Experimental reactivation of latent canine herpesvirus-1 and induction of recurrent ocular disease in adult dogs

Latent canine herpesvirus-1 (CHV-1) infection is common in domestic dogs, but recrudescent CHV-1 diseases are poorly characterized. To determine if administration of an immunosuppressive dosage of prednisolone to adult dogs latently infected with CHV-1 results in recurrent ocular disease, adult beagles with and without experimentally induced CHV-1 latent infection were divided into groups: group 1 latently infected and administered prednisolone, group 2 latently infected and administered placebo, and group 3 not latently infected and administered prednisolone. Prednisolone (3.0 mg/kg/day) was administered to dogs in groups 1 and 3 for seven consecutive days beginning on study day 1. Samples for CHV-1 polymerase chain reaction and serum neutralization (SN) assays were collected, and physical, ophthalmologic, and in vivo ocular confocal microscopic examinations were performed at intervals for 42 days. Bilateral ocular disease (i.e., conjunctivitis or keratitis) was detected in 83% of group 1 dogs between study days 3 and 18. In vivo confocal microscopic abnormalities included conjunctival leukocyte infiltration and corneal leukocyte infiltration, abnormal epithelial cell morphology, and Langerhans cell infiltration. Ocular viral shedding was detected in 50% of group 1 dogs on study days 10 and 13. Fourfold elevations in CHV-1 SN titers were detected in 100% of group 1 dogs by study day 14. Dogs in control groups did not develop clinical ocular disease (P < 0.05), CHV-1 titer elevations (P < 0.005), or viral shedding. Administration of an immunosuppressive dosage of systemic prednisolone to adult dogs latently infected with CHV-1 may result in viral reactivation and ocular disease recrudescence.     

Outbreak of ocular disease associated with naturally-acquired canine herpesvirus-1 infection in a closed domestic dog colony

Objective  To describe clinical and virological findings of an outbreak of ocular disease attributed to naturally-acquired primary canine herpesvirus-1 (CHV-1) infection in a closed domestic dog colony.
Animals studied  Twenty-seven 10- to 16-week-old laboratory Beagles.
Procedure  Complete ophthalmic examinations were performed and ocular samples collected for CHV-1 polymerase chain reaction and virus isolation.
Results  The prevalence of ocular morbidity was 100% in examined dogs. Lesions were restricted to the ocular surface and included bilateral conjunctivitis (100% of dogs); punctate, dendritic, or geographic ulcerative keratitis (26% of dogs); and non-ulcerative keratitis (19% of dogs). Conjunctival petechiae were detected in 22% of dogs. Punctate and dendritic corneal ulcers were frequently organized into discrete groups or linear arrangements. Non-ulcerative keratitis appeared clinically as a perilimbal ring of superficial corneal vascularization and leukocyte infiltration. CHV-1 was detected in ocular samples by polymerase chain reaction or virus isolation in all dogs sampled.
Conclusions  In susceptible populations of domestic dogs, CHV-1 may be associated with outbreaks of highly contagious ocular infection in the absence of concurrent overt systemic disease. This naturally-acquired outbreak of CHV-1 infection provides an opportunity to report the spectrum and prevalence of ocular lesions associated with primary ocular CHV-1 infection in dogs. Conjunctivitis was the most frequent ocular lesion detected. Ulcerative and non-ulcerative keratitis were less prevalent and of variable clinical appearance. Dendritic ulcerative keratitis, a classic and relatively specific ocular lesion associated with alphaherpesvirus infection, was detected in < 20% of dogs.     

