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Neosporosis in Dogs

Bert E. Stromberg, PhD, Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota;J. P. Dubey, MVSc, PhD, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, USDA;Paul Ettestad, DVM, MS, Epidemiology and Response Division, New Mexico Department of Health;Jodie Low Choy, BVSc, BVMS, IVAS Cert, Menzies School of Health Research; University Avenue Veterinary Hospital, Northern Territory, Australia;Joseph Taboada, DVM, DACVIM, Office of Student and Academic Affairs, School of Veterinary Medicine, Louisiana State University;Charles O. Thoen, DVM, PhD, Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University;John F. Timoney, MVB, PhD, Department of Veterinary Science, College of Agriculture, Food and Environment, University of Kentucky;Ian Rodney Tizard, BVMS, BSc, PhD, DSc (Hons), DACVM, Department of Veterinary Pathobiology, College of Veterinary and Biomedical Sciences, Texas A&M University;Geoffrey W. Smith, DVM, PhD, DACVIM-LAIM, Zoetis;Martin E. Hugh-Jones, VetMB, MPH, PhD, MRCVS, School of Veterinary Medicine, Louisiana State University;Henry R. Stämpfli, DMV, Dr Med Vet, DACVIM-LAIM, Department of Clinical Studies, Ontario Veterinary College, University of Guelph;Kate E. Creevy, DVM, MS, DACVIM-SAIM, College of Veterinary Medicine & Biomedical Sciences, Texas A & M University;Gad Baneth, DVM, PhD, DECVCP, Koret School of Veterinary Medicine, Hebrew University, Rehovot;Katharine F. Lunn, BVMS, PhD, DACVIM-SAIM, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University;Reinhard K. Straubinger, DrMedVetHabil, PhD, Institute for Infectious Diseases and Zoonoses, Department of Veterinary Sciences, Faculty of Veterinary Medicine, LMU;Jodie Low Choy, BVSc, BVMS, IVAS Cert, Menzies School of Health Research; University Avenue Veterinary Hospital, Northern Territory, Australia;Manuals Staff;Márcio Garcia Ribeiro, DVM, PhD, Department of Animal Production and Preventive Veterinary Medicine, Faculty of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil;Thomas Wittek, Dr Med Vet, DECBHM, University Clinic for Ruminants, Department of Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna;Yasuko Rikihisa, PhD, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University;Janet E. Foley, DVM, PhD, Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis
Reviewed/Revised Jun 2018 | Modified Mar 2025

Neosporosis is caused by the protozoan parasite Neospora caninum. Neosporosis has been recognized in dogs, cattle, horses, and other animals, but the dog is the definitive host. (A definitive host is an animal that a parasite requires in order to mature normally.) Infection is uncommon but can be acquired by ingesting contaminated food and water, or ingesting infected tissues. It may also be transferred from a mother to a fetus still in the womb (transplacentally). The disease is best known for causing loss of pregnancy in cows, especially on farms with dogs.

Neosporosis, dog

Dogs typically do not show signs of infections. However, signs may be seen in some puppies and adult dogs. Most severe infections occur in young puppies, which typically develop partial paralysis of the legs, particularly the hind legs. The paralysis is often progressive and results in rigid contracture of the muscles. The outlook for these puppies is poor. In adult dogs, neurologic signs (such as inflammation of the brain and spinal cord), skin inflammation with sores, inflammation of the liver, pneumonia, and inflammation of the heart may occur. The outlook worsens in dogs with severe signs or those that are not treated promptly.

Your veterinarian will recommend proper antibiotic treatment. There is currently no vaccine.

Also see professional content regarding neosporosis.

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