A 14-year-old Lhasa Apso cross showed no signs of cognitive dysfunction until stress began to creep into his home.
First, his owner was hospitalized for a period, so a dog sitter showed up. Then the other dog in the household died. By that time the Lhasa Apso was becoming needier and was experiencing sensory issues and apparent deafness.
“The absence of the owner was a stress for the dog, and that’s when it started showing its very clear indicators of cognitive decline,” said Jeff Nichol, DVM, co-author of a paper on cognitive dysfunction syndrome and who has completed a behavior residency.
Dr. Nichol, who practices in Albuquerque, N.M., viewed the events that stressed the dog as fortuitous. Specialists like him say that too often cognitive dysfunction goes unnoticed by owners and therefore goes unreported to veterinarians. When obvious signs appear, treatment may start too late.
While cognitive dysfunction syndrome (CDS) is incurable, there are ways to stave it off and even get a pet to show improvement, Nichol said.
Such was the case of the Lhasa Apso. Nichol started the dog on Novifit, fish oil, Senilife, gabapentin and Zylkene.
“This dog has improved pretty significantly, and at this point it’s going on over a year now and he’s continuing to do better,” Nichol said. “[CDS] appears not to be advancing.”
Supplements and diets are among the tools that specialists like Nichol use to treat CDS. That’s in addition to Anipryl (selegiline), a drug that many veterinarians prescribe for the disease.
While Anipryl is widely accepted as a viable treatment, Nichol has heard from some practitioners who questioned the drug’s effectiveness. He believes that in many unsuccessful cases the pet was diagnosed in more advanced states of CDS.
“When it is diagnosed early, the selegiline, Anipryl, seems to be significantly more reliable,” he said.
According to the manufacturer, Zoetis Inc. of Florham Park, N.J., the recommended oral dosage is 0.5 to 1.0 mg/kg once daily, preferably in the morning. Initially, dogs should be dosed to the nearest whole tablet, and adjustments should be made based on response and tolerance, the company instructs.
“It is the only medication that is FDA-approved for the control of clinical signs associated with canine cognitive dysfunction syndrome,” said Sharon L. Campbell, DVM, MS, Dipl. ACVIM, the Zoetis veterinary specialty operations medical lead for analgesia, sedation and anesthesia.
When speaking about CDS, Nichol repeatedly drives home the importance of diagnosing the disease early. But he acknowledges it may be easier said than done.
His solution is for veterinarians to raise the subject. Pet owners receive a one-page questionnaire that has a simple scoring system using queries about disorientation, social relationships, sleep-wake cycles, memory and activity level.
Nichol recommended that practitioners hand out some form of the questionnaire to all clients with pets ages 7 or older.
Get a Thorough Diagnosis
A comprehensive exam of symptomatic pets is crucial, said Natasha Olby, VetMB, Ph.D., Dipl. ACVIM.
“If faced with a dog showing some cognitive challenges, at the very least I would do a full physical exam and full neurological exam to rule out other things,” said Dr. Olby, a professor of neurology and neurosurgery at North Carolina State University’s College of Veterinary Medicine. “And then I would always do full baseline bloodwork.”
She also suggested testing liver function and blood pressure. “I would always get a baseline of thyroid function as well,” she added.
This approach helps determine whether symptoms like confusion and memory issues are caused by other diseases of the forebrain.
On the other hand, veterinarians working with an elderly canine they suspect could be in cognitive decline should look beyond the brain, she said.
A 2012 paper co-authored by Nichol, Gary M. Landsberg, DVM, and Joseph A. Araujo, Ph.D., drew parallels between CDS and Alzheimer’s disease.
“CDS in companion animals parallels AD progression in several respects,” the paper stated.
“Therefore, it is prudent to commence treatment early. Understanding age-related brain pathology and cognitive dysfunction is essential to fully appreciate the potential value of using biomarkers and/or cognitive status in the future diagnosis and treatment of CDS progression.”
Choosing Supplements for CDS
As with Alzheimer’s, CDS advances slowly in some patients and rapidly in others, Nichol said. He’s seen veterinary patients go from early stages of CDS to a severe decline in as little as three months after diagnosis, even during treatment. Yet, other pets have staved off the severest stages for 18 months.
“For the dog whose life expectancy is 13 or 14 years, 18 months is a lot,” Nichol added.
When presented with an early CDS case, Nichol typically starts the pet on nutritional supplements. And while the responses vary, pets treated sooner typically fare far better.
“I found that when we start them early or even midstage, some supplements make a big difference,” Nichol said.
