Why are my Cat's Gums Inflamed?
The younger cat (now almost 10 months old) seems to have a problem wtih gingivitis and definitely has a problem with bad breath. The vet didn't mention her needing a teeth cleaning when she was spayed, and she seems very young to need dental work. I don't see any tartar at all. The inflammation is worst around her first upper premolars (which are tiny, barely sticking through the gum.) There seems to be no inflammation around her back molars or the incisors.
Could this be due to the malnutrition, and what can I do to improve it?
I suspect your 10-month-old cat may be suffering from the early stages of stomatitis. Stomatitis is a syndrome in which the cat's immune system attacks the mouth. It is very painful and usually causes bad breath.
Stomatitis is marked by severe gum inflammation without concomitant tartar or bacterial infection. It can occur in any cat, but in my experience it is most common in stressed cats. Stress from overcrowding (as occurs with hoarding) seems to be a major trigger for the problem. Malnutrition also causes severe physiological and psychological stress.
You already are doing what you can to improve it at home: relieve overcrowding and provide adequate nutrition and love. However, it is possible that medical intervention will be necessary to control the problem. Medications that modulate the immune system sometimes are used to treat stomatitis. Extraction of multiple teeth may be necessary.
I also strongly recommend that you have your vet assess your cat's mouth. Stomatitis is not the only possible cause of the symptoms you describe. Your vet should be able to offer more insight and help plan a course of action.
One final note: there is a chance that your cat simply is teething. Adult teeth generally replace deciduous (baby) teeth between four and six months of age, but in a malnourished cat the process could be delayed. Teething can sometimes cause bad breath and gum irritation. Your vet should be able to rule this out.
Photo: no inflammation.