I have a 6-month-old colt that has a swollen lymph node under the right jaw the size of an small orange he does not have any clinical signs of illness, eating well, drinking and is playing with the other foals. There have never been any strangles on the place or any of the other horses have never had it. He has not had any nasal discharge or cough. Could you could please give me advice on a possibility what this might be?
Swollen areas under the jaw should always be examined by your veterinarian, especially in young horses. While Strangles (or infection with Streptococcus equi ssp equi) can present with the exact symptoms that you are describing, there are other sources of the swelling possible. First, it is good to rule out the fact that the swelling is in fact a lymph node. There are salivary glands in the area that can become swollen and filled with saliva (a salivary mucocele). Second, you want to rule out dental (tooth) involvement. Depending on where the swelling is, it could be an infected tooth root on the mandible. Most of these things will be apparent to your veterinarian when he/she performs the examination. Your vet might also want to perform a needle aspiration of the contents of the swelling, and potentially culture the contents to confirm or rule out bacterial involvement, and therefore confirm or rule out Strangles.