Neosporosis is a disease that is caused by neospora caninum, a parasite similar in structure to toxoplasma gondii. Microscopic examination of the neospora caninum reveals that N.caninum sporozoite (the body of the parasite) closely resembles the T. gondii sporozoite, and the the two diseases share many of the same symptoms. However, the N. caninum infection has a more severe impact on a dog's neurological and muscular system than T. gondii does.
The infection by neosporoa causes neosporosis – a condition that causes death of living cells and tissues (necrosis) due to invasion of N.caninum. It is associated with tissue damage from the rupture of a cyst and subsequent invasion of tachyzoite microorganisms – the stage at which the sporozoite organism multiplies rapidly in the tissues throughout the body.
Adult dogs get infected by ingesting infectious cysts found in feces and raw meat whereas neosporosis is usually transferred to a puppy from the mother while the pup is still in the womb.
The parasite appears to have an affinity for the muscles and nerves of the body. Infected young puppies may experience multiple organ dysfunction and death.
Signs of Neospora infection in a young dog start as a gradual ascending paralysis affecting the limbs combined with muscle atrophy. Contracture of the muscles occurs in the affected limbs. The condition affects the dog's rear legs more severely than its fore legs. Neospora infection sometimes leads to joint deformation in the limbs of a puppy. Dysphagia (difficulty swallowing) and megaesophagus (lack of peristalsis) along with a cervical weakness occasionally occur leading to the death of the puppy.
Older dogs mostly suffer neurological disorders from this condition such as Seizures, tremors, behavrioral changes and blindness. Other signs include stiffness of cervical muscles and dysphagia (difficulty swallowing). Signs develop gradually and eventual paralysis of the respiratory organs leads to the death.
Many a times, the infection spreads throughout the body, affecting most of the organs including skin (dermatitis).