Canine inverted papillomas associated with DNA of four different papillomaviruses

Inverted papillomas are uncommon papillomavirus (PV)‐induced canine skin lesions. They consist of cup‐ to dome‐shaped dermal nodules with a central pore filled with keratin. Histologically they are characterized by endophytic projections of the epidermis extending into dermis. Cytopathic effects of PVs infection include the presence of clumped keratohyalin granules, koilocytes and intranuclear inclusion bodies. Different DNA hybridization studies carried out with a canine oral papillomavirus (COPV) probe suggested that a different PV than COPV might cause these lesions. Canine papillomavirus 2 (CPV2) was discovered a few years ago in inverted papillomas of immunosuppressed beagles. Two other cases, presenting with distinct clinical and histological features have also been described. This study was carried out on four dogs with clinical and histological signs of inverted papillomas. Molecular biological analyses confirmed that PV DNA was present in all four lesions but demonstrated that the sequences in each case were different. One corresponded to COPV, the second to CPV2, and the third and fourth to unknown PVs. These findings suggest that inverted papillomas are not caused by one single PV type. Similar observations have also been made in human medicine.     

Novel papillomavirus isolated from the oral mucosa of a polar bear does not cluster with other papillomaviruses of carnivores

Papillomatosis has been documented in several carnivores, and papillomavirus (PV) types have been characterized from lesions in a number of carnivore species: the canine oral PV (COPV), the Felis domesticus PV type 1 (FdPV-1) isolated from a Persian cat, the Procyon lotor PV type 1 (PlPV-1) isolated from a raccoon, the canine PV type 2 (CPV-2) from a dog's foot pad lesion and the canine PV type 3 (CPV-3) associated with a canine epidermodysplasia verruciformis - like disease. A tissue sample was taken from a papillomatous lesion on the oral mucosa of a polar bear (Ursus maritimus). Extracted DNA was used as a template for multiply primed rolling-circle amplification (RCA), and restriction enzyme analysis of the RCA product indicated the presence of papillomaviral DNA. The genome of this PV was cloned and the complete genomic sequence was determined. The Ursus maritimus PV type 1 (UmPV-1) genome counts 7582 basepairs and is smaller than that of other papillomaviruses from carnivore species. UmPV-1 contains the typical noncoding region NCR1, but unlike the carnivore PVs of the Lambda genus, UmPV-1 does not possess a second noncoding region NCR2. Phylogenetic analysis based on a nucleotide sequence alignment of the L1 ORF of UmPV-1 and 51 other PV types indicates that UmPV-1 does not cluster with any of the other carnivore PVs, but branches off near the root of the common branch of the genus Alphapapillomavirus.     

Demonstration of papillomatosis in nutrias (Myocastor coypus Molina)]

The occurrence of the papillomatous disease of the coypu having a contagious character was recorded for the first time in Czechoslovakia in 1975. The papillomatous lesions of the size of a pea to bean occurred on the skin of the extremities, tail head and in the oral and nasal cavities. The females were affected first, followed by their young and then by the young borne by healthy mothers after contact with the diseased animals. On the whole the disease affected 57 animals (60%). The disease spontaneously disappeared within 2.5 to 3.5 months of the occurrence of the papillomatous lesions. The virus etiology of the disease was demonstrated by means of the electron-microscopic detection of virus particles the structure of which corresponded to that of the papillomatous viruses.     

Pathology and immunohistochemistry of papillomavirus-associated cutaneous lesions in Cape mountain zebra, giraffe, sable antelope and African buffalo in South Africa

