This article primarily concerns the USA and domestic cats. The causes of cat death must be related to the region where the cat lives. Old age has been excluded. The list is unique as there is no official information but there should be because it would help people to take proactive measures to prevent unnecessary cat deaths.

Phineas Poe died of FIP. Photo Christopher Sims

Top 10 causes of cat deaths

1. Kitten mortality complex
2. Euthanasia of unwanted cats
3. Car accidents and other traumas
4. Feline leukaemia virus
5. Kidney disease
6. FIP
7. FIV
8. Cancer
9. Feline distemper
10. Neglectful ownership
11. Diabetes (added inadvertently as an 11th!)

Full details on the diseases mentioned above are on this website. Please use the search facility. or go here: cat health problems

Notes as to why I arrived at the above list

A study in Britain in 2012 concluded that the leading causes other than old age for cat deaths were cancer, kidney failure and traffic accidents¹. However, is it fair to say that the no.1 cause of death in cats at least in the USA, is euthanasia or deliberate killing of healthy unwanted cats. Not having figures for kitten mortality complex I have placed it at second.

“The feline leukemia virus is responsible for more cat diseases than any other infectious agent and is secondary only to trauma as the leading cause of death in household cats”.(Note: FeLV cats are adoptable).

The quote above is from a highly reliable source⁵ and is very helpful in assessing the top 10 causes of cat deaths. The top 2 based on that assessment are therefore:

• Trauma and most often road traffic accidents – I have made the reasonable assumption that the most common trauma (injury) suffered by the domestic cat is due to being hit by a car on the road. That assumption fits in nicely with the 2012 GB study mentioned above.
• FeLV (Feline Leukemia Virus Disease Complex).

However, Dr. Eric Barchas writing for catster.com estimates that, in well managed catteries, 15-27% of kittens die before they are 9 weeks of age. Therefore, kitten mortality complex, a spectrum of illnesses affecting young kittens must rank as one of the major causes of cat deaths. Kitten mortality complex includes death due to the classic viral infections such as herpes virus group and calicivirus virus group. We don’t know where to place it in the list but my guess is it should be in the top three and probably at the top.

At the other end of a cat’s life we have to include kidney failure as a major killer. What normally happens, however, is that a veterinarian diagnoses kidney failure and at the end of the a decision is made to euthanise the cat. Therefore kidney failure is often an indirect cause of death in cats. 

The well-known FIP (feline infectious peritonitis) is described as carrying a “high mortality rate” and “comparatively high in multi-cat households”⁵. It affects kittens most often up to 3 years of age. Seventy percent of FIP patients are under a year in age².

Wikipedia states that its incidence in at 1 in 5000 in households where there are one or two domestic cats. There is no specific information which assists me in placing this disease in the top 10 killers of cats but common sense tells me it is.

The incidence of FIV is yet to be determined we are told but it is believed to affect 1-3% of cats in the general population in the USA. The disease causes diseases such as kidney infections and gum disease and general illnesses such as diarrhea and eye conditions. Cats with FIV “will remain in apparent good health for many months or years”³. We don’t know how many cats die indirectly from FIV but its prevalence and impact on general health suggests that it should be in the top 10.

Cancer must be in the list because there is a “high cancer rate in cats”⁵. However, the high rate is seen to be linked to FIV and Feline leukemia so there is an overlap.

Feline distemper aka feline panleukopenia aka “panleuk” is described as “one of the most serious and widespread diseases”⁵ and a leading cause of death in kittens (there is an overlap here with kitten mortality complex). If kittens get the disease from their mothers the mortality rate is 90%. Secondary bacterial infections often cause death.

Feline diabetes is a growing concern to vets in the USA. Elizabeth Hodgkins DVM (Your Cat) states, “about 2.5% of my patients” have the disease. She goes on to write, it is a “very serious, often fatal disease”. I’ll place feline diabetes in the just outside the top 10 especially as it is a growing feline health problem.

I may well have missed out a cause. If so please tell me in a comment. However, I have to include the death of a cat through the neglect of his/her owner as in the top ten causes. We have no idea how many cats die because their owner for example over-treated them with insecticide, created an unsuitable environment, allowed their cat to wander in dangerous areas, failed to take their cat to the vet promptly, abandoned their cat to a cat shelter were she was euthanised and so on. There are countless possibilities. This cause might even be at the top.

Sources: 

1. petrib.com
2. abcd-vets.org
3. vet.cornell.edu
4. Myself
5. Cat Owners Home Veterinary Handbook