Multiple parasitic lesions in a lamb carcass
In a 4 months old female lamb carcass multiple nodular lesions were observed, whitish, some of them calcified, in the lung, liver, heart and different skeletal muscles.
Some of the cysts observed at the level of serous membranes, such as those of the liver, showed viable cisticerci. Due to thier location, these could be classified as visceral cysticercosis or Cysticercus tenuicollis (larval stage of Taenia hydatigena, which is very common in small ruminants and its final host is the dog).
Muscular nodules, both in skeletal muscle and myocardium, corresponded microscopically to granulomatous type lesions type with a strong component of eosinophilic leukocytes characteristic of parasitic processes. In this case it is therefore compatible with muscular cysticercosis or Cysticercus ovis. It is the larval stage of Taenia ovis, another parasite that has the dog as definitive host. It is not a zoonosis, but it can lead to economic losses since the carcass becomes unfit for consumption.
Furthermore, microscopically Sarcocystis cysts were observed in the muscle fibers of the heart. Usually these parasites are associated with eosinophilic myositis lesions, although in this case it colud not be appreciated macro nor microscopically.
It is reccomended to revise the program of anti-parasite treatment (particularly of dogs) in the farms with carcasses that have this problem.