Skin lesions associated with papillomaviruses have been reported in many animal species and man. Bovine papillomavirus (BVP) affects mainly the epidermis, but also the dermis in several species including bovine, the best-known example being equine sarcoid, which is associated with BVP types 1 and 2. This publication describes and illustrates the macroscopic and histological appearance of BPV-associated papillomatous, fibropapillomatous or sarcoid-like lesions in Cape mountain zebra (Equus zebra zebra) from the Gariep Dam Nature Reserve, 2 giraffes (Giraffa camelopardalis) from the Kruger National Park, and a sable antelope (Hippotragus niger) from the Kimberley area of South Africa. An African buffalo (Syncerus caffer) cow from Kruger National Park also had papillomatous lesions but molecular characterisation of lesional virus was not done. Immunohistochemical staining using polyclonal rabbit antiserum to chemically disrupted BPV-1, which cross-reacts with the L1 capsid of most known papillomaviruses, was positive in cells of the stratum granulosum of lesions in Giraffe 1, the sable and the buffalo and negative in those of the zebra and Giraffe 2. Fibropapillomatous and sarcoid-like lesions from an adult bovine were used as positive control for the immunohistochemistry and are described and the immunohistochemistry illustrated for comparison. Macroscopically, both adult female giraffe had severely thickened multifocal to coalescing nodular and occasionally ulcerated lesions of the head, neck and trunk with local poorly-circumscribed invasion into the subcutis. Necropsy performed on the 2nd giraffe revealed neither internal metastases nor serious underlying disease. Giraffe 1 had scattered, and Giraffe 2 numerous, large, anaplastic, at times indistinctly multinucleated dermal fibroblasts with bizarre nuclei within the sarcoid-like lesions, which were BPV-1 positive in Giraffe 1 and BPV-1 and -2 positive in Giraffe 2 by RT-PCR. The sable antelope presented with a solitary large lesion just proximal to the right hind hoof, which recurred after excision, and was BPV-1 positive by RT-PCR. Other wart-like growths were present elsewhere on the body. The Cape mountain zebra either succumbed from their massive lesions or were euthanased or removed from the herd because of them. The lesions were BPV-1 and/or -2 positive by RT-PCR. The buffalo lesions were wart-like papillomatous projections in the inguinal and udder region. Stratum granulosum cells that stained immunohistochemically positive in the various species appeared koilocyte-like, as described in human papillomaviral lesions.     

POXVIRUS INFECTION OF THE SKIN OF AN EASTERN GREY KANGAROO

A solitary cutaneous papillomatous lesion, present for 6 weeks, was surgically removed from the hind limb of an 18-month old eastern grey kangaroo (Macropus giganteus). The lesion did not recur within 6 months of excision. Poxvirus particles were demonstrated in epidermal cells of the lesion by electron microscopy.     

Detection of canine oral papillomavirus-DNA in canine oral squamous cell carcinomas and p53 overexpressing skin papillomas of the dog using the polymerase chain reaction and non-radioactive in situ hybridization

Nineteen cutaneous and mucocutaneous papillomas, as well as 29 oral and 25 non-oral squamous cell carcinomas of dogs were analyzed immunohistologically for the presence of papillomavirus (PV)-antigens. Canine oral papillomavirus (COPV)-DNA was detected in formalin-fixed, paraffin-embedded tissues by polymerase chain reaction (PCR) and non-radioactive in situ hybridization (ISH). Furthermore, the expression of the tumor suppressor protein p53 was investigated. PV-antigens were detectable in more than 50% of the oral and cutaneous papillomas, while no PV-antigens could be demonstrated in venereal papillomas. One squamous cell carcinoma was PV-antigen positive. Only two cutaneous papillomas of the head showed a strong p53-specific immunostaining, while overexpressed p53 was detectable in approximately 35% of all squamous cell carcinomas. It was possible to amplify fragments of the E6, E7 and L1 gene by polymerase chain reaction (PCR) from five of eight oral and from five of eight cutaneous papillomas as well as from three oral squamous cell carcinomas. Nine of 10 papillomas showed a strong nucleus-associated hybridization signal typical for COPV-DNA. In three squamous cell carcinomas COPV-DNA was located in nests of the epithelial tumor cells surrounding ‘horn pearls' or disseminated in the carcinoma tissue. These observations support the view that COPV may also induce non-oral papillomas in the dog and confirm the opinion that a progression of viral papillomas into carcinomas in dogs may occur.     

Molecular characteristics of cutaneous papillomavirus from the canine pigmented epidermal nevus

To investigate the relation between the canine pigmented epidermal nevus (PEN) and cutaneous papillomavirus, we cloned and sequenced the L1 gene of papillomavirus from the canine pigmented epidermal nevus (PEN). Amplification of DNA sample with the L1 consensus primers yielded an expected fragment of approximately 450-bp. The nucleotide sequences of the fragment showed about 64% of sequence similarity to the L1 region of human papillomavirus isolate CP6108 and less than 57% sequence similarity to those of canine oral papillomavirus (COPV). In situ hybridization determined the presence of papillomavirus DNA mainly in the upper stratum granulosum of skin in this case. The results indicated that the canine cutaneous papillomavirus from the PEN lesion was genetically close to human papillomavirus rather than COPV.     

Ulcerative and papillomatous digital dermatitis of the pastern region in dairy cattle: clinical and histopathological studies.

