks old. The immune system is not fully competent until 3-4 months so pups rely on maternally derived antibodies from the dam's colostrum (they receive 95% of their antibody protection via colostrum). These wane at around 8 weeks old which leaves puppies very susceptible to disease between 8-16 weeks. This is why vaccination from 8 weeks old is very important. Table 1 shows some of the differences between a healthy and a sick pup that can be picked up and aid early intervention.

Table 1

HEALTHY NEONATE SICK NEONATE
Round, full abdomen Bony appearance, slack abdominal wall or swollen tight abdomen
Sleek coat Dirty unkept coat
Warm skin                  Reduced body temperature
Elastic skin (hydrated) Inelastic skin (sign of dehydration)
90% of time spent asleep Restlessness
Activated sleeping pattern (body twitching when asleep in first 3weeks) Loss of body twitching
Only cries if disturbed or before a feed for a few minutes Persistent crying
Strong suck reflex Poor suck reflex
Doubles birthweight by the 10th day Low birthweight/ progressive weight loss
Eyelids closed until days 10-14 Swelling around eyelids

It is useful to know the normal birth ranges for your breed and to record the birth weights of your pups. It is also recommended to monitor weight changes up to day 10. A pup that is small compared to the breed average is likely to be physiologically immature and disadvantaged compared to stronger litter mates. It is thought that the lungs, kidneys and liver function in these pups is poor. If a pup fails to gain weight at a regular rate for more than 24hours, there may be an underlying health problem or some difficulty feeding. A study has shown a low survival rate in puppies when individuals lost more than 10% of their birthweight. Inadequate nutrition of the dam can lead to low birthweight pups.

Excluding fading puppy syndrome, the most common causes of neonatal death are:

  • Maternal/management related factors
  • Infections
  • Low birthweight
  • Gross congenital abnormalities
  • Illness in Neonatal Puppies2

Management related factors include a variety of elements that should be carefully considered before deciding to breed. This includes the kennel construction and whelping facilities and the type of heating. It is good practice to record the temperature in the whelping environment and be aware of any risks of draughts and heat loss. It is recommended that the environment is maintained between 27.5oC to 36oC in the first few days. It is useful to have a plan in place for the whelping routine and supervision, especially over the first 3 days. It is important that anyone involved has appropriate knowledge and experience with whelping bitches. Have a set hygiene policy that is known by everyone involved. This should include using a parvicidal disinfectant to clean the whelping facilities. The presence of disease carriers should be ruled out for example mice or birds that can access the kennels. There should be a worming and vaccination program in place that is followed. Bitches should be wormed every day from day 42 up until 5 days before whelping so as to prevent parasites crossing the placenta which can affect the pups after they are born. Also litters should be wormed from 2 weeks of age and every 2 weeks until 3 months old, then every month until 6 months old (this can vary slightly depending on the product used).

It is vital to consider the health and temperament of the dam before mating. If you have a maiden bitch, it is advised to avoid excessive disturbance as this may lead to aggression towards people or even the litter. Any concurrent illness in the dam can lead to reduced lactation and poor mothering so if you have a litter of sick pups, the dam should be checked by a vet as well as the litter. Many vets provide a pre-breeding check for bitches and stud dogs which can influence the decision to breed or not. It is beyond the scope of this article to talk about genetic testing however for your reference all the advised screening programs for each breed are listed on the kennel club website.

Infections have been found as a cause of death in about 16% of neonatal mortalities however, there is usually an underlying reason for contracting an infection. Infection is much more likely in pups which are colostrum deprived, for example, if pups do not suck in the first 12-24 hours. It is difficult to detect diarrhoea in the new-born pup due to good mothering by the dam, however sometimes there is inflammation around the anus and a wet tail. Antibiotics given unnecessarily to the bitch can upset the balance of bacterial flora in the pup and so cause diarrhoea. Antibiotics should never be given without the instruction of a vet as antibiotic resistance is becoming a major concern worldwide in both human and animal medicine due to overuse. Acquired colostral antibodies from dams should provide immunity against canine distemper virus, canine hepatitis virus and canine parvovirus infections, provided the dam is up to date with her vaccines.

