Fading Kitten Syndrome

What Is Fading Kitten Syndrome?

Caring for a newborn kitten can be a rewarding experience—but it also can be heartbreaking if they experience fading kitten syndrome. 

Fading kitten syndrome refers to a kitten’s failure to thrive during the period between birth and when they wean from their mother or a bottle. This period lasts about four to five weeks, when a kitten is most vulnerable to sickness.

Fading kitten syndrome is typically fatal, but recognizing the symptoms can help you to understand when to get veterinary help.

Symptoms of Fading Kitten Syndrome

Kittens that fail to meet normal development milestones may be experiencing fading kitten syndrome. Some of these milestones include:

• Ability to turn over from their back by day three of birth

• Ability to support themselves on their feet by 2 weeks of age

Other symptoms of fading kitten syndrome include:

• Constant noises that indicate distress (such as whining or crying), even after feeding

• Gradually worsening lethargy

• Lack of appetite

• Poor suckling reflex

• Weakness

• Inability to gain weight

• Labored breathing

• Vomiting

• Diarrhea

• Nasal or eye discharge

Causes of Fading Kitten Syndrome

Fading kitten syndrome can have several causes. Some include:

• Trouble during birthing

• Lack of maternal antibodies (cells that help protect kitten’s immature immune system)

• Bacterial or viral infections

• Parasites

• Malformations present at birth (e.g., heart defects, gastrointestinal defects, brain defects, lung defects)

• Low birth weight

• Trauma

• Maternal neglect

• Malnutrition

Genetics can also play a role in fading kitten syndrome.

If a mother cat has a blood type that differs from her kitten, her maternal antibodies may attack the kitten’s red blood cells, causing anemia that can lead to fading kitten syndrome. This condition is called neonatal isoerythrolysis.

How Veterinarians Diagnose Fading Kitten Syndrome

To diagnose fading kitten syndrome, your veterinarian will examine your newborn kitten in the first few weeks of life. Your vet will check them routinely every few weeks until the kitten is weaned to determine if they are thriving.

If your vet doesn’t think your kitten is reaching their milestones—such as not suckling correctly (or at all), or not gaining weight—they will recommend diagnostic testing. This testing will help your vet figure out if there is a specific diagnosis for why the kitten is not thriving and is declining in health.

Diagnostic testing typically involves blood work, fecal and urine testing, and imaging (X-rays and/or an ultrasound).

Unfortunately, sometimes a diagnosis can’t be made before a kitten passes away or is humanely euthanized due to poor prognosis or poor quality of life.

If you have other cats or kittens at home, your veterinarian might recommend that a necropsy (autopsy) be done. This is to ensure that your other cats are not at risk of developing a contagious disease.

Treatment of Fading Kitten Syndrome

Fading kitten syndrome may be treatable if an underlying cause can be identified in time— but this is typically not the case.

For example, some bacterial infections can be treated if caught early enough, while some congenital (condition present at birth) defects may not, especially if the kitten’s quality of life would be poor. 

Treatment includes supportive care while the veterinarian works to identify an underling cause. Supportive care usually includes:

• Fluids can be given intravenous (IV) or subcutaneous (under the skin) to keep the kitten hydrated and help regulate other body functions, like correcting low blood pressure.

• Dextrose is a sugar solution that is given to kittens to support blood sugar levels. Young kittens still have developing body systems, and they often can’t regulate their own blood sugar, or they have low blood sugar from not eating. Adding this sugar solution to your kittens' fluids or given by mouth is helpful to aid their survival.

• Antimicrobials such as antibiotics, antifungal, or antiviral medications are given to combat specific organisms such as bacteria, yeast, and some viruses. These medications can be given by mouth but if you kitten is not eating well, most can be given by injection instead.

• Nutritional support is provided to your kitten when they are not eating well on their own. Typically, a feeding tube will have to be placed either in your kitten's nose or directly into the stomach to provide them with the calories, vitamins, and minerals they need to hopefully recover from their illness. Cats are unique in that if they do not eat enough calories per day, their body will go into hepatic lipidosis or liver failure, which can be fatal regardless of the underlying cause of the kitten's illness.

• Oxygen support is provided to kittens either by placing a nasal canula directly in the nose or by putting them in a special oxygen cage. Oxygen helps kittens that are having trouble breathing.

• Body temperature support is provided to ensure your tiny kitten can stay warm. Young kittens can’t regulate their body temperature effectively, which can result in a temperature too high (hyperthermia) or too low (hypothermia). Heat support can be provided with a heating blanket, or warmed bottles placed around the kitten. Cold compresses can be used along with ice on the paw pads to help a high temperature come down.

A delay in evaluation and treatment could result in:

• Low blood sugar

• Dehydration

• Low body temperature

Unfortunately, even with treatment, some kittens will pass away.

Recovery and Management of Fading Kitten Syndrome

Recovery from fading kitten syndrome is possible if an underlying cause can be identified and treated in time. Unfortunately, fading kitten syndrome is often fatal, with the highest rate of mortality being in the first week of a cat’s life. 

If a kitten does survive this crucial period and grows stronger, long-term management is aimed at proper nutrition, providing sanitary conditions and preventative health care, and close monitoring to ensure they gain weight. 

The long-term outlook for kittens that recover is good, unless there is a congenital or chronic viral infection that affects the kitten’s life expectancy. 

Prevention of Fading Kitten Syndrome

Fading kitten syndrome is not often a preventable condition.

It can potentially be prevented by ensuring that your new kitten’s mother cat (or queen) has adequate prenatal veterinary care.

The queen should be fully vaccinated, have flea and tick prevention and undergo routine deworming.

It’s important to ensure that your new kitten is taken to the vet within three days to determine if they are healthy. If kittens are displaying signs of illness, take them to the vet immediately.