Alzheimer’s or Cognitive Dysfunction in Dogs - Symptoms, Causes and Treatment

Cognitive dysfunction syndrome, commonly known as dementia or Alzheimer's disease in dogs, consists of a series of behavioral and cognitive changes that occur in some dogs as they age.

It is a degenerative disease that commonly occurs in geriatric dogs. Statistics show a prevalence of 14 to 35% in senile dogs, although it is most likely an underdiagnosed pathology.

When dogs suffer from cognitive dysfunction or Alzheimer's disease, they develop plaques in their brain parenchyma caused by a protein called beta-amyloid.

Although it is not known how exactly it affects the formation of these amyloid plaques in the brain, it is known that this protein has a neurotoxic effect that it produces:

• Impairment of neuronal function
• Degeneration of synapses
• Degradation of neurotransmitters
• Neuronal death

Moreover, the extent and location of beta-amyloid deposits are known to be related to the severity of cognitive dysfunction in canine Alzheimer's patients. As a curiosity, it is worth noting that these beta-amyloid deposits also develop in human patients with Alzheimer's disease.

The syndrome of cognitive dysfunction may be associated with a variety of behavioral changes. These changes can be classified into the following categories:

• Memory loss and learning delay: they often forget patterns or commands they already knew or are unable to learn new ones. Some animals may urinate or defecate at home. In advanced cases, they may also not recognize their caregivers or the people around them.
  
  
• Change in social behavior: some dogs become grumpier and refuse petting, they greet their caregivers with less vigor, they have difficulty socializing with other dogs, they are more likely to be aggressive, etc.
  
  
• Change in sleep-wake rhythm: it is common for them to change their sleep schedule so that they sleep during the day and stay awake at night.
  
  
• Decreased movement and exploration behavior: They spend most of their time resting or sleeping, decrease interaction with other family members, and lose interest in their environment.
  
  
• Anxiety or irritability: Some dogs may experience increased agitation, which could lead to less rest, anxiety when left alone, vocalizations, and stereotypies. We leave you with this other post on compulsive behaviors in dogs to provide you with more information on this topic.
  
  
• Disorientation: They get lost in previously familiar places and are unable to avoid certain obstacles (such as stairs, doors, etc.).

If your senior dog is showing any of these symptoms, they may be suffering from Alzheimer's disease or another neurological problem. Read this other post about neurological problems in older dogs to learn more.

Alzheimer's disease in dogs is diagnosed by exclusion, meaning all other causes that might be responsible for these symptoms must be excluded. Due to this, it is essential to establish a list of differential diagnoses that must be ruled out one by one before making a diagnosis.

In the list of differential diagnoses, it is necessary to include all pathologies that can potentially cause changes in the dog's behavior. Some of the most important are:

• Endocrine disorders: such as hypothyroidism, diabetes, or Cushing's syndrome.
  
  
• Musculoskeletal disorders: such as osteoarthritis, arthritis, herniated disks, etc.
  
  
• Cardiovascular diseases: such as heart failure, hypo- or hypertension, etc.
  
  
• Neurological diseases: such as tumors, encephalitis, etc.
  
  
• Primary behavioral problems: It is important to distinguish primary behavioral disorders from those associated with Alzheimer's disease in dogs. To do this, it is necessary to know if the behavioral issue existed when the animal was young and if there has been any change that may have triggered the problem.

To rule out all of these differential diagnoses, one or more of the following tests may need to be performed:

• Clinical examination: special attention to neurologic examination.
  
  
• Laboratory tests: blood tests, hormone profile, urinalysis, etc.
• Imaging tests: X-ray, ultrasound, CT or MRI.

The diagnosis of cognitive dysfunction can only be made after all possible differential diagnoses have been excluded.

Currently, treatment of Alzheimer's disease in dogs is based on the combination of:

• Behavioral treatment
• Pharmacological therapy
• Dietary management and nutritional supplements

However, we must clarify that there is no curative or definitive treatment for this syndrome, but that therapy only helps to minimize the clinical signs and slow down the progression of the loss of cognition.

Behavioral treatment

In order to preserve the animal's cognitive functions and slow the progression of the disease, it is necessary to:

• Maintain a routine: this will make the environment more predictable and less stressful.
  
  
• Provide good environmental enrichment: with games that stimulate eyesight, hearing, taste, touch and smell, as well as short walks and positive training of new simple commands.
  
  
• Facilitate orientation: for dogs with orientation problems, placing scented candles with different scents in each room can be very helpful, as it helps them remember each room.
  
  
• Do not punish for inappropriate behavior: such as urinating in the house or not sleeping at night, as this will only help them become more anxious. In these cases, it is especially important to provide positive training and reward positive behaviors to reinforce them.
  
  
• Reduce anxiety or irritability: using collars or diffusers with pheromones can be a great help. For dogs with an altered wake-sleep cycle, it is advisable to place these diffusers in their resting area.
  
  
• Treat them with patience: The observed changes in the animals' behavior can be frustrating for the owners, but in such cases, it is essential to rationalize the issue and realize that these changes are not voluntary on the animal's part. These behaviors are simply the result of its nervous system degenerating. Therefore, at this stage of their life, it is especially important to treat them with the patience, affection, and care they deserve.

Pharmacotherapy

Pharmacological treatment should be aimed at alleviating behavioral problems and cognitive disorders. The most commonly used medications to treat cognitive disorders in older dogs are:

• Nicergoline: at a dose of 0.25 mg per kg body weight per day. It causes vasodilation at the cerebral level, which increases cerebral irrigation and consequently improves the supply of oxygen and glucose to the brain.
  
  
• Selegiline: at a dose of 0.5 mg per kg body weight per day. It causes an increase in dopamine levels, which are undersupplied in dementia patients. In addition, it has antidepressant and neuroprotective effects. It is recommended to be administered in the morning, especially in patients with changes in sleep-wake rhythm.

On the other hand, other drugs such as melatonin can be used to try to restore the sleep-wake rhythm, or benzodiazepines to reduce the level of anxiety.

Dietary management and nutritional supplements

Currently, there are commercial diets specifically designed for dogs with age-related behavioral changes that contain nutrients and antioxidants that can combat the symptoms of cellular aging.

In addition, there are a number of supplements that can be very useful in the treatment of this syndrome. The most important are:

• Vitamin E: has a neuroprotective effect, acting against free radicals and protecting cells from the toxicity caused by beta-amoloid deposits.
  
  
• Vitamin B6: is involved in the synthesis of neurotransmitters and supports synaptic transmission.
  
  
• Phosphatidylserine: This phospholipid, found as part of the cell membrane of neurons, helps improve symptoms in dogs diagnosed with cognitive dysfunction.
  
  
• Docosahexaenoic acid (DHA): It is an omega-3 fatty acid whose deficiency contributes to the occurrence of cognitive changes, so it is beneficial to supplement it in these patients.
  
  
• Ginkgo biloba: some studies show that its use seems to be able to improve memory in senile dogs.

Caring for an older dog is not always easy, but in most cases, early diagnosis can go a long way toward combating all kinds of diseases associated with this stage of life. Read this other article to learn how to recognize the symptoms of old age in dogs.

Once you know the main aspects of this syndrome, you are probably wondering how long a dog with cognitive dysfunction can live.

Although Alzheimer's disease in dogs is not fatal in itself, it can affect the life expectancy of affected animals, as behavioral changes sometimes occur that force caregivers and veterinarians to consider euthanizing the animal.

In most cases, dogs can live with a good quality of life if an appropriate treatment protocol is established, however, cognitive decline usually occurs slowly and gradually.

If you want to learn more about euthanasia in dogs, do not hesitate to take a look at this AnimalWised article we recommend.

Although there is as yet no effective way to prevent the onset of Alzheimer's disease in dogs, there are a number of preventive measures that can help delay the onset of this syndrome in geriatric dogs:

• Mental stimulation
• Development of simple games
• Positive training of simple commands
• Moderate physical activity

We leave you with the following article, in which we discuss some intelligence games for dogs, so that you can mentally stimulate your dog at home and prevent Alzeheimer's and other neurological disorders in dogs.

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 Alzheimer’s or Cognitive Dysfunction in Dogs - Symptoms, Causes and Treatment, we recommend you visit our Neurological diseases category.