Canine cognitive dysfunction, Societal disassociative disorder and other cognitive dysfunction


also see thyroid disease also see Vestibular disease also see Brain tumor also see Canine Cognitive Disorder

also see Hyperadrenocorticism

Sleep/wake cycle disruption, constant barking at night and crying for food in older beagle

Question: Dear Dr. Richards: We own a 14 year old, 15 inch, 39 pound beagle. About eight months ago we realized that his hearing was almost totally gone, he does not respond to our voice any longer. But we have another dog and he seems to cue off her. He has always been a typical beagle---begging for food, howling in the car, a little high maintenance but not a problem until recently. His sleep/wake cycle is off. From approx 1:30 am though 5 am he constantly barks and wants to go outside (where his food bowl is). Sometimes he goes to his food bowl and other times he just sits there and looks back at the door. Then he wants a treat when he comes in. The cycle just keeps repeating throughout the night, with perhaps 20-30 minutes in between cycles. In the past, we have always fed our dogs around 5 am and 5 pm each day. Now, in order to quiet him, we have been giving him small amounts of food several times throughout the night--nothing else seems to calm him down. We have tried petting him, cuddling on the couch, we've purchased new beds, turned up the heat, nothing works. I should mention that on the weekend when we are home during the day, he seems to sleep hard in the morning and then starts crying/begging for his dinner starting around 2:00 pm (we feed him around 4:00 on the weekends now just because he's so persistent). From time to time it appears like he has severe trembling around his mouth and his teeth chatter together but it seems to last only seconds and happens infrequently. A few months ago he had another problem (limping on back leg) and our vet put him on a steroid (don't remember the name of it). This did seem to cause him to sleep through the night. We discontinued the steroid when his limping stopped. However, while he appears to have no problems walking, the vet says that he does seem to have tenderness in his spine (he usually walks with us at least a mile a day, as he has all his life, much longer walks and runs when he was younger). Naturally we've tried various medications. He has been on Thyroxine(0.3mg) for several years, and we have been giving him Rimadyl (40mg) on and off for the last few years, particularly in the winter. Our vet has done the usual tests re blood work for older dogs (last one was completed three months ago) and I've been told that it's always excellent, no liver damage or anything else to worry about. We put him on Science Diet prescription dog food for older dogs about a month ago. When the night disruptions became frequent, our vet put him on Alprazolan (2mg) half a tablet at bedtime. This seemed to have no effect and he became even worse over the following two weeks. Now we have him on .5mg of Dexamethazone, 500 mg of methocarbamol and 25 mg of Amitriptyline. It's only been a few days but it seems to be helping him--he is getting us up every 2-3 hours instead of the constant crying and barking all night. I have to laugh that this seems like "better" but this after two weeks of almost no sleep. Our vet doesn't really know what the problem is. We started this last round of meds as a last ditch attempt before putting him to sleep. Do you have any insights or recommendations? We don't want to be selfish, could he be in pain? It's difficult for us to think about putting him to sleep because in many ways he's the dog he's always been----he doesn't go to the bathroom in the house, he loves to eat, enjoys walks and trips to the woods. But not sleeping through the night is grating on my husband and me. He is an inside dog and we can't leave him outside howling all night. And we can't sleep when he's crying/barking inside. We are willing to do our part to make him more comfortable but don't really want to start looking for brain tumors (MRI) or anything that requires difficult treatment measures. We don't mind spending money on our pets, but we would probably draw the line at any treatment that would cost more that $1,000. We would appreciate an objective perspective. Thank you. Kara and James Answer: Kara- In you most recent email you said that your beagle was responding reasonably well to the use of dexamethasone, amitriptyline and methocarbamol. It is hard to tell which of these medications might be the most helpful. They work for somewhat different conditions and it is possible, especially with methocarbamol, that side effects of the medication may be helpful, since drowsiness is somewhat common as a side effect of methocarbamol. Methocarbamol is considered to be a muscle relaxant but it is unclear how it works and it is thought that some of its effect may simply be central nervous system depression. This is not a major problem but it is best to use methocarbamol carefully when it is used with another central