ABSTRACT: There is a wealth of information available in textbooks, scientific publications and conference proceedings, as well as advice from veterinarians and anecdotal personal experience regarding the care of neonatal puppies.

Neonatal survival in domestic dogs can be improved by effective management of the bitch and appropriate neonatal care. This article aims to bring this information together to provide the veterinary nurse with a useful and informative reference guide for the practice file.

Part one of this two-part series considered the healthy neonatal puppy and how to identify and care for the healthy neonate from birth. This month, part two describes the sick neonate and detail some different conditions to which neonatal puppies are particularly susceptible; including hypoglycaemia, hypothermia, hypoxia and dehydration.

The sick neonate

A number of factors can help reduce the incidence of illness in neonates, including:

•   maintenance of breeding records including details of the health status of breeding stock, aiming to reduce unfavourable factors;

•   good management during whelping and the immediate postnatal period;

•   ensuring puppies receive adequate colostrums;

•   recognising the signs of ill health early; and

•   sending dead puppies for post-mortem examination.1-2

Signs that a neonatal puppy may be sick include being underweight with a thin, bony appearance and a slack abdomen; failure to suck; the puppy’s skin feeling cold and inelastic; a coat in poor condition; persistent crying and possibly a loss of body twitching. Neonatal puppies can be difficult to treat owing to their immature temperature regulation and immune systems and their small size.

Sick puppies with minor signs of disease

Early supplemental feeding and nursing care are important for puppies with minor signs of disease; these include failure to gain weight, tiredness and being slow to feed. After adequate intake of colostrum, milk should be given every two to three hours by feeding bottle or orogastric tube.3 4

To tube feed, measure the distance from the tip of the nose to the last rib using the tube and then mark the tube at three quarters of this length (used as a guide to determine distance to the stomach). An 8 French gauge urinary catheter works well and should be lubricated on the outside with a small amount of water before being fed into the mouth, over the tongue to the back of the throat with the puppy upright and the head in a normal position (Figure 1). 

Figure 1: Schematic representation of an orogastric tube placed in a neonatal puppy

Most puppies will swallow the tube, which is normally visible on the left side of the neck as it travels down the oesophagus. Just before administration, negative pressure should be applied to the syringe and if air is aspirated it should be assumed that the tube has inadvertently been placed into the trachea and the tube should be withdrawn and then replaced. Food can then slowly be introduced into the stomach.3’4

A useful video demonstrating tube feeding of puppies is available at http://video.vetguide.org/tube-feeding-to- puppy-kopek-yavrusu.html. The perineal region of each pup should be regularly stimulated to ensure expulsion of urine and faeces as described in part one of this article series.

When treating minor disease, body temperature should be maintained and recorded every few hours along with environmental temperature (see normal values for temperature in Part one, VNJ 27: 11, January 2012). Hydration status should be checked – this can be estimated from the amount of weight gain (measured three times daily), mucous membrane colour (Table 1) and urine colour (normal hydration presents as urine with no colour).2

Puppies with minor signs of illness may be at risk of overgrowth of commensal bacteria in the gut which may spread systemically; therefore the collection of bacteriological samples from faeces and blood for aerobic and anaerobic culture should be considered, followed by administration of broad spectrum antimicrobial preparations (commonly oral clavulanic acid potentiated amoxicillin at 12.5 to 25mg/kg twice daily).

Once the downward spiral of failing to suck has begun, circulatory collapse and death can quickly follow. This is complicated by the close relation of a number of clinical signs (Figure 2).

Figure 2: The interrelating nature of clinical signs in the sick neonatal puppy

Sick puppies with more serious signs of disease

Immediate aggressive treatment is required in cases with more serious clinical signs; these include dehydration, persistent crying and failure to feed. Treatment should aim to reverse hypothermia and hypoxia, treat or prevent dehydration and prevent commensal organism overgrowth.

A thorough clinical examination – including assessments of mucous membrane colour and capillary refill time, measurements of rectal temperature, colour of the ventral abdominal skin, respiratory and heart rate checks and examination of urine colour and skin elasticity – should be conducted following immediate care to stabilise the puppy.2

Hypoglycaemia

Neonatal puppies are at high risk of hypoglycaemia owing to low glycogen reserves at birth and low functional capacity of the liver.3 5 6 Failure to suck may result in hypoglycaemia in 24-36 hours.4

Hypoglycaemia is a serious condition in the neonate, and response to glucose administration may be poor in very young puppies.4 Clinical signs include crying, tremors, irritability, increased appetite, lethargy, coma and seizures.4

A pup suspected of being hypoglycaemic can be evaluated by placing a drop of blood on a glucose reagent stick or by using a glucometer. It is most simple to take 0.05 ml of blood from the jugular vein, using a 25-gauge needle attached to an insulin syringe. Care must be taken when interpreting laboratory results as normal glucose values for neonates are different from those of adult dogs.