Fading puppy syndrome (FPS) can explain as much as up to 50% of neonatal deaths. However, not a lot is known about this mysterious illness and there are many myths surrounding the disease. So what do we actually know about FPS? FPS is a failure to thrive syndrome in puppies that would otherwise be expected to survive but instead enter a period of rapid decline shortly after birth. These puppies are born to healthy mothers, appear healthy at birth and of normal birthweight but fail to gain weight and usually die within 5 days. A post-mortem investigation is required to differentiate between puppies dying of a specific cause and those with FPS. There is no evidence that an infectious agent is likely to cause FPS. Most current thinking is that the cause is multifactorial. When the clinical signs have been compared in these puppies, no specific signs of ill health were linked with any identifiable cause of death. Some of the puppies are ill for 3 or more days whereas others die suddenly. Difficulty feeding is a common sign, some pups appear latched to the teat however on post mortem there is no milk found in the stomach or intestines suggesting they are not actually feeding. In 43% of cases, pups cry for prolonged periods of time unlike healthy litters. There are many recorded signs but each case can vary dramatically: pups lying on their side and paddling their limbs, gasping, unable to right their position, wandering, restlessness, maternal rejection, slow movements, abnormal sleep, weak sucking, dehydration, not feeding, coma and death.The course of illness typically lasts 24-48 hours. Post mortems have failed to find an exact cause however there are some common findings. There is usually significant weight loss compared to the birthweight and no food in the gastrointestinal tract. Brown fat is very important in young animals as it helps to keep them warm. Fading puppies typically showed extremely depleted brown fat suggesting they were at severe risk of hypothermia, however this is very unlikely to be the primary disorder. Another common finding in fading puppies is lower levels of a lung surfactant. This is comparable to sudden infant death syndrome in children. This could lead to reduced oxygen getting to the organs and breathing/sucking difficulties. However, if is not clear if this is the primary cause of death in these puppies or a consequence of another process in the body.

It has been suggested that canine herpes virus (CHV) plays a role in FPS. While this can not be ruled out, in practice, CHV is found to be sporadic, especially in maiden bitches and causes death in 7-14 days. This is unlike FPS which usually results in death in the first 5 days of life. CHV may not be involved in FPS but it is widespread in dogs all over the world and is associated with an acute and usually fatal infection of puppies in the first few weeks of life. The pups become infected during whelping from the bitch or other littermates. In adult dogs, it causes a mild respiratory infection but infection of the pregnant bitch can induce stillbirth, abortion and mortality among pups. It has also been suggested that it may be a cause of infertility. Thankfully, there is a vaccine proven safe in pregnant bitches and effective at preventing CHV in litters born to vaccinated dams as they pass on immunity via colostrum. The bitches require two injections under the skin. The first needs to be given about 10days post mating and the second injection 1-2 weeks before whelping. This regime needs to be followed with each pregnancy.

It is obviously very difficult to set up a preventative or treatment program for FPS as we do not know the exact cause. However there are a few simple steps that can be taken to reduce overall mortality in neonatal puppies. Use an accurate scale to record the weight of pups at least once a day. Should any pups fail to gain weight or they lose weight in a 24 hour period, it is recommended to start supplementary bottle feeding. Pups of a low birthweight will also benefit from supplementary feeding. Pups that lose 10% of their birthweight have poor survival rates. The dam should be checked for any lactation problems if pups are losing weight. Good supervision is essential in the first 48-72 hours from whelping. Regular booster vaccinations and introducing the dam to the whelping environment at least 2 weeks prior to whelping will enhance maternal antibodies which will be protective when passed in the colostrum to pups. It is vital to ensure pups suck within the first 12-24 hours and obtain this colostrum as it will help protect them for at least 8 weeks. As most neonatal infections are acquired via the umbilicus, the application of an antiseptic to the umbilicus is a sensible preventative measure. Antibiotics appear to have little value in the treatment of fading puppies and should only be used if instructed by your vet.

Fading puppy syndrome is the cause of up to 50% of neonatal deaths however it is important to rule out other causes of mortality as, in up the 30% of deaths blamed on FPS by breeders, there can be a specific cause found. If a puppy dies of no obvious cause, it is important, if possible, to have a post mortem carried out to know the prognosis for the rest of the litter and if any treatment is needed. Many problems can be avoided with careful planning and implication of management/health care regimes. Good records should be kept with all litters as they will be useful for your vet to look at to try establish a pattern, if you do encounter problems.