Cat Spraying and Prozac

Question
Hello,  we have a 3 yr old male who is spraying inside the house.  We are working closely with the vet who has prescribed Buspar (didn't work) and has now prescribed Amitriptylin.

I have been researching online for weeks and have seen so many people recommend prozac first...as it is supposed to be most effective.  I have mentioned this to my vet and she says it has not been shown to be effective...and I've asked her more than once.  I don't know what to believe and I don't want to doubt my vet, but I don't want to have to lose my kitty either.

The vet has told me in the past that our kitty  may have a minor heart problem because he pants a lot, so I am a bit fearful of the amitriptylin  - and would rather try the prozac first if it is known to be effective.

I just want to make sure I am understanding everything correctly, and maybe have some data to show the doctor about the prozac, without her getting upset with us.

Also, should I be concerned about using the amitriptylin?

Thank you.

Answer
Dawn, yes, amitriptyline is strongly contraindicated for cats with heart rhythm problems.  In fact, some vets require a cat to undergo an EKG before they'll start a cat on treatment with this medication because it's highly likely to worsen heart rhythm problems.  

Although nothing has been confirmed in your kitty's case, I think the POSSIBILITY of heart problems is plenty enough to make the use of amitriptyline inadvisable, especially considering that there are so many other choices.

I'm not a vet, I have no professional training.  But I subscribe to several publications put out by vets and veterinary colleges, including those from Tufts and Cornell, and they all support the idea the Prozac is the most effective treatment available for spraying problems.  A study published in Cat Fancy Magazine last year also revealed that Prozac was most effective at treating the problem AND was the treatment that could most often be discontinued successfully without a relapse of the behavior.  Following Prozac in success was an antidepressant called clomipramine (Clomicalm).  I believe the success rate was approximately 90% with Prozac and only about 70% with buspar and amitriptyline.

I have used both Prozac and amitriptyline in my own cats.  I must say that both drugs resolved the behavior.  The cat on Prozac suffered no side effects and went off of it after 4 months without a relapse.  He hasn't sprayed in over 4 years, now.  

The cat on amitriptyline did suffer some drowsiness and increased appetite at first.  Every time he goes off the medication, he relapses.  So he's on it permanently.  We have not switched him to Prozac because amitriptyline also helps treat a chronic pain problem he suffers.  He has to have liver tests run every six months because this medication is metabolized through the liver and is not recommended for cats with liver problems.

Every vet is certainly going to recommend what they have seen work.  Maybe your vet doesn't go with Prozac because it's new and she has limited experience with it.  Maybe people aren't usually willing to put up the cost (Prozac was 4 times as expensive as amitriptyline from my vets).  Or maybe it simply hasn't been as successful in the cases she's treated.  But it's a vet's job to let you know all the options out there and then go with your wishes.  If you've expressed the desire to try Prozac with your vet and don't feel she was open to it, then I would have to recommend seeking a second opinion.  I work with two animal hospitals with 6 vets on staff, and when I have a concern, they are always happy to have the next vet give their opinion.