Other health problems

Why Does My Dog Have a Lump on Their Neck?

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: December 1, 2020
Why Does My Dog Have a Lump on Their Neck?

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The appearance of a lump in the neck of our beloved dog is an understandable cause for concern. As we often pet them here, we may be more likely to detect it than other locations (e.g. some dogs may not enjoy being petted in their sensitive belly area). Lumps can appear like a ball under the skin or seem to be more of a raised area closer to the surface. It is important to determine the appearance and consistency of the lump, whether hard or soft, painful or not. It's also important to note if a dog has other symptoms.

Before we get started, if a dog has a lump in their neck, they need to get a checkup with the vet. They are the only one able to give an adequate diagnosis. If you are wondering why your dog has a lump in their neck, AnimalWised tells you what might be the causes, but only to give you an idea of the possible reasons.

You may also be interested in: Lump on My Cat's Neck - Causes and Treatment
  1. Types of lump on a dog's neck
  2. Inflamed lymph nodes
  3. Sebaceous cysts on a dog's neck
  4. Abscesses in a dog's neck
  5. Tumors on a dog's neck
  6. Allergic reaction causing lumps on a dog's neck
  7. Other types of lump on a dog's neck

Types of lump on a dog's neck

Not only are there various reasons for a dog having lumps on their neck, there are different kinds of lump. You may find a large lump on the side of a dog's neck, small bumps which look like pimples or anything in between. The consistency of the lump is also important as whether the texture is hard or soft has a bearing on what might be the problem. Another important factor is how long the dog has had it. Sometimes we see a lump has appeared on our dog overnight, but some lumps may not develop so suddenly.

We need to examine this further by looking at the different types of lump on a dog's neck:

  • Inflamed lymph nodes
  • Sebaceous cysts
  • Abscesses
  • Tumors
  • Allergic reaction
  • Other types of lump

Below we detail each type further, looking into what may cause the lump and what type of treatment options might be available.

Inflamed lymph nodes

Like humans, dogs have lymph nodes. They appear on different parts of the body such as the neck and limbs. These lymph nodes are ganglia, i.e. clusters of nerve cells located throughout the nervous system which often seem fatty. Their function is to act in the dog's defense against different pathogens, such as the tonsils at the back of the mouth which protect against airborne pathogens which may be breathed in. When a bacteria or virus tries to enter the body, the lymph nodes trigger an immune response to mobilize a defense.

During this process, the lymph node closest to the invasion of pathogens is likely to become inflamed as it gets to work. This is one of the reasons you may feel a lump in their neck. It is simply the node reacting and doing its job to defend against sickness rather than creating it in the first place. How can one identify an inflamed ganglion in the neck?

The first thing will be to examine the mouth as often it is an oral problem which will trigger a response to the ganglia in the neck. If there is an injury or abnormality there may be oronasal disease, some of which may be contagious. This is particularly the case if they are observed with the following symptoms:

It could also be a dental problem such as an infected tooth or some sort of gum disease. The vet will be able to determine if the lump is indeed connected to the node or if it is present for some other reason.

Why Does My Dog Have a Lump on Their Neck? - Inflamed lymph nodes

Sebaceous cysts on a dog's neck

A sebaceous cyst is actually a misnomer. It might make us think that it is a problem with the sebaceous gland, but this is not actually the case. The cyst is not full of sebum and does not originate in the sebaceous gland. However, since they are so commonly referred to as sebaceous cysts, even veterinarians will refer to them as such.

They appear as a lump of varying sizes and are made up of different substances, mainly fatty tumor-like cysts made of keratin or fibrous tissue. They are generally not harmful, but it is possible they can become infected. The dog may not even notice them, but they can become large and unsightly.

Sebaceous cysts in dogs do not generally require treatment, but if they are on the neck it is possible they can become problematic. One of the major reasons is because the cyst can become irritated by the dog's collar and increase infection or irritation. If this is the case, surgery is a viable option. The procedure is relatively simple and dos not require much recovery time. While sebaceous cysts can appear on almost any part of the skin, when removed form the neck, the dog may not even need a protective collar.

Abscesses in a dog's neck

Another cause of a lump in our dog's neck might be due to an abscess. These are collections of pus which stay under skin and are caused by an infection, usually a bacterial one. For example, if our dog is playing around too roughly (or even fighting), the neck is a common place to receive a bite or scratch.

Sometimes, the skin closes over, but there remains an infection on the inside. The pus collects and a abscess forms. It can happen with dirty or clogged hair follicles also. Even a sebaceous cyst as described above can develop into an abscess.

Pimples are often similar to sebaceous cysts, but they are temporary and caused by dirt collecting in a hair follicle. When the follicle becomes infected and inflamed, it will lead to folliculitis. This presents as a raised lump on the skin and is most commonly caused by the bacteria Staphylococcus pseudintermedius[1]. Folliculitis is usually temporary and should resolve themselves naturally, but treatment may be necessary for acute or chronic cases.

They can also be caused by a foreign object which gets caught in the dog's flesh such as a foxtail or similar barbed splinter. If our dog suffers some pain and we are unsure of its cause, we should get it checked out in case there is an infection. It is something to consider when we go walking in the country or anywhere there is high bushes. When you return from these areas, we should give our dog an inspection, especially as there may also be the presence of ticks which can also impart blood diseases. Check their legs in particular.

