Table 1.

Summary and comparison of Alzheimer’s and Alzheimer’s-like diseases symptoms.

Disease	Species	Symptoms		Literature
		Neuropathological	Behavioral
Alzheimer’s disease	Human	Oxidative stress Neuroinflammation Disruption of neuronal cytoskeleton Impaired neuronal transport Synaptic dysfunction Senile plaques and Aβ aggregates NFTs, hyperphosphorylated tau accumulations Brain atrophy Neuronal loss	Loss of cognition and recognition Disorientation Apathy Poor judgment Intensified aggression or passiveness Changes in interest in food Poor judgment Difficulties in speaking, swallowing and walking Worsening memory	[18,19,21,22,23,24,25,56]
Alzheimer’s-like disease	Domestic cat	Aβ oligomers aggregates in cats aged 8 and more Senile plaques in cats aged 10 and more NFTs only in the presence of Aβ Neuronal loss Neuronal degradation	Spatial disorientation or confusion Altered social relationships Intensified aggression or passiveness Changes in daily schedule and wake-sleep pattern Changes in interest in food Decreased grooming Inappropriate vocalization	[66,67,68,69,70,71]
	Camel	Diffuse-type senile plaques in the cerebral cortex	No data	[91]
	Elephant	Aβ cerebral deposition		[90]
	Cattle	Aβ cerebral deposition		[89]
	Horse	Tau accumulations Axonal transport deficiencies Diffuse Aβ plaques		[87]
	Sea lion	CSF markers which are found in AD		[92]
	Dolphin	Amyloid and tau pathology in the brain		[92]
	Gorilla	Diffuse-type senile plaques Vascular amyloid		[95,97]
	Baboon	Diffuse-type senile plaques Vascular amyloid Hyperphosphorylated tau in the oldest individuals		[93,98]
	Squirrel monkey	Senile plaques Diffuse-type senile plaques Vascular amyloid		[94]
	Chimpanzee	Diffuse-type senile plaques Vascular amyloid		[96]
	Macaque	Senile plaques Vascular amyloid		[95]
	Sheep	NFTs Aβ cerebral deposition		[88]
	Cheetah	Amyloid plaques NFTs		[20]
	Bears	Amyloid plaques NFTs		[20]
	Goats	NFTs		[20]
Canine Cognitive Dysfunction (CCD)	Dog	Cortical atrophy Dysfunction in the neurotransmitter systems Increased oxidative damage Extracellular deposition of diffuse Aβ Neuronal loss Decreased neurogenesis Tau abnormalities, but not NFTs Ventricular enlargement Oligomers of Aβ in the CSF	Loss of cognition and recognition Loss of house training Disorientation Changes in their sleep-wake cycle	[74,75,76,77,78,79,80,81,82,84,85,86]