Treating a hypoglycaemic (<30 to 40mg/dl) puppy involves slow intravenous dextrose administration at 0.5 to lg/kg as part of a 5-10% solution of dextrose in lactated Ringers or normal saline, or by giving l-2ml of 10-25% glucose intravenously to severely depressed puppies.6 Blood glucose concentration should then be monitored to check for hyperglycaemia.14

Evaluating blood biochemistry and haematology may provide other useful information; normal values for puppies from birth to four weeks of age, along with adult values can be found in standard textbooks.4’7 It is important to keep accurate records when taking blood samples from puppies and
to take no more than 10 per cent of the puppy’s circulating volume in one week, especially when taking repeat samples to check blood glucose levels in the hypoglycaemic puppy.2’6

Hypothermia

Hypothermia in the neonate is a body temperature less than normal (36°-37°C) and is significant when values are less than 34.4°C at birth, 35.6°C on days one to three, and less than 37.2°C at week one.4 Hypothermia causes gut motility to slow and ileus, leading to a bloated abdomen, poor respiratory function, poor sucking and increased risk of bacterial infection.4

Reversal of hypothermia requires slow warming, not exceeding 1°C per hour* using heat pads wrapped in towels, heat lamps or bottles – although care must be taken to check the environmental temperature regularly to prevent overheating.

Maintenance of the correct environmental temperature (see Part one, VNJ 27: 12, Jan 2012) and a medium environmental humidity (65% is ideal, but humidity should not be below 55%, which can be measured by hygrometer) are important.3'4 Warming the puppy in an oxygen cage or incubator, if available, can be a quick and safe alternative.

Puppies should not be fed if their body temperature is less than 34.4°C and/or if no bowel sounds can be heard.4 Providing dextrose at the same rate a previously described6 with any fluid supplementation can help meet the increased calorific demand, which results from the increase in metabolic rate associated with reheating4

Hypoxia

Hypoxia causes a failure to suck, decreases or halts gut motility, and can lead to translocation of intestinal bacteria and chilling, causing a decrease in resistance to bacterial infection.4 Poor respiratory function leads to inadequate elimination of carbon dioxide and a resultant respiratory acidosis.

Clinical signs are abdominal distension and increased respiratory effort and rate – although puppies can not hyperventilate until they are several days old, making hypoxia difficult to recognise.4’8 Oxygen can be administered using a constant flow oxygen mask 9-10 or by placing the pup in a 30-40% oxygen environment, such as a homemade oxygen tent or incubator.4 8 Alternatively a tracheal catheter can be used for endotracheal intubation.1 This is useful when treating pups that also have upper respiratory tract problems.

Puppies with poor respiratory effort can be given doxapram at 0.1ml IV to stimulate breathing.9 There are, however, no studies investigating the true efficacy or adverse effects of doxapram in puppies. Artificial ventilation may be useful to encourage lung surfactant – a protein that reduces surface tension of fluid and allows lung alveoli to expand more efficiently.

Dehydration

Approximately 80 per cent of a neonatal puppy’s body weight is water; therefore dehydration can occur quickly.4'8 When treating a dehydrated puppy, fluid should be administered to meet the ongoing maintenance requirement (generally 60 to lOOml/kg/day or 3-4ml/kg/hour – note, therefore, that a typical Labrador retriever neonate, weighing 0.4kg, will require only 1.4 ml per hour) as well as to replace the deficit.

Oral electrolytes may be considered in mild cases only when bowel sounds are present, but may not be successful because often there is already ileus, and absorption of the fluid is therefore minimal.4 Generally, intravenous, intraperitoneal or intraosseus administration is required.6

For intravenous treatment, over-the- needle catheters are the easiest to keep in position, and human neonatal scalp catheters are perhaps easier to place in small vessels – certainly when trying to place a catheter in a dehydrated puppy. The jugular vein may be preferable to the cephalic vein as the latter commonly results in catheter kinking. Sterile site preparation is important when placing a jugular catheter, along with keeping the neck stretched whilst maintaining the airways.4

When considering intraperitoneal administration, it should be remembered that dosing is required every eight hours, recurrent needle placement may cause sepsis, and fluids are relatively slowly absorbed, especially where there is hypovolemia.

