two days old kittens with eyes barely open, soft focus, illustrating fading kitten syndrome

If you own a pregnant cat and have heard about fading kitten syndrome, you are probably concerned about the health and safety of the kittens to come. But what exactly is fading kitten syndrome?

Fading kitten syndrome is a devastating ailment where kittens are born healthy, but slowly become ill and die within their first few weeks of life. The cause of this syndrome can be attributed to numerous factors such as infections, toxins, traumas, metabolic issues, or genetics.

This article explains exactly what fading kitten syndrome is, what causes it, and how it can be treated.

What Is Fading Kitten Syndrome?

Fading kitten syndrome is also known as failure to thrive. It is characterized by a rapid decline in the health of a young kitten in the first few weeks of life, often for no reason that is apparent to the owner.

The mortality rate in kittens affected by fading kitten syndrome is very high, so it’s important to be aware of the symptoms and act quickly if you suspect fading kitten syndrome in your kittens.

Symptoms of Fading Kitten Syndrome

The initial signs in kittens affected with fading kitten syndrome can be difficult to recognize. Common signs are failure to nurse or bottle feed, decrease in activity, listlessness, poor temperature regulation, and lethargy.

As their health declines kittens can start to show:

  • Low body temperature
  • Poor weight gain
  • Weakness or lack of energy
  • Lack of responsiveness to stimulation
  • Dehydration
  • Respiratory distress

It is important to note that fading kitten syndrome is caused by a variety of underlying conditions, and not all kittens with fading kitten syndrome will display the same symptoms.

closeup image of a newborn ginger kitten, illustrating fading kitten syndrome

Causes of Fading Kitten Syndrome

Fading kitten syndrome occurs as a result of several different factors. Often, more than one contributing factor can be found at the same time.

Inadequate Nutrition And Hydration

Kittens can suffer from fading kitten syndrome if they are not receiving enough nutrition or hydration. This can be due to a number of causes, such as their mother’s inability to produce enough milk, or an improper technique when bottle-feeding.

Kittens may also not be getting enough to eat due to weakness, physical defects, or because of too much competition from litter mates (e.g. they are the runt of the litter or too many kittens for the number of available teats).

Bacterial, Viral, Or Parasitic Infections

Infections are one of the most common causes of fading kitten syndrome. Bacterial infections, viral infections, and parasites can all lead to fading kitten syndrome in kittens if left untreated.

Neonatal bacterial infection is the most common type of infectious cause; particularly, Escherichia coli, streptococci, Pasteurella species, and staphylococci. Common viral infections include panleukopenia (feline distemper), calicivirus, and feline leukemia virus.

Roundworms are the most common parasitic infection in cats. Kittens become infected with the worm larvae across the placenta during pregnancy, or through the milk after birth.

Trauma And Stress

Another possible cause of fading kitten syndrome is trauma. This can be an injury that happened after it was born, or it can be from a difficult birth (dystocia). Breeds with atypical conformation, such as Persian cats, may suffer from a much greater frequency of dystocia.

Dystocia can also result in stress in the newborn kitten which can be difficult to recover from, such as hypoxia (low oxygen) during delivery or hypothermia (low body temperature) resulting from mismothering after a difficult and exhausting labor.

ginger mother cat and kittens in a basket bed, illustrating fading kitten syndrome

Congenital Defects

In some cases, fading kitten syndrome can be caused by congenital defects, or malformations during fetal development.

Defects such as cleft palate, heart defects, and hydrocephalus, along with many other potential congenital anomalies, can cause fading kitten syndrome in newborn kittens.

Neonatal isoerythrolysis

Neonatal isoerythrolysis is a condition where a kitten born to one type of blood group is exposed to another type of blood group via their mother’s milk. Antibodies from the mother’s colostrum (first milk) are ingested by the kitten, producing an immune reaction that can cause fading kitten syndrome.

Some breeds, such as British Shorthair and Devon Rex cats, are more likely to have mother-kitten blood type mismatches that cause neonatal isoerythrolysis.

Diagnosing The Cause Of Fading Kitten Syndrome

Fading kitten syndrome has a high fatality rate, so prompt diagnosis and treatment is essential.

The best thing you can do for affected kittens is to take them to the vet as soon as possible. The vet will examine the kitten and perform tests, such as a blood test or X-rays, to identify any underlying conditions that may have caused fading kitten syndrome.

