Mycoplasma as a cause of canine urinary tract infection

Mycoplasmas were isolated from 60 specimens of urine obtained by cystocentesis from 41 dogs (23 males and 18 females) with urinary tract infection. Mycoplasmas were isolated in pure culture from 41 (68%) of the specimens, and were isolated in conjunction with one or more bacterial species from 19 (32%) specimens. Clinical signs of urinary tract infection were noted in 20 of 31 dogs in which mycoplasmas were isolated in pure culture, and numbers of WBC in the urine sediment were above the reported normal range in 22 of 25 urine specimens from those 20 dogs. Twenty-four of 29 mycoplasma isolates were found to be Mycoplasma canis, 4 were found to be M spumans, and 1 was identified as M cynos.     

Presumptive herpesvirus-associated erythema multiforme in a cat

Erythema multiforme (EM), an uncommon immune-mediated skin disorder of cats, conceivably could be triggered by feline herpesvirus type-1 (FHV-1) infection, in a manner analogous to human herpesvirus-associated EM (HAEM). This report describes a 10-year-old Persian-mixed cat with a presumptive diagnosis of HAEM.     

Canine distemper virus infection: proliferation of canine footpad keratinocytes

The proliferation of footpad keratinocytes of canine distemper virus (CDV)-infected dogs was investigated. Footpads of 19 dogs inoculated experimentally with a virulent distemper strain (A75/17) and of two noninoculated control dogs were collected at necropsy. Dogs were divided into four groups according to results of the postmortem examination: dogs with severe distemper (group 1), dogs with mild distemper (group 2), inoculated dogs without distemper (group 3) and noninoculated dogs (group 4). There was no distinct difference of epidermal thickness among the four groups. Infection of the footpad epidermis with CDV was demonstrated using immunohistochemistry for viral nucleoprotein and in situ hybridization for nucleoprotein messenger ribonucleic acid (mRNA). Only group 1 dogs had viral antigen and mRNA in the footpad epidermis with the same distribution. Footpad epidermis of group 1 dogs had more mitotic figures in the basal layer, and significantly more basal keratinocytes were positive for the proliferation markers Ki-67 and proliferating cell nuclear antigen. Double-staining for Ki-67 and viral nucleoprotein identified rare double-labeled basal keratinocytes. These findings suggest that the presence of CDV particles in the footpad epidermis is associated with keratinocyte proliferation.     

Parvovirus infection in a Beagle colony

The clinical and pathological features of an outbreak of parvovirus infection are described. In young puppies these were vomiting, diarrhoea and myocarditis whereas in older animals they were weight loss and enteropathy. Other features seen were interstitial pneumonia, lymphoid depletion and, in one dog, renal tubular degeneration. The haematological picture was inconsistent, a reduced number of circulating neutrophils or lymphocytes occurring in some cases whereas in others neutrophilia or lymphocytosis was present.     

Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

Non-cytocidal infection of keratinocytes by canine distemper virus in the so-called hard pad disease of canine distemper

A late, but not uncommon sequel to canine distemper virus (CDV) infection of dogs is thickening of footpads and nasal planum, the so-called hard pad disease, originally described as vacuolar degeneration of epidermal keratinocytes with inclusion body formation and massive hyperkeratosis. However, in a recent study of footpads of naturally CDV-infected dogs only hyperkeratosis was observed without any of the other changes. Instead, acanthosis was frequently noticed. CDV nucleoprotein was present in the suprabasal keratinocytes and eccrine epithelial glands only. No CDV nucleoprotein was present in basal keratinocytes. This observation in combination with lack of obvious cytocidal changes strongly suggested the possibility of a restricted viral infection with presence of viral mRNA but without protein expression. Therefore, the presence of CDV nucleoprotein mRNA was investigated using in situ hybridization and compared to the localization of the nucleoprotein in footpads of clinically healthy and distemper dogs. Viral nucleoprotein and nucleoprotein mRNA in nearly all cases co-localized to the same compartments and basal keratinocytes did not contain nucleoprotein mRNA. These findings dispute the idea of a restricted viral infection of footpad keratinocytes in dogs with natural CDV infection. Instead, a migration of the virus to the epidermal surface along with the proliferating and differentiating epithelium is the most likely explanation for the lack of virus antigen in basal keratinocytes.     