Corneal ulceration associated with naturally occurring canine herpesvirus-1 infection in two adult dogs

CASE DESCRIPTION: An 8-year-old Labrador Retriever with diabetes mellitus in which bilateral phacoemulsification had been performed 3 weeks earlier was evaluated for acute onset of blepharospasm, and a 7-year-old Miniature Schnauzer with chronic immune-mediated thrombocytopenia was reevaluated for keratoconjunctivitis sicca that had been diagnosed 4 weeks earlier. CLINICAL FINDINGS: Dendritic corneal ulcerations were detected in both dogs. Canine herpesvirus-1 (CHV-1) was isolated from corneal swab specimens obtained during the initial evaluation of each dog and during recheck examinations performed until the ulcerations were healed. Canine herpesvirus-1 serum neutralization titers were detected in both dogs. Results of virus isolation from oropharyngeal and genital swab specimens were negative for both dogs. The isolated viruses were identified as CHV-1 via immunofluorescence, transmission electron microscopy, PCR assay, and gene sequencing. Negative controls for PCR assay and virus isolation included conjunctival swab specimens from 50 dogs without extraocular disease and corneal swab specimens from 50 dogs with corneal ulcers, respectively. TREATMENT AND OUTCOME: Lesions resolved in both dogs after topical administration of idoxuridine or trifluridine and discontinuation of topically administered immunosuppressive medications. CLINICAL RELEVANCE: To the authors' knowledge, this is the first report of corneal ulcerations associated with naturally occurring CHV-1 infection and may represent local ocular recrudescence of latent CHV-1 infection. The viruses isolated were identified as CHV-1, and the morphology, antigenicity, and genotype were similar to those for CHV-1 isolates obtained from a puppy that died from systemic CHV-1 infection.     

Acute primary canine herpesvirus-1 dendritic ulcerative keratitis in an adult dog

We present a report of dendritic ulcerative keratitis in a 4-year old locally immunosuppressed dog suspected to result from acute primary canine herpesvirus-1 (CHV-1) infection. The dog was presented for evaluation of mild blepharospasm and conjunctival hyperemia in the right eye (OD) shortly after attending a public boarding facility. For approximately 3 months, the dog had been receiving topical prednisolone acetate 1.0% and tacrolimus 0.02% in both eyes (OU) q12h for treatment of follicular conjunctivitis. Ophthalmic examination revealed three regions of corneal fluorescein retention OD. The lesions had a dendritic pattern, were approximately 2-3 mm in length, and were located at the dorsomedial, lateral, and ventromedial aspects of the cornea. No additional abnormalities were noted on complete ophthalmic and physical examinations. CHV-1 was identified in conjunctival samples OD by polymerase chain reaction, and paired CHV-1 serum virus neutralization antibody titers were positive and consistent with acute infection. Topical prednisolone acetate and tacrolimus were discontinued. The dog was treated with cidofovir 0.5% OU q12h for a period of 4 weeks, with resolution of corneal disease noted within 1 week of treatment. In conjunction with previous studies, this case report supports a central role for alterations in host immune status in the pathogenesis and clinical manifestations of CHV-1 ocular disease in dogs.     

Feline herpesvirus

Feline herpesvirus (FHV-1; felid herpesvirus 1 (FeHV-1)) is an alphaherpesvirus of cats closely related to canine herpesvirus-1 and phocine herpesvirus-1. There is only one serotype of the virus and it is relatively homogenous genetically. FeHV-1 is an important cause of acute upper respiratory tract and ocular disease in cats. In addition, its role in more chronic ocular disease and skin lesions is increasingly being recognised. Epidemiologically, FeHV-1 behaves as a typical alphaherpesvirus whereby clinically recovered cats become latently infected carriers which undergo periodic episodes of virus reactivation, particularly after a stress. The primary site of latency is the trigeminal ganglion. Conventional inactivated and modified-live vaccines are available and protect reasonably well against disease but not infection, although viral shedding may be reduced. Genetically engineered vaccines have also been developed, both for FeHV-1 and as vector vaccines for other pathogens, but none is as yet marketed.     

