Anytime someone mentions a kitten has diarrhea or has vomited on social media, someone immediately suggests that it might be panleukopenia. They do this solely on seeing either of those symptoms. And to be fair, I was likely guilty of this when I was a new foster. I refer to this as “Foster Parent Panleuk Paranoia,” the belief that a kitten’s symptoms panleukopenia.
And while diarrhea and vomiting are symptoms of panleukopenia, and it is a good idea to always be aware of when a kitten is at risk of developing panleukopenia, it’s also good to understand what panleukopenia really looks like.
Most of this information is from my own personal experience. I’ve dealt with close to 100 kittens with panleukopenia. This high number comes from, in part, taking kittens that are severely ill and also having space where I can take kittens who have tested positive for panleukopenia.
Diarrhea
Diarrhea isn’t the best indicator for panleukopenia, but it is the one symptom that causes most people to consider it, especially if they see bloody diarrhea, so I’ll discuss it first.
In my experience, panleukopenia doesn’t cause “diarrhea” it causes “severe diarrhea.” I usually refer to it as “dripping diarrhea” because the kittens often have accidents outside of the litter box where they drip stool. But as Merck Manual says, “Diarrhea may begin a little later than the vomiting but is not always present.”
Diarrhea should also be accompanied by several other symptoms not typically seen with other common diarrhea causes such as depression/lethargy, high fever, or a rapid decline. A kitten who vomits and has diarrhea with no other symptoms likely has parasites (such as roundworms) or is reacting to a recent diet change. A kitten who has diarrhea, vomiting and a high fever would be suspect for panleuk.
Bloody Diarrhea is Not a Good Indicator of Panleukopenia.
Bloody diarrhea can occur when a kitten has had diarrhea for 2 to 3 days. Diarrhea is irritating on both the intestines and the anus. And a kitten who has had diarrhea for several days without other severe symptoms, is not likely to have panleukopenia.
Vomiting
Vomiting in kittens is more likely to be roundworms or diet change, especially if the kitten is active and behaving normally. I have rarely experienced it with panleukopenia, so I can’t say much about it. According to Merck Manual, “Vomiting usually develops 1–2 days after the onset of fever; it is typically bilious and unrelated to eating.”
Hypersalivation may be seen in some cases, associated with nausea or abdominal pain.
Rapid Decline
Whenever a kitten rapidly declines or is found dead, you should immediately consider panleukopenia even if there are no other symptoms. In my experience, I will often notice mild symptoms in kittens, like a decrease in appetite and energy, about 10 to 12 hours before the kitten becomes extremely lethargic.
Because mild depression and lack of appetite can be caused by a number of issues and usually not caused by panleukopenia, it’s not enough to panic at those first symptoms. But the symptoms are unlikely to improve when the kitten is given dextrose and subcutaneous fluids.
Sudden Death
A kitten who is suddenly dies or goes from appearing healthy to severely ill within 24 hours should be considered suspect of panleukopenia. These cases are considered to be “peracute” cases, versus acute. Peracute cases are 100% fatal. (Source)
Lethargy/Depression
On several of the cases that developed in my home, mild lethargy was one of the first signs I noticed. Unfortunately, this is a symptom of a lot of things. But when you notice it, it is a good idea to keep a sharp eye for other symptoms.
High Fever
The normal rectal body temperature of a 4-week-old kitten is between 99 to 101°F. For kittens 2- to 3-weeks-old, the normal temperature is slightly cooler, or 97 to 100°F. Anything over 102.5 is considered a fever in cats. A “high fever” would be between 104 to 107°F.
Loss of Appetite/Anorexia
Lack of or decreased appetite is another sign that you may notice right away. I recall one kitten who was notorious for his love of canned food strangely not seeming hungry one night. The following morning he had developed neurological symptoms and was diagnosed with panleukopenia.
Dehydration
Obviously, when a kitten or cat has severe diarrhea and a lack of appetite, dehydration will soon follow. But people often talk about seeing a cat hunched over a water dish not drinking as a key sign of panleukopenia. I’ve only seen it once, and it didn’t happen until later.
Neurological Symptoms
Out of the 60+ panluek kittens I have had, only 3 had neurological symptoms. The AVMA describes what it looks like best “Infected cats may even show signs that resemble those seen when a cat has been poisoned or has swallowed a foreign object.” Kittens often stumble and have difficulty moving. When set down, they limbs may be unable to support them although they are able to move around. They may also have tremors.
Severe URI
Panleukopenia destroys the immune system, which means other illnesses have a better chance at taking hold. I had one kitten with a severe URI that took a week before he improved. Had he not had several siblings already perish from panleukopenia, I doubt I would have thought about it being in play. He did survive, and I called him Miracle. You can read his story here.