Use of human immunoglobulin for treatment of severe erythema multiforme in a cat

A 5-month old female domestic shorthair cat developed lethargy and severe ulcerative skin lesions that covered more than half of its body after routine administration of rabies vaccine, anthelmintic, and ear medication. Clinical and histologic findings were consistent with a severe cutaneous drug reaction or erythema multiforme. The cat's condition continued to deteriorate despite drug withdrawal and supportive care. Administration of human intravenous immunoglobulin was well tolerated by the cat and led to rapid resolution of ulcerative cutaneous lesions, accompanied by substantial improvement in the cat's demeanor within 8 days. Human intravenous immunoglobulin appears to be a novel promising treatment for life-threatening cutaneous drug reactions.     

Ultrastructure of cultured canine oral keratinocytes

Keratinocytes from explants of the oral mucosa of dogs were grown in culture for five passages. The ultrastructure of primary cultures and fully developed subcultures passaged 1, 3, and 5 times was examined. At every stage, the cells had the morphologic characteristics of epithelial cells and formed a multilayered squamous epithelium. The basal cells had the characteristics of metabolically active cells, whereas the suprabasal cells and the cells at the media interface expressed many, but not all, of the organelles and cell surface characteristics associated with keratinocyte differentiation. Keratohyalin granules were located in the suprabasal and superficial cells. Cell size and shape and the relationship between cells in the layers also reflected the morphologic characteristics of the parent tissue. Cells maintained this typical structure through all passages and the cultures changed minimally for up to a week after development.     

Diagnosis of erythema multiforme associated with thymoma in a dog and treated with thymectomy

A 7 yr old Labrador retriever initially presented for severe halitosis, mild ptylism, and depigmentation of the nasal planum. Erythema multiforme was diagnosed based on clinical signs and dermatopathology. Treatment was initiated but the condition did not resolve. Six months later, the dog was diagnosed with a mediastinal mass. Trucut biopsy was performed and histopathologic diagnosis was consistent with a thymoma. A median sternotomy was performed, the thymoma was excised, and the dog recovered well. Four months postoperatively, there were no longer any obvious erythema multiforme lesions and the skin condition was controlled without medication. Erythema multiforme may be a paraneoplastic disorder associated with thymoma in the dog, similar to thymoma-associated exfoliative dermatitis in the cat. Clinical signs of erythema multiforme may warrant performing thoracic radiographs or thoracic CT to rule out thymoma as an underlying cause.     

Haemoplasma infection is not a common cause of canine immune-mediated haemolytic anaemia in the UK

Objective : The aim of this study was to investigate whether the two canine haemoplasma species, Mycoplasma haemocanis and “Candidatus Mycoplasma haematoparvum,” are commonly associated with immune-mediated haemolytic anaemia (IMHA) in UK dogs. Methods : Three groups of dogs were recruited to the study: anaemic dogs with primary IMHA (n=37); anaemic dogs not meeting the inclusion criteria for primary IMHA (n=77) and non-anaemic dogs (n=113). DNA was extracted from 100 μl of blood and subjected to real-time quantitative polymerase chain reaction (qPCR) assays for both species of Mycoplasma. Each assay incorporated co-amplification of canine glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an endogenous internal control. Results : Canine GAPDH was successfully amplified by qPCR from all 227 canine blood samples but none contained M. haemocanis or “Candidatus M. haematoparvum” DNA. Clinical Significance : Haemoplasma infection is uncommon in dogs in the UK and no evidence was found that these organisms act as triggers for IMHA.     