The study was carried out on a single herd of 500 Holstein breed dairy cattle. Only 50 dairy cows (10%) were found to be suffering from focal ulcerative and papillomatous digital dermatitis of the pastern region. The cows were subjected to clinical and histopathological examinations. Early ulcerative stage was seen in 30 cows and late papillomatous stage was observed in 20 cows. The topical application of oxytetracycline solution or benzathine penicillin powder appeared to be effective for the treatment of the ulcerative lesions. The histopathological findings showed signs of epidermopoiesis and papilloma formation. The dermal reaction revealed signs of fibroplasia and perivascular aggregation of inflammatory cells. Silver stained sections indicated the presence of longer filamentous spiral spirochetes, cocci and large-sized anaerobic bacilli invading the stratum spinosum. In conclusion it can be said that bovine digital dermatitis was observed in ulcerative and papillomatous form at the pastern region bordering the dewclaws. Spirochetes are frequently associated with and may be responsible for pathological changes in the lesion.     

Tissue distribution of psittacid herpesviruses in latently infected parrots, repeated sampling of latently infected parrots and prevalence of latency in parrots submitted for necropsy.

Psittacid herpesvirus-1 (PsHV-1) is the cause of an acute fatal disease in parrots and is implicated as the cause of papillomatous lesions of the digestive tract. Not all infections cause disease and some parrots are infected asymptomatically. Latently infected parrots are potential sources for virus dissemination. Tissues from parrots that died spontaneously with a history of coming from flocks where a PsHV-1 outbreak had occurred were examined for PsHV-1 DNA. Fourteen of 16 parrots examined were infected with at least 1 variant of PsHV-1; of these 13 (93%) had viral DNA in either or both the oral and cloacal mucosa, suggesting that most latently infected parrots could be detected by sampling these sites. Nine of 9 parrots shown to be infected 5 years prior to this study were positive again on repeat sampling and were infected with the same virus genotype. Opportunistic sampling of parrots submitted for diagnostic necropsy indicated that the prevalence of PsHV-1 in parrots in the sampled population was approximately 9.3%. PsHV-1 genotypes 1, 2, and 3 were found in these birds, but genotype 4 was not. Six necropsy specimens were found to be infected with two PsHV-1 genotypes and it was concluded that infection with one serotype did not protect against infection with another. Psittacid herpesvirus 2 (PsHV-2) was identified in 4 African grey parrots and a blue and gold macaw. Prior to this study PsHV-2 had only been found in African grey parrots.     

Effect of lameness on milk yield in dairy cows

OBJECTIVE: To examine the relationship between lameness and milk yield in dairy cows. DESIGN: Cohort study. ANIMALS: 531 dairy cows. PROCEDURE: Cows affected with lameness were classified into 1 of 3 groups on the basis of type of diseases or lesions observed, including interdigital phlegmon (foot rot), papillomatous digital dermatitis (foot warts), or claw lesions. Cows not affected with lameness were classified as healthy. From Dairy Herd Improvement Association records, 305-day mature equivalent milk yield data were collected at the end of lactation or when the cow left the herd. Milk yield was compared between cows affected with lameness and healthy cows. RESULTS: 167 (31%) cows were affected with lameness during lactation. Lame cows had claw lesions (60%), papillomatous digital dermatitis (31%), or interdigital phlegmon (9%). Milk yield in lame cows with interdigital phlegmon (mean, 17,122 lb) was significantly less, compared with healthy cows (19,007 lb). CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, interdigital phlegmon was associated with a 10% decrease in milk production. Lame cows with claw lesions or papillomatous digital dermatitis produced less milk than healthy cows, but the difference was not significant.     

Idiopathic mucosal penile squamous papillomas in dogs

A new papillomatous clinical entity is described affecting the penile mucosa of dogs. The animals, 11 male dogs of different breeds, ageing from 6 to 13 years, were presented for genital mass and occasional haematuria. Surgical incision of the prepuce skin of the anaesthetized dogs showed the presence of single pedunculated, soft, pink-red, cauliflower-like masses arising from the penile mucosa, with diameter ranging from 2 to 8 cm. In all cases, histopathological examination of the excised masses showed normal epithelial differentiation with digitiform expansion of all the layers and elongated rete ridges slanted towards the periphery of the lesion. Evidence of ballooning degeneration or basophilic intranuclear inclusion bodies was not found. Both immunohistochemistry and polymerase chain reaction techniques failed to reveal papillomavirus. According to the histological World Health Organization classification of papillomatous lesions and due to the lack of evidence of a viral origin the masses were identified as idiopathic mucosal penile squamous papillomas. Urinary problems resolved after surgical excision, haematuria was therefore considered secondary to ulceration of the papillated masses.     

