Why Is My Dog's Occiput Getting Bigger? (9 Common Reasons)

If that bump on top of your dog's head is getting bigger, you may be wondering what is going on. Veterinarian Dr. Ivana shares several possible causes for a dog's occiput to become more prominent.

What's Up With That Bump on Your Dog's Head?

If you wake up one day and notice that your dog's occiput is getting bigger, you may be wondering what may be going on. Last time you knew, that bony structure at the top of your dog's head wasn't that prominent, and now your dog is looking more and more like Pluto, the famous bloodhound.

You're likely not imagining things if your dog's head seems to be pointier. Turns out, there can be several medical conditions that can cause your dog's occiput to appear larger.

In this article, veterinarian Dr. Ivana Crnec, a licensed veterinarian graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia, goes over the following topics:

• What is a dog's occiput?
• What bone is an occiput composed of?
• Is the occiput really a sign of intelligence in dogs?
• What are some functions of the dog's occiput?
• What dog breeds have an occiput?
• Causes of an enlarged occiput in dogs?

What Is a Dog's Occiput?

As dog lovers, we know that the canine’s skull comes in many shapes and sizes— from dogs with small heads, like Yorkies, to giant-headed dogs, like Mastiffs; from flat-faced Pugs to long-muzzled Afghan Hounds and from dogs with round heads, like Chow Chows to dogs with square heads like Boston Terriers.

However, regardless of the head’s shape and size, all dogs have one thing in common: a bump on the top of the head. The only difference is in some breeds, it is more visible than in others,

The bump on a dog’s head is called an occiput.

What Bone Is a Dog's Occiput?

A dog's occiput consists of the last part of the occipital bone, which extends to the back of the dog’s head and connects with the neck.

Like all cranial bones, the occiput is a flat bone. Veterinarian Vivian Carrol on petMD describes a dog's occiput as a “fin-like projection or knob-like bump on the top of a dog’s skull.”

The "Dog's Knowledge Knot"

In the past, it was believed that the size of the occiput was an indicator of the dog’s intelligence and that there was a correlation between the occiput’s size and the dog’s sense of smell—the bigger the occiput, the more powerful the dog’s ability to smell.

This belief was supported by the fact that scent hounds, like Bloodhounds, have a pronounced occiput.

Today, the occiput is an intriguing anatomical part of the dog’s skull, and it is known by many slang terms, such as knowledge bump, wisdom bump, knowledge knot, love knot, smart bump, and dumb bump.

What's the Function of a Dog's Occiput?

The occiput is a normal part of the dog’s head anatomy. Therefore, it has several functions. Let’s take a closer look at them.

Extra Protection

The main role of the occiput is to provide the dog’s skull with additional protection. Namely, in the wild, when predators attacked dogs, they often aimed for the head. A larger occiput would mean better protection against such attacks.

Muscle Attachment

Same as all cranial bones, the occipital bone serves as a broad surface to which the muscles moving the head and neck can attach. This enables the head and neck to move in relation to the spine.

Nerve Endings

Finally, the occiput harbors several nerve endings linked with the fight or flight system. Many holistic vets practicing acupuncture and massages pay extra attention to this area. When properly handled, it can relax and calm the dog down.

What Dog Breeds Have a Occiput?

All dogs have an occiput. It's just that in some dog breeds, it's very visible, while in others, it is barely perceptible. Dog breeds with a pronounced and strikingly visible occiput include:

• Golden Retrievers
• Labrador Retrievers
• English Setters
• Bloodhounds
• Basset Hounds
• Boxers
• Pointers
• Spaniels
• Collies
• German Shepherds
• Doberman Pinchers

Why Is My Dog's Occiput Getting Bigger?

Normally, the occiput grows along with the dog or, better said, as its skull grows. Simply put, the occiput grows at the same rate as the skull, meaning when the skull stops growing, the occiput will stop too.

Once the dog’s growth is over, the occiput should remain roughly the same size throughout the dog’s life.

However, there are some situations in which the occiput seems larger or grows. Some of them are normal, and others are indicative of medical issues.

