2Neonatal mortality in puppies 9.23 to 26% of all whelps50% of these deaths attributed to fading puppy complexLittle research has been done on subject
3Causes of neonatal mortality (Fox, 1961) InfectionCanine hepatitis virusStaph, StrepE coliProteusStaph or strep toxinParasites
4Causes of neonatal mortality GeneticsCongenital defectsInbred litters have higher mortality than hybrid crosses of inbred litters - Fox 1963
5Causes of neonatal mortality EnvironmentTemperature: Hypothermia or hyperthermiaToxins: cleaning fluid fumes, etc
6Causes of neonatal mortality NutritionIn uteroFailure of lactationInattention of damLow birth weight/immaturityIcterus neonatorum
7Definition of fading puppy complex Apparently normal newborn which fails to thrive and dies in the first 2 weeks of life
8Signs of fading puppy complex Failure to gain weight at same rate of siblingsDecreased activityInability or refusal to suckleHigh pitched cryProgression to lethargy, loss of tone, death
9Case study - DexAugust 24 2nd in birth order Normal birth weight No difficulty whelping Nursed well
10August 29Failure to gain weight – weight 295 gms 12:00 PM– crying, refuses to suckle. Treated with warming, pedialyte via feeding tube every two hours 6:00 PM High pitched cry, increasing lethargy, abdominal breathing, sternal retractions 10:00 PM In respiratory distress, retracting, lethargic. Administered 0.16 mg (0.6 mg/kg) of dexamethasone SQ
11August 304:00 AM - lusty crying, suckled when placed on breast. Calmed by nursing. Milk confirmed in stomach via oral gastric tube7:00 AM – nursing strongly, abdomen expanded after feeding. Weight 272 gms.1200 PM – back with litter, competing for teats successfully.
12August 31 7:00 AM Weight 301 gms 12:00 PM – not nursing as well 4:00 PM – 36 hours after dexamethasone dose, no longer nursing, crying constantly. Administered 0.16 mg dexamethasone SQ.10:00 PM – once again nursing well, having trouble competing. Nursed with one other sibling
13September 1 Weight 301 gm Back to normal by 7:00 AM Placed on decreasing dexamethasone doses daily for the next 10 daysContinued to gain weight at an accelerated rate until he caught up with litter mates.
17The physiology of immaturity Effects of anoxia take longer to appear in the brain of the neonate than older puppies (Mott, 1961)
18The physiology of immaturity Best and Taylor 1952Older dogs exposed to cold increase the secretion of cortisol, neonatal puppies do notAlso found a lack of compensatory vasoconstriction on rewarming neonates.
19The physiology of immaturity Randall et al 1995Study of beagle puppies found 2 week old puppies have lower cortisol than adults, but do respond to ACTH administration
20The physiology of immaturity Cowan 1975Histamine injected into 1-7 day old puppies causes lower secretion and peak rates of cortisol secretion than adults.
21The physiology of immaturity Bardens et al 1961Puppies have low glycogen reserveWith stress can develop a metabolic derangement of of glycogen metabolism which appears to be similar to Von Gierke’s syndromeGlycogenosis precipitated by stress was alleviated with administration of glucose and corticosteroids.
22Adrenal crisis in humans Shock, progressive lethargy, vomiting, deathTreatment is administration of hydrocortisone, IV fluidsRecovery with treatment is rapid
23Dexamethasone Trade names: Azium, Decadron Classification: glucocorticosteroidOnset of action: 4-8 hoursDuration of action: hoursInjectable formulation is also absorbed orallyCan be given SQ, IM, IV or orally
24Question?Is fading puppy complex an adrenal crisis in the neonate who is physiologically unable to respond to a stressor? Caveat – there are some stressors that are not survivable for example overwhelming infection, severe congenital defects.
25Supportive treatment for the fading puppy WarmingOral or IV glucoseRehydrationReversal of the underlying stress or causeDexamethasone administered early if warming, glucose and hydration do not have any effect.
26Dexamethasone dosing schedule Initial dose 0.6 mg/kg of body weight subcutaneouslyDrug vial is 4 mg/ml for precise dosing must dilute to 1 mg/ml. This is 0.25 cc in 0.75 cc of saline.Use a U100 ½ cc insulin syringe this is divided up into 0.01 cc increments.Decrease the daily dose by 0.05 mg/kg every day until the puppy is off of the medicine. As long as the puppy is doing well, after the first dose the remainder can be given orally.
28BibliographyBest, CH and Taylor, NB. The Physiological Basis of Medical Practice Baltimore and Wilkins CompanyCowan, JS. Adrenaocorticotropin Secretion Rates Following Histamine Infection in Adult and Newborn Dogs Canadian Journal of Physiology and Pharmacology 53:Fox, MW. The Pathophysiology of Neonatal Mortality in the Dog J. Small. Anim. Pract. 6:Khan, AK; Dutt, R; Deori, S; Das, GK. Fading Puppy Complex – An Overview Intas Polivet. 10(11):Mott, JC. The ability of young mammals to withstand total oxygen lack Brit med Bull. 17:2Randolf, JF; Scarlett, JM; Corbett, JR; Canter, SA; Reimers, TJ. Adrenocortical function in neonatal and weanling Beagle pups Am Jour Vet Res. 56(4):551-17Ranjan, A. Fading Puppy Syndrome: An Overview Veterinary Practioner. 11(2):
29Other pertinent information Freshman, JL Evaluating Fading Puppies and KittensDavidson, A Approaches to Reducing Neonatal Mortality in Dogs