nervous system depressant. Amitriptyline was originally approved as an anti-depressant for people. Currently there is some feeling that its major effect may be suppression of chronic pain. It is a central nervous system depressant and has to be used cautiously with other CNS depressants and with monoamine oxidase inhibitors ( something to consider if you need to change medication combinations as time goes on). Dexamethasone is a corticosteroid. The predominant effect of corticosteroids is reduction of inflammation but they also suppress production of cerebrospinal fluid, which can be a significant benefit in certain conditions that affect the brain (most importantly hydrocephalus or increased pressure in the brain). It can be helpful in reducing inflammation around tumors and this can also be a significant benefit if tumors are located in places that can be contributing to the problem, such as a brain tumor. It is also useful in controlling inflammation associated with disc injuries or arthritis. I thought it was important to cover what the medications are most commonly used for in case it helps to see how they might be helping. If the thyroxine level was normal on the last test that is a good sign that the medication isn't the problem. When the symptoms of your beagle's condition are considered, the first thing that came to mind (after the possibility of medically induced hyperthyroidism) was canine cognitive dysfunction. This is a syndrome that occurs fairly commonly in older dogs and is associated with things like forgetting house training, forgetting feeding schedules, wanting to go in and out aimlessly, disturbances in sleep patterns and a number of other problems. It is thought to be responsive to the use of selegiline (Anipryl Rx). This medication would not be a good combination with amitriptyline, though, as it has some monamine oxidase inhibiting ability. The manufacturer recommends at least a two week time period between the use of amitriptyline and the use of selegiline. There is a also a condition that is sometimes referred to as societal disassociative disorder (or something very close to that) that occurs in dogs who are losing their sensory input. It usually takes a combination of decrease in vision and hearing to produce this disorder. Wandering at night is a problem with this disorder and patients with it seem to be more clingy when they are awake, apparently in an effort to reassure themselves of their surroundings by close contact with someone (or another pet) they are familiar with. This disorder also sometimes responds to selegiline and can also respond to anti-anxiety medications like alprazolam. It seems a little less likely with the poor response to this medication. Hyperadrenocorticism occurs somewhat more frequently in dogs who have concurrent hypothyroidism and it sometimes produces symptoms nearly identical to canine cognitive dysfunction. Since hyperadrenocorticism (Cushing's disease) is the overproduction of corticosteroids it doesn't make a lot of sense that adding a corticosteroid would be beneficial if this problem was present, though. An increase in appetite is a common sign of hyperadrenocorticism and a side effect of dexamethasone and other corticosteroids, so there is a chance this is a contributing factor to the begging more frequently. Chronic pain can produce almost all the signs that you are seeing. Dogs with chronic back pain are often unable to sleep well and sometimes pace or wander constantly. It would be reasonable to try a good pain relief medication at some point in the effort to help your beagle. Carprofen (Rimadyl Rx), deracoxib (Deramaxx Rx) and similar medications work the best for us -- and are OK to use with amitriptyline to get a better response in the case of chronic pain. The symptoms most closely resemble canine cognitive dysfunction but attempting to treat this means withdrawing medications that you are having some success with. It may be worth doing this if the improvement doesn't quite work well enough or particularly if it stops working well. You would have to stop at least the amitriptyline and it would probably be better to stop both the amitriptyline and the methocarbamol. If the night time restlessness is the main problem that is disrupting your family life you might want to consider trying melatonin. I am pretty hesitant to use melatonin with central nervous system depressants, though. There is not much information on the use of melatonin for sleep disorders in dogs but there is a published dosage for thunderstorm anxiety of 1 to 3mg/dog. We have tried 2 to 3mg at night for a couple of dogs who seemed to have sleep disorders and both owners thought it was somewhat helpful. Melatonin is an over the counter supplement available at pharmacies and vitamin/supplement type stores. This is a web site from Pfizer that has more detailed information about canine cognitive dysfunction which you could share with your vet if you feel it is worthwhile to discuss this option with him or her: Mike Richards, DVM 1/7/2005

