Fading kitten syndrome: Factors predisposing to ‘faders’ and treatment options

Abstract

Practical relevance: Fading kitten syndrome is a condition where one or more kittens of a litter are born apparently healthy but gradually become inactive, sick and die; typically faders are considered those that die during the first 2 weeks of life. Fading has many potential aetiologies, including a wide variety of infectious, toxic, traumatic, metabolic and genetic diseases. Regardless of the underlying cause, the approach to a sick neonate is similar, and initiating supportive care is the first priority, followed by a detailed physical examination. Where possible, the cause of disease should be determined, and this may inform adjustments to the treatment protocol. Clinical challenges: Most perinatal and neonatal diseases present similarly and a specific cause cannot usually be determined from clinical signs alone, which can make diagnosis challenging. When examining a kitten, it is important to remember that there are distinct physiological differences between adults and neonates. In addition, some procedures can be more difficult to perform than in adults, such as blood collection, and some diagnostic tests are harder to interpret, such as radiography. When treating kittens, differences compared with adults again need to be considered. Aim: The aim of this review is to provide guidance to veterinarians who are presented with a fading kitten. As well as reviewing the potential causes of fading kitten syndrome, the diagnostic approach and treatment options are discussed. Algorithms summarising possible pathways to neonatal mortality in kittens, and diagnostic and therapeutic options in fading kittens, are also provided. Evidence base: Information provided in this review is based on the published feline literature and papers discussing puppies and/or a range of species including cats, as well as the author’s own clinical experience.

Neonatology: Topics on Puppies and Kittens Neonatal Management to Improve Neonatal Outcome

“…Insufficient colostrum intake in the first 12 h of life results in failure to transfer passive immunity, making newborns vulnerable to various infectious diseases [ 36 , 39 ]. In addition, neonates who are not adequately breastfed will develop failure to gain weight, the neonatal triad (hypothermia, hypoglycemia, and dehydration) and fading, progressing to death [ 11 , 13 , 36 , 37 ]. On the other hand, females with deficient and aggressive maternal instincts can cause trauma and lacerations in newborns.…”

“…However, prolonged and dystocic deliveries can lead to pronounced asphyxia and severe hypoxia in newborns, leading to failure of respiratory adaptation and higher mortality rates in the transition period [ 3 , 11 , 44 ]. This condition is considered the main cause of more than 60% of losses of canine and feline neonates during the first two days of life (early mortality) [ 10 , 20 , 45 ].…”

“…There are a wide variety of factors that can potentially affect the health of a litter during pregnancy, birth, and the first few weeks of life, which require adequate attention from both the breeder and the veterinarian. Maternal, neonatal, environmental, and birth-related factors can directly influence litter viability [ 11 , 12 , 13 ]. Furthermore, lack of knowledge, management errors, lack of neonatal care, and neglect also influence neonatal mortality.…”

Reproductive Management in Catteries: Optimising health and wellbeing through veterinarian-breeder collaboration

“…Ideally, kittens should be weighed after parturition, then at least once (preferably twice) daily until about 4 weeks of age and thereafter twice per week until weaning. Insufficient or lack of weight gain, or even loss of weight, are critical signs of an underlying problem and an indication for careful examination of the dam and the kittens (as discussed in accompanying reviews on feline breeding and pregnancy management 183 and fading kitten syndrome 184 ). An unsatiated, ‘crying’ kitten can also signify insufficient milk production by the dam.…”

“…185 The risk of neonatal isoerythrolysis, a potentially fatal condition in kittens associated with blood group incompatibility between a type B queen bred with a type A tom, is discussed in accompanying reviews on feline breeding and pregnancy management, and fading kitten syndrome. 183,184…”