Phenotypic analysis for a cell line of canine epidermal keratinocytes

Epidermal keratinocytes have the potential to produce inflammatory mediators that are considered to play an important role in skin diseases such as atopic dermatitis (AD). Thus, cell lines of canine epidermal keratinocytes are useful for studying the biological reactivity of keratinocytes in vitro. However, there has been no report on properly analyzing the phenotype of canine keratinocyte cell lines. In this work, we performed phenotypic analysis of CPEK, which was derived from the epidermis of an adult dog in order to examine the phenotypic similarity with epidermal keratinocytes. The present findings indicated that CPEK cells expressed markers for epidermal keratinocytes including cytokeratin 14, alpha6 integrin and PCNA. Our findings demonstrated that CPEK could be a useful cell line for investigating the central role of epidermal keratinocytes in the pathogenesis of AD in vitro.     

IgG autoantibodies directed against desmoglein 3 cause dissociation of keratinocytes in canine pemphigus vulgaris and paraneoplastic pemphigus

Pemphigus is a group of autoimmune blistering diseases of the skin and mucous membranes. In human patients with pemphigus vulgaris (PV) and paraneoplastic pemphigus (PNP), IgG autoantibodies against desmoglein (Dsg) 3 and Dsg1 play pathogenic roles in blister formation. In contrast, the target for IgG autoantibodies that induce keratinocyte dissociation has not been elucidated in canine pemphigus. The aim of the present study was to determine whether anti-Dsg IgG autoantibodies are present and disrupt the cell-cell adhesion of keratinocytes in canine PV and PNP. The extracellular domains of canine Dsg3 were recognized by IgG in 3/5 (60%) canine PV sera tested. IgG against the extracellular domains of canine Dsg1 was detected exclusively in two dogs that had PV with the mucocutaneous phenotype. In addition, anti-Dsg3 IgG was identified in canine PNP serum. Furthermore, incubation of normal human keratinocytes (NHK) with mucocutaneous canine PV serum and canine PNP serum resulted in dissociation of the NHK sheets, whereas the removal of anti-Dsg3 IgG from these canine sera blocked this dissociation. The present study indicates for the first time that circulating anti-Dsg3 IgG antibodies capable of dissociating keratinocytes are present in dogs with PV and PNP.     

Bartonella spp infection as a possible cause of uveitis in a cat

A 6-year-old castrated mixed-breed cat was evaluated because of unilateral anterior uveitis. The cat was seronegative for antibodies to Toxoplasma gondii, coronaviruses, and feline immunodeficiency virus, and antigens for FeLV p27 and Cryptococcus neoformans. Antibodies to Bartonella spp were detected in serum and aqueous humor. The antibody coefficient (C value) for IgG antibodies to Bartonella spp in the aqueous humor was 4.42; values > 1 suggest ocular production of antibodies and supports a diagnosis of ocular infection. Topical administration of prednisolone and oral administration of prednisone failed to induce a response; however, the uveitis resolved rapidly after the cat was given doxycycline orally. Clinical or laboratory evidence of immunodeficiency in this cat was not detected. Detection of a serum IgG antibody titer to Bartonella spp and ocular production of IgG antibodies to Bartonella spp, exclusion of other causes of uveitis, and response to doxycycline suggests that the cat may have had bartonellosis resulting in uveal tract inflammation.     

