Dealing with the sick newborn puppy

The “Fading Puppy Syndrome” is well recognized in veterinary practice; this paper offers a practical approach to the problem.
 

Introduction

Veterinary patients younger than three weeks of age are fragile and — for various reasons — can deteriorate very rapidly when ill. For 85% of puppies that die within the first month of life, clinical signs appear less than five days before death, so newborn puppies that appear to be unwell must be seen as an emergency as soon as an owner has contacted the clinic — and treatment is usually implemented before (and most of the time without) any precise etiological diagnosis. Clinical signs in neonatal puppies are usually nonspecific, and can include respiratory distress, crying, abdominal distension and pain, anorexia, poor weight gain, weakness and hypothermia, but none are pathognomonic for a particular underlying cause.

Initial factors to consider

The owner should be asked to bring not only the sick puppy to the clinic, but also its littermates and the dam; apart from anything else, checking all individuals in a litter can allow early identification of other sick puppies. Examination of the dam may identify a condition that can impact on a puppy’s health — such as metritis, mastitis, agalactia/hypogalactia, invaginated teats (which prevent suckling), or (rarely) vulvar vesicles indicative of a maternal herpesvirus infection. If the owner has been monitoring the weights of the neonates, it is useful for them to bring the figures or growth curves as well. Advice on the correct way to transport neonatal puppies is also vital; since newborn pups have poor thermogenesis, it is important that the ambient temperature during transportation is maintained at around 28°C. However, excess heat is also to be avoided, since newborns are unable to move away from anything that is too hot. Microwavable heated pads or hot water bottles should be used with caution to avoid induced hyperthermia and to prevent skin burns (and cylindrical bottles may also roll and crush newborns). Hyperthermia will not only interfere with the clinical evaluation, as overheated newborns cry and are often hyperactive, it also increases a puppy’s metabolism and thus its energetic expenditure.

Once at the clinic, certain hygiene precautions are advisable. Newborns have an immature immune system and must be protected against nosocomial infections, so time spent in the waiting room should be as short as possible, with no contact with any surface or other animals. Examination should be on a clean, dry surface, preferably heated (e.g., a heat pad set at 28-35°C), using disinfected gloved hands. Ideally, the clinician should also wear fresh clothing.

Clinical examination of the dam

A general clinical examination should include an assessment for signs of bacteremia; for example, is there evidence of infection on the skin, ears or mouth (including dental tartar) of the dam that could represent a source of bacteria? Is there any foul-smelling vaginal discharge indicative of metritis? Check the mammary glands for signs of mastitis, inadequate development of the mammary tissue, and the teat anatomy to verify if the neonates can suckle easily (Figure 1). The dam’s body condition score should also be evaluated to check on her ability to secrete sufficient milk, and her maternal behavior should also be assessed; is the dam interested in her crying pups? However, the clinician should be cautious of the mother when handling the litter, since over-maternal dams may bite in such situations.
 

The neonatal clinical examination

The clinician should first verify some key facts regarding a puppy’s nutrition over the previous days: how was feeding during the first 8 hours of life managed (i.e., the period where the intestinal barrier is open to allow passive transfer of colostral antibodies) [1], and is the owner bottle-feeding the puppies (as aspiration with potential respiratory complications is possible)? If the puppies were weighed, calculating their growth rate between birth and two days of age is also informative: 96% of puppies that lose weight over this period have had inadequate passive immune transfer [2]. Ideally, there should be no weight loss over the two first days of life. Later on, the weights should be compared to the reference growth curve for the breed (Figure 2) [3]. The aim is a daily gain of around 2-4 g per kilogram of the expected adult weight, with a minimum target of 1.5 times the birth weight at day 7 and 3 times the birth weight at day 21.  [...]