Changes

==Overview==

==Overview==

Cognitive dysfunction syndrome (CDS) is a condition that leads to an overall progressive decline in cognitive function and increase in brain pathology, with similar pathological changes seen in dogs and humans with Alzheimer's disease (AD); canine CDS is being researched as  naturally occurring mode of AD<ref name="Landsberg1">Landsberg GM, Hunthausen W, Ackerman L. The effects of aging on the behavior of senior pets. In: Handbook of behavior problems of the dog and cat. 2nd edn. Oxford; Saunders,2003: 269–304.</ref><ref>Milgram NW, Head E, Weiner E, Thomas E. Cognitive functions and aging in the dog: acquisition of non spatial visual tasks. Behav Neurosci1994; 108:57–68.</ref><ref>Cummings BJ, Head E, Afagh AJ, Milgram NW, Cotman CW. Beta-amyloid accumulation correlates with cognitive dysfunction in the aged canine. Neurobiol Learn Mem1996; 66:11–23</ref><ref>Tapp PD, Siwak CT, Gao FQ, et al. Frontal lobe volume, function, and beta-amyloid pathology in a canine model of ageing. J Neurosci2004; 24: 8205–13.</ref><ref>Borras D, Ferrer I, Pumarola M. Age related changes in the brain of the dog. Vet Pathol 1999; 36:202–11.</ref><ref>Colle M-A, Hauw J-J, Crespau F, et al. Vascular and parenchymal beta-amyloid deposition in the aging dog: correlation with behavior. Neurobiol Aging 2000; 21:695–704.</ref><ref>Salvin HE, McGreevy PD, Sachev PS, Valenzuela MJ. Underdiagnosis of canine cognitive dysfunction; a cross-sectional survey of older companion dogs. Vet J 2010; 184:277–81.</ref>. Similar pathological changes have also been observed in the cat<ref>Cummings BJ, Satou T, Head E, et al. Diffuse plaques contain C-terminal A beta 42 and not A beta 40: evidence from cats and dogs. Neurobiol Aging1996; 17:653–59</ref>. In comparative studies of the effect of selegiline, a drug licensed for the treatment of canine CDS, similar responses were seen in canine and human patients<ref>Ruehl WW, Bruyette WW, DePaoli DS, et al. Canine cognitive dysfunction as a model for human age-related cognitive decline, dementia, and Alzheimer’s disease: clinical presentation, cognitive testing, pathology and response to l-deprenyl therapy. Prog Brain Res 1995; 106:217–25.</ref><ref>Campbell S, Trettien A, Kozan B. A noncomparative open-label study evaluating the effect of selegiline hydrochloride in a clinical setting. Vet There 2001; 2:24–39.</ref>.

Cognitive dysfunction syndrome (CDS) is a condition that leads to an overall progressive decline in cognitive function and increase in brain pathology. Similar pathological changes are seen in dogs and humans with Alzheimer's disease (AD); canine CDS is being researched as a naturally occurring mode of AD<ref name="Landsberg1">Landsberg GM, Hunthausen W, Ackerman L. The effects of aging on the behavior of senior pets. In: Handbook of behavior problems of the dog and cat. 2nd edn. Oxford; Saunders,2003: 269–304.</ref><ref>Milgram NW, Head E, Weiner E, Thomas E. Cognitive functions and aging in the dog: acquisition of non spatial visual tasks. Behav Neurosci1994; 108:57–68.</ref><ref>Cummings BJ, Head E, Afagh AJ, Milgram NW, Cotman CW. Beta-amyloid accumulation correlates with cognitive dysfunction in the aged canine. Neurobiol Learn Mem1996; 66:11–23</ref><ref>Tapp PD, Siwak CT, Gao FQ, et al. Frontal lobe volume, function, and beta-amyloid pathology in a canine model of ageing. J Neurosci2004; 24: 8205–13.</ref><ref>Borras D, Ferrer I, Pumarola M. Age related changes in the brain of the dog. Vet Pathol 1999; 36:202–11.</ref><ref>Colle M-A, Hauw J-J, Crespau F, et al. Vascular and parenchymal beta-amyloid deposition in the aging dog: correlation with behavior. Neurobiol Aging 2000; 21:695–704.</ref><ref>Salvin HE, McGreevy PD, Sachev PS, Valenzuela MJ. Underdiagnosis of canine cognitive dysfunction; a cross-sectional survey of older companion dogs. Vet J 2010; 184:277–81.</ref>. Similar pathological changes have also been observed in the cat<ref>Cummings BJ, Satou T, Head E, et al. Diffuse plaques contain C-terminal A beta 42 and not A beta 40: evidence from cats and dogs. Neurobiol Aging1996; 17:653–59</ref>. In comparative studies of the effect of selegiline, a drug licensed for the treatment of canine CDS, similar responses were seen in canine and human patients<ref>Ruehl WW, Bruyette WW, DePaoli DS, et al. Canine cognitive dysfunction as a model for human age-related cognitive decline, dementia, and Alzheimer’s disease: clinical presentation, cognitive testing, pathology and response to l-deprenyl therapy. Prog Brain Res 1995; 106:217–25.</ref><ref>Campbell S, Trettien A, Kozan B. A noncomparative open-label study evaluating the effect of selegiline hydrochloride in a clinical setting. Vet There 2001; 2:24–39.</ref>.

