I have two small cats . Although they are adults, they weigh 6 and 9lbs, which is fairly light. However, carrying one of them in my arms is much different from carrying one or both of them in a carrier, which is often bulky, difficult to manoever and forces me to rely on arm and hand strength I don’t have. Over the years, I have learned a few things about carriers, that I think can help you.
First, if you have two cats, they may not want to be separated. Mine are much more docile about being in a carrier and getting into a carrier if I let them share one. So this means I have one large carrier for two small cats. Wanting to make sure they both have some degree of mobilitiy in the carrier, I’ve recently upgraded them to a dog carrier; dog carriers come in a greater range of sizes, precisely because dogs do. Do exercise some caution with carriers specifically made for dogs though – they often don’t close as securely (having an option to secure the dog inside the carrier with his leash) and escape artist cats, can and do get free.
In the beginning I had a large plastic carrier. This was problematic because it had no shoulder strap and it was so wide that I could not hold it steady, causing the cats to rock back and forth as I walked, something they didn’t enjoy. In addition, they couldn’t see out well, and would sometimes chew on the plastic – damaging the carrier and causing kitty acne problems.
Then I switched to one of the soft mesh shoulder bags. These were easier to carry with the shoulder straps and more comfortable for the cats, as I was able to keep them more level. These bags also allow them to see everything, but in the city, actually made them nervous – there was too much activity and noise for them to feel safe. My nervous cat hyperventilated repeatedly when I took her out in this bag.
Eventually I settled on staying with the mesh bag for my comfort, but lining it with a blanket to provide the cats some privacy and a way to hide from the noise of the city. This, of course, only works for short trips. If you need to take your cats on a long car trip, hard bulky cases that you can put food and water dishes in are more appropriate, but you may want to consider a second bag for actually carrying them around.
When choosing a soft/mesh bag, look for one of the ones approved for airplane transport of small pets. These are the most secure structurally., and also the hardest for your cat to break out of. Unfortunately, these bags are expensive (upwards of $80) and may not accomodate a fatter cat in the most comfort possible. Less expensive bags of this style may be prone to animal escapes, as I’ve found cats can open the top zippers by butting their heads against them repeatedly.