Seroprevalence of Canine Herpesvirus-1 and Brucella canis in Finnish Breeding Kennels with and without Reproductive Problems

We compared the serological status of Brucella canis and canine herpesvirus-1 (CHV-1) in Finnish breeding kennels with and without reproductive problems. Dogs from kennels with reproductive problems had significantly higher CHV-1 titres than dogs from kennels having no reproductive problems (p < 0.001). In dogs from kennels with reproductive problems 100% (32/32) had positive titres, whereas in dogs from kennels without reproductive problems 65% (22/34) had positive titres. The median titre for dogs from kennels with reproductive problems was 1 : 160 and for dogs from kennels without reproductive problems 1 : 80. The high prevalence of positive CHV-1 titres in this study indicates that prevention of the disease is difficult and reinforces the need to minimize the reproductive problems caused by CHV-1. All 388 dogs from 94 kennels had negative B. canis titres.     

Brucella canis endophthalmitis in 3 dogs: clinical features, diagnosis, and treatment

Objective  To describe historical, clinical and diagnostic features of dogs with Brucella canis endophthalmitis and the response to medical therapy.
Animals studied  Three dogs with naturally acquired B. canis endophthalmitis.
Procedure  Dogs were treated symptomatically with topical ophthalmic anti-inflammatories and a novel antimicrobial protocol that included doxycycline, enrofloxacin, rifampin and streptomycin.
Results  All dogs presented with chronic or recurrent uveitis in the absence of overt systemic disease. Clinical ophthalmologic abnormalities were unilateral in each dog and included mild-to-moderate anterior uveitis, iris hyperpigmentation, marked vitreal infiltrates, and multifocal chorioretinitis. Dogs were diagnosed with canine brucellosis serologically and by blood culture ( n  = 2 dogs) or polymerase chain reaction of aqueous humor and blood ( n  = 1 dog). Active ocular inflammation resolved in all dogs during treatment, with preservation of vision in 2 dogs. Following treatment, B. canis could not be cultured from blood samples and serological values declined with seronegativity achieved in all dogs after a median of 96 weeks (range: 36–112 weeks) of therapy.
Conclusions  Brucella canis infection should be included in the differential diagnosis for dogs with intraocular inflammation, regardless of previous history or neuter status. This is the first report of apparently successful medical therapy of canine brucellosis with ocular involvement.     

Acute and latent infection by bovine herpesvirus type 5 in experimentally infected goats

The ability of alphaherpesviruses to infect different ruminant species may have important implications for control/eradication efforts. Serological data indicate that goats may be naturally infected with bovine herpesviruses. To investigate the susceptibility of goats to bovine herpesvirus-5 (BoHV-5), 3-4-month-old kids were inoculated intranasally with each of three Brazilian BoHV-5 isolates (G1, n=8; G2, n=5; G3, n=5). The acute infection was characterized by virus shedding in nasal secretions for up to 14 days (titers up to 10(5.97)TCID(50)/mL), mild respiratory signs and conjunctivitis. All animals seroconverted to BoHV-5, developing virus neutralizing (VN) titers from 4 to 32 to the homologous viruses. At day 60 post inoculation (pi), two animals from each group were euthanized for tissue collection and the remaining goats were submitted to dexamethasone administration (0.4 mg kg(-1) for 5 days). Dexamethasone treatment resulted in virus reactivation in 9 out of 12 animals, as ascertained by virus shedding and/or by increase in VN titers. Virus shedding was detected in 8/12 animals and lasted from 1 to 9 days. Latent viral DNA was detected by PCR in the olfactory bulb and/or trigeminal ganglia of 6/6 goats euthanized at day 60 pi and in 12/12 animals euthanized 40 days post-dexamethasone. These results show that young goats are susceptible to BoHV-5 and may shed virus upon reactivation of latent infection. Thus, it is reasonable to expect that goats raised in close contact with cattle in areas where BoHV-5 is endemic may be infected and therefore should be considered potential reservoirs of the virus.     

