The question as to whether feral cats look different to non-feral cats is on the face of it straightforward but it can be a little bit tricky to answer properly. This is partly because feral cats can be at various stages of health, from those who are injured through fights to those who are very ill and dying and, at the other end of the spectrum, to those who are well cared for in the community by TNR volunteers. The latter group are fed, spayed and neutered and there will be volunteers who can look after feral cats to a reasonable standard thereby prolonging their lives.
If the question refers to a feral cat who is ill and perhaps dying then there’s obviously a huge difference between that cat and a well cared for domestic cat in a nice home. You can see the difference immediately. But the photograph on this page shows some really quite nice looking cats and they are meant to be feral cats. I suspect that they are semi-domesticated or semi-feral cats living in a colony under a TNR program. However, if you look closely the eyes of some are guncky because they may be suffering from a mild infection and, in any case, they are living in an environment which makes it difficult to keep clean.
Looking at the photograph on this page, I am sure that you can pick out one or two cats who look very much like your domestic cat. There is no difference on the face of it. However, most feral cats who are part of a TNR program have been ear tipped which makes them distinguishable from domestic cats (see above). This is when people who do TNR programs remove the tip of the left ear (usually) of feral cats who have been spayed and neutered. It’s a good sign that the cat is being cared for and poses no threat in terms of procreating more feral cats.
I think the truth of the matter is that there will often be a farily marked difference between feral cats and domestic cat in terms of appearance because they are often dirty and unkempt. It is very tough to see a feral cat in this state because we know, by observing domestic cat behaviour, that they are very particular about personal hygiene. Domestic cats groom themselves frequently.
Clearly, some feral cats do not groom themselves at all or hardly at all which must be due to chronic illness most of the time. They are just too sick to be motivated enough to care for themselves. On that topic, you will often see young feral cats with eye problems. These are going to be viral infections, probably the herpesvirus, which is effectively a feline cold, which leads to a secondary bacterial infection which in turn can damage the eye quite severely and can even destroy the eye.
Eye infections, ear infections are common in feral cats. More profound viral infections such as Feline Infectious Peritonitis, Feline Immunodeficiency Virus, Feline Leukaemia Virus to name three well-known ones, curtail the lifespan of feral cats and make them very sick. Some people argue that feral cats live about three years which is an exaggeration but it may apply in some instances. Feral cats can live quite decent, long lives under TNR programs, for instance.
As mentioned, there are a range of types of feral cat. For example, community cats which are very prevalent in Mediterranean and warm countries look very similar to, and act very much like, domestic cats. They are not dissimilar to domestic cats because they are cared for in the community but aren’t owned in the sense that Westerners think of the word. But in Asia, for example, there are many community cats.
So the question is tricky to answer. It depends upon the type of feral cat we are referring to. A very sick, classic feral cat trying to survive alone will look very different because they will look ill, scrawny, thin, and dirty compared to a well-kept domestic cat. At the top end of the scale, as mentioned, there is little difference except for that well-known ear tipping which removes a part of their left ear. That will be a distinguishing mark.
You will rarely see long-haired feral cats and it is said that feral cats do not communicate with each other through the meow. The classic domestic cat meow is for domestic cats pretty much exclusively because it was learned by domestic cats over 10,000 years of domestication as a means to request attention or demand something such as food.
P.S. If the question is asking if between feral cats there differences in appearances, the answer is Yes. The variation is as for domestic cats. Although sometimes a female breeds for a long time creating many offspring that are noticeably the same in appearance.
