Newborn kitten with twisted and weak back legs.

Hi, One of the kittens recently born to my cat has twisted and very weak back legs. The kitten can't move them properly, and they stay almost pointing upwards or stiff. You can see this clearly in the picture. I'm really worried it could be something serious like a birth defect or nerve damage. Can anyone help me understand: What kind of condition this might be? Is it dangerous or painful for the kitten? Can it be treated or improved in any way? Thank you so much for your time and help!

Aw, I'm sorry for your kitten and as usual, I'm afraid that it's not something I'd want to diagnose without a full history and examination and then perhaps a second opinion and / or one or two further tests.  How is the kitten now?  You have already identified several of the things that I might be wondering about, including 1) infectious diseases, that might have impacted the kitten's development;  2) developmental abnormalities resulting from either genetics or the diet, affecting the development and articulations of the joints 3) conditions (from any of those origins) leading to problems connecting the nerves with the muscles, or with the development of muscle tone.  4) pathological fractures, ie changes in the bone density that lead towards very easy fractures during kittenbirth   5) the result of spinal damage or positioning in the womb.   Your vet, with or without help from a consulting pathologist,  should be able to help you to rule some of these possibilities in or out and offer a prognosis.  Please do speak to them sooner rather than later.

Aw, I'm sorry for your kitten and as usual, I'm afraid that it's not something I'd want to diagnose without a full history and examination and then perhaps a second opinion and / or one or two further tests.  How is the kitten now?  You have already identified several of the things that I might be wondering about, including 1) infectious diseases, that might have impacted the kitten's development;  2) developmental abnormalities resulting from either genetics or the diet, affecting the development and articulations of the joints 3) conditions (from any of those origins) leading to problems connecting the nerves with the muscles, or with the development of muscle tone.  4) pathological fractures, ie changes in the bone density that lead towards very easy fractures during kittenbirth   5) the result of spinal damage or positioning in the womb.   Your vet, with or without help from a consulting pathologist,  should be able to help you to rule some of these possibilities in or out and offer a prognosis.  Please do speak to them sooner rather than later.