Dog hereditary diseases

"Multisystem degeneration (Canine Multiple System Degeneration, CMSD) is a progressive hereditary neurological disease related to motor disorders. The pathology is characterized by degeneration and death of neurons in the structures of the extrapyramidal system, which is involved in controlling movements and maintaining muscle tone. This disease was first described in 1946 in Kerry Blue Terrier dogs as "chorea due to degeneration of the striatum of unknown etiology." Later, in the 1970s, the hereditary nature of the disease was revealed. CMSD in Chinese crested dogs is associated with deletion (loss) of 4 pairs of nucleotides in the SERAC1 gene. This gene encodes a protein of the same name, which plays an important role in intracellular cholesterol transport and mitochondrial function. In humans, a different mutation in the same gene, SERAC1, causes a rare hereditary disease - 3-methylglutacone aciduria, type VI, characterized by increased muscle tone, delayed psychomotor development, deafness and a number of metabolic disorders. The nature of the inheritance of the disease is autosomal recessive. The disease develops only if both copies of the gene contain a mutation. Symptoms: The disease debuts at the age of 3-6 months. The first noted clinical sign is a head tremor, especially noticeable when the dog is eating. Soon after, dysmetry is observed, the animal seems to incorrectly assess the distance to objects, and a "goose gait", most pronounced in the forelimbs. Nevertheless, the animal can still maintain a stable position. At this stage, changes in the cerebellum are already noticeable – cerebellar atrophy is observed on MRI, and histological examination shows the loss of Purkinje cells. From 6-8 months of age, falls become noticeable. There is a condition characterized as festination ("fussiness" in movements) in combination with dysmetry. By 12-18 months, postural instability develops – the animal is no longer able to maintain a static pose. MRI shows significant changes in the structures of the extrapyramidal system. Despite the severity of the disease, sick dogs retain normal thinking and social behavior. Most animals die due to complications of the disease, or are euthanized by the age of 18 months."