Viral reproductive pathogens of dogs and cats.

This article reviews the current literature on the viral agents that cause reproductive failures in domestic carnivores (dogs and cats). A meaningful update is provided on the etiologic, clinical, pathologic, diagnostic, and prophylactic aspects of the viral infections impacting canine and feline reproduction as a consequence of either direct virus replication or severe debilitation of pregnant animals.

Detection and molecular characterization of a canine norovirus.

We identified a novel calicivirus in a pup with enteritis. The isolate was related genetically (90.1% aa identity in the capsid protein) to a lion norovirus strain.

2006 AAHA canine vaccine guidelines.

In 2005, AAHA's Canine Vaccine Task Force met to reexamine and revise guidelines on the use of vaccines in dogs. The results of the Task Force's work are summarized and tabulated in this article and are published in their entirety on the AAHA website (www.aahanet.org). The 2006 AAHA Canine Vaccine Guidelines contain information on new technological developments in vaccines, an introduction to conditionally licensed vaccines, and detailed recommendations on the use of available vaccines. Perhaps the most noteworthy addition to the guidelines is a separate set of recommendations created for shelter facilities. Vaccines are classified as core (universally recommended), noncore (optional), or not recommended. The Task Force recognizes that vaccination decisions must always be made on an individual basis, based on risk and lifestyle factors.

Report of the American Animal Hospital Association (AAHA) Canine Vaccine Task Force: executive summary and 2003 canine vaccine guidelines and recommendations.

The AAHA has undertaken the development of this document in an effort to inform veterinary practitioners, clarify misunderstandings held by veterinarians, and encourage practitioners to recognize that immunization of patients is a medical procedure. As such, it is bound by the same tenets that govern the recommendation of other medical procedures-principally, that it be tailored to the needs of the individual patient. Many diseases we immunize against are ubiquitous. Many are serious and some even life threatening. Some are of limited demographic concern given the exposure risk for each patient. These factors have all been considered in developing the AAHA Canine Vaccination Guidelines. In the end, each veterinarian must do what he or she determines to be in the best interest of the patient. Vaccination of individual animals produces not only individual immunity but also population or herd immunity. Since we have no readily available and reliable way to determine if each patient has developed an adequate immune response, we encourage the practice philosophy of vaccinating more patients while vaccinating each patient no more than needed.

Virologic and serologic identification of minute virus of canines (canine parvovirus type 1) from dogs in Japan.

Minute virus of canines (MVC), also known as canine parvovirus type 1, was initially believed to be a nonpathogenic agent, since it was first isolated from canine fecal specimens in the late 1960s. However, subsequent pathological as well as epidemiological studies suggested that MVC is a pathogen of neonatal puppies and is widely distributed among domestic dogs in the United States. The virus also has been shown to cause fetal deaths. Nevertheless, the virus was not detected in dogs outside the United States until recently, presumably because of a lack of widespread availability of the only susceptible canine cell line, WRCC/3873D, used for MVC isolation. We examined 470 clinical specimens from 346 dogs by PCR and detected MVC-specific gene fragments from four diseased puppies (positive rate, 1.2%). Viruses were recovered from three PCR-positive rectal specimens by using WRCC/3873D and MDCK cells. The isolates possessed antigenic and genomic properties similar to those of the U.S. reference strain GA3 and were identified as MVC. In addition, seroepidemiological evidence that 5.0% of dogs possessed anti-MVC antibodies also indicated the presence of MVC infection among dogs in Japan. From this study and several recent European reports describing MVC field cases, it is evident that MVC is distributed among domestic dogs worldwide.

The canine minute virus (minute virus of canines) is a distinct parvovirus that is most similar to bovine parvovirus.

We characterized the genome and proteins of the canine minute virus (the minute virus of canines (MVC)). The genome sequence showed MVC to be an autonomous parvovirus encoding a large nonstructural protein 1 gene, a smaller nonstructural protein, and overlapping VP1 and VP2 protein genes. The virus was most closely related to bovine parvovirus (BPV), with which it was 43% identical at the DNA sequence level, while the NS1 and VP1 proteins were 33.6 and 41.4% identical to those of BPV, respectively. Spliced messages of the NS1 gene transcripts were detected by RT-PCR. VP1 and VP2 proteins were detected in purified capsids, as were modified versions of each protein, and VP3 was also found in full capsids.

Evolutionary dynamics of viral attenuation.

The genetic trajectory leading to viral attenuation was studied in a canine parvovirus (CPV) strain grown on dog kidney cells for 115 transfers. Consensus sequences of viral populations at passages 0, 3, 30, 50, 80, and 115 were obtained from PCR products covering 86% of the genome; clones from each of the 80th and 115th passages were also sequenced, covering 69% of the genome. Sixteen changes were fixed in the 115th-passage virus sample. Levels of polymorphism were strikingly different over time, in part because of a plaque-cloning step at passage 112 that reduced variation: passage 80 had 19 variants common among the clones, but passage 115 had only a single common variant. Several mutations increased in the culture at the same time, with most reaching fixation only after the 80th passage. The pattern of evolution was consistent with recombination and not with separate selective sweeps of individual mutations. Thirteen of the changes observed were identical to or at the same positions as changes observed in other isolates of CPV or feline panleukopenia virus.