Causes of Sudden Death in Cats 8


When an outdoor-access cat goes missing from its home range, this frequently means that something has happened to the cat to prevent it from returning home.  Death, injury or illness may all prevent a cat from returning home.  When sick or injured, a cat may hide within its home range and may die if not found.  This behavior has been observed in both outdoor-access and indoor-only cats.  Understanding the frequency of different causes of death in owned cats (particularly sudden death where the owner does not know that the cat is sick or injured), may help us better determine priority areas to search for a missing cat.

Olsen and Allen (2001) conducted a study on sudden and unexpected causes of death for cats in a city of over 200,000 people and surrounding towns in Saskatchewan, Canada. During a 10-year period, one large veterinary facility treated 994 cats of which 79 (8%) were brought in for autopsies by their owners because they died suddenly and unexpectedly.  Of these 79 cats, 49 (62%) were outdoor-access, 11 (14%) were indoor-only, and 19 (24%) were unknown.

Table 1. Underlying causes of sudden and unexpected deaths in 79 cats.

Table 1 shows the relative frequency of different causes of sudden death.  By far the most frequent cause of sudden death (34%) was attributed to trauma caused by road traffic accidents (RTAs).   All but two of the RTA deaths were outdoor-access cats, so that means that 51% (25 out of 49 total) of outdoor-access cat deaths were due to RTAs.  Other types of death due to trauma were 3 dog bites and 1 gun shot.

Heart disease (20%), primarily hypertrophic cardiomyopathy, was the second most frequent cause of sudden death followed by intestinal disease (8%).  Five of the 6 cases of intestinal disease were under six months old and died of enteritis due to feline panleukopenia.  Surprisingly, three of these kittens were indoor-only.  Respiratory disease accounted for 6% of deaths; three of these cats died of pneumonia and were 2-10 months old.  The other two cats died from breathing obstructions.

Urinary tract diseases (5%) were more likely to occur in older cats.  Three cats aged 8, 10, and 18 years died of renal disease.  One 6 year old cat died of a urethral obstruction.  This is unusual only because urinary obstructions usually have visible symptoms such as frequent urination or straining prior to death.  Diseases associated with feline leukemia virus (FeLV: 4%) were the last relatively frequent cause of sudden death.  All three FeLV-related deaths were outdoor-access cats.  The remaining four causes of sudden death all accounted for few cats (1% each).  The cause of death could not be determined in 13% of cases.

In this particular study, road traffic accidents accounted for a high percentage of deaths (51% of outdoor-access cats autopsied).  This number is even likely to be an underestimate because the data were collected from autopsy reports.  If a cat was obviously hit by a car, its owner would probably be less likely to go through the expense of getting the body autopsied.  There were also no cases of poisoning or death by predators, besides the three presumed dog bites.  However, predator deaths may also be underestimated since these bodies are less likely to be recovered.

Unfortunately, since Olsen and Allen (2001) did not collect data on the entire population of cats in the study area, it is not possible to determine whether certain characteristics (e.g. age, sex, access to outdoors, etc.) may predispose cats to different causes of sudden death.  In upcoming blog posts, I intend to focus on the most common causes of sudden death and find out what is known about them.  The first paper I’m going to review is a very informative study on the factors that may predispose domestic cats to road traffic accidents.

Olsen, Tammy and Andrew Allen.  2001.  Causes of sudden and unexpected death in cats: a 10-year retrospective studyCanadian Veterinary Journal 42: 61-62.


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8 thoughts on “Causes of Sudden Death in Cats

  • Rose Batts

    MY cat died on my birthday yesterday. I didn’t know he was seriously ill although I noticed he was experiencing breathing problems but I thought he needed air so I would let him go outside and he acted alright. The night before he died, he was gaging and I just though he had swallowed something. He had not been to he Vet for a year because he terrified me with his actions there. He was about 10.5 years old, slightly overweight and had been healthy other that not having his last shots. I am guilt-stricken about this and I know if I had taken him to the Vet he would not died. Please tell me something to make me feel less guilty.

    • Danielle Post author

      I’m so sorry to hear that your cat passed away suddenly on your birthday. It can be very difficult to tell when to take a pet to vet when they aren’t acting right but are not obviously sick or injured. I have sadly experienced similar circumstances with several pets when I was growing up. For more support, I would suggest contacting one of the pet loss grief hotlines such as ASPCA: http://www.aspca.org/pet-care/pet-loss. Sincerely, Danielle

    • Doug Hatley

      I discovered this website by searching & asking, “what underlying disease would cause a cat to die suddenly?” My cat was barely 5 yrs. old. She spent equal time indoors & outdoors. She was an avid hunter & ate most of the prey she caught, especially squirrels. She ate all, sometimes even the tail. I’m only telling this part, hoping someone can shed some light on this matter. She was a very pet, very loving, & highly intelligent animal. She always wanted to please & only had to be told “no” once given each particular situation. Just after midnight on Sat. 7/08/17, she wanted out the front door. Before I could reach the lock & knob, she flopped over on her side but got up & trotted out same as usual. I had been suspicious all evening that something wasn’t right with her. That Fri. had been the 1st hot day of the summer & was oppressively humid. She had been in & out all evening. Within an hour of her exit for what was to be the last time, I went looking for her. I was up really late that night because it was Fri. night going into Sat. We live in the country but she rarely travels past a 5 acre radius from the house. So I began searching. The next day, I combed the entire property. Later, all surrounding neighbors were contacted. Nothing! Her body has never been recovered. We don’t believe she was a victim of a predator or auto-related accident. Our area is partially forested so we believe she suddenly became ill & hid. She had been to the vet less than 3 weeks earlier & had received a clean bill of health & received her necessary vaccines. To the other patrons of this site, please don’t blame yourself! I, myself, feel as if there was something I could have done differently so that my cat would be here still. Of all the cats we’ve had through the years, this is the 1st to go missing at such a young age. Lastly, she was a stray about 4 mos. when we took her in.

  • Marsha McCroden

    My sister’s kitten died two days ago. Magie was six months old but looked like an eight-week old kitten. He never grew, and we don’t know why. He just got smaller and more fragile, and Kathy held him whenever she was home, and she telecommutes. He got a lot of love. She fed him with a spoon, and gave him water through an eyedropper (she showed me how so I could do it when she wasn’t home. His back legs atrophied and he’d try to sit up and fall over. If anyone can help us understand what happened I’d really appreciate it.