Diseases (Viral)

  • Analysis of the Genome Sequence of an Alpaca Coronavirus

    Coronaviral infection of New World camelids was first identified in 1998 in llamas and alpacas with severe diarrhea. In order to understand this infection, one of the coronavirus isolates was sequenced and analyzed. It has a genome of 31,076 nt including the poly A tail at the 3′ end. This virus designated as ACoV-00-1381 (ACoV) encodes all 10 open reading frames (ORFs) characteristic of Group 2 bovine coronavirus (BCoV). Phylogenetic analysis showed that the ACoV genome is clustered closely (> 99.5% identity) with two BCoV strains, ENT and LUN, and was also closely related to other BCoV strains (Mebus, Quebec, DB2), a human corona virus (strain 043) (> 96%), and porcine hemagglutinating encephalomyelitis virus (> 93% identity). A total of 145 point mutations and one nucleotide deletion were found relative to the BCoV ENT. Most of the ORFs were highly conserved; however, the predicted spike protein (S) has 9 and 12 amino acid differences from BCoV LUN and ENT, respectively, and shows a higher relative number of changes than the other proteins. Phylogenetic analysis suggests that ACoV shares the same ancestor as BCoV ENT and LUN.More »
  • BVD Virus and Alpacas - The Detective Story

    A personal story of discovery and the potential cause of deaths in alpacas from BVD (bovine viral diarrhea) and the way it can travel from cattle to alpacas with devastating results – a breeders story from Canada.More »
  • BVD Virus: A Newly Recognized Serious Health Problem

    Bovine viral diarrhea (BVD virus or BVDV), a serious problem in cattle, has now been proven to also cause illness, abortions, and most important of all, the persistently infected (PI) state in alpacas. The virus’s ability to produce persistently infected crias, the main way this disease would be spread, and its ability to cause abortions are extremely important for the alpaca industry.More »
  • BVDV in Alpacas

    In 2005 a serious ailment was identified in alpacas for the first time. Bovine Viral Diarrhea Viruses (BVDV) is able to compromise the immune system of an unborn fetus, resulting in an animal that is "persistantly infected" shedding huge amounts of virus and endangering entire herds. This illness has led to significant changes across the alpaca industry, including changes in show rules and an increased awareness of infection control on individual farms. The following is from notes taken during a presentation by Dr Tara Timpson DVM at the SOJAA meeting February 18th 2006.More »
  • Bovine Viral Diarrhea - An Emerging Disease In Camelids A Review

    Bovine Viral Diarrhea (BVD) is an emerging disease in both New World Camelids (NWCs) and Old World Camelids (OWCs). The virus has been isolated from NWCs particularly in alpacas and dromedaries, but there are no reports of BVD in Bactrians. BVD is an important infectious disease. Both sub-genotypes 1a, 1b and genotype 2 have been isolated from NWCs but the ncp BVDV 1b is primarily implicated in cases of BVD in NWCs. A BVD strain unique to camelids has not yet been isolated. In NWCs virtually all infections have been caused by the non-cytopathic (ncp) BVDV, Persistently infected crias have also been detected. Llamas and alpacas demonstrate clinical signs such as ill thrift, diarrhea, respiratory ailments and abortions. As in bovines, identification and elimination of PI animals, has the highest priority to avoid infection of the entire herd. BVD was also observed in dromedaries and interestingly, both genotypes of the Pestivirus, BVDV-1 and BVDV-2, were isolated from dromedaries in Egypt. Both isolates revealed a cytopathic effect (cpe) and so far no ncp virus has been isolated from dromedaries. Also in dromedaries, BVD infections caused intrauterine death, stillbirth, weak calf syndrome with congenital deformities, neonatal respiratory disorders in young dromedary calves and acute hemorrhagic gastroenteritis in adult dromedaries. So far, no PI dromedaries have been described.More »
  • Bovine Viral Diarrhea Infections in New World Camelids—A Review