One he often prescribes is Senilife, which contains a blend of antioxidants like phosphatidylserine, pyridoxine, ginko biloba extract, resveratrol and d-alpha-tocopherol.
Its maker, Ceva Animal Health of Lenexa, Kan., reports the antioxidants work together to help reduce brain-aging behaviors in as little as seven days.
“The components work synergistically and have a specific neuroprotective action to help combat … the brain-aging-related behavior signs often seen in senior pets,” said Jennifer Styrsky, DVM, Ceva’s behavior marketing manager.
Dr. Styrsky recommends administering Senilife as a dog enters life’s senior stage.
Nichol also prescribes Novifit, Activait and Zylkyne among the myriad supplements for dealing with CDS.
Challenge a Pet's Brain to Treat CDS
Mental exercise is another recommended treatment.
“There’s very clear research and experience that show we need to challenge the brains of these old-timers,” Nichol said.
Interactive food puzzles and toys are a valuable part of CDS therapy. “It improves the relationship, which is sometimes diminished because of the dementia,” Nichol said.
His 2012 paper, published in Veterinary Clinics of North America, states: “Enrichment should focus on positive social interactions as well as new and varied opportunities for exploration, climbing, perching, hunt-and-chase games and other stimulating ways to obtain food and treats. Food toys that require pushing, lifting, dropping, batting, pawing or rolling to release food help older dogs and cats to remain active and alert. By scattering favored food, treats or catnip in different locations, pets can learn to hunt, search and retrieve.”
The paper advises maintaining the day-night cycle by opening window blinds, providing outdoor activities during daylight and reducing exposure to artificial light at night.
Dietary Changes for CDS
North Carolina State’s Olby cited cases in which specially formulated food, such as Hill’s Prescription Diet Brain Aging Care has aided in slowing progression of the disease.
“The Brain diet, marketed as B/D, is high in antioxidants—vitamins E and C are also there, for example—and it is supplemented in mitochondrial cofactors as well as omega 3 fatty acids,” Olby said. “This diet was tested in dogs in a research setting and in a blinded clinical trial.”
Another strategy outlined in Nichol’s paper is a diet containing medium chain triglycerides (MCTs), which the liver converts to ketone bodies. Supplementation with MCTs is approved for Alzheimer’s patients.
“Since a decline in cerebral glucose metabolism and reduced energy metabolism are associated with cognitive decline, MCT-induced ketone bodies provide an alternate energy source that can be used by the brain,” the paper stated.
The diet called out in the paper, Purina One Smartblend Vibrant Maturity 7+ dog food, “significantly improved performance on several cognitive tasks,” the paper noted.
The manufacturer, St. Louis-based Nestlé Purina PetCare Co., stated that the food contains botanical oils.
“Scientists at Nestle Purina have been studying aging in pets for more than a decade and set out to provide energy to the brain through a second pathway,” said Flavio Pellegrini, a brand manager with Purina One. “After looking at hundreds of ingredients, they tested an alternate source of energy called… MCTs, which enter the cell through an alternate pathway, to see if they could change the behavior of senior dogs.”
The results were better than expected, Pellegrini said. “After only a short time-consuming MCTs, dogs were making fewer errors and adapting to new situations faster,” he said.
Karen Overall, VMD, Ph.D., Dipl. ACVB, CAA, a senior research scientist in the University of Pennsylvania biology department, has been part of a large cognitive study for nearly two years.
“We have added a second study, with some support from the AKC Canine Health Foundation, to retest dogs 8 and older,” Dr. Overall said. “We are seeing physical failings as dogs age, but few behavioral ones. My hypothesis? These are all dogs who have led and do lead rich intellectual and cognitive lives with excellent care and great social and mental stimulation. They are not living stuffed animals who do nothing.”
What Vets Should Know about CDS
Nichol highlighted one CDS takeaway for general practitioners: “It’s a grossly underdiagnosed disease.”
For one, cognitive dysfunction is not at the forefront of the minds of many veterinarians dealing with older pets, he said.
“They make the same mistake pet owners do,” Nichol said.
Some veterinarians may write off symptoms of CDS as normal aging. However, normal aging usually doesn’t include diminished problem-solving skills and an inability to remember things, he said.
He likes to draw the Alzheimer’s parallel to illustrate his point. Friends and relatives of Alzheimer’s human patients notice cognitive decline.
“But with dogs and cats, they don’t drive, they don’t have an appointment schedule, so people miss it early,” Nichol said.
Originally published in the August 2016 issue of Veterinary Practice News. Did you enjoy this article? Then subscribe today!