The most common ailments in dogs and cats

VPI, the biggest provider of pet insurance in the U.S., looked into its database of nearly half a million pets to determine which ailments sent cats and dogs to the vet most frequently in 2011. The results:

1.    ear infection
2.    skin allergies
3.    skin infection
4.    non-cancerous skin growth
5.    upset stomach
6.    intestinal upset/diarrhea
7.    arthritis
8.    bladder infection
9.    bruise or contusion
10.    underactive thyroid

1.    bladder infection
2.    chronic kidney disease
3.    overactive thyroid
4.    upset stomach
5.    periodontitis/dental disease
6.    diabetes
7.    intestinal upset/diarrhea
8.    ear infection
9.    skin allergies
10.    lymphosarcoma (cancer of lymph nodes)

VPI customers spent $46 million treating these afflictions last year.

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We gleaned a few interesting factoids from comparing the two lists. Dogs and cats share five of the most common ailments between them: ear infections, skin allergies, upset stomach, intestinal upset/diarrhea, and bladder infections. It's probably no surprise that dogs had more dermatological issues than cats, as dogs tend to spend more time outside, and thus get exposed to more allergens, get more cuts and scrapes, and so on. (That might also explain why the dog list contains bruises, and the cat list doesn't.)

But the differences between the lists were even more interesting, in our opinion. The top-ranking ailment among cats, bladder infection, made sense – our own cats have come down with those – but we didn't expect to see a sometimes-related illness, kidney disease, ranked so highly. We also didn't expect to see no cancers on the list of illnesses for dogs, or that particular cancer on the list for cats, as we've heard of that type of cancer but haven't known any owners whose pets suffered from it. (Lymphosarcoma also ranked as the priciest condition per vet visit; treating it cost owners an average of $426 per trip to the vet. The most expensive condition in dogs, non-cancerous skin growths, is a relative bargain at $220 per visit.) And it's fascinating that dogs, whom we tend to associate with more activity, tend to have under-active thyroids…while cats, whom we think of as sleeping most of the day, are more likely to have over-active thyroids.

And we have a few questions. Why is diabetes more prevalent in cats – and does it track with the obesity issues many American pets have faced in recent years, as the condition seems to in humans? Aren't "upset stomach" and "intestinal upset/diarrhea" basically the same thing – and if those conditions got merged on the lists, what conditions would make the top ten in their places?

We can't say whether pet insurance is the right choice for you, but regular vet visits can catch many of these conditions before they become chronic – and more expensive.

Do the lists above look right to you? Have you dropped beaucoup bucks at the vet on any (or all) of these ailments, or do your pets have other illnesses more often? Were you surprised at the cost of the treatments, in your own experience or from seeing the prices here? Talk to us about sick pets and/or spending in the comments, or give us a holler on Twitter: @YahooShinePets.

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