Intraosseus administration – as a last resort when venous access is not possible –   is, therefore, preferable. It is usually performed via the medial aspect of the proximal tibia or the trochanteric fossa of the femur, and fluid is administered at the same rate as for intravenous infusion, as previously described.

After the site has been prepared aseptically, an 18- to 20-gauge needle is used to push longitudinally into the medullary cavity (an intravenous over-the-needle catheter may be used when the cortical bone is soft enough). The catheter can be fixed and left in position for up to 72 hours. Thereafter, a new catheter should be placed into a different bone to avoid fluid leakage caused by repeated puncture (Figure 3).

Figure 3: The placement of an intraosseus catheter in a neonatal puppy

In most cases, it should be assumed that there is acidosis (often respiratory in nature – see hypoxia above) when selecting which fluids to administer to treat a fluid deficit. Isotonic crystalloid solution, at a dose governed by the hydration status, is suggested; and fluid should be warm when administered, but no more than 1°C above the puppy’s current body temperature. Fluid should be warmed during administration when using a fluid pump, to prevent cooling.

Dehydration can be assessed by the equation: deficit = bodyweight x percentage dehydration (Table l).4

The neonate may not be able to metabolise lactate into bicarbonate, owing to reduced liver function and this should be remembered when considering the use of lactated Ringers solution; although in most cases lactated Ringer’s solution with 20mmol/l added potassium is adequate. When acid-base status is not known, 2mmol/l can be administered over 10-15 minutes.6 The volume of fluid for immediate replacement should be approximately 3ml/kg bodyweight per hour* and the risks of over-hydration can be minimised by regularly weighing the neonate and administering fluid using a syringe pump.6

Over-hydration can cause cardiovascular overload, pulmonary oedema and intracranial haemorrhage, which can lead to death.8 Signs of over-hydration are froth at the lips, increased heart rate, laboured breathing, peripheral oedema and seizures.4

Risk of sepsis

Hypovolemia in some neonates might be complicated by sepsis and septic shock can result in further depletion of glycogen reserves. The use of corticosteroids is controversial; but additional bolus glucose therapy can be provided using 10 per cent dextrose given intravenously at 2-4ml/kg as a slow bolus – for example, over a one-hour period of time.9

Neonates that are already compromised are at increased risk of bacterial infection. Prevention of commensal organism overgrowth can be achieved by administering broad spectrum antimicrobial therapy, such as ampicillin, amoxycillin and cephalosporins, whilst waiting for results from bacteriological examination.

Bacterial septicaemia may be challenging to diagnose and death can occur suddenly. A decrease in weight gain, persistent diarrhoea, abdominal distension and pain, unusual vocalisation and sloughing of the extremities can indicate septicaemia.1'2 A diagnosis before death is often not possible, but complete blood cell counts and serum biochemistry results may indicate future organ failure.2

Absorption of oral treatments can be di
fferent in neonates to that in adults and dosage of any medication should consider the immaturity of a neonatal puppy’s kidneys.2

Causes of death in neonates

Many factors may lead to death in the neonatal puppy, including congenital defects, dystocia, injury, reduced immunity, infections (bacterial, parasitic or viral), illness or poor nutrition of the dam, poor maternal behaviour and poor husbandry.

Fading puppy syndrome is reported to be responsible for approximately half of neonatal deaths.11 Puppies in that study (Blunden 1986), which died from known causes, showed signs including frequent crying, restlessness, progressive weight loss, hypothermia progressing to diarrhoea and/or dyspnoea, with resultant dehydration or cyanosis and ultimately fading and then death from day seven onwards.

The puppies that died from fading puppy syndrome (apparently unknown causes), after commonly being of a normal birth weight, faded from day two, showing signs of depression, persistent crying, poor sucking response, progressive weight loss and restlessness. This progressed to weakness, dehydration, hypothermia and death between three to five days after birth.11

It is thought that this syndrome occurs because pups have poor lung surfactant production and, therefore, do not have adequate respiration, which results in a failure to suck.12

Approximately 20 per cent of neonatal deaths result from infection (depending on the country),11 although this is greatly reduced with vaccination programmes and good husbandry. Infectious agents include canine distemper virus, canine herpes virus and canine parvovirus. Certain bacteria are able to exploit the vulnerability of the neonate and death can occur rapidly with few clinical signs.6

Infectious diseases normally progress rapidly and death can be common; but prompt action – including testing the bitch for canine herpes virus antibodies and for canine brucellosis, and sending samples for microbial culture sensitivity testing – may help prevent illness in the remaining littermates.2

Bacteria have been isolated from puppies with enteritis, peritonitis, pleuritis and pneumonia. Parasitic causes of death can result from infection with Neospora caninum, Toxocara canis or Toxoplasma gondii} Injuries resulting in death can occur at any age.

