WHAT is Hydrocephalus in Dogs? 23 Symptoms Revealed

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What is hydrocephalus in dogs? Chances are that you might never see a hydrocephalus dog in your lifetime unless you work in a veterinary hospital, a shelter, or any facility with dogs. 

You might wonder what hydrocephalus in dogs has to do with them and how often it happens? What are the risk factors? Should we concern ourselves about genetics and add it to our breeding checklist?

Right from middle and high school, we all had that one person in school or class we nicknamed “big head.” Probably, it was us that name was given to.  What we might not know is that we wrongly gave/accepted that nickname if the person (we) didn’t have hydrocephalus. This is because not all big heads are a result of hydrocephalus.

Hydrocephalus in dogs may be rare to you, but it does occur. Let’s learn about one in the dog today. 

Hydrocephalus in Dogs
From Jessica Zubizarreta: “Two teacup chihuahua puppies surrendered to shelter after mom passed during delivery. Puppies were sent to foster care but quickly started showing congenital defects, presumed to be from inbreeding- most notably, severe hydrocephalus. Puppies had to be humanely euthanized due to many seizures.”

What is Hydrocephalus in Dogs? 

Hydrocephalus comes from the Greek word; hydro, meaning water, and Cephalus, meaning head. So literally, hydrocephalic dogs mean water in the head/on the brain of a dog. Medically, hydrocephalus is when excessive cerebrospinal fluid (CSF) escapes into the brain, thus, causing brain swelling. 

Cerebrospinal fluid is fluid around the brain and the spinal cord and housed in the skull and spinal vertebrae, respectively. It provides protection and nutrients to the brain and the spinal cord. Certain cavities in the brain procedures CSF, and the body absorbs it by other cavities to prevent buildup.

In the brain, the cavities drain CSF into the lymphatic system, where it mixes with the blood. These cavities are the subarachnoid space, foramen of Monro, aqueduct of Sylvius, foramina of Luschikae, and Magendie. Hydrocephalus occurs when a blockage occurs in these structures either congenitally or through an acquired method.

Dogs with dome in a newborn puppy is normal and should close in a few weeks, around nine to 12 weeks. The place where the dome shape fuses in an unaffected puppy is the rostral colliculi. Sometimes, this fusion creates a problem when there is not enough space left for the drainage of CSF. 

Hence, CSF leaks into the brain, a part called the white matter, because there is no space for drainage, which causes swelling and impedes the normal development of the brain in hydro pups.

Accumulation of CSF in the brain is due to certain factors such as:

  • Blockage in the drainage sites in the brain.
  • Too much production of cerebrospinal fluid in the brain 
  • There is a decreased absorption of the CSF in the brain. 

Since the skull prevents the brain from expanding, this increases the pressure in the brain (known as intracranial pressure in dogs), and the fluid presses on brain tissues that are sensitive, leading to brain damage, which can be irreversible. Most likely, death occurs. 

Symptoms of Hydrocephalus in Puppies

A video discussing examples of Hydrocephalus in Puppies

Hydrocephalus puppy symptoms vary depending on the cause and severity. However, there are general symptoms that run across hydro in dogs. Some dogs with hydrocephalus show no symptoms at all but might show signs of pain if not treated. 

Common hydro puppy symptoms are:

  • A dome skull
  • Open fontanel in dogs (soft spot on the head)
  • Dog seizures
  • Canine blindness
  • Weak hind limbs
  • Slow growth
  • Puppy runting (smaller than litter size)
  • Telorism in dogs
  • Staring into space 
  • Change in behavior
  • Restlessness (lethargy)
  • Difficult housetraining
  • Dog circling, as a compulsive behavior
  • Difficulty eating and drinking
  • Uncoordinated movement or lack of coordination
  • Throwing front limb about when walking
  • Bumping into walls and other things
  • Crossed limbs when standing
  • Inability to think or loss of memory (dog dementia)
  • Labored breathing
  • Coma
  • Unresponsive to stimuli
  • Dog head pressing 

These symptoms may not be entirely cut in stone and can differ. Once you notice anything different in your dog, kindly inform your veterinarian as soon as possible.

Since the presence of the fluid in the brain affects normal brain development and function, most of these symptoms are neurological. 

Puppy With A Big Head – Causes

There are two main causes of a water head puppy. These are those presented at/ gotten before birth (congenital) and acquired after birth. 

