Neonatal mortality in puppies is around 10-20% in the first 3 months of life, with most deaths occurring in the first week. It is however not unusual to lose whole litters, and the change from a perfectly healthy suckling puppy to a seriously ill puppy can occur within a few hours. It is important to stress to owners that early intervention can make a significant difference to the outcome of the treatment. One should also be realistic about the support that can be provided and explain the different possible outcomes as well as the costs involved.

History and Physical Examination

Because clinical signs are often unusual or non-specific it is important to obtain a comprehensive history from the owners. Comparisons to litter mates can also be helpful. Neonates cannot regulate their body temperature in the first 2 weeks of life and therefore need to be examined in a warm environment (28-32°C)

Heart rate in the first week is between 200 and 250 beats/min and body temperature is 36-37°C. Checking oral mucous membranes will help to assess hydration, with tacky to dry mucous membranes indicating 5-7% dehydration. When puppies reach 10% dehydration they also have a noticeable decrease in skin elasticity. Check for cleft palates. Hair coat can give some indication of prematurity or heavy ectoparasite infestation. Any discharge from eyes or nose, and any urine staining or diarrhoea should be noted. The abdomen should be well rounded without being tight or painful to palpation. Depending on age, response to stimuli and sucking reflex should be present.

The Most Common Paediatric Emergencies

Hypothermia

Puppies have almost no subcutaneous fat when they are born and use non-shivering thermogenesis for heat regulation. Due to the surface area to weight ratio in newborns, heat loss is much greater than in older animals. As long as the newborn stays close to its mother and is adequately fed it can maintain thermal balance.

Hypothermia for newborns is anything below 34°C at birth, 35.5°C from days 1-3 and below 37°C at 1 week of age. Mild hypothermia is expressed through restlessness, crying, reddened mucous membranes and the skin feeling cold to touch. In more severe cases the neonates become lethargic and uncoordinated. Moisture appears around their lips, and heart rates and respiratory rates start to fall.

The biggest problem of hypothermia in the neonate is the decrease in gut motility, which eventually leads to ileus. Owners will often try and remedy 'cold puppies' by encouraging food intake in whichever way possible. Tube-fed or syringe-fed hypothermic neonates will either regurgitate or aspirate, which results in pneumonia or bloat, which results in respiratory distress.

It is important to rewarm neonates slowly. If outside heat sources (lamps, heat pads, hot water bottles) are used the patient needs to be checked frequently and the position to the heat source changed at regular intervals. In severe cases warm fluids can be given intravenously, intraperitoneally or intraosseously. The temperature of the fluids should never be more than 2°C warmer than the body temperature of the patient; otherwise they may develop cyanosis, diarrhoea and fitting.

Rewarm neonates slowly and do not feed them until gut motility is re-established.

Trauma

Unfortunately dropping or stepping on young puppies is a common occurrence. This leads to great distress for the owner and it is sometimes difficult to establish what has really happened. If the puppy has survived the fall and shows no obvious sign of injury it is best to send them home under close observation. In case of fractures the outcomes tend to be positive as the growing bone has a good potential for mending as long as it is set properly. Internal organ damage or bleeding is very difficult to treat.

Infectious Causes

More than 90% of passive immunity of the neonate is provided through colostrum intake and therefore depends on the immune status of the dam. It is important that the puppies are born into the normal environment of the dam so that she can provide the necessary antibodies. Permeability of the gut for immunoglobulins starts to decline after 8 hours and is no longer present after about 48 hours. Passive immunity can last for 6-16 weeks and may interfere with vaccinations.

Canine herpesvirus has been much discussed by breeders recently. In the author's experience it is quite a rare occurrence in the UK. The virus is acquired in utero or at birth and causes neurological symptoms. Puppies cry continually and die within 24-48 hours. Treatment is usually unsuccessful and mortality is close to 100%. The most useful diagnostic tool is post-mortem examination of the puppies as there are classical changes to the liver and kidneys. There is now a vaccine available that is given after mating and before parturition.

Fading puppies is a general term used to describe the loss of neonates through lack of suckling and weight loss. The onset can be sudden and starts from 24 hours to 2 weeks of age. Clinical signs are not specific and causes may be as varied as bacterial infections, poor mothering, inadequate whelping facilities and congenital abnormalities. Treatment needs to be aggressive with antibiotics, fluids and glucose.

Diarrhoea in neonates is very common and is usually caused by overfeeding. Starvation followed by small frequent meals and oral rehydration can be used. Antibiotics should be avoided in these cases as they further upset the gut flora.

Hypovolaemia

The neonate is particularly susceptible to dehydration as water makes up over 80% of their body weight and water turnover is double that of an adult. Because of the neonate's limited ability to conserve fluids and the immaturity of the kidneys, fluid requirements are high (13-22 ml/100g body weight per day) but total volumes that can be given are low. Maintenance dose is 6 ml/kg/hr with an addition of 50% of the deficit over 6 hours. Fluids may be given intravenously, intraosseously, intraperitoneally or subcutaneously, the latter two not having very high absorption rates. In most cases lactated Ringer's with 20 mmol/l maintenance potassium is sufficient. In severely acidotic patients bicarbonate should be added.

Hypoglycaemia

Puppies are born with very little glycogen stores and poor gluconeogenic response of the liver. In a warm healthy environment neonates will last 24 hours before blood glucose levels fall below normal levels. Clinical signs are tremors, crying and irritability followed by more severe signs of lethargy and coma. Well fed puppies will only cry for a short time at the initial start of feeding (squabbling over the best place) and then settle down to drink. Neonates that are fed sufficiently will have a well rounded abdomen, which is soft and shows no pain reaction on palpation. Puppies will feed every 2-4 hours and sleep most of the time between feeding. They do not, however, sleep through the night.

Other common causes of hypoglycaemia, besides starvation, are congenital metabolic diseases (e.g., glycogen storage disease and hepatic shunts).

Most hypoglycaemic puppies will respond to feeding (make sure body temperature is adequate). In severe cases intravenous dextrose at 0.5-1 g/kg as part of a 5-10% Ringer's solution or normal saline solution can be administered.

Conclusion

Provide warmth, fluids and food for the puppies and try to get them back to their mothers as soon as possible.