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Cher, Feline Specialist
Category: Cat
Satisfied Customers: 21337
Experience:  Feline Healthcare & Behavior Specialist 40+ years Experience
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What is the proper dosage of Penicillin VK for a 15 lb cat

Resolved Question:

What is the proper dosage of Penicillin VK for a 15 lb cat with an apparent UTI? I have 500 mg tablets and by using a tablet cutter I can split down to lower mg pieces. For example I have been able to halve one 500 mg tablet consecutively 5 times to yield an approximately 31.25 mg piece.
Also, can I put the piece into a soft cat treat and will that still allow proper absorption and dosing?
Submitted: 8 years ago.
Category: Cat
Expert:  Cher replied 8 years ago.

While your cat may be exhibiting symptoms of a UTI, the symptoms you describe also sound like he may have a urethral obstruction, and in a male cat, this is a serious emergency. If your regular vet is closed now and doesn't have emergency hours, you need to bring your cat to the nearest ER vet center, as soon as possible, for treatment.

The antibiotics you have, may help temporarily, but only for the UTI, not the blockage. If you can split the 500 mg. Pen VK down to 31.25 mgs, this dosage should be alright; it can be given 3 times a day (every 8 hours). The proper dosage would be 30 mg., but because you can only get it down to the amount you mentioned, that's the best you can do.

Try your very best to have your cat evaluated and treated by any local vet who may have emergency hours, or an ER vet center in your area, immediately. He may need to be catheterized to drain his bladder, and if this is not done, he will continue to be very uncomfortable, and the toxins can back up in his system, and cause severe illness. Because he's a senior, it's very important to have him seen, now. If you're not sure where there is an ER vet center in your area, and you're locate in the US, try this site:

I hope all will be well with your furry boy, and he's feeling much better, very soon!

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