Central nervous system lesions caused by canine distemper virus in 4 vaccinated dogs

Abstract

We examined the cerebellum and cerebrum of 4 vaccinated dogs, 3–60-mo-old, that displayed clinical signs of canine distemper virus (CDV) infection, and died 7–40 d after developing neurologic signs. The main histologic lesions were demyelination, gliosis, meningitis, perivascular lymphocytic cuffing, and inclusion bodies. These lesions were similar in all 4 cases regardless of the time since vaccination, except that meningoencephalitis and gliosis were subacute in 3 dogs and chronic in 1 dog. However, these differences did not appear to be related to their vaccination status. Immunohistologically, a CDV-positive immunoreaction was seen mainly in astrocytes, neurons and their axons, lymphocytes around and in the blood vessels of the pia mater and choroid plexus, ependymal cells of each ventricle, and the cells of the choroid plexus. The histologic and immunohistologic changes were similar in the cerebellum and cerebrum. The genetic characterization of the virus strains in 2 of these naturally occurring canine distemper cases confirmed that they were South American wild-type strains (Kiki and Uy251) belonging to the EU1/SA1 lineage. These strains are not included in the commercial CDV vaccines available in Uruguay.

High Prevalence of Antibodies against Canine Parvovirus and Canine Distemper Virus among Coyotes and Foxes from Pennsylvania: Implications for the Intersection of Companion Animals and Wildlife

“…Dogs and wild canids are particularly susceptible to infection with these pathogens due in part to their behavior, sociality, and scent communication ( 8 ). While vaccination for CDV and CPV is safe and highly effective, fatal CDV infections have been reported in vaccinated dogs infected with CDV lineages not represented in current vaccines ( 9 ). The emergence of new CDV lineages coupled with vaccine noncompliance has resulted in well-documented outbreaks and spillover events between dogs and wildlife ( 10 – 14 ).…”

Canine distemper virus infection of vaccinal origin in a 14-week-old puppy

“…1,16 Vaccine-associated canine distemper cases have been reported in various breeds following vaccination with attenuated-live CDV vaccines. [1][2][3]7,8,15,16,20 Clinical signs typically developed within 3 wk of vaccination and could include seizures and circling or changes in behavior. Most cases describing CDV in vaccinated animals were determined to be due to emergence of a new wild-type strain or were suspected to be the result of an inadequate immune response to a vaccine or vaccine failure.…”

“…Emergence of new wild-type strains resulting in inadequate vaccine protection, complications by lingering maternal immunity, improper vaccine handling or vaccination protocols, vaccination failure in an immunocompromised host, and reversion to virulence of a MLV vaccine have been reported. 1 – 3 , 5 – 9 , 12 , 15 – 17 , 19 , 20 Although rev-ersion to virulence is considered a potential cause of disease in vaccinated animals and has been reported for other viral diseases 4 , 13 or in other species, 5 , 14 there are few definitive reported cases in the literature of CDV MLV vaccine reversion in canids. 1 We report here a case of a 14-wk-old puppy with rhinitis, gliosis, and bronchopneumonia consistent with vaccination-associated canine distemper.…”

“…Most cases describing CDV in vaccinated animals were determined to be due to emergence of a new wild-type strain or were suspected to be the result of an inadequate immune response to a vaccine or vaccine failure. 8 , 15 , 20 Reports of reversion to virulence of the CDV vaccine are rare, 7 and most were demonstrated under experimental conditions (serial passage in dogs). 1 , 12 Reversion to virulence is most commonly reported in immunosuppressed animals (immunocompromised or animals with concurrent infections, e.g., parvovirus), or is demonstrated in isolated cases as post-vaccinal encephalitis.…”

Meningoencephalitis caused by concurrent infection with canine distemper virus and a unique Sarcocystis sp. in a gray fox

“…Modified-live CDV vaccines are virulent in a variety of nontarget species in the suborder Caniformia , and their use is not recommended in nontarget species. 3,5,12,23,31,32 Gray foxes are a highly CDV-susceptible species, and vaccine-induced CDV has been reported. 17,33 Recombinant CDV vaccines are preferable for use in nondomestic carnivores.…”