Recently, a dog was admitted to a veterinary hospital in northern Michigan with symptoms that looked just like those of canine parvovirus type 2 (also known as CPV, CPV2, or just “parvo”) – vomiting, profuse and bloody diarrhea, and lack of appetite – but the dog tested negative for CPV. Soon, other veterinarians in the area began reporting an uptick in the number of cases of suspected CPV – but some dogs tested positive for parvo and some did not, and most of the young dogs with the parvo-like symptoms died.
These cases were reported to the Michigan Department of Agriculture and Rural Development (MDARD), which also received reports from animal control agencies in northern Michigan regarding dogs with the same symptoms. Today, MDARD is working in partnership with local animal control agencies, the Michigan Association of Animal Control Officers, local veterinarians, the Michigan State University Veterinary Diagnostic Laboratory (MSU VDL), and U.S. Department of Agriculture to share information about these cases, which have affected dogs who are fully vaccinated against CPV and dogs with incomplete immunization alike.
Officials at one shelter, the Otsego County Animal Shelter, have been quoted as saying they have seen deaths in only those dogs who were not “properly vaccinated.” They have urged all dog owners in the state to contact their veterinarians to make sure their dogs are current on their vaccinations.
As officials learn more, MDARD is encouraging animal shelters, boarding and daycare kennels, and veterinary staff to follow their strictest intake and vaccination protocols when bringing in new dogs/puppies and continue to follow required isolation protocols and recommended cleaning/disinfection procedures for surfaces and equipment.
For dog owners, especially those living in or traveling with pets to Michigan, MDARD strongly recommends keeping up with routine vaccinations by ensuring dogs/puppies are vaccinated against parvovirus, rabies, canine distemper, adenovirus, parainfluenza, and leptospirosis. And if dogs or puppies are exhibiting signs of illness, keep them at home and away from other dogs and contact your veterinarian.
Fear of viral mutation
CPV first emerged among dogs in Europe around 1976. By 1978 the virus had spread unchecked, causing a worldwide epidemic of myocarditis (inflammation of the heart) and gastroenteritis (inflammation in the intestines).
CPV is closely related to feline panleukopenia virus (FPV), a virus that has been known since the 1920s to infect cats, mink, and other animals. CPV probably arose as the result of two or three genetic mutations in FPV that allowed it to expand its host range to infect dogs. FPV in cats is highly contagious and has a high mortality rate.
The Baker Institute for Animal Health at Cornell University’s College of Veterinary Medicine first isolated the virus in 1978, and by 1979 had developed the first vaccine for parvo. By 1981, Baker Institute scientists had created an improved attenuated vaccine for the disease. Today, Dr. Colin Parrish of the Baker Institute continues to study the virus and its evolution in order to determine whether existing vaccines provide adequate protection from modern strains of CPV.
The original CPV2 has disappeared in the dog population and has been replaced by new antigenic variants, designated CPV2a and CPV2b, which became widespread during 1979 to 1980 and 1984, respectively.
Until DNA sequencing can identify the virus that has affected and killed dogs in Michigan, and researchers learn what vaccination protocol can best protect dogs, owners are encouraged to check their dogs’ vaccination status.
Until more is known about this illness, extraordinary caution might include avoiding walking dogs (and especially puppies) in public places in Michigan, and keeping your dogs away from other dogs. Most importantly, if you live in or have traveled through Michigan, or your dog has been exposed to dogs who live in or have been taken through Michigan recently, and your dog or puppy shows any signs of being ill with vomiting, diarrhea, lack of appetite, or lethargy, contact your veterinarian right away.