Seroprevalence of canine herpesvirus-1 in Turkish dog population

Canine herpesvirus-1 (CHV-1) is the agent of reproductive and respiratory disorders in adult dogs, and the infection generally results in haemorrhagic disease conditions and neonatal death. In this study, virus neutralisation test that used complement (VNT) as well as in-house ELISA were utilised to investigate the CHV-1 seroprevalence in the Turkish dog population. Among the 560 serum samples, 39.3% of the samples tested by ELISA were CHV-1 positive while 29.4% of the samples tested by VNT were CHV-1 positive. Compared to the individual dogs (39.0%), there was a higher CHV-1 seroprevalence (62.1%) found in the colony dogs (62.1%) (p = 0.0002). However, there was an insignificant difference between male and female dogs. Although the highest antibody prevalence (56.7%) was found in Golden Retrievers, there were no significant variations detected among the dog breeds used in this study. Neutralizing antibody titres were very low (?1:16) in a high portion of the tested animals, confirming the rapid decrease of CHV-1 antibodies after the course of infection. The results of this study show that CHV-1 seroprevalence is moderately high in the Turkish dog population.     

Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus

OBJECTIVE: To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats. ANIMALS: 14 young adult, FHV-1-naive cats. PROCEDURE: Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30. RESULTS: Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroid-induced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered. CONCLUSIONS AND CLINICAL RELEVANCE: Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects.     

Attachment and penetration of canine herpesvirus 1 in non-permissive cells

Canine herpesvirus 1 (CHV-1) has a relatively narrow host cell range when compared to other alphaherpesviruses. The early events of CHV-1 infection in a permissive Madin-Darby canine kidney (MDCK) and non-permissive cell lines. In order to quantify attachment and penetration, were investigated quantitative competitive PCR (QCPCR) method was established for quantitation of CHV-1 DNA. In all non-permissive cells tested, no significant decrease in viral attachment was observed. When CHV-1 was treated with heparin, viral attachment to MDCK cells was reduced by 25% of the input CHV-1 attached to MDCK cells even in the presence of 50 microg/ml heparin. However, the attachment of CHV-1 to non-permissive cells was severely impaired by heparin treatment. In permissive MDCK cells, about 80% of attached CHV-1 penetrated into cells. However, only 4-10% of CHV-1 attached to non-permissive cells penetrated into cells. Our data indicated that CHV-1, like other herpesviruses, attached to permissive MDCK cells through two mechanisms: the first one is through the interaction mediated by heparan sulfate (HS) on the cell surface and the second involves unidentified viral component and the cellular receptor. In contrast, the non-permissive cells lacked the cellular receptor for the second attachment mechanism and the defect in viral penetration into non-permissive cell might be related to the lack of the cellular receptor.     

Latent infection by bovine herpesvirus type-5 in experimentally infected rabbits: virus reactivation, shedding and recrudescence of neurological disease.

Latent infection with bovine herpesvirus type-5 (BHV-5) was established in rabbits inoculated with two South American isolates (EVI-88 and 613) by intranasal or conjunctival routes. Nine rabbits (613, 8/27; EVI-88, 1/34) developed neurological disease and died during acute infection and other three (613, n=2; EVI-88, n=1) developed a delayed neurological disease, at days 34, 41 and 56 post-inoculation (p.i.). Between days 56 and 62 p.i., the remaining rabbits were submitted to five daily administrations of dexamethasone (Dx) to reactivate the infection. Twenty-five out of 44 rabbits (56.8%) shed virus in nasal or ocular secretions after Dx treatment. Virus shedding was first detected at day two post-Dx and lasted from one to 11 days. The highest frequencies of virus reactivation were observed in rabbits inoculated conjunctivally (10/15 versus 15/29); and among rabbits infected with isolate 613 (12/16 versus 13/28). Virus reactivation upon Dx treatment was accompanied by neurological disease in nine rabbits (20.4%), resulting in six deaths (13.6%). Virus in moderate titers and mild to moderate non-suppurative inflammatory changes in the brain characterized the neurological infection. Three other rabbits showed severe neurological signs followed by death after 31 to 54 days of Dx treatment. Virus, viral nucleic acids and inflammatory changes were detected in their brains. The late-onset neurological disease, after acute infection or Dx treatment, was probably a consequence of spontaneous virus reactivation. These results demonstrate that BHV-5 does establish a latent infection in rabbits and that clinical recrudescence may occur upon reactivation.     