Normal Causes of an Enlarged Occiput in Dogs

The group of normal causes of an enlarged occiput includes growing up and getting old. In these cases, the occiput does not really enlarge; it just looks bigger in comparison with other head structures and overall anatomy.

Growing Up

As a young puppy grows and transitions from puppyhood to adulthood, it goes through periods of intense growth.

During those times, it is normal for the occiput to appear larger. However, these are temporary changes, and once the puppy reaches its adult size, the occiput will blend in and be more or less in sync with the dog’s overall appearance.

Getting Old

It is also possible for the occiput to appear larger in senior dogs. This is because older dogs tend to lose muscles and get skinnier.

As a result, the occiput may appear more pronounced during the dog’s mature years than it did when it was an adult.

Abnormal Causes of an Enlarged Occiput in Dogs

As noted, some causes of enlarged occiput are abnormal and indicate health problems. Here is a closer look at the abnormal causes of enlarged occiput in dogs.

Head Injuries

Dogs are rambunctious creatures and often accidentally injure themselves. In such cases, it is common for their heads to sustain injuries.

Minor head injuries result in bumps and bruises, and more significant injuries may cause concussions. If your dog sustains a head injury, it is important to see a vet. Dogs with concussions require proper medical care.

Hematomas and Seromas

Other causes of an enlarged occiput are hematomas and seromas. Hematomas are blood-filled pockets, and seromas are fluid-filled pockets. Hematomas usually occur after injuries, and seromas following surgical procedures.

In both cases, veterinary care is important as it will speed up the recovery and make the process less painful and more comfortable.

Muscle Atrophy

The dog’s occiput can seem larger if the muscles attaching to the cranial bones start to waste away (a condition known as muscle atrophy). Muscle atrophy in dogs is a severe condition that requires veterinary attention.

Masticatory Muscle Myositis (MMM)

Masticatory muscle myositis in dogs is an autoimmune condition. It occurs when the dog’s immune system misidentifies its own muscle tissues as foreign bodies and attacks them.

While the condition primarily affects the masticatory muscles (that participate in chewing), it can also affect other muscles on the head. If affected, the muscles become swollen and very painful.

MMM is more common in large breed dogs such as Labrador Retrievers, Weimaraners, German Shepherds, and Rottweilers.

The treatment involves long-term use of immuno-suppressive medications, such as corticosteroids.

Hair Loss

Yes, hair loss in the head area may result in a seemingly enlarged occiput in dogs. There are many causes of hair loss in dogs.

For example, a dog may start losing hair as a result of inadequate nutrition and endocrine conditions. Hair loss can also be a secondary issue triggered by severe skin allergies. Parasites and mite infestations can trigger hair loss.

When a dog loses hair on the head, the occiput becomes more pronounced.

Multilobular Bone Tumor

Also known as osteochondrosarcoma, the multilobular bone tumor in dogs is a slow-growing tumor usually affecting the flat bones of the skull. Usually, the tumor is benign and does not cause metastasis. The treatment of choice is surgical removal.

If surgery is not an option, radiation therapy and chemotherapy might be considered. They can also be used in conjunction with surgical removal.

Bug Bites

Finally, a dog’s occiput can become enlarged due to bug bites. Dogs are naturally curious creatures and often get in trouble when playing with bugs.

Usually, dogs get bug bites in the mouth and muzzle area. However, bites on the head and occiput are also possible.

In most cases, bug bites are benign and resolve on their own. However, if your dog is prone to allergies, it is best advised to see your vet or emergency veterinarian following a bug-bite incident.

When in Doubt, Call the Vet

All in all, the occiput or protuberance on the top of some dogs’ skulls is a normal part of the head. And contrary to popular belief, it is a matter of anatomy and skull structure and not level of intelligence and keen sense of smell.

As part of the skull, the occiput grows in correlation with the skull. Once the skull growth is over, the occiput stops growing too. Therefore, if your dog’s occiput suddenly looks larger than usual, it is important to call the vet.

An enlarged occiput in dogs can be a red flag indicating various health issues—while some are minor, others require veterinary attention.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2023 Adrienne Farricelli