Fading kitten syndrome occurs when newborn kittens fail to thrive due to one or more health concerns. Sometimes, the cause of fading kittens is unknown, and it's heartbreaking for cat owners and rescuers who care for newborn kittens. It can be frustrating to helplessly watch some kittens inexplicably fade and die under the most attentive care. However, an extremely perceptive caregiver might be able to recognize the signs of fading kitten syndrome, increasing kittens' chances of survival. Here's what you should know about fading kitten syndrome.

What Is Fading Kitten Syndrome?

Fading kitten syndrome, also called failure to thrive, is a collection of signs that develop in newborn kittens which signify rapidly declining health. Kitten mortality is highest during the first week of life, accounting for up to 90% of feline deaths. An estimated 16% of kittens die before weaning.

Fading kitten syndrome has many potential causes but few signs. Unfortunately, often the first and only indication of this syndrome is the unexplained death of a very young kitten. Because of this, fading kitten syndrome has been compared to sudden infant death syndrome (SIDS) in human babies.

Symptoms of Fading Kitten Syndrome in Cats

There are some indications that a kitten may be at risk of developing fading kitten syndrome. People who rescue and foster pregnant cats or kittens should take time to learn to spot the signs of fading kitten syndrome as the offspring of stray and feral cats are particularly prone to this condition.

Kittens that develop fading kitten syndrome are often the smallest of the litter. They have a low birth weight and are not as active as their litter-mates. These kittens may appear lethargic, weak, or listless.

Healthy kittens nurse almost immediately after birth. A fading kitten is often not strong enough to grasp and suckle the mother cat's nipple. Some can nurse but will vomit or spit up milk. During the first 72 hours or so of nursing after birth, healthy kittens that are nursing well receive special milk called colostrum. This colostrum provides essential nutrients and antibodies. Colostrum gives the kitten passive immunity, allowing them to grow and thrive until they can receive vaccinations and stop nursing. If a kitten fails to nurse and needs to be bottle-fed it will not receive colostrum and is more likely to develop fading kitten syndrome.

Mother cats sense when there is a weak or sick kitten and may abandon it in favor of their other kittens. This is an instinctual reaction designed to protect the healthier kittens.

Since newborns can't regulate their body temperature, they depend on their mom for warmth. Therefore, abandoned kittens or those that wander away from their mom can rapidly develop hypothermia. Hypothermic kittens are lethargic and their mouth and gums may be pale or blue-tinged rather than a healthy pink. This can rapidly be fatal unless human intervention occurs.

Causes of Fading Kitten Syndrome

While there is no definitive cause or set of causes underlying the development of fading kitten syndrome, there are factors that contribute to kittens' early deaths.

Disease or Malnutrition of the Mother Cat

If this is the queen's first litter of the season, she may not have access to the amount of food required to grow healthy kittens. Depending on the environment, a queen can have up to five litters of kittens within a year. This is physically taxing on the female cat, causing malnourishment and illness. This combination does not bode well for late-season kittens, resulting in higher rates of stillbirth, congenital abnormalities (birth defects), and kittens with fading kitten syndrome. This is why it's so imperative to take a suspected pregnant cat to the veterinarian for a prenatal check-up. Your vet will discuss your options and how to take care of a pregnant cat.

Birth Defects

Kittens can be born with a number of issues that prevent them from thriving. These may occur due to developmental issues in gestations or hereditary (genetic) conditions. Some feline birth defects include cleft palate, heart defects, hydrocephalus, and cerebellar hypoplasia.

Infectious Diseases

There are a number of viral and bacterial infections that quickly affect an entire litter of kittens, and the weakest kittens in the litter are the most susceptible. Keep litters of stray or feral queens completely separate from your household cats. If possible, donate your time or money to local feral and rescue cat organizations that help spay and neuter stray cats.

Neonatal Isoerythrolysis

Neonatal isoerythrolysis occurs when the queen and kitten have different blood types. The kitten's red blood cells are destroyed by antibodies they receive from the mother cat's colostrum.

Fleas and Other Parasites

When fleas bite, they ingest blood and secrete saliva. A flea infestation on a newborn kitten can lead to severe anemia or transmit tapeworms, both of which are potentially fatal in tiny kittens. In general, kittens are susceptible to many parasitic agents including protozoal infections, intestinal worms, and tick-borne diseases.

What To Do if You Have a Fading Kitten

Contact your veterinarian immediately if you have a young kitten with any signs of illness, no matter how subtle. Your vet may ask you to bring the mother and the entire litter to the vet for examinations. Sadly, fading kittens often decline rapidly and may die, even with treatment. However, early detection and treatment can improve the kitten's chances of recovery.

Diagnosing fading kitten syndrome is generally based on the observation of symptoms in a newborn kitten, including lethargy, lack of nursing, and/or difficulty breathing. A veterinarian may also test the kitten for any infections or parasites.

Treatment and Prevention

After a thorough examination and possible diagnostic tests, your veterinarian will recommend a course of action. Medications may be prescribed to treat any infection present. Supportive care, such as fluid therapy, can help manage hypothermia, malnutrition, and dehydration. Unfortunately, the prognosis is guarded in cases of fading kitten syndrome; most kittens with these symptoms will die within hours to days of signs appearing.

Since fading kitten syndrome is a rather mysterious syndrome that often occurs in feral cats, there is no sure-fire way to prevent it. The best course of action is to treat the specific signs in an ailing kitten and hope for the best. However, if you have a pregnant cat, keeping her healthy will give her kittens the best chances for healthy lives.

In the unfortunate event that a fading kitten does not survive, know that you did your best to help them and try to direct your attention to the mother cat and other kittens to make sure they are healthy and thriving.