Speaking of ticks, any sort of insect bite may elicit an eruption in the form of an abscess. They are not fatty lumps, but can feel quick soft and have some give when you touch them. These kind of lumps are prone to bursting, either as part of the healing process or because they have been knocked against something. Either way, it puts the dog at risk of further infection, so we need to be careful. The abscesses are diagnosed by the vet, usually by examining and taking a sample. They are treated by disinfection, antibiotics and sometimes even draining the area of pus.

Why Does My Dog Have a Lump on Their Neck? - Abscesses in a dog's neck

Tumors on a dog's neck

Sometimes, the lump in your dog's neck may be the result of a tumor. Tumors are abnormal growths of cells, a type of neoplasm. An organism's cells multiply and replace themselves many times of the course of their lives. However, the mechanism of this replication may have some errors, especially in later in life. This can cause the cells to grow disproportionately and out of control.

Often this process can occur very quickly. This is how the bulges, lumps or tumors are formed. They may seem to appear overnight, but it is possible the beginning of the tumor dates from a long time prior. They can appear anywhere in the body whether under the skin or in particular organs, spreading throughout the organism during a process known as metastasis.

There are many factors in the appearance of tumors in your dog. This cause determines whether they are benign or malignant. The damage they cause, in both form and severity, largely depends on which part of the body they occur. It is therefore advisable we take our dog to the vet once a year for younger dogs or twice for those over the age of seven years. This is to help with the early detection of tumors such the prognosis will be affected by the speediness of the diagnosis. They can also determine whether they might be cancerous and advise on the right course of treatment.

For this reason, it is important to check our dogs regularly at home just in case these lumps may be present. Through a blood test and/or biopsy, the vet can then decide whether the lump is something which needs to be treated and what this treatment may be. Whether benign or malignant, the lump may be removed in a surgical procedure. If it is cancerous, it may also be accompanied by radio or chemotherapy.

The presence of a lump might also indicate a cyst which is not cancerous. These could be lipomas which are cysts of fatty tissue which collect and are removed in a relatively simple procedure. However, it is always a vet who needs to provide the diagnosis and determine a benign fatty tumor with something malignant.

Allergic reaction causing lumps on a dog's neck

There may also be a lump or bulge in your dog's neck due to a reaction from an injected vaccination. This is usually a side effect and will go away of its own accord relatively quickly. Normal dogs are injected at the withers, but some vets may puncture a little higher on the neck.

If your dog has just undergone a vaccination shot, then this might likely be the cause of the lump. However, if the lump doesn't go away in a few days or if it gets worse, take the dog to the vet. There are rare instances where a reaction to vaccinations can occur, know as vaccine-associated adverse events (VAAEs). These are especially the case in small-breed neutered dogs[2]. They most commonly occur 72 hours after injection and require immediate treatment.

Why Does My Dog Have a Lump on Their Neck? - Allergic reaction causing lumps on a dog's neck

Other types of lump on a dog's neck

The above causes of lumps on a dog's neck are the most common, but here are some other possible reasons. They include:

  • Squamous cell carcinoma: while this is is a type of tumor, it is important to note because it is possible it will be cancerous. Since squamous cell carcinoma is often related to exposure to sunlight, it is possible they can appear on the dog's neck. Will usually show broken skin and scabbing after time.
  • Mast cell tumor: more common on the torso and perianal area, it is possible the dog can develop mast cell tumors on their neck. Mast cell tumors appear as lesions and can be either benign or malign.
  • Parasite: insects such as botlfies or screwworms, can bury themselves into the skin of a dog and leave eggs or larvae in the tissue of the dog. If this is the case, it can be very irritating and even threaten their overall well-being if they proliferate. They will need to be extracted by a professional.
  • Warts: can be caused by various types of virus. They are a symptom of the viral infection and prognosis will depend on its type and progress. Many warts on a dog's neck can be removed by burning off with liquid nitrogen.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Why Does My Dog Have a Lump on Their Neck?, we recommend you visit our Other health problems category.


1. Hillier, A., et al. (2014). Guidelines for the Diagnosis and Antimicrobial Therapy of Canine Superficial Bacterial Folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases). Veterinary Dermatology, 25(3), 163-e43.

2. Moore, G. E., et al. (2005). Adverse Events Diagnosed Within Three Days of Vaccine Administration in Dogs. Journal of the American Veterinary Medical Association, 227(7), 1102-1108.

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We just notice a lump under my daughters neck it’s sometimes hard and sometimes hard but doesn’t hurt to touch what could it be
My dog has bump on his neck and his breath smells so bad. I bought stuff for his breath but it still smells. Do I have to be scared or worried about me getting something from him
My 14 year old very active male dog has two lumps in his neck. One fatty and one hard lump. Not sure what to do. Had needle aspiration but didn’t give definitive results. He’s panting and seems anxious. Vet says he’s not in pain and can breathe. Not sure if we should get biopsy with hope it can be removed and is not malignant. We wouldn’t put him through chemo or radiation at this point. Thoughts?
Administrador AnimalWised
Hi Joy,

Our thoughts depend on the veterinarian's advice as well as the many other considerations you will need to make. Often an expensive surgery or treatments like chemotherapy are both prohibitively expensive and unfair for an old dog. It will depend on how it affects his quality of life.
Hi. I have pitbull puppies at 1month old.... 1 of the pups has a lump on the side of her neck it was hard now there is a hold at the bottom of her neck and fluid is coming from this hole and it seems like the lump is gone a little smaller.... Can you tell me what to do plz
Administrador AnimalWised
Hi Nadia,

Just as if we were ill we would go to a doctor, these puppies sound like they need to see a veterinarian.
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Why Does My Dog Have a Lump on Their Neck?