Phaeohyphomycosis caused by Alternaria alternata in a cat

Phaeohyphomycosis caused by Alternaria alternata was diagnosed in a 6-year-old cat. A lesion in the nose resulted in enlargement of the dorsum of the nose. Similar appearing lesions had been removed from the dorsum of the nose 1 and 4 years earlier. The lesion recurred 3 months after surgical excision and irregular administration of ketoconazole. A second cytoreductive operation followed by 5 months' treatment with ketoconazole resolved the infection. Nasal trauma occurring at 8 months and at 5 years before initial examination may have predisposed the cat to development of the Alternaria infection.     

Lesions Associated with Attachment of the Parasitic Copepod Phyllothyreus cornutus (Pandaridae: Siphonostomatoida) to Interbranchial Septa of Blue Sharks

Abstract

Lesions associated with the parasitic copepod Phyllothyreus cornutus on the interbranchial septa of blue sharks Prionace glauca were observed in detail. Female copepods were associated with grossly visible, soft, papillomatous lesions on the interbranchial septum in which their second antennae were embedded. Attached male copepods were either not associated with any appreciable lesions or were attached within shallow ulcerations. Histologically, the papillomatous lesions were marked by epithelial hyperplasia over a lamina propria replaced by granulation tissue or fibrosis with lymphoid nodules. Lesions associated with male copepods consisted of epithelial ulceration and subacute, necrotizing, heterophilic branchitis. Lesions associated with female copepods appeared suggestive of long-term local attachment whereas those associated with males were suggestive of more ephemeral associations with the fish. The observed lesions did not appear capable of impairing respiration; however, the overall impact of Phyllothyreus cornutus infections on the well-being of the blue shark remains unknown.     

Cyclosporine decreases skin lesions and pruritus in dogs with atopic dermatitis: a blinded randomized prednisolone-controlled trial

During the last decade, oral cyclosporin (CsA) has proven to be effective, in randomized controlled trials, for the treatment of atopic dermatitis (AD) in human patients. The purpose of this blinded randomized controlled trial was to test the hypothesis that CsA was successful in reducing the gravity of clinical signs of AD in dogs. Thirty dogs with nonseasonal AD were randomly allocated to receive an oral solution of either NEORAL CsA (5 mg kg-1) or prednisolone (0.5 mg kg-1) once daily for 6 weeks. Before, and 3 and 6 weeks after therapy, skin lesions were graded by clinicians using the Canine AD Extent and Severity Index (CADESI). Pruritus was assessed by the owners using a visual analog scale (PVAS). In both groups, CADESI and PVAS values were significantly lower at 6 weeks post treatment than before the initiation of therapy (Friedman test, P < 0.0004). The percentage reductions in CADESI and PVAS values from baseline were not statistically different between groups (Mann-Whitney test, P > 0.3). In this experiment, the tolerability and safety of oral CsA and prednisolone appeared similar. One-fifth of dogs given oral CsA occasionally developed diarrhoea or soft stools. One dog that was given CsA developed a generalized papillomatous skin eruption during the second half of the trial. Our study provides randomized controlled trial evidence that CsA reduces the severity of clinical signs in dogs with nonseasonal AD. Moreover, the anti-allergic efficacy of CsA appears comparable with that of prednisolone. We propose that oral CsA should be considered as a valuable alternative to glucocorticoid therapy in dogs with AD.     

Oral vesicular lesions in horses without evidence of vesicular stomatitis virus infection

OBJECTIVE: To report clinical and serologic findings in horses with oral vesicular lesions that were consistent with vesicular stomatitis (VS) but apparently were not associated with VS virus (VSV) infection. DESIGN: Serial case study. ANIMALS: 8 horses. PROCEDURE: Horses were quarantined after appearance of oral lesions typical of VS. Severity of clinical signs was scored every 2 to 5 days for 3 months. Serum samples were tested for antibodies by use of competitive ELISA (cELISA), capture ELISA for IgM, serum neutralization, and complement fixation (CF). Virus isolation was attempted from swab specimens of active lesions. RESULTS: 2 horses with oral vesicular lesions on day 1 had antibodies (cELISA and CF) against VSV; however, results of CF were negative by day 19. Five of the 6 remaining horses were seronegative but developed oral lesions by day 23. Virus isolation was unsuccessful for all horses. CONCLUSIONS AND CLINICAL RELEVANCE: Horses were quarantined for 75 days in compliance with state and federal regulations. However, evidence suggests that oral lesions were apparently not associated with VSV infection. The occurrence in livestock of a vesicular disease that is not caused by VSV could confound efforts to improve control of VS in the United States and could impact foreign trade. Vesicular stomatitis is of substantial economic and regulatory concern.     

