If your dog has swelling under the neck, there can be several causes. The swelling can be something that is temporary or it may signal something in the body that needs addressed. Any swelling of a dog's face and neck should be evaluated by the vet to play it safe. Swelling under the dog's neck can be due to something minor, but at times it can be indicative of something serious, such as an allergic reaction or even cancer. Following are several causes for swelling under the neck in dogs.
An Allergic Reaction
Dogs who like to spend a lot of time outdoors may be subjected to annoying insect bites. Depending on what insect bites the dog, the symptoms may be various. Usually, when a dog gets swollen by the neck area from an insect bite, the swelling would come on quickly and the dog may be rubbing his face and neck area against the ground or on furniture. The area may be itchy, and the dog may try to scratch it.
An allergic reaction from a bee sting or other bug bite can lead to neck and facial swelling. Generally, the swelling pops up just about a few minutes to hours after being stung or bitten by insect.
In this case if you witnessed the bug bite, the allergic reaction can be stopped with antihistamines like plain Benadryl (diphenhydramine only) given at a dosage of at 1 to 2mg per pound of body weight every 8 hours, suggests veterinarian Dr. Kara. It needs to be given for at least 3 days to allow the allergen enough time to clear and prevent relapses.
If your dog has swelling under the neck consider that causes of allergic reactions, include exposure to allergens or recent vaccinations. The swelling and hives often though are more spread out to the entire head, rather than being localized only to the neck area. In severe cases, if your dog has trouble breathing and swallowing difficulty, report promptly to your vet.
Salivary Gland Problem
Sometimes, a dog's salivary gland may cause problems and a visible swelling in the neck area. In this case though there is often some level of drooling.
In the case of a blockage of the duct that carries the saliva into the mouth, the back -up may be a contributing factor to the swelling; however, the swelling is usually only on one side, and it would be unlikely to happen on both sides, explains veterinarian Dr. Karen.
Many people are used to having swollen lymph glands under the neck when they have some sort of infection going on and in dogs this can happen too. The technical term for this is "lymphadenitis" which means that lymph glands swell because of infection or inflammation.
The lymph nodes that swell are typically those that are next to the infection area. For example, in the case of a dog with a sore throat caused by Streptococcus bacteria, the submandibular lymph nodes found just under the back curve of the dog's jaw where it meets the throat, will be the ones to enlarge and inflame.
Generally, along with the swollen lymph nodes there may be other accompanying symptoms, and therefore, in the case of a dog with a sore throat, the dog may also be reluctant to eat and may swallow more frequently, explains veterinarian Race Foster.
Generally, the lymph nodes by the neck tend to drain all of the head and most commonly swollen glands in this area are caused by some sort of inflammation around the mouth specifically the teeth and gums but so can infected ears or any sort of wound or skin infection on the head, further adds Dr. Karen.
A Case of Lymphoma
Lymphoma is a cancer affecting the dog's lymphatic system. In a normal healthy dog, lymphocytes work to help protect the body from infection, but with lymphoma things get awry and the lymphocytes become cancerous.
The most common type of lymphoma affecting dogs is multicentric lymphoma, that first shows up when the dog's lymph nodes get swollen. These swellings are typically firm, rubbery, right under the skin and non-painful.
One of the most common lymph nodes to swell are the ones right under the jaw (mandibular) just where the jaw connects with the neck.
Other symptoms often appearing later on are lethargy, loss of appetite, lethargy, weight loss, and sometimes increased drinking and urination. Cancer can be ruled out by having the lymph node biopsied or a fine needle aspiration and then sent out to a pathologist.