Congenital Hydrocephalus in Dogs

Congenital hydrocephalus in dogs may be a result of a genetic condition, teratogens, or even an infection that crossed the placenta during brain development. In summary, it is a birth defect. It can also result from hemorrhages that clot in the brain after a prolonged labor or vitamin A deficiency gotten from the mother before birth. 

Additionally, congenital hydrocephalus can result from cysts in the nervous system, underdeveloped cerebellum, which affects fluid drainage, and abnormal skull size limiting brain growth and CSF function.

Congenital hydrocephalus leads to an enlarged fontanel (soft spot in the skull), a dome-shaped skull known as Waterhead or apple head, and eyes that seem to look/gaze downwards (known as the setting sun sign). 

A congenital hydrocephalus dog does not show signs when they are very young or might show signs at birth. Congenital hydrocephalus diagnosis occurs during the weaning of the puppy (eating solid food and walking on its own).

Visible signs include: change in behavior, failure to obey basic commands or when housetraining a puppy, falling over on one side, circling, and change in / abnormal walking.

Pet owners should note that not hydro puppies are hydrocephalus dogs, and it can be a result of other factors. 

Acquired Hydrocephalus in Dogs

This occurs some years after birth and is usually due to infections, tumors, or trauma into the brain or any of its structures that maintains and drains the cerebrospinal fluid.

A dog brain tumor is the most common form of acquired hydrocephalus. Other causes are parainfluenza virus, deficiency of vitamin A, intracranial inflammation, and brain hemorrhage that clots.

Signs of acquired puppy hydrocephalus are similar to those of the congenital hydrocephalus and include; losing vision, circling, head pressing, seizure, pacing and restlessness, and behavior change.

Susceptible Breeds and Hydrocephalus in Dogs

Since hydrocephalus might have a genetic predisposition to it, there are certain breeds of dogs that are at risk / prone/ susceptible to getting hydrocephalus. Mostly, smaller dog breeds and those with snub noses or brachycephalic dog breeds are at a higher risk of developing hydrocephalus.

These dog breeds include:

Note that not all dogs from these breeds would develop mild hydrocephalus in dogs during their lives, and other dogs from less susceptible breeds may also be hydrocephalus.

picture of a brown toy french poodle sitting on the floor with its mouth open

Is Hydrocephalus in Dogs Genetic?

A congenital hydrocephalus dog can have some genetic predisposition to it. Thus, you should not breed dogs that display hydrocephalus dog symptoms or those that have produced a hydro pup.

When buying, breeding, or adopting a dog certain kinds of breeds or even dogs in general, look out for a family history of symptoms of hydrocephalus in dogs before making a decision.

Acquired hydrocephalus, depending on the underlying cause, can be genetic also. For example, a dog’s generation with frequent brain tumors is most likely to be a genetic condition and, thus, shouldn’t be allowed to breed. Also, some dogs might have a gene mutation that affects their ability to absorb or convert vitamin A from their diet.   

In summary, it is not safe to breed hydrocephalic dogs, whether congenitally or acquired.

Is a Puppy With Hydrocephalus in Pain?

In the case of puppies, hydrocephalus in a dog will induce pain due to the pressure built up in the skull. This pain, depending on the severity and underlying cause, can range from moderate to severe. This pain might also result from the effect of the pressure on the eyes and the seizure occurrence. 

For acquired hydrocephalus in a puppy, the pain might be a result of an infection or a tumor in the brain. The pain, depending on the location of the tumor, can affect other parts of the body, such as the neck.

Pain will prevent the dog from eating or performing normal activities. Your dog might withdraw and hide from you. Your puppy might be aggressive, experience dog shaking, or twitching. Remember that every dog responds differently to pain, and these signs might not necessarily be for all dogs.

A prescribed pain medication given to your dog can be at your request or if the veterinarian sees it necessary. 

The Hydrocephalus Dog Lifespan Explained

A Rescue Story About Hydro Puppies

When it comes to water on the brain in dogs, the life expectancy for dogs with hydrocephalus varies depending on the age, type, and severity of the disease. Dogs with moderate or mild hydrocephalus can live a normal healthy life, usually occasionally on medication or rarely without any intervention. Dogs with severe hydrocephalus have a shortened lifespan, and death can occur at any time.

Dogs with congenital hydrocephalus do well after surgery in the absence of brain damage. However, dogs with acquired hydrocephalus do not readily do well due to the infection or tumor in the brain, which can cause encephalitis. 

