I just wanted to follow up and send you a link about the above topic. My response above was not as thorough as could be. The link has some good information and examines the studies about canned food and hyperthyroidism and also the dental disease issue.
http://meowmeowmom.wordpress.com/2008/08/28/pop-goes-the-pop-top-can/
I know this person and she is very thorough and educates herself about many of these issues. She is founder and involved in two feline organizations.

Thank you again,

Though I don’t have the full study in front of me, I believe that the FISH-BASED canned foods were shown to be most problematic and with other factors other than just canned food being found. This makes sense with the ever increasing chemical toxicity found in fish. And also there is the BPA found in the linings. I myself feed the large non pop-top poultry-based foods because of this. I know BPA is controversial and there are calls to ban it’s use. Let’s hope that BPA is banned, so there is one less possible chemical toxin which can effect cats and humans.

I want to point out there was another study done more recently which found greater PBDEs in hyperT cats. This is another common chemical (flame retardant) in many household products and also in carpet, carpet pad (cats are near the floor) and who knows what else. It also ends up in dust, and is found in high concentrations in fish … The canned fish-based foods were found to have higher levels PBDEs, and the cats tested were too.
http://www.sciencedaily.com/releases/2007/08/070815122354.htm

PBDE’s have been banned is several states, so let’s hope it also is banned completely so there isn’t another possible chemical toxin possibly affecting cats and humans.
With all the other toxins and chemicals cats may be exposed to, I feel we need to point out the details of studies and not just say that canned food is linked to hyperthyroidism. It’s really about the unfortunate amount of chemicals found today in the food chain. It’s not inherently the canned food.

As I said above, I still believe that a canned diet is a better choice for cats. I do try to stay away from feeding fish and fish-based foods (maybe a couple times a month is okay) and am cognizant of not using chemical cleaners etc on floors or chemical outside where cats walk and then clean their paws.

Also, I disagree that dry food is a good teeth cleaning agent (not sure if that’s what you are saying, but I hear it so often I am assuming). I think that’s a myth. Could dry food be linked to dental disease? What about all the crappy poor quality grain-based kibble residue that get left behind in the cat’s gums. Grain is a carbohydrate which can convert to sugar and can cause inflammation, tartar and gum issues. Are there unbiased, studies that preport wet food is “BAD” for dental health? As you say, “Wet food is linked to dental disease.”
I find that hard to believe, my cat lost many of his teeth eat eating a dry diet for a majority of his life. Can you reference the unbiased studies showing wet food is linked to dental disease? And could you describe the mechanism for how dry food cleans the teeth? (an often heard assumption)

I just wanted to address these issues, because I don’t feel it’s a simple as saying “canned food is linked to hyperthyroidism.” It’s good to be informed about these studies, but also be aware of the details and limitations of the study and other factors in the study. And let’s stop using all these unnecessary chemicals that end up in the food chain (or develop non-toxic substances). And again, I just don’t agree that dry food is better for dental health, or wet food is linked to dental disease.

I just wanted to address these issues as I am a strong believer and promoter of feeding a species appropriate diet — preferably quality grain-free canned or properly prepared raw.

Thank you for reading and being open and letting me post…
Sorry if I rambled and missed any spelling errors…

1) type of protein – too high in plant-based versus animal-based proteins

2) carbohydrate load is too high

3) water content is too low”

http://www.catinfo.org/index.htm – this is a wonderful website if you are interested in more information :-)

So keeping your cat on canned food shouldn’t be a problem.
If you are concerned about dental disease…”all cats require a regular dental program of brushing, rinsing, along with regular veterinary dental exams and professional cleaning, if required. ” Try adding a dental diet(i.e TD) in as a treat…this has worked wonders for my cat.

C.A.P