THE WASHINGTON POST – Sullivan, also known as Sully, a Boston terrier, began behaving oddly at age nine. He would poop inside the house, circle the kitchen island and bark at nothing.
At first, his human Bridget Allen thought these acts were part of normal ageing. One day, though, Sully didn’t return home from a nearby wooded area he knew well. Allen’s son found him wandering by a stream, filthy and acting confused.
A short time later, he fell off the bed while sleeping and urinated on the floor. “Something wasn’t right,” recalled Allen, a retired high school English teacher from Caledonia, Michigan, about Sully’s behaviour in 2012.
Her veterinarian said it sounded like “classic” dementia. “I felt like I had been kicked in the gut,” Allen said. “I had no idea that dogs could develop dementia.”
They can, and so can cats.
“We all know that Alzheimer’s disease and other dementias are among the most common conditions humans can encounter as they age,” said associate professor of neurology Stephanie McGrath at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences. “What people don’t realise is that our pets – dogs and cats – can get it, too, and it’s probably also very common.”
Experts aren’t sure how many companion animals suffer from dementia. Estimates range from 14 to 35 per cent of the pet dog population age eight and older, according to one study. Another study suggests nearly one-third of cats ages 11 to 14 and 50 per cent of cats 15 and older are affected. Many experts believe these numbers are probably conservative.
“This is highly, highly underreported,” said Canadian veterinary behaviourist Gary Landsberg and veterinary scientific director of CanCog, an animal health research organisation.
SIGNS OF COGNITIVE DECLINE IN PETS
For pet parents trying to determine whether their cat or dog has dementia, “knowing their pet’s normal behavior is important ”, said associate professor of behavioural medicine Margaret Gruen at North Carolina State University’s College of Veterinary Medicine. “You’re really looking for a change over time.” Some signs are:
Confusion and disorientation – Forgetting things pets have learned, such as house training or using the litter box.
Changes in their sleep-wake cycle – Among cats, an increase in vocalisation, meaning more crying or howling – an obvious and frequently reported sign.
“With cats, there is excessive vocalisation and disorientation and changes in interaction with humans or other animals, such as hissing and swatting,” said clinical associate professor Starr Cameron in small animal neurology at the University of Wisconsin at Madison’s School of Veterinary Medicine, who studies cat dementia. “Some cats are up all night and vocalising. They go outside the litter box or can’t find it.”
MEDICAL CONDITIONS THAT MIMIC DEMENTIA IN PETS
Informing a vet early about any changes in a pet’s behaviours is important because the pet may have a medical condition different from a cognitive disorder that could be treated, Landsberg said.
Many conditions, such as arthritic pain, cancer, hearing or vision loss, hypertension and chronic kidney disease, can prompt symptoms that mimic dementia in pets and must be ruled out before diagnosing a cognitive disorder, experts said.
“My 18-year-old kitty Momo has always been a vocal kitty,” Cameron said, “but when she was 15 or 16, I noticed she was vocalising more.” Cameron suspected Momo had dementia.
Momo “became grumpier with the other cat and the dog. She was moody,” Cameron said.
Bloodwork, however, revealed hyperthyroidism, or an overactive thyroid. Momo was treated, and “now she’s back to Momo,” Cameron said.
STUDYING PET DEMENTIA
Scientists are studying pet dementia to help companion animals and their humans cope and to better understand human brain diseases such as Alzheimer’s.
“Dogs are good natural models. They can develop deficits similar to humans,” said director of the Arizona Canine Cognition Center Evan MacLean at the University of Arizona.
Researchers are analysing post-death brain tissue from pets, including one study that compares samples from dogs who had dementia with those who did not, to better understand “how the dog brain ages”, said McGrath, who is conducting the study. “We are also trying to understand when dogs who are healthy agers become dogs afflicted by dementia.”
Some research already has found evidence of beta-amyloid plaques and tau tangles in the brains of aging dogs and cats. An abnormal buildup of both of these naturally occurring proteins, a hallmark of human Alzheimer’s disease, can disrupt nerve cell function.
CAN COGNITIVE DECLINE IN PETS BE PREVENTED?
It’s unknown if cognitive disorders in pets can be prevented.
Some experts think exercise may help, as it does in humans with dementia. One recent study suggests that exercise reduces the risk in dogs, though MacLean, the lead author, pointed out that it was not conducted over a lengthy time period.
After Sully was diagnosed with dementia, and other medical conditions were ruled out, the vet suggested that Allen “take him home and love him up. You’ll know when he’s had his fill of this life.” She did just that. Two years later, after his symptoms worsened, Allen decided it was time to let Sully go.
“I felt like the essence of him was no longer there,” she said. “I couldn’t believe he would want to live like that if he had the choice. As painful as it was, I felt giving him peace was the right thing to do.” – Marlene Cimons
What to do if you suspect cognitive decline in your pet
- Consult your vet and make sure they rule out other medical conditions.
2. Ask your vet about treatment, including medication, supplements, diet or other interventions. The Food and Drug Administration has approved one drug called selegiline (brand names Anipryl, Eldepryl, l-deprenyl, Selgian and Zelapar), which can reduce symptoms of cognitive dysfunction in dogs. Sometimes veterinarians use it “off label” in cats.
3. Ask your vet about certain foods that, some experts say, may support brain health. They may require vet authorisation.
4. Keep pets on a routine, as “they may have trouble coping with changes”, Gruen said.
5. Improve their environment. Provide ramps to avoid steps. Put down a yoga mat or area rug on a slippery floor. “Some dogs may stop entering certain rooms to avoid a hardwood floor,” Gruen said. “It’s important to find ways to maintain their activities of daily living, just as we do with humans.”
6. Enrich their environment. “Teach your dogs a few new commands and reward them,” Landsberg said. “Give them brain enrichment toys. Put treats in toys that roll around, so they have to find them.”
7. Keep up their social interaction, “either with other pets or humans, and play with them,” Landsberg said.
8. Reduce stress. Special stress-reducing plug-in diffusers are available for both cats and dogs.
9. Encourage exercise. Exercise during the day can help animals sleep better at night.