Effect of topical ophthalmic application of cidofovir on experimentally induced primary ocular feline herpesvirus-1 infection in cats

OBJECTIVE: To evaluate the efficacy of twice-daily ophthalmic application of 0.5% cidofovir solution in cats with experimentally induced primary ocular feline herpesvirus-1 (FHV-1) infection. ANIMALS: Twelve 6-month-old sexually intact male cats. PROCEDURES: Cats were randomly assigned to either a treatment or control group. Ocular infection with FHV-1 was induced (day 0) in all cats via inoculation of both eyes with 10(4) plaque-forming units of a plaque-purified FHV-1 field strain. Twice daily for 10 days beginning on day 4 after virus inoculation, the treatment group received 1 drop of 0.5% cidofovir in 1% carboxymethylcellulose in both eyes, and the control group received 1 drop of 1% carboxymethylcellulose in both eyes. A standardized scoring method was used to evaluate clinical signs of FHV-1 infection in each cat once daily for 24 days. The amount of ocular viral shedding was assessed by use of a quantitative real-time PCR procedure every 3 days during the study period. Clinical scores and viral quantification were averaged over the pretreatment (days 0 to 3), treatment (days 4 to 14), and posttreatment (days 15 to 24) periods for each cat. RESULTS: During the treatment period, clinical scores and amount of viral ocular shedding were significantly lower in the treatment group, compared with findings in the control group. CONCLUSIONS AND CLINICAL RELEVANCE: Twice-daily application of 0.5% cidofovir solution in both eyes significantly decreased the amount of viral shedding and the severity of clinical disease in cats with experimentally induced ocular FHV-1 infection.     

Protection of puppies against canine herpesvirus by vaccination of the dams.

Six bitches free of canine herpesvirus 1 (CHV-1) were vaccinated against the virus; a first injection was given 10 days after the presumed date of mating and a second six weeks later. Six similar bitches were left unvaccinated as controls, and all the pups were challenged oronasally with a virulent strain of CHV-1 at three days of age. All the vaccinated bitches seroconverted and had high antibody titres when the puppies were challenged, but the control bitches remained seronegative. In the control group, 62 per cent (18 of 29) of the pups died of CHV-1-induced disease; most of them showed typical clinical signs and macroscopic lesions, and CHV-1 infection was confirmed by the isolation of the virus or by PCR. None of the puppies in the vaccinated group died of CHV-1 infection. The efficacy of the vaccine was confirmed in CHV-1-positive breeding units. The rate of pregnancy tended to be higher in vaccinated bitches and the mortality of pups before weaning was significantly reduced in the litters born to vaccinated bitches.     

Reactivation of Bovid herpesvirus 1 and 2 and Parainfluenza-3 virus in calves latently infected

Two experiments were carried out to determine whether Bovid herpsvirus (BHV) 2 is able to induce a recurrent infection in experimentally infected calves. In the first experiment the stress induced by dexamethasone (DMS) treatment failed to reactivate the clinical condition or to induce shedding of BHV2. However, treatment with DMS reactivated a latent BHV1 infection in all calves previously inoculated with BHV2 and also in two noninoculated controls. Probably, because of the interference by BHV1 the study failed to resolve the question as to whether BHV2 could induce a recurrent infection. Consequently, a second experiment was performed using calves devoid of antibody to BHV1 and, therefore, probably, free of virus. By this study it was demonstrated that BHV2 can remain as a latent infection in cattle, which, when immunosuppressed as with DMS, can be reactivated. A finding of considerable interest in this experiment was that in 1 calf a concurrent piroplasma infection was also, unexpectedly, discovered.Recrudescence of latent BHV1 infection was induced by DMS treatment of calves possessing antibody to the virus. The infection once reactivated, was readly transmitted by contact to three other calves devoid of antibody to BHV1. In the same experiment Parainfluenza-3 (PI-3) virus was unexpectedly isolated from all calves. It was speculated that all calves were latently infected with PI-3 virus with concurrent infection by BHV1 acting as a stress inducing PI-3 reactivation.These studies seem to indicate that mixed infections could have an important role in the mechanism involved in the establishment of latent infections and viral reactivation.     

The clinical efficacy of topical and systemic therapy for the treatment of feline ocular chlamydiosis

Twenty-four specific-pathogen-free-derived cats aged four to 11 months were challenged by ocular application of a field isolate of Chlamydia psittaci to evaluate the effect of topical and systemic therapy on the course of disease. The cats were monitored for 35 days post-challenge, with severity of clinical signs being measured using a scoring system, and ocular shedding of the organism monitored by culture of conjunctival swabs. All cats developed active C psittaci infection, and after 7 days the cats were randomly assigned to one of four treatment groups: Group P (placebo) was given twice-daily ophthalmic tear-replacement ointment; group F was given twice-daily topical 1% fusidic acid ophthalmic viscous drops; group C was given twice-daily topical 1% chlortetracycline ophthalmic ointment; and group D was given doxycycline at 10 mg/kg daily per os in addition to twice-daily topical 1% fusidic acid ophthalmic ointment. Within 24 h of commencement of therapy, group D had significantly lower median clinical scores than group P, and with the exception of day 16, this trend was maintained throughout the observation period. Median clinical scores of cats in group F were not appreciably different to those in group P, whereas the median scores of cats in group C generally fell between those of groups P and D. The median duration of C psittaci shedding was 10 and 15 days for groups D and C respectively, but four of the six cats in groups F and P were still shedding organisms at the end of the study (day 35). In this study, systemic therapy with doxycycline proved superior to topical therapy in the treatment of feline chlamydiosis.     

Intrapreputial infection of young bulls with bovine herpesvirus type 1.2 (BHV-1.2): acute balanoposthitis, latent infection and detection of viral DNA in regional neural and non-neural tissues 50 days after experimental reactivation

Venereal infection of bulls with bovine herpesvirus type 1.2 (BHV-1.2) may result in acute balanoposthitis followed by the establishment of latent infection, presumably in dorsal root nerve ganglia. We herein report the characterization of the acute and latent infection of young bulls with a Brazilian BHV-1.2 isolate and the investigation of neural and non-neural sites in which viral DNA persists during latent infection, i.e. 110 days after inoculation and 50 days after experimental reactivation. Intrapreputial inoculation of BHV-1.2 isolate SV-56/90 (10(6.5)pfu per animal) resulted in severe balanoposthitis, characterized by redness of the penis and preputial mucosa, coalescent vesicles and fibrinous exsudate in all four infected bulls. Virus shedding was detected in preputial secretions and semen up to days 14 and 13 pi, respectively. Dexamethasone administration at day 60 pi led to reactivation of the infection in all animals, resulting in virus shedding in preputial secretions and/or in semen. At day 50 post-reactivation (pr), the animals were euthanized and regional tissues were collected for PCR and virus isolation. Viral DNA was consistently detected in the dorsal root ganglia of nerves genito-femoral (4/4) and obturator (4/4); frequently in the pudendal (3/4), sciatic (3/4) and rectal caudal nerve ganglia (2/3). In addition, viral DNA was detected in the pelvic sympathetic plexus of one bull and in regional lymph nodes (deep inguinal (2/4); sacral (1/4); medial iliac (1/4)) of two bulls. No infectious virus could be recovered from homogenates of DNA positive tissues, indicating the absence of actively replicating virus. These results demonstrate that BHV-1.2 DNA may persist in several sacral nerve ganglia and in regional lymph nodes as well during latent infection, i.e. 50 days after experimental reactivation. These findings may help in understanding the pathogenesis of acute and latent genital infection by BHV-1.2.     

Doxorubicin and cyclophosphamide for the treatment of canine lymphoma: a randomized,placebo‐controlled study*

Median survival times (STs) for doxorubicin‐treated canine lymphoma range from 5.7 to 9 months. Because dogs treated with multi‐agent protocols have longer STs, we sought to evaluate whether adding cyclophosphamide would improve outcome in canine lymphoma patients while maintaining an acceptable level of toxicity. Thirty‐two dogs with stage III–V multicentric lymphoma were treated with doxorubicin every 3 weeks for five total cycles and prednisone at a tapering dose for the first 4 weeks. Dogs were randomized to receive either cyclophosphamide or placebo concurrently. Seventeen dogs received doxorubicin and placebo, while 15 dogs received doxorubicin and cyclophosphamide. Response, toxicity, progression‐free interval (PFI) and ST were evaluated. The combination of doxorubicin and cyclophosphamide was well tolerated, causing no increase in adverse events over doxorubicin alone. Despite a numeric improvement in outcome in cyclophosphamide treated dogs, the addition of cyclophosphamide did not result in statistically improved response rate, PFI or ST.     

Detection of high levels of canine herpes virus-1 neutralising antibody in kennel dogs using a novel serum neutralisation test

It is widely held that only cells of canine origin support canine herpesvirus-1 (CHV-1) replication and, that cytopathic effect (CPE) develops relatively slowly. Here we show that mink fetal lung cells (NBL-7 cell line) are permissive for CHV-1 and can be used to produce a sensitive test for neutralising antibody by plaque reduction in the presence of complement. The test was applied to the investigation of CHV-1 virus neutralising antibody levels in three kennel populations. The results showed that 26 out of 28 dogs were neutralising antibody positive (titre >/=2), and, 11 out of 28 had titres of >/=1024. The serum samples were analysed by enzyme linked immunoassay (ELISA); 27 out of 28 were graded as ELISA IgG positive (titre >/=500) and 26 of 28 were graded as ELISA IgM positive (titre >/=50).     

First molecular study of Canine herpesvirus-1 in reproductive specimens of adult dogs in southeast of Iran

Canine herpesvirus-1 (CHV-1) is recognized to be enzootic in the dog population with a widespread distribution. This pathogen leads to a lethal generalized illness in newborn puppies and is associated with reproductive disorders. CHV-1 should be considered as an important pathogen of neonatal death and infertility; so, it appears to pose a threat for breeding kennels. Although serologic data point to the circulation of CHV-1 among dogs of Iran are available, no definitive diagnosis has been conducted based on the molecular assay. So, this research was done to detect the prevalence of CHV-1 in dogs of Kerman. In this study, the presence of CHV-1 in vaginal specimens and biopsies of the uterus of dogs referring to the Veterinary Hospital of Shahid Bahonar University of Kerman was determined. Fifteen uterine samples and seven vaginal samples were included in group of the pregnant dogs. Moreover, thirteen uterine samples and twenty vaginal samples were related to the dogs displaying suspicious clinical signs such as reproductive disorders. Samples were collected and evaluated using real-time PCR. Viral DNA was detected in 21 samples from a total of 140 (15 %) collected samples which were related to 14 uterine samples (20 %) and 7 (10 %) vaginal specimens. The association of this virus with age, breed, housing, pregnancy and reproductive disorders was not significant. Five positive reproductive samples were belonged to the dogs with a history of reproductive disorders including pyometra, metritis, stillbirths, vaginitis and vaginal prolapse. This study is the first molecular detection of CHV-1 in reproductive samples of dogs in Iran. Considering the significant prevalence of this virus, it is necessary to carry out management measures in controlling and preventing this disease. Tracing CHV-1 requires further research on this virus in dogs of this region.