Re: Non-FD but has heartworms * update*
Jill and Remi said:
So DH just got back from the vet with Chloe and it is not good news. I had them do the x-rays on her lungs even though two vets said they sounded clear. The x-rays showed no clean spots on her lungs and her pulmonary artery is bigger than her rib.
Oh darn. I was so much happier when I thought it was an antibody test! So she is one of the rare ones to have a real HW infection.
Re: treatment. The treatment of choice for dogs, Immiticide, is extremely toxic to cats to the point that it is rarely even used as a last resort. Dogs can also be treated surgically, as you saw in the video, but this procedure is much more risky in cats. The average-sized dog has a nice big jugular vein into which you can easily place one of the inflexible "grabber" instruments to pull out worms. A better video of this procedure is on the American HW Society (AHS) website. You have to pull the worms out whole, without breaking them, because breaking the worms can result in anaphylaxis. Cats are, of course, very small in comparison to dogs so going through the jugular vein is rarely even attempted. An experienced surgeon + cardiologist + anesthesiology team can try to get them out by opening up the chest and trying to pull them from the heart. This, too, is just as risky as it sounds. Cats are exquisitely sensitive to HW antigen, so if a worm breaks during this procedure, the cat doesn't have a chance.
Personally I would not try surgical extraction for my own cat. Maybe there are vets out there who have had a ton of positive experience with this; the specialist at Auburn would probably know. As is, it is very high risk for a cat who is not having symptoms. I would give Heartgard and await a "self-cure"; pred use is up to the vet, the AHS recommends a single tapering course of pred for cats believed to have adult worms. (The AHS is generally regarded as the last word in HW in the US--they do a lot of research and have conferences, etc.) Some vets are trying out doxycycline, an antibiotic which may weaken the worm and shorten its lifespan. It's commonly used in dogs with HW but not yet in cats; I would consult a specialist about its use. You'd have to get it compounded.
One last thing. I'm not sure what your vet would think of this, but it doesn't hurt to ask. If I knew my cat had adult HW in his heart, I would get a script for an Epi-Pen (or a syringe with some epinephrine in it, if the Epi-Pen Jr. is too high for a cat dose). That is not a guarantee that if your cat had anaphylaxis, that you would make it to the ER, but it gives the kitty a chance. People have also tried Dex SP (a steroid) to buy time. Unlike dogs, cats (and humans!) with anaphylaxis often have severe respiratory distress (dogs have other signs, neuro and GI most commonly) and it's key to get them treatment right away. So I'd want to have an epi-pen (or at least dex SP) and directions to the ER at home, ready, and then I'd try not to think more about it. Your little one is unlikely to experience this, as I mentioned already the majority of cats kick the heartworms on their own without incident (though they may have signs of asthma throughout their lives). In the superstitious vet world, though, being prepared almost always means it will never happen
Please keep us posted on your vet's consult with Dr. Dillon. I'm good friends with a cardiologist practicing in Tennessee, but even she hasn't seen many HW cats. I'll pick her brain anyway though.
Take care (and try not to worry! be prepared and then forget about it! you have a great new kitty, that's the main thing!)
Jess