Your dog might be on supportive treatment to keep it comfortable. You can discuss the prognosis with your veterinarian before you make any decision.  However, a dog with hydrocephalus will have a guarded prognosis, which means there is not enough information to tell the outcome, and there is a possibility it can result in a good or bad outcome.

How is Hydrocephalus and SB in Dogs Diagnosed?

For young dogs and puppies, the clinical signs and the large fontanel is suggestive or diagnostic of canine hydrocephalus. However, it is prudent to run certain tests and imaging to rule out any other disease/ infection/ condition such as tumors. 

It’s also prudent for the vet to investigate all the available open fontanel dog treatment options.

Your veterinarian would run a blood test for biochemistry analysis and complete blood count and urinalysis to rule out certain diseases that can manifest as hydrocephalus, such as viral infections.

The hospital would also use various imaging procedures (CT, MRI, X-rays) to diagnose canine hydrocephalus. 

A dog ultrasound is the first line of imaging tests employed in diagnosing. It will show the opening or the increase in the opened areas of the brain, known as brain ventricles. Equally, one can use a Computed tomography (CT) scan or a Magnetic Resonance Imaging (MRI) to diagnose congenital hydrocephalus.

For acquired hydrocephalus, the main diagnostic image of choice is the CT or the MRI. Sometimes, the veterinarian would connect electrical sensors in multiple locations on the head. Known as the Electroencephalography (EEG), it is very safe and poses no harm to your dog.

Also, the veterinarian can take an x-ray to see if there are any abnormalities or open spaces in the brain.

Treating Dogs With Dome-Shaped Heads

Treating can be successful in the early/ acute stages of hydrocephalus. Treatment often targets reducing the production of CSF in the brain and also reducing inflammation.

Administering anti-inflammatory drugs such as prednisone, dexamethasone, prednisolone for dogs, or cortisone, collectively known as steroids or corticosteroids, is the first line of treatment.

For dogs that have had the hydrocephalus for a long time, such as in chronic cases or more severe cases, administration of acetazolamide, dog furosemide, omeprazole, or other proton-pump inhibitors and anti-seizure drugs like phenobarbitone is to manage the condition. Make sure to give them just as your veterinarian prescribes.

Ventriculoperitoneal dog shunt surgery is a surgery where a tube connects the brain ventricles to the abdomen and is performed under special circumstances by a neurosurgeon (brain surgeon) in specialized hospitals. This fluid in the abdomen reabsorbs into the body. 

The surgery has a high success rate when performed early on a hydrocephalus dog. Like all surgery, it has associated risks and complications. It is advisable to discuss it with the attending veterinarian and the specialist.

For acquired hydrocephalus, the main goal is to treat the cause of the hydrocephalus (underlying disease condition), and this would, in turn, correct the hydrocephalus. Treatment options include antimicrobials, chemotherapy, radiation therapy, and sometimes surgery. 

Always make sure to follow up on the treatment plan of your veterinarian, as well as any review or follow-up visits. If your veterinarian refers you to a specialist, be sure to go and follow all treatment plans at the specialist. 

frontal picture of a brown french bulldog lying on the ground
WHAT is Hydrocephalus in Dogs? 23 Symptoms Revealed I Love Veterinary - Blog for Veterinarians, Vet Techs, Students


Dogs with hydrocephalus can live normal lives if detected early. However, do not breed them or their parents to prevent the condition from reoccurring. This condition does not spread from one dog to another. Hence a pet owner can rest assured of the safety of the rest of the kennel. 

Pet owners should ensure that vaccinations such as parainfluenza and dog parasite control measures are up to date. Also, add dog vitamin supplements to it’s food if it is deficient in it.  

Hydrocephalus in dogs doesn’t have to be a death sentence because there are various treatment plans available, and your dog can live a normal happy life with you.

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Currently a Veterinary House Officer at the University of Ghana, Akosua plays a pivotal role in disease diagnosis, treatment, and student supervision. Akosua's educational journey in veterinary medicine has been instrumental in shaping her commitment to public education and awareness. Her veterinary training equips her to communicate complex topics for public understanding. Her online presence on Instagram reaches a wider audience. She actively engages in public speaking, inspiring a deeper understanding of responsible pet care and the role of veterinary professionals in fostering a healthier coexistence between humans and animals.