    Bovine virus diarrhea virus (BVDV) has recently been identified as an important infectious disease of new world camelids (NWC) particularly alpacas. Both sub-genotypes 1a, 1b and genotype 2 have been isolated. However, non-cytopathic BVDV 1b is reported to be primarily implicated in cases of BVDV in NWC's. Although suspected a BVDV strain unique to camelids have not been isolated. The most important source of BVDV is the immuno-tolerant persistently infected cria. Natural transient infection of BVDV in NWCs is reported to go almost undetected except for vague signs of illness, including lethargy and anorexia. Diarrhea does not appear to be a constant finding. Embryonal/fetal disease in NWC's includes early pregnancy loss, abortion and premature birth or the birth of persistently infected crias. Persistently infected disease can occur in both acute and chronic forms. In NWCs the chronic form of the condition is most commonly reported. Signs include chronic ill-thrift, poor weight gain or being underweight, intermittent illness, chronic diarrhea, joint swelling and episodes of nasal discharge and pneumonia despite antibiotic treatment. The mortality rate in NWCs appears to be close to 100%. Seroprevalence of BVDV in NWCs ranged from 2.05% to 11.11% however the possibility that the correct (homologous) BVDV strain is not being used in serological assays need to be considered. The importance of cattle as a source of BVDV for camelids is unclear although there is consensus of a spill-over from cattle to NWC's. Assays available for BVDV in cattle appear to work for camelids. An antigen ELISA which is the usual method for detecting BVD in cattle has not been validated in NWC's.More »
  • Bovine Viral Diarrhea Virus (BVDV)

    Bovine Viral Diarrhea Virus (BVDV) is a Pestivirus classified into two genotypes, “Type 1” and “Type 2”, that infects domestic and wild ruminant herds world-wide. In addition to cattle, BVDV is also known to infect camelids and deer. Related viruses include hog cholera virus in swine and border disease in sheep. For cattle producers, the virus causes an estimated $2 billion per year in economic losses through decreased weight gains, decreased milk production, reproductive losses, and death.More »
  • Comparison of Clinical, Hematological, and Virological Findings in Alpacas (Lama pacos) Inoculated with Bovine Viral Diarrhea Virus Isolates of Alpaca or Bovine Origin

    Clinical evidence demonstrates that alpacas may contract and propagate bovine viral diarrhea virus (BVDV). The objective of this research was to compare and characterize clinical signs, hematological findings, viremia, and seroconversion resulting from intranasal inoculation of alpacas with BVDV 1b and BVDV 2 isolates from cattle and a BVDV 1b isolate of alpaca origin. Three groups of six alpacas were intranasally inoculated with a different isolate (Group 1: BVDV 1b of bovine origin; Group 2: BVDV 2 of bovine origin; Group 3: BVDV 1b of alpaca origin). Following inoculation, all three genotypes induced viremia, nasal shedding and seroconversion in naïve alpacas. The onset of viral detection in serum was significantly different among groups; the median onset was 4, 2, and 7 days for Groups 1, 2, and 3, respectively. Onset of viral detection in white blood cells was significantly different with median onset at 3, 2, and 4 days, and median cessation at 13, 9, and 13 days, respectively. The median onset of viral nasal shedding was 8 days and was not significantly different between groups. Virus was detected after inoculation until a median of 8 days in nasal secretions, 10 days in serum, and 12 days in white blood cells. A reduction in mean total leukocytes was observed in all three groups when compared to pre-inoculation leukograms. Results demonstrate that BVDV 1b and 2 strains cause alpacas to exhibit viremia and nasal shedding of virus in a temporal pattern that is similar to the outcome of acute infection of cattle.More »
  • Controlling the Spread of BVDV

    There are solutions to the spread of BVDV and other infectious diseases. We can extrapolate from other livestock species’ proven methods to protect and treat alpacas. Finally, we can develop alpaca-specific, protective protocols and treatments.More »
  • Eastern Equine Encephalitis (EEE) in Alpacas: Updated 2/2007

    Eastern equine encephalitis is a rare but serious disease caused by the Eastern equine encephalitis (EEE) virus, a member of the family Togaviridae, genus Alphavirus. Eastern equine encephalitis is found mainly along the eastern seaboard and Gulf coast of the United States. EEE is a mosquito borne infection of wild birds that can be transmitted to other birds, humans, horses and other animals by mosquitoes.More »
  • Eastern Equine Encephalitis in Alpacas

    There is nothing more exhilarating than seeing a vigorous female cria up on long wobbly legs starting to explore her world. Her owner had called me about the birth and I arrived soon after to help greet her. So it was doubly heartbreaking to learn just a couple of weeks later, that the same beautiful animal suddenly sickened in front of her owner’s watchful eyes and, in spite of the best vet care possible, died within a few hours.More »
  • Effector Functions of Camelid Heavy-Chain Antibodies in Immunity to West Nile Virus