Behavior changes in older dogs- protecting food - canine cognitive dysfunction

Question: I know you have a lot of questions to answer so I'll try to make mine short (hope the answer's short too): Could my 10-year-old pomeranian be suffering from dementia? Over the past several months she has become protective of her food, daring my other pomeranian to eat while she's eating. Her aggression has worsened to her growling viciously at him if he is on the other side of the room, and more than once I have caught her growling at nothing and no one in particular. When I call her name, she snaps out of it. She also seems to be eating more, as though fearful someone else will get her food. Got any ideas what's wrong? Thank you. LS Answer: LS- There are actually a lot of reasons for behavioral changes in older dogs and I'll list some of them below. The answer to your question, though, is that dogs do have a recognized clinical syndrome referred to as canine cognitive dysfunction, in which they show signs that could be interpreted as a dementia. Affected dogs may have almost any behavioral change. Most commonly the symptoms are more along the line of forgetting housebreaking routines, forgetting habits like showing up in the kitchen at dinnertime or going outside and then seeming not to know why they did that --- and repeating the process over and over. Increases or decreases in aggression are sometimes seen, though. This problem is treated using selegiline (Anipryl Rx). It seems to help about half the dogs we think might have cognitive dysfunction. I am not sure if we are just not diagnosing this condition well or if the medication is only effective half the time, though. The most common causes of behavioral changes in which there is increased aggression around food and an increased appetite are probably the hormonal diseases, especially hyperadrenocorticism (Cushing's disease). Other possibilities include hypothyroidism and diabetes mellitus. It is usually a good idea to consider having your vet do a good physical examination and to run a general screening blood test, as well as specific tests for Cushing's disease and/or hypothyroidism if the exam or screening blood tests are normal or have abnormalities that indicate these diseases are likely. Brain tumors can cause behavioral changes and may represent as much as 1 to 2% of the natural causes of death in dogs. In your dog's age range this would have to be a consideration. Medications can cause these effects, especially prednisone or other corticosteroids. So if you are using any medications it is best to check with your vet about the possibility of a medication reaction. These would not be likely with the monthly heartworm medications, though. Mike Richards, DVM 7/2/2001

Cognitive dysfunction in dogs and quality of life

Question: I hate to take your time with this problem but I like your input. I'n 76 and have had quite a few dogs in my life - the only tough thing is when they must be put to sleep. My male German Shepherd had cancer for over a year which I did all I could do At the age of 12 he was so sick I knew what I had to do (I have tears just writing this) My female Shepherd (KC) Is now 12 and 1/2 and is almost there. She's taking Rimadyl 100mg twice a day and Sulfatrimethoprim 960 mg once a day. She's 95+ lbs. She has problems walking and sleeps 23 hours a day. She was devastated when I took her crate away because she would go in and try to turn around and would get all jammed up. She wwill not take her pills as before with cheddar cheese coating - I have to force them down. She eats part of her dog bone and leaves the rest. She comes outside with me but stands there until I tell her what to do. Since she does not mess in the house,I can go on but is that the fair thing to do. My vet's office says I will know when it is time. I got a 8lb. puppy (German Shepherd) when he was 6weeks old - He's now 1 and 1/2 and weighs 95 lbs and he is the light of my life. He is the smartest and most loving dog I have ever had. He is the reason KC is still here - He gave her new life after her friend was put to sleep. but he leaves her pretty much alone now. Any advice or comments? Ray Answer: Ray- I am curious about what the sulfa-trimethoprim tablet is for, just in case there is something that might make your shepherd's life more comfortable as an alternative (just thinking here, not suggesting a problem). It sounds like you may be dealing with some signs of a disorder referred to as "cognitive dysfunction" in dogs. This disorder causes confusion about everyday tasks and everyday experiences. There is a medication that helps some dogs with this problem, selegiline (Anipryl Rx). Our experience has been pretty variable with this medication but it doesn't appear to be harmful. It is expensive (about 50 to 70 dollars per month) but some dogs really seem to improve a lot in their overall attitude when it is used. I really do think that most dogs reach a point where they are in a enough pain, discomfort or distress that it becomes obvious that they are not enjoying life. At that point, I think it is good that we can offer euthanasia as an alternative to living on in misery. Our practice experience matches your vet's advice --- at some point the question "when should I consider euthanasia" no longer seems relevant, because you just know that it is time with a certainty that makes you sure there is no longer a question. When dogs that are on Rimadyl (Rx) lose interest in eating it is a really good idea to have your vet examine them. She may be having gastrointestinal upset or she may be having liver problems that can sometimes occur with Rimadyl. Or she may have a decreased appetite for other reasons -- but it is important to be sure the medication isn't causing this change and it may be helpful to find out if there is an identifiable cause for the problem, too. Please talk to your vet about this change and see if he or she agrees that it would be a good idea to do some lab work to be sure that liver disease is not a problem and to check her for other problems at the same time. I'm willing to bet she knows how much you care for her and that is very important when she doesn't feel well. Almost everyone does better when they have someone caring for them and rooting for them. Don't underestimate the value of just being there for her. Mike Richards, DVM 5/4/2000


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...