Your vet will examine the kitten to determine if any underlying congenital defects are incompatible with life, determine how underweight or dehydrated it might be, and whether or not its body temperature is normal.

mama Abyssinian cat and kittens, illustrating fading kitten syndrome

Once the obvious physical causes have been ruled out, further tests can be conducted to diagnose other causes of fading kitten syndrome. The vet will likely conduct blood tests to assess the kitten’s current levels of hydration, nutrition, electrolytes, blood sugar, and pH.

Other tests help pinpoint the underlying causes such as bacterial infections, viral infections, parasites, congenital defects, or neonatal isoerythrolysis.

Once a diagnosis has been made, your veterinarian can then provide treatment appropriate for the underlying condition. Sometimes, when the underlying condition is incompatible with life, humane euthanasia will be recommended.

Treatment Of Fading Kitten Syndrome

One of the most important treatments for fading kitten syndrome treatment is rehydration. No matter the underlying cause, affected kittens are likely to be dehydrated because they are aren’t taking in enough milk.

At the same time that they are not taking in enough fluids, the kittens are losing a great deal of moisture in their feces, urine, and respiratory secretions, so it is essential to replace lost water.

A second very important treatment for affected kittens is warming them, provided that they do not have a fever due to a bacterial or viral infection. Kittens who are not eating enough will not have the energy needed to keep themselves warm.

3 newborn kittens isolated on a white background to illustrate fading kitten syndrome

The kittens’ veins are too small for intravenous (IV) injection, so the veterinarian will likely give your kitten subcutaneous fluids. That is, a sterile electrolyte solution is injected under the skin so it can be absorbed by the kitten’s body.

They will place the kitten in a neonatal incubator, or something similar, to keep the kitten warm. Your veterinarian may also prescribe antibiotics to treat any underlying bacterial infections that have been diagnosed.

In cases of neonatal isoerythrolysis, a blood transfusion may be necessary to ensure the survival of the kitten.

The next critical thing is to make sure the kitten is getting adequate nutrition. Bottle feeding may be tried, but in smaller and weaker kittens syringe feeding may be needed. The video below shows how to syringe-feed kittens:

fading kitten syndrome - feeding an ailing kitten

While I always strongly recommend seeking immediate veterinary care for these kittens, I also recognize that this is not always possible to do. Just keep in mind that without veterinary care, the chances of the kitten’s survival are very poor.

Supportive care (keeping the kitten warm and providing adequate nutrition) is the primary means for fading kitten syndrome treatment, but usually, additional treatments are needed.

Supportive care alone may work where the underlying cause is mismothering or being too small to compete for a teat, but will not be effective in most other cases. In any case, early intervention leads to the best chance of success.

Long-Term Prognosis For Recovered Kittens

The long-term prognosis for fading kittens that recover with treatment is generally good, though some individuals may experience life-long health issues related to the fading kitten syndrome, such as poor growth or impaired development.


Fading kitten syndrome is a serious condition that requires immediate veterinary attention to provide the best chance of survival. Treatment usually involves rehydration and warming, as well as treating any underlying medical conditions.

If not treated rapidly, fading kittens typically have a very poor prognosis but those lucky enough to receive prompt and appropriate treatment have a better chance of recovering.

Having fading kitten syndrome does not guarantee that kittens will have long-term health issues, but it is something to be aware of. With early intervention and effective treatments, fading kitten syndrome can often be successfully managed.

Disclaimer: This article is intended for information purposes only, and does not constitute medical advice. Always consult your veterinarian if you have specific concerns about your pet’s health.

white kitten looking backward while laying on her back, illustrating kitten recovered from fading kitten syndrome


  • Dr. Wendy Wilkins, DVM, PhD

    Dr. Wendy Wilkins is an experienced veterinarian and epidemiologist with over 20 years of expertise. She holds a Doctor of Veterinary Medicine (DVM) degree and a Doctorate in Epidemiology from the University of Saskatchewan. Throughout her career, Dr. Wilkins has excelled in clinical practice, academia, research, and regulatory veterinary medicine. She is a respected voice in knowledge dissemination, delivering factual information in a readable and understandable manner through articles, books, and public engagements.

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