    Three classes of IgG have been described for camelids. IgG1 has a conventional four-chain structure, while IgG2 and IgG3 do not incorporate light chains. The structures and antigen-binding affinities of the so-called heavy-chain classes have been studied in detail; however, their regulation and effector functions are largely undefined. The aim of this study was to examine the participation of conventional and heavy-chain IgG antibodies in the camelid immune defense directed against West Nile virus (WNV). We found that natural infection or vaccination with killed WNV induced IgG1 and IgG3. Vaccination also induced IgG1 and IgG3; IgG2 was produced during the anamnestic response to vaccination. When purified IgGs were tested in plaque-reduction neutralization titer (PRNT) tests, IgG3 demonstrated PRNT activities comparable to those of conventional IgG1. In contrast, IgG2 demonstrated only suboptimal activity at the highest concentrations tested. Flow cytometric analysis revealed that macrophages bound IgG1, IgG2, and IgG3. Furthermore, subneutralizing concentrations of all three isotypes enhanced WNV infection of cultured macrophages. Our results document distinctions in regulation and function between camelid heavy-chain isotypes. The reduced size and distinct structure of IgG3 did not negatively impact its capacity to neutralize virus. In contrast, IgG2 appeared to be less efficient in neutralization. This information advances our understanding of these unusual antibodies in ways that can be applied in the development of effective vaccines for camelids.More »
  • Experimental Infection of Pregnant Goats with Bovine Viral Diarrhea Virus (BVDV) 1 or 2

    Infections with bovine viral diarrhea virus (BVDV) of the genus pestivirus, family Flaviviridae, are not limited to cattle but occur in various artiodactyls. Persistently infected (PI) cattle are the main source of BVDV. Persistent infections also occur in heterologous hosts such as sheep and deer. BVDV infections of goats commonly result in reproductive disease, but viable PI goats are rare. Using 2 BVDV isolates, previously demonstrated to cause PI cattle and white-tailed deer, this study evaluated the outcome of experimental infection of pregnant goats. Pregnant goats (5 goats/group) were intranasally inoculated with BVDV 1b AU526 (group 1) or BVDV 2 PA131 (group 2) at approximately 25–35 days of gestation. The outcome of infection varied considerably between groups. In group 1, only 3 does became viremic, and 1 doe gave birth to a stillborn fetus and a viable PI kid, which appeared healthy and shed BVDV continuously. In group 2, all does became viremic, 4/5 does aborted, and 1 doe gave birth to a non-viable PI kid. Immunohistochemistry demonstrated BVDV antigen in tissues of evaluated fetuses, with similar distribution but reduced intensity as compared to cattle. The genetic sequence of inoculated viruses was compared to those from PI kids and their dam. Most nucleotide changes in group 1 were present during the dam’s acute infection. In group 2, a similar number of mutations resulted from fetal infection as from maternal acute infection. Results demonstrated that BVDV may cause reproductive disease but may also be maintained in goats.More »
  • Foot and Mouth Disease: Are Llamas and Alpacas at Risk?

    Are llamas and alpacas at risk? Unfortunately, the answer is both yes and no. Yes, llamas and alpacas have been infected with FMD. No they do not appear to be very susceptible to it. FMD infection in alpacas in Peru was confirmed in the 1970's. FMD risk in llamas and alpacas was researched in the USA and Argentina. Routes of infection included tongue scarification, intramuscular injection, intradermal injection, intravenous injection, and cohabitation. Llamas and alpacas appear to be fairly resistant of infection by natural exposure (cohabitation) but can and do succumb to infection when any of the other exposure methods were used. Infected llamas developed mild clinical signs including fever, anorexia, lesions to the footpads, and lameness. Virus did not persist in any camelids beyond 14 days after infection. Certainly, the risk of llamas or alpacas becoming infected seems extremely low.More »
  • Humoral Response to West Nile Virus Vaccination in Alpacas and Llamas

    Objective—To determine humoral responses to an equine West Nile virus (WNV) vaccine in healthy alpacas and llamas and compare responses in alpacas and llamas with responses in horses. Design—Clinical trial. Animals—28 alpacas, 56 llamas, and 16 horses. Procedure—Horses received 2 vaccinations at 4- week intervals, and alpacas and llamas received 3 vaccinations at 3-week intervals. Fifty-five llamas received a fourth vaccination 3 weeks after the third. Blood samples were collected immediately prior to each vaccination, 3 weeks after the last vaccination for alpacas and llamas, and 4 weeks after the last vaccination for horses and tested for virus-neutralizing antibodies. Samples from 29 randomly selected vaccinated llamas were used. Results—None of the animals developed any local or systemic adverse reactions. Four of 28 (14%) alpacas, 4 of 29 (14%) llamas, and 7 of 16 (44%) horses were seropositive 3 (llamas and alpacas) or 4 (horses) weeks after administration of the first vaccination; 27 of 28 (96%) alpacas, 26 of 29 (90%) llamas, and 15 of 16 (94%) horses were seropositive after administration of the second vaccination; and all 28 alpacas and 28 of 29 (97%) llamas were seropositive 3 weeks after administration of the third vaccination. Conclusions and Clinical Relevance—Results suggest that vaccination with the equine WNV vaccine is safe in alpacas and llamas. Administration of 3 vaccinations generally resulted in virus-neutralizing antibody titers similar to those observed following 2 vaccinations in horses; however, because it is not known what antibody titer would be protective against clinical WNV disease in alpacas or llamas, we cannot conclude that the vaccine was efficacious.More »
  • Investigation of Coronavirus as the Cause of Alpaca Respiratory Syndrome

    In 2007, beginning in the summer and extending into the fall and winter, many alpacas became ill, showing symptoms of runny noses and coughing. Some were noted to have fevers and more severe respiratory symptoms. As breeders began discussing these symptoms, what appeared to be a viral “cold” type of disease became known throughout the alpaca community as “the snots.”More »
  • Knowledge Gaps Impacting the Development of Bovine Viral Diarrhea Virus Control Programs in the United States

    Infections with BVDVs result in major economic losses for beef and dairy producers worldwide. The success of control efforts in Scandinavia has led to a consensus that BVDV eradication in Europe is a realistic goal.More »
  • Persistent Infection with Bovine Viral Diarrhea Virus in an Alpaca

    Clinical Findings—In addition to pyrexia and clinical signs of disease of the upper portion of the respiratory tract, the cria had inappetence and was in an unthrifty condition. Hematologic abnormalities included low WBC count, low hemoglobin concentration, and low PCV. Samples of blood were submitted for bovine viral diarrhea virus (BVDV) isolation and serologic evaluation. Other adults and newborn crias in the herd were similarly examined. Bovine viral diarrhea virus was detected in the cria, and a diagnosis of persistent infection with BVDV was made at 5.5 months of age. Persistent BVDV infection was suspected in another cria born into the herd but was not identified in any of the adult alpacas. Treatment and Outcome—Despite several treatments with antimicrobials, no permanent improvement of the cria's condition was achieved. Because of the poor prognosis, the owners requested euthanasia of the cria; BVDV was isolated from specimens of multiple organs collected at necropsy. Clinical Relevance—To date, BVDV infection in New World camelids has not been regarded as a major disease entity. Findings in the cria of this report illustrate that some strains of BVDV readily infect alpacas. Clinical description of the disease plus clinicopathologic findings suggest that persistent BVDV infection may be greatly overlooked as a cause of chronic anemia and failure to thrive in alpacas.More »
  • Persistent Infections After Natural Transmission of Bovine Viral Diarrhoea Virus From Cattle to Goats and Among Goats

    Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle worldwide. Infection of a pregnant animal may lead to persistent infection of the foetus and birth of a persistently infected (PI) calf that sheds the virus throughout its life. However, BVD viruses are not strictly species specific. BVDV has been isolated from many domesticated and wild ruminants. This is of practical importance as virus reservoirs in non-bovine hosts may hamper BVDV control in cattle. A goat given as a social companion to a BVDV PI calf gave birth to a PI goat kid. In order to test if goat to goat infections were possible, seronegative pregnant goats were exposed to the PI goat. In parallel, seronegative pregnant goats were kept together with the PI calf. Only the goat to goat transmission resulted in the birth of a next generation of BVDV PI kids whereas all goats kept together with the PI calf aborted. To our knowledge, this is the first report which shows that a PI goat cannot only transmit BVD virus to other goats but that such transmission may indeed lead to the birth of a second generation of PI goats. Genetic analyses indicated that establishment in the new host species may be associated with step-wise adaptations in the viral genome. Thus, goats have the potential to be a reservoir for BVDV. However, the PI goats showed growth retardation and anaemia and their survival under natural conditions remains questionable.More »
  • Serologic Survey of Viral Antibodies in the Peruvian Alpaca (Lama pacos)

    Sera from more than 100 alpacas (Lama pacos) from the Peruvian southern sierra were examined for antibodies to 8 viruses known to infect other domestic animals. On the basis of these serologic findings and previously published serologic or clinical data, it is now known that the alpaca can be infected with the following viruses: parainfluenza-3, bovine respiratory syncytial virus, bovine herpesvirus-1, bluetongue virus, border disease virus, influenza A virus, rotavirus, rabies virus, vesicular stomatitis virus, foot-and-mouth disease virus, and contagious ecthyma virus.More »
  • West Nile Virus Update: Infection, Clinical Disease, and Vaccination in Camelids

    The first reports of WNV clinical disease in camelids occurred during the 2002 epizootic, which happened to be a particularly bad year for WNV in other species as well, accounting for 284 human deaths and countless bird and horse losses. Confirmation of camelid clinical neurologic disease resulting from WNV infection was made from post-mortem testing using immunohistochemistry and reverse- transcriptase polymerase chain reaction (PCR) from cases in Ohio and Iowa, respectively.More »