Streptococcal infection as a cause of reproductive tract problems of swine

This study determined that streptococci were the etiological agents responsible for a high percentage of breeding sows experiencing infertility and abortions.No isolations of virus were obtained from fetuses, or placentae. There was no positive serology obtained from sows that aborted when tested for evidence of virus, leptospira, brucella, and eperythrozoon antibodies. Streptococci were the predominant isolates obtained from the genito-urinary tract of sows and boars. Cultures were taken from 75 sows and 46 (61%) yielded hemolytic streptococci; 27 of these streptococci belonged to a specific serogroup. Of the 75 sows studied, 46 were infected, and of these, nine aborted, 14 were infertile, and 23 farrowed normally. There was a significantly (P < 0.02) higher number of sows that had abortions or were infertile in the infected group. A random sample of 18 sows given penicilin therapy indicated a significant benefit from treatment (P < 0.02) in the reproductive performance of infected animals.Twelve out of 16 boars yielded hemolytic streptococci with seven isolated being of a specific serogroup.The percentage distribution of all streptococci isolates belonging to a specific serogroup was 63.4% group C, 22% group D, and 7.3% each fooup A and G.     

Multidrug- and methicillin resistant Staphylococcus pseudintermedius as a cause of canine pyoderma: a case report

A case of a dog with a long-term inflammatory skin disorder due to infection with methicillin-resistant Staphylococcus pseudintermedius (MRSP) is described. After initial diagnostics of MRSP, follow-up swabs of the dog (nose, skin) were taken twice after four and seven weeks. MRSP was constantly isolated from the skin and once from the nose. Since infected humans might be a source of reinfection, the owners of the dog were screened (nasal) three times during their pet's therapy. Thereby, the male owner was found to be colonized with MRSP once in the first sampling round. Comparative typing of all MRSP-isolates by pulsed-field gel electrophoresis (PFGE), SCCmec typing, multilocus sequence typing (MLST), spa typing, PCR-detection of the leukotoxin encoding operon (LukI) and the Staphylococcus intermedius-exfoliative toxin (SIET) as well as antimicrobial resistance profiling by broth microdilution revealed that all five MRSP isolates from the dog and the single isolate from the owner were indistinguishable by any of the applied methods. All isolates were assigned to a certain strain, a multidrug-resistant MRSP belonging to sequence type (ST) 71, spa type (t)05, harbouring SCCmecIII as well as the genes encoding LukI and SIET. In this case, a number of reasons might have contributed to therapy failure and re-infection, respectively (e. g. contact to other MRSP-colonized dogs, contact to MRSP-colonized humans, refusal to clip the dog's fur). In addition, MRSP-contaminated objects or surfaces in the household, which were difficult to disinfect or simply not considered as a potential source of MRSP, might have served as a source of re-infection. These results envision the possibility of a dog-to-human transmission of MRSP and the relevance of this aspect as a potential source of re-infection in cases of bacterial-supported long-term skin disorders in canine patients. First cases of MRSP infections in humans have been described only recently. However, the general pathogenic potential of multidrug resistant MRSP in humans is unknown so far and needs further investigation.     

Heterobilharzia americana infection as a cause of hepatic parasitic granulomas in a horse

CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination. Histologic examination of the mass revealed that it was squamous cell carcinoma, and the horse was euthanized because of the unlikelihood that the mass could be adequately resected and its close proximity to the urethra. OUTCOME-At necropsy, in addition to the squamous cell carcinoma, hundreds of round, white to pale yellow nodules were disseminated throughout the liver, resulting in a so-called starry-sky appearance. Similar granulomas were seen in the right caudal lung lobe and small intestinal serosa. A single granuloma in the liver, which differed from the others by its larger size, contained a pair of adult schistosomes. Several hepatic granuloma specimens were used for PCR amplification and sequencing. Use of primers specific for a portion of the Heterobilharzia americana small subunit rRNA gene resulted in amplification of a 487-base pair product that had 100% sequence identity with H americana. CLINICAL RELEVANCE-Severe cases of disseminated granulomas in the liver of horses may result in a liver with a grossly abnormal starry-sky pattern. To our knowledge, this is the first report documenting the association of granulomas with H americana infection along with adult schistosomes in the liver of a horse.     

Neospora caninum infection as a cause of reproductive failure in a sheep flock

Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.     

Streptococcus equi infection as a cause of panophthalmitis in a horse

Streptococcus equi was isolated from a corneal ulcer in a horse. