Introduction

According to the World Health Organization's (WHO) 2023 report, more than 55 million people have dementia worldwide, and every year, there are nearly 10 million new cases.¹ Dementia is currently the seventh leading cause of death and is especially prevalent among women. It primarily affects older individuals and progressively impairs memory, cognitive functions, social behaviours, and the ability to carry out daily activities.

Many countries have developed policies to encourage early detection, diagnosis, and prevention of dementia, and to improve care. One such policy involves the use of non-pharmacological care for dementia. Among the available interventions, animal-assisted therapy (AAT) is a popular and well-researched treatment option. It is believed that animals can help people with dementia by providing companionship and support in daily activities, potentially improving both mental and physical health, including better moods and fewer behavioural issues.

Overview of dementia

Dementia is caused by various diseases or injuries that either directly or indirectly damage the brain. 

The primary symptoms of dementia include: 

• Depression 
• Anxiety 
• Psychomotor agitation
• Aggression 
• Shouting 
• Wandering 
• Restlessness 
• Apathy 
• Delusions
• Hallucinations² 

Alzheimer’s disease is the most common form of dementia. Some types of dementia or dementia-like symptoms are reversible, such as those related to alcohol and drug use. Although, depression-induced dementia, structural brain lesions, and most other forms are not reversible. 

Currently, there is no cure for irreversible dementia.³ Most treatments are symptomatic, typically aiming to improve psychological or behavioural symptoms. However, much can be done to support people living with the disease and their caregivers.

The benefits of animal-assisted therapy (AAT) for dementia patients

Animal-assisted interventions (AAI) represent a cost-effective, non-pharmacological approach aimed at improving the prognosis for dementia patients. Research has demonstrated that AAI can enhance well-being, cognitive abilities, emotional state, behaviour, reduce depression, and even decrease the length of hospital stays for those with dementia.^4,6

Emotional enhancement

AAT has proven to be an effective therapy for improving the emotional state of elderly individuals with dementia.⁷ A notable study conducted in 2020 with therapy dogs showed positive effects on the participants' mood. Most participants responded with smiles and laughter while interacting with the therapy dogs, who followed commands like shaking hands or sitting down. This interaction alleviated social isolation and boredom and reduced anxiety levels.⁸

Reducing depression symptoms

Recent reviews of AAT studies have shown a significant reduction in depression levels among dementia patients receiving animal-assisted therapy, addressing the uncertainties of earlier reports.⁹ 

Therapy dogs are adept at understanding subtle body language, and initiating engaging and emotionally fulfilling interactions. They respond appropriately to the patients' actions, helping to foster a bond through genuine affection and pleasure. Furthermore, AAI activities that require memory, such as checking the animal's health or walking and feeding them, can positively affect the hippocampus and help mitigate symptoms of depression.¹⁰

Non-pharmacological management of problematic behaviours

AAT also serves as a non-drug approach to managing problematic behaviours in elderly individuals with dementia. The presence of animals can divert attention from distressing symptoms and provide a sense of calm and security, reducing behavioural issues like aggression and agitation.

Types of animals used in AAT for dementia

The most suitable animals for AAT include fish, cats, dogs, and horses.¹¹ Other animals such as birds, rabbits, dolphins, pigs, chickens, and any other well-prepared animal (regardless of size) can also be beneficial. 

Decisions about which animal to use must consider several factors including potential allergies of the patients or residents, whether they are afraid or dislike some animals, and the animal's temperament. 

When selecting dogs for AAT, it's important to consider specific factors such as breed, size, age, gender, and behavioural characteristics. For instance, large, young, energetic male dogs might not be the best choice for visits to nursing homes as they can be overly exuberant and may accidentally knock over or step on frail individuals, increasing the risk of falls and injuries.¹²

Robotic therapy animals

Interestingly, robotic pets have also been used in therapeutic settings, and studies have confirmed their physiological, psychosocial, and behavioural benefits. However, these robotic pets cannot yet fully replicate the benefits of therapy with living animals.¹³

Ethics and welfare

Ethical considerations are crucial in any AAT program. These are based on a thorough understanding of the needs and behaviours of therapeutic animals. Without appropriate training, suitability assessments, and knowledge of a dog’s body language, choosing dogs to work in such settings could compromise their welfare. 

For example, a model for using dogs in therapy might include:

• Developing handler profiles
• Listing job characteristics specific to the working environment and needs
• Creating dog profiles to identify their individual needs
• Preparing and training the program team
• Conducting assessments or re-assessments of the dogs, which is preferably reviewed annually¹⁴

Principles to ensure the welfare of therapy animals include:

• Sufficient rest to avoid adverse health effects
• Protection from abuse, discomfort, and stress (physical and mental)
• Adequate medical care
• Ensuring that no abuse or distress occurs, and suspending the program immediately if abuse or distress is identified

Clinical recommendations for using AAT in dementia care

Duration of therapy

Initially, when using AAT to improve cognitive functions, a longer duration is required. Previous studies have demonstrated improvements in depressive symptoms after six weeks of one-hour AAT sessions for older adults.¹⁵ Therefore, a treatment period shorter than four weeks is generally insufficient to yield significant improvements.

Research limitations

To date, all studies related to AAT have inevitably been limited by small sample sizes.¹⁶ Although these samples are adequate to validate the research findings, further studies with larger sample sizes are needed. 

An important unresolved question remains whether the presence of animals provides additional benefits compared to interventions based solely on human interaction.

Effectiveness of AAT

The impact of AAT on dementia may not be as significant as previously anticipated. AAT has not been shown to effectively alleviate neuropsychiatric symptoms, which include a range of issues such as; 

• Agitation 
• Apathy
• Sleep problems 
• Anxiety 
• Appetite changes 
• Delusions 
• Hallucinations
• Depression^9,17 

However, mitigating these neuropsychiatric symptoms is crucial for dementia patients, as a substantial body of epidemiological evidence suggests that these symptoms play a predictive role in the progression of dementia and its associated mortality rates.¹⁸

Safety concerns

When facilitating interactions between elderly individuals and pets, certain safety concerns must be addressed, including potential allergies, the risk of biting, and fear.¹⁹ It is essential to carefully manage these interactions to ensure both the safety of the patients and the welfare of the animals involved.

Summary

Current research on the effectiveness of AAT interventions has some limitations. A significant and unresolved issue is whether the presence of animals offers additional benefits compared to interventions solely relying on human interaction. Overall, AAT represents a cost-effective and empathetic approach to dementia care, aiming to enhance patients' mental and physical health and alleviate the burden on caregivers. The approach is gaining traction, although more standardised research is needed to establish its benefits over traditional, human-only interventions.