Effects of feline cognitive disfunction (FCD)  include impairment of memory, learning, information processing and perception, as well as increased behavioural disinhibition; this leads to observed signs of confusion/disorientation, deranged sleep patterns, inappropriate elimination, and reduced social interaction. Previously learned behaviours, such as elimination habits, may be forgotten and affected cats show increased [[Feline Fear and Stress|fear and anxiety]]. Disinhibition can lead to an increase in irritability and [[Feline Aggression|aggressiveness]]. [[Feline Social Behaviour|Social relationships]] with both other animals and humans can also be affected. In general, cognitive dysfuncion is less frequently reported in cats than dogs.  

Effects of feline cognitive dysfunction (FCD)  include impairment of memory, learning, information processing and perception, as well as increased behavioural disinhibition; this leads to observed signs of confusion/disorientation, deranged sleep patterns, inappropriate elimination, and reduced social interaction. Previously learned behaviours, such as elimination habits, may be forgotten and affected cats show increased [[Feline Fear and Stress|fear and anxiety]]. Disinhibition can lead to an increase in irritability and [[Feline Aggression|aggressiveness]]. [[Feline Social Behaviour|Social relationships]] with both other animals and humans can also be affected. In general, cognitive dysfuncion is less frequently reported in cats than dogs.  

It is thought that FCD affects 28% of cats between the ages of eleven and fourteen, and 50% of cats over fifteen years old <ref name="Landsberg2">Landsberg, G.M., Denenberg, S., Araujo, J.A., 2010. Cognitive Dysfunction in Cats: A Syndrome we Used to Dismiss as 'Old Age'. Journal of Feline Medicine and Surgery 12: 837</ref>. Although clinical signs in cats generally seem to become evident at around ten to eleven years old, neurones in the caudate nucleus start to show functional changes by six-seven years of age<ref>Levine MS, Lloyd RL, Fisher RS, Hull CD, Buchwald NA. Sensory, motor and cognitive alterations in aged cats. Neurobiol Aging 1987; 8: 253–63</ref><ref>Levine MS, Lloyd RL, Hull CD, Fisher RS, Buchwald NA. Neurophysiological alterations in caudate neurons in aged cats. Brain Res 1987; 401:213–30</ref><ref>Harrison J, Buchwald J. Eyeblink conditioning deficits in the old cat. Neurobiol Aging 1983; 4:45–51</ref>. Diagnosis of CDS in cats is a greater challenge than in dogs, as the signs are often less apparent due to the cat's independent outdoor lifestyle.

It is thought that FCD affects 28% of cats between the ages of eleven and fourteen, and 50% of cats over fifteen years old <ref name="Landsberg2">Landsberg, G.M., Denenberg, S., Araujo, J.A., 2010. Cognitive Dysfunction in Cats: A Syndrome we Used to Dismiss as 'Old Age'. Journal of Feline Medicine and Surgery 12: 837</ref>. Although clinical signs in cats generally seem to become evident at around ten to eleven years old, neurones in the caudate nucleus start to show functional changes by six-seven years of age<ref>Levine MS, Lloyd RL, Fisher RS, Hull CD, Buchwald NA. Sensory, motor and cognitive alterations in aged cats. Neurobiol Aging 1987; 8: 253–63</ref><ref>Levine MS, Lloyd RL, Hull CD, Fisher RS, Buchwald NA. Neurophysiological alterations in caudate neurons in aged cats. Brain Res 1987; 401:213–30</ref><ref>Harrison J, Buchwald J. Eyeblink conditioning deficits in the old cat. Neurobiol Aging 1983; 4:45–51</ref>. Diagnosis of CDS in cats is a greater challenge than in dogs, as the signs are often less apparent due to the cat's independent outdoor lifestyle.