Where illness results in death, it is important that neonates are chilled and sent for a post-mortem examination including histological, viral and bacterial examinations.2

Conclusion

Although there are physiological differences between the neonate and adult dog – which result in an increased potential for morbidity and mortality – careful management and monitoring can significantly improve the health and survival of the neonate.

It is important that any illness is diagnosed, and treatment – that reflects and targets all clinical signs –   is administered rapidly. It is well documented that managing the bitch through pregnancy and parturition, as well as providing adequate warmth and nutrition and minimising exposure to disease during the first three weeks of life, can help optimise neonatal survival.

Timely identification and treatment of the sick neonate is instrumental in reducing mortality, and the veterinary nurse plays a crucial role in advising clients and managing and treating the sick neonate. 

Author(s)

Rachel Moxon BSc(Hons)

Rachel graduated from the Nottingham Trent University with a Degree in Animal Science. Since then she has worked in equine nutrition and exercise physiology research in Kentucky, USA. before joining Guide Dogs (UK) as a canine research associate focusing on reproduction, based at the Guide Dogs National Breeding Centre in Warwickshire.

Gary England

BVetMed PhD DVetMed CertVA DVR DipVRep DipECAR DipACT FHEA FRCVS

Gary graduated from the Royal Veterinary College in 1986. He has British. European and American specialist qualifications in animal reproduction and is Professor of Comparative Veterinary Reproduction at the School of Veterinary Medicine and Science, University of Nottingham.

To cite this article use either

DOI: 10.1111/|.2045-0648.2012.00142.x or Veterinary Nursing Journal Vol 27 pp 61 -65

References

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2 CASAL. M [2010] Clinical approach to neonatal conditions. In: BSAVA Manual of Canine and Feline Reproduction and Neonatology. 2nd Edn. England. G. C W & von Heimendahl. A lEdsI British Small Animal Veterinary Association. Gloucester, UK pp 147-154

3.   GRANDJEAN. D.. PIERSON. P.. RIVIERE. S.. GRELLET. A. BOOGAERTS. C.. COIUARD. L. THOREL. J.. OVERALL. K. and ZABEL. U [2009] Practical Guide to Dog Breeding. 4th Edn Royal Canin, Aimargues, France.

4.   CASAL. M [2010] Management and critical care of the neonate In: B5AVA Manual of Canine and Feline Reproduction and Neonatology 2nd Edn England. G. C W. & von Heimendahl. A [Eds] British Small Animal Veterinary Association, Gloucester, UK pp 135-146.

5.   BLUNDEN, T S (1998) The neonate congenital defects and fading puppies In: Manual of Small Animal Reproduction and Neonatology Simpson, G , England, G C. W & Harvey, M lEdsl British Small Animal Veterinary Association, Cheltenham, UK

6   STURGESS. K. [1998] Infectious diseases of young puppies and kittens. In: Manual of Small Animal Reproduction and Neonatology Simpson. G.. England. G. C W & Harvey. M lEdsl British Small Animal Veterinary Association. Cheltenham. UK

7   HOSKINS. J D (2001) Veterinary Pediatrics, 3rd Edition – Dogs and Cats from Birth to Six Months W B Saunders Company, Philadelphia

8   LAWLER. D F. [2008] Neonatal and pediatric care of the puppy and kitten Theriogenology 70:384-392

9   TRAAS, A M [2008] Resuscitation of canine and feline neonates. Theriogenology 70: 343-348

10   VERONESI, M. C„ PANZANI, S., FAUSTINI, M and ROTA, A [2009] An agpar scoring system for routine assessment of newborn puppy viability and short-term survival prognosis. Theriogenology 72. 401-407

11   BLUNDEN. A. S. [1986] A review of the fading puppy syndrome latso known as fading puppy complex! Veterinary Annual 26: 264-269

12   BLUNDEN. A. S.. HILL, C M.. BROWN. B. D and MORLEY C. J. [1987] Lung surfactant composition in puppies dying of fading puppy complex. Research in Veterinary Science 42
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• VOL 27 • February 2012 • Veterinary Nursing Journal