Pathogenesis of canine parvovirus enteritis: sequential virus distribution and passive immunization studies

After oral inoculation, the sequential distribution of canine parvovirus was studied in 14 nine-week-old seronegative beagle dogs. Two or three dogs were necropsied on days 1 through 6 after inoculation. Tissues were collected for virus isolation, immunofluorescence testing, and light microscopy. Virus was isolated from, and fluorescent cells were seen in the tonsil, retropharyngeal and mesenteric lymph nodes one and two days after inoculation. Virus infection of systemic and intestinal lymphoid tissues occurred as early as three days after inoculation and was associated with viremia. Intestinal epithelial infection was first seen four days after oral inoculation. All dogs were viremic before intestinal epithelial infection was found. Fecal virus excretion first occurred four days after oral virus inoculation. Intestinal virus infection and lesions became progressively more severe between four and six days after inoculation. The severity of intestinal lesions was variable and related to the severity of systemic lymphoid tissue lesions and the magnitude and duration of viremia. Four littermates of virus-infected dogs were passively immunized against canine parvovirus with convalescent canine serum 24 hours after oral virus inoculation. Neither clinical signs, lymphopenia, nor fecal virus excretion occurred in passively immunized dogs. Intestinal epithelial infection was not demonstrable by immunofluorescence testing when passively immunized dogs were necropsied four, five, and six days after virus inoculation.     

Detection of novel papillomaviruses in canine mucosal, cutaneous and in situ squamous cell carcinomas

Papillomavirus (PV) DNA is frequently uncovered in samples of human skin squamous cell carcinomas (SCC). However, the role of these viruses in the development of such cancers in canine species remains controversial. While approximately 100 human PVs are known, only one single canine oral PV (COPV) has been identified and studied extensively. Therefore, we applied a narrow-range polymerase chain reaction (PCR) suitable for the detection of classical canine and feline PVs, as well as a broad-range PCR, which has been used for the detection of various novel PVs in humans, in order to analyse 42 paraffin-embedded samples, representing three different forms of canine SCCs. Ten samples of skin tissues with various non-neoplastic conditions served as controls. While none of the negative controls reacted positively, PV DNA was discovered in 21% of the tested SCC samples. Interestingly, the classical COPV was amplified from only one sample, while the other positive cases were associated with a variety of thus far unknown PVs. This study suggests that a fraction of canine SCC is infected with PVs and that a genetic variety of canine PVs exists. Therefore, these results will facilitate the future study of the role of PVs in the development of canine skin cancers.     

Uveodermatologic syndrome in a rat terrier

A 4 yr old intact male rat terrier presented with severe bilateral nonresponsive panuveitis. Bilateral uveitis, blepharospasm, conjunctival hyperemia, diffuse corneal edema, peripheral bullous retinal detachment, and secondary ocular hypertension were noted. Ocular lesions progressed despite aggressive medical treatment and were followed by cutaneous depigmentation and crusting along the nasal planum. Intensive oral and topical anti-inflammatory and topical antiglaucoma medications were administered, but the ocular disease progressed. A bilateral enucleation was performed. Uveodermatologic syndrome was diagnosed from histopathologic examination of a skin biopsy as well as histopathology of both globes after bilateral enucleation. To maintain control of the dermatologic lesions, oral azathioprine was initiated, but it was not well tolerated by this patient. Immunosuppressive doses of oral cyclosporine and anti-inflammatory doses of oral prednisone were used to control the depigmentation and crusting skin lesions.     

Tracheal Obstruction due to Glossal Entrapment by a String Foreign Body in a Peahen (Pavo cristatus)

A female juvenile peahen (Pavo cristatus) presented with acute respiratory distress after the owner observed the bird apparently “choking” the night before presentation. A swelling at the base of the throat was also noted by the owner approximately 2 days prior to the “choking” incident. An air sac breathing tube was placed immediately following presentation and the respiratory rate and effort returned to normal. While performing a physical examination on the patient, a string foreign body was identified and removed from the oral cavity. The string had been wrapped around the base of the tongue, initially resulting in a laceration at the base of the tongue and displacing the glottis caudally, but eventually retroflexed the tongue resulting in occlusion of the glottis. Once the string was transected, the tongue was replaced into normal anatomic position. Three days after presentation, the bird was able to breathe normally with the air sac tube occluded, thus the air sac tube was removed. The lesions under the tongue completely resolved 8 weeks following the initial presentation. Although there have been reports of string foreign bodies in avian species, there are no reports of these foreign bodies causing entrapment of the tongue with subsequent obstruction of the glottis.