Natural parvovirus infection in laboratory rabbits

Laboratory rabbits from various commercial and private sources were found to have high serum antibody titers specific for lapine parvovirus (LPV). By both immunofluorescence and hemagglutination inhibition assays, 75% of these sera were positive for LPV. This finding, together with the recovery of LPV from kidneys of neonatal rabbits, suggested that LPV infection is common in commercially available rabbits in the United States. It was concluded that use of infected rabbits could interfere with research in which rabbit cell cultures or in vitro immunologic assays are used.     

An outbreak of fatal herpesvirus infection in domestic rabbits in Alaska

A herpesvirus infection affecting mini Rex and crossbred meat rabbits was identified in a rabbitry in Alaska. Illness affected over half of the 55 rabbits on the premises, and 16 rabbits died or were euthanatized because of illness. Disease affected all ages from adults to nursing young and occurred over an approximately 2-month period. Clinical signs included conjunctivitis and periocular swelling, ulcerative dermatitis, progressive weakness, anorexia, respiratory distress, and abortion. Hemorrhagic dermatitis and panniculitis were associated with epidermal microvesicular degeneration, dermal and subcutaneous vascular necrosis, and thrombosis. Eosinophilic intranuclear inclusions consistent with herpesvirus were found within the epidermis and superficial follicular epithelium and within mesenchymal cells within the dermis and subcutis. Syncytial cells containing viral inclusions occurred within the epidermal and superficial follicular epithelium. Other findings were hemorrhagic necrosis of the myocardium with rare intranuclear inclusions within stromal cells, multifocal pulmonary hemorrhage, hemorrhage with sinus erythrophagocytosis in lymph nodes, and massive necrosis and fibrin deposition within red pulp of the spleen. A virus isolated from the skin produced syncytia, intranuclear inclusions, and cell lysis typical of herpesvirus in rabbit kidney cells in vitro. The viral isolate was characterized ultrastructurally as an enveloped virus with icosahedral nucleocapsids 100 nm diameter, consistent with a herpesvirus.     

Natural and experimental pox virus infection in the domestic cat

Three naturally occurring cases of cowpox virus infection in the domestic cat are described. Isolate L97 was identified as cowpox virus on the basis of morphology, serology and characteristic cytopathic effect in tissue culture and on the chorioallantoic membrane of embryonated eggs. All three cases showed multiple skin lesions, slight conjunctivitis or purulent ocular discharge but there were no respiratory signs. Two animals recovered, the third was put down as a stray. The disease was reproduced in experimental cats. Isolate L97 was inoculated into two cats intravenously and two cats by skin scarification. All four developed skin lesions at the site or sites of inoculation, and in one cat multiple lesions developed. The two intravenously inoculated animals also developed severe oedema of the neck and brisket around the site of inoculation into the jugular vein, and one cat died. Serological and pathological findings on both the natural and experimental infections are described. Serum neutralising antibody titres in both natural and experimental early convalescent cases were significantly enhanced by the addition of complement.     

Clinical toxicoses of domestic rabbits.

Toxicoses are an uncommon presentation to rabbit practitioners; however, veterinarians who accept rabbits as patients should be familiar with the basic concepts of toxicosis management and the specific syndromes associated with clinical toxicoses. The objective of this article is to present clinically relevant information for veterinarians presented with rabbits exhibiting characteristic signs of toxicosis. In addition, specific mention is made to the most common clinical toxicoses, including lead, chemicals, rodenticides, aflatoxins, and poisonous plants.     

Fatal toxoplasmosis in domestic rabbits in the USA.

Three rabbits from two sources died after an acute illness characterized by fever, lethargy and diarrhea in one rabbit and no clinical signs in two rabbits. The most striking lesion in all three rabbits was foci of necrosis of the spleen and liver associated with massive presence of multiplying Toxoplasma gondii tachyzoites. The diagnosis was confirmed by specific staining with anti-T. gondii serum in an avidin-biotin complex immunohistochemical stain.     

Evolution of coccidial infection in commercial and domestic rabbits between 1982 and 1986

Caecal samples were collected from 751 domestic rabbits of various origin and from 1229 diarrhoeic rabbits issued from 61 commercial rabbitries. They were screened for coccidiosis. In 1982, the year of introduction of the anticoccidial robenidine in commercial rabbit feeds, a dramatic decrease of coccidial infection ratio was detected in commercial rabbitries: only 6% of samples contained greater than 100 oocysts per gram against 85% in 1979, when sulphaquinoxaline/pyrimethamine was used. Only Eimeria magna, E. media and E. perforans were detected, whereas the highly pathogenic species E. flavescens and E. intestinalis had disappeared from commercial units. After 4 years of continuous use of robenidine, infection ratio rose progressively, although still far below the 1979 levels. Most of the other species reappeared, but only in very low proportions (1-4% of samples). The percentage occurrence of E. magna, E. media and E. perforans on the contrary rose progressively to 25, 26 and 34%, respectively, suggesting drug resistance. In domestic rabbitries, the incidence of coccidial infection was markedly higher and all nine species of Eimeria were detected. Eimeria magna, E. media and E. perforans were very common, E. flavescens, E. intestinalis, E. piriformis and E. stiedai were less common, whereas E. irresidua and E. coecicola were relatively rare. Notwithstanding the lower activity of robenidine against E. stiedai, no rise of hepatic coccidiosis became evident.     

Spirometra sp. in a domestic cat in India

Adult Spirometra sp. were found in an experimental cat. This is the first report from northern India. It is suggested that this infection may have resulted from the feeding of raw fish offal.     

Parvovirus infection in domestic companion animals.

Parvovirus infects a wide variety of species. The rapid evolution, environmental resistance, high dose of viral shedding, and interspecies transmission have made some strains of parvovirus infection difficult to control within domestic animal populations. Some parvoviruses in companion animals, such as canine parvovirus (CPV) 1 and feline parvovirus, have demonstrated minimal evolution over time. In contrast, CPV 2 has shown wide adaptability with rapid evolution and frequent mutations. This article briefly discusses these three diseases, with emphasis on virus evolution and the challenges to protecting susceptible companion animal populations.     

Genotypic characterization and phylogenetic analysis of Cryptosporidium sp. from domestic animals in Brazil

The purpose of the present study was the genetic characterization, sequencing and phylogenetic analysis of 18S rDNA sequences of Cryptosporidium isolates obtained from different animal hosts in Brazil. Fecal samples containing Cryptosporidium oocysts were obtained from chickens, ducks, quails, guinea pigs, dairy calves, dogs and cats. For amplification of 18S rDNA sequences the Secondary-PCR product of the extracted DNA from fecal suspension of each studied animal was utilized. The primary genetic characterization of Cryptosporidium sp. was performed using RFLP with the enzymes SspI and VspI. DNA samples were sequenced and subjected to phylogenetic analysis. The results showed C. baileyi infecting two ducks and one quail and C. melagridis infecting one chicken. The sequences obtained from Cryptosporidium sp. infecting guinea pigs were not identified within groups of known Cryptosporidium species. The isolates found parasitizing cats and one dog were diagnosed as C. felis and C. canis, respectively. One isolate of calf origin was identified as C. parvum. The phylogenetic analysis showed clear distribution of isolates between two Cryptosporidium sp. groups according to their gastric or intestinal parasitism. A great genetic distance was observed between C. felis and C. canis from Brazil when compared to the reference sequences obtained from GenBank. The results obtained during this study constitute the first report of rDNA sequences from C. baileyi, C. meleagridis, C. felis, C. canis and C. parvum isolated in Brazil.     

Lead-induced toxicosis in two domestic rabbits

Lead toxicosis developed in 2 pet rabbits. Both rabbits had decreased appetite or anorexia; also, one had mild anemia and one had pleural effusion. Treatment with the calcium chelate of ethylenediaminetetraacetic acid was effective in both rabbits. The rabbit's propensity for gnawing may result in lead toxicosis, and may be seen more frequently as rabbits become more popular as pets.     

Toxoplasma gondii infection in sentinel and free-range chickens from Argentina

This study aimed at isolating and genotyping Toxoplasma gondii from serologically positive free-range chickens from Argentina, and to evaluate the use of sentinel animals during a short time period of exposure to determine environmental contamination with T. gondii oocysts. Two groups of chickens on six farms were compared in this study: (i) young, 2-3 month-old broiler-type chickens reared as sentinel animals on the farms and (ii) adult chickens reared on the same farms for more than one year. Seroconversion rates of 7.0% or 5.7% were observed in sentinel broiler chickens reared for a period of 74 days (January-April 2010) or 88 days (August-November 2010) respectively, as shown by a T. gondii specific immunofluorescent antibody test. Fifty-three percent (17 of 32) of adult chickens were positive and showed higher titres than sentinel animals. Isolation of T. gondii from tissues (brain and heart) of serologically positive chickens was achieved from six of seven free-range adult birds with IFAT titres of 200 and higher. The isolated parasites were analysed by multi-locus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The isolated T. gondii showed three different genotypes: two genotypes consisted in atypical allele combinations, and the remaining genotype had exclusively clonal type II alleles. All isolates obtained at a single farm, corresponded to the same genotype. The T. gondii genotypes observed are identical to those described in cats, dogs, chickens and capybaras elsewhere in South America. Two isolates, which showed different allele combinations in PCR-RFLP, were characterized in a mouse virulence assay. While one isolate showed a low virulence a second isolate was of intermediate virulence to mice.