Canine Cognitive Dysfunction

Written by Dr. Jacqueline Brister, DVM

Summary

Canine cognitive dysfunction is a degenerative or progressively worsening disease of the brain in older dogs. It is similar to some forms of dementia in people and is often referred to as "canine dementia."

The number of neurons, or brain cells, decreases over time and healthy brain tissue is slowly lost. Dogs lose the ability to function in their normal routines, such as using the bathroom in appropriate areas, following commands correctly, and recognizing their surroundings and loved ones.

Symptoms and Identification

Signs of dementia in dogs may initially begin slowly or be very subtle. With time, canine dementia can become very severe and lead to many troublesome signs and symptoms, including:

  • Changes in normal actions and behavior

  • Anxiety and/or confusion or disorientation resulting in wandering, staring, or sleeping in unusual places

  • Housebroken pets may start using the bathroom in the house instead of outside

  • Trouble following or responding to normal commands such as "sit" or "stay"

  • Keeping increasingly abnormal sleep schedules, such as sleeping more in general, or show restless, repetitive activity (e.g. pacing, barking) at night

  • Unusual behavior towards pet parents or other pets is also common (distancing themselves or unusual aggressive/disgruntled behavior)

  • Loss of enthusiasm for certain activities like dinner, treats, or walks

Identifying or diagnosing canine cognitive dysfunction is difficult. It can look like many other disorders (e.g. brain cancer, brain inflammation/encephalitis/meningitis, stroke, certain types of infection, liver disease, vestibular disease, some seizure disorders), so testing can be tricky.

Lab work such as a complete blood count/CBC and chemistry testing will help show how the internal organs are working, if the electrolyte levels are unbalanced, and if the pet has unusual red and white blood cell counts. Blood pressure may also be checked because hypertension, or elevated blood pressure, can sometimes cause similar symptoms.

Urinalysis to check for urinary tract infections as well as testing for endocrine organ diseases (e.g. diabetes, Cushing's disease) may also be performed to ensure the cause of the symptoms is not related to these problems.

In some cases, advanced imaging such as computed tomography/CT or magnetic resonance imaging/MRI may be necessary to evaluate the brain itself. No single test will specifically show that a dog has dementia/cognitive dysfunction, but testing helps point the veterinarian in the right direction for treatment.

Affected Breeds

While no specific breeds appear to be more affected by canine dementia than others, spayed female dogs are the most likely to develop the disease. Dementia/cognitive dysfunction most often develops in older dogs, typically over nine years of age.

Treatment

Cognitive dysfunction cannot be cured. Treatment options are aimed at slowing down disease progression and decreasing symptoms. Examples of treatment options include:

  • Dietary Changes

  • Environmental Adjustments

  • Addition of Supplements or Medications

Diets rich in antioxidants, vitamins (e.g. vitamins C and E), essential fatty acids (e.g. DHA, EPA), and mitochondrial cofactors (e.g. L-carnitine, alpha-lipoic acid) can be helpful. Pre-formulated diets (e.g. Purina(R) Pro Plan(R) Bright Mind, Hill's(R) Prescription Diet(R) b/d(R) Canine, Purina ONE Smartblend(R) Vibrant Maturity(R) Adult 7+ Formula) are better than homemade diets because they ensure a balanced diet to meet the needs of a senior pet.

A common supplement is the addition of medium-chain triglyceride (MCT) oil to the diet, such as that found in coconut oil. Discuss adding this with your veterinarian first because diarrhea is a common side effect. Other supplements or medications that can be of benefit to some dogs include selegiline, SAMe, and melatonin. Again, your veterinarian will need to be closely consulted before using such therapies.

Lastly, environmental adjustments include daily walks and playtime (at the pet's energy level), as well as the regular introduction of new toys and/or food puzzles. These will help keep the pet's mind sharp and engaged, slowing down the loss of brain function. Food puzzles are an especially entertaining way to keep a dog's mind sharp. They can be simple, such as hiding a treat under a cup or in a closed fist (often while the dog is looking at first so that they understand the game) and having them find it, or more advanced (for truly food-motivated treat lovers) such as manufactured food puzzles with sliding boxes and windows. Bear in mind that this should be fun and interesting for the dog in order for them to benefit from it.

Unfortunately, no standard treatments exist, and many options are used in a "trial and error" fashion to find what works for each pet. If your dog has cognitive dysfunction, it is very important to recheck with your veterinarian frequently to find what works best.

Cognitive dysfunction can be very debilitating for pets and their owners. In many cases, quality of life will eventually decline to the point that humane euthanasia should be discussed in order to allow a cherished pet to pass on with as much dignity and love as possible.

Veterinary Cost

Cost ranges quite a bit depending on what tests are performed to achieve a diagnosis. Initial consultation with a veterinarian will include a full physical examination and potentially lengthy discussion.

  • Consultation Costs Range from $35-75

  • Lab Work Ranges from $100-300

  • Advanced Imaging is Usually $1,00-1,500 (although it will not likely be necessary)

  • Monthly Cost of Medications and Food Range from $50-200

Prevention

Not much can be done to prevent cognitive dysfunction from happening. Some research suggests that it can be a genetic disorder and will occur no matter what is done or changed. Keeping your pet on an age-appropriate diet and ensuring they remain physically and intellectually active (i.e. walks, play, food puzzles) can help keep their mind sharp. Taking your pet to the veterinarian at the first signs of dementia is also important because it ensures treatment and management measures can be started sooner, extending good quality of life.

References

Dewey CW: Encephalopathies - Disorders of the Brain. Practical Guide to Canine and Feline Neurology, 3rd ed. Wiley Blackwell, Ames IA 2015 pp. 147-154.

Head E, Milgram NW, Cotman CW: Neuropathology and cognitive dysfunction in aging dogs. Vet Med 2002 Vol 97 (2) pp. 6-9.

Landsberg GM, Nichol J, Araujo JA: Cognitive dysfunction syndrome: a disease of canine and feline brain aging. Vet Clin North Am Small Anim Pract 2012 Vol 42 (4) pp. 49-68.

Head E: Brain aging in dogs: Parallels with human brain aging and Alzheimer's disease. Vet Ther 2001 Vol 2 (3) pp. 247-260.

Siwak CT, Tapp PD, Milgram NW: Behavioral correlates of age-associated cognitive changes in dogs. Vet Med 2002 Vol 97 (2) pp. 20-22.

Salvin HE, McGreevy PD, Sachdev PS, et al: Underdiagnosis of canine cognitive dysfunction: a cross-sectional survey of older companion dogs. Vet J 2010 Vol 184 (3) pp. 277-281.

Dewey CW, Davies ES, Xie H, et al: Canine cognitive dysfunction: Pathophysiology, diagnosis, and treatment. Vet Clin North Am Small Anim Pract 2019 Vol 49 (3) pp. 477-499.

Head E: Oxidative damage and cognitive dysfunction: antioxidant treatments to promote healthy brain aging. Neurochem Res 2009 Vol 34 (4) pp. 670-678.

Head E: Combining an antioxidant-fortified diet with behavioral enrichment leads to cognitive improvement and reduced brain pathology in aging canines: strategies for healthy aging. Ann N Y Acad Sci 2007 Vol 1114 pp. 398-406.

Landsberg G: Therapeutic options for cognitive decline in senior pets. J Am Anim Hosp Assoc 2006 Vol 42 (6) pp. 407-413.