Sundowners Syndrome in Senior Dogs: A Vet‘s Guide

Recognize the signs of this distressing dementia-related condition and learn how to help your dog thrive

As dog lovers, we cherish the bond we share with our canine companions through all stages of life. Watching a once lively pup slow down and grow grey around the muzzle is a bittersweet hallmark of the passing years. But what happens when the aging process brings more than just a slower pace and distinguished grey coat? For many owners of senior dogs, a heartbreaking shift occurs as their dog‘s world seems to unravel at the edges. Typically in the evening hours around sunset, their confused canine may pace, whine, and appear lost in a home they‘ve known for years.

This distressing phenomenon is known as sundowners syndrome, and it‘s a reality for up to 60% of dogs over the age of 11 showing signs of cognitive dysfunction syndrome (CDS) or "doggie dementia" [1]. As veterinary professionals, our role is to guide owners through the challenges of sundowners syndrome with expertise and empathy. By working together to implement strategic treatment plans, we can vastly improve quality of life for the dog and restore a sense of control for the caregiver.

Understanding Sundowners Syndrome

Sundowners syndrome is a collection of distressing behavioral signs associated with canine cognitive dysfunction syndrome (CDS) that appear to be triggered or exacerbated by the onset of evening. These signs may include [2]:

Restlessness, agitation, inability to settle down
Pacing, wandering, circling
Disorientation, getting lost in familiar places
Staring blankly, seeming "lost in space"
Unusual vocalizations (barking, whining, howling)
Disrupted sleep-wake cycle
House soiling accidents
Activity level changes
Interactions changes

Prevalence and Risk Factors

Researchers are working to understand all the factors that contribute to the development of CDS and sundowners syndrome. In a recent survey, 82% of owners of dogs aged 16 and up reported noticing at least one behavioral change consistent with cognitive decline [3].

While age is the greatest risk factor for CDS, certain dog breeds may be predisposed according to the Canine Cognitive Dysfunction Rating scale [4]:

Breed	Prevalence
Smooth Coated Collie	100%
Miniature Schnauzer	83%
Poodle (Miniature)	78%
Mixed Breed (Small)	69%
English Springer Spaniel	56%

Other potential risk factors include:

Early spay/neuter [5]
Obesity [6]
Lack of exercise/enrichment [7]
Neurological conditions [8]

What‘s Happening in the Brain?

The aging dog brain undergoes structural and chemical changes that impair cognition, memory, learning, and behavior. These include [9]:

Accumulated oxidative damage
Chronic low-grade inflammation
Vascular changes
Depletion of neurotransmitters like dopamine
Buildup of neurotoxic beta-amyloid plaques

In sundowners syndrome, experts believe a disrupted circadian rhythm is to blame for the worsened disorientation and distress in the evening hours [10]. With impaired cognition and senses, the changing light and shadows as the sun sets may be disorienting and overstimulating for these dogs.

"Just like older people with dementia, dogs with cognitive dysfunction often have difficulty regulating their sleep-wake cycles. We suspect this contributes to their distress and behavior changes in the evening hours." – Dr. Marsha Reich, DVM, DACVB

Signs of Sundowners in Dogs

Detecting sundowners syndrome requires a discerning eye. After all, senior dogs commonly show behavioral changes consistent with general aging like slowing down or sleeping more. So when should you suspect sundowners? Use the acronym DISHA to help identify signs that may point to cognitive decline [11]:

Disorientation
Altered Interactions
Sleep-wake cycle changes
House soiling
Activity level changes

A key distinguishing factor of sundowners syndrome is the worsening of confusion and anxiety in the late day/early evening. You may notice your typically calm dog begin to pace, tremble, shadow you closely, or vocalize for no apparent reason as night approaches. Some dogs appear "lost" in corners or behind furniture. Appetite, activity level, and desire for affection may also dip dramatically in the evening compared to earlier in the day.

Of course, any persistent behavior change in a senior dog could indicate a medical issue and warrants a checkup with the vet. But if your dog shows signs on the DISHA list that seem to surge around sunset, cognitive dysfunction and sundowners syndrome should be on the radar.

Diagnosing and Treating Sundowners

There is no one definitive test for sundowners syndrome. Diagnosis relies on careful consideration of the dog‘s age, clinical signs, medical history, and ruling out potential underlying conditions that may mimic cognitive impairment.

After a thorough exam, lab work, and any necessary imaging, your vet can determine if the signs match sundowners and help you establish a comprehensive treatment plan.

The multimodal approach typically involves using medication, supplements, and dietary/lifestyle modifications synergistically to improve the dog‘s cognition, mood, and overall well-being. Let‘s break these down further:

Medication Options

Selegiline (Anipryl): This is the only FDA-approved drug to treat CDS in dogs. It works by regulating dopamine levels in the brain. In one study, selegiline improved clinical signs in 77% of dogs after 60 days of treatment compared to just 41% receiving placebo [12].
Antidepressants/anti-anxiety agents: For dogs struggling with the distressing aspects of sundowners like nighttime restlessness and agitation, medications like fluoxetine, trazodone, gabapentin, or clomipramine may be prescribed.

Dietary Interventions

Therapeutic "Brain Diets": Prescription diets like Purina Pro Plan Neurocare and Hill‘s b/d are formulated with brain-supportive nutrients like omega-3 fatty acids, antioxidants, and medium-chain triglycerides (MCTs). MCTs provide an alternative energy source for the brain which can improve cognition. One study found that dogs eating a diet with 5.5% MCTs showed dramatically improved cognition scores after just 30 days [13].
Supplemental Support: Omega-3s, SAM-e, melatonin, Denamarin, Neutricks, Senilife, and Aktivait are just some of the research-backed supplements that may help improve cognitive function and/or regulate sleep cycles for dogs with sundowners.

Environmental Enrichment

Keeping the aging canine brain active and engaged (without undue stress) is crucial for promoting cognitive health. Some brain-stimulating enrichment ideas include:

Food puzzle toys
Scent games (e.g. nose work, hide-and-seek)
Short, positive training sessions reviewing basic cues
Gentle walks exploring new environments
Relaxing car rides
Massage, brushing, petting

"Enrichment looks a bit different for dogs with cognitive decline. Focus on providing brain-stimulating activities in short spurts with plenty of rest periods in between to prevent overstimulation and confusion." – Dr. Vicki Berkley, DVM, CCRT

Safety & Management Strategies

Keeping a dog with sundowners safe and serene requires a strategic approach to their living space. Some tips:

Maintain a predictable daily routine
Ensure safe, quiet places to rest undisturbed
Walk earlier in the day before confusion sets in
Keep the environment calm and quiet, especially in the evening
Play soothing music or white noise
Secure potentially hazardous areas (stairs, pools, etc.)
Install gates, ramps, non-slip mats if needed
Use pheromone diffusers for added calm
Ensure easy outdoor access for late-night potty needs
Provide extra affection and reassurance

Coping With Canine Cognitive Decline

Caring for a beloved dog through cognitive decline is a labor of love that can challenge even the most devoted owners. Sundowners syndrome can feel particularly overwhelming as the distressing behaviors often occur when you‘re winding down for the day yourself. But by staying attentive to your dog‘s changing needs and working closely with your veterinary team, you can continue to share a meaningful bond with your dog through this time.

Remember, you‘re not alone in this journey. Seeking support from fellow dog owners via online communities for CDS such as Dog Dementia and Unforgettable Dogs can be an invaluable way to share advice, frustrations, and sweet moments with those who truly understand.

Above all, be kind and patient with yourself. You‘re doing the very best you can for your dog with the tools and knowledge you have. Some days will feel harder than others, but focusing on the joyful moments you‘re able to create together can make navigating this chapter so much more meaningful.

"Having sundowners syndrome doesn‘t mean your dog can‘t enjoy a full, happy life. It just means that life looks a little different now. As long as you stay tuned into your dog‘s unique needs and work with your vet to adjust their treatment plan as necessary, you can absolutely help them thrive." – Dr. Julie Buzby, DVM, CAVCA

Key Takeaways

Sundowners syndrome is a distressing manifestation of canine cognitive dysfunction characterized by worsening confusion and anxiety in the evening hours.
Risk factors include age, genetics, spay/neuter status, obesity, and lack of lifetime enrichment.
Identifying signs early with the DISHA acronym and intervening promptly provides the best chance for successful management.
Treatment involves strategic use of medication, supplements, prescription diets, and brain-supporting lifestyle/environmental modifications.
Working with your veterinarian, utilizing well-reputed support services, and practicing self-compassion can make navigating sundowners syndrome feel much less daunting.

If you suspect your senior dog may be affected by sundowners syndrome, don‘t wait to broach the subject with your trusted veterinarian. With a solid plan in place and a flexible, compassionate mindset, you can continue to enjoy the extraordinary human-canine bond for months or years to come. After all, our dogs have given us a lifetime of love and devotion—seeing them through this final chapter is the ultimate gift we can give in return.

Sundowners Syndrome in Senior Dogs: A Vet‘s Guide

Recognize the signs of this distressing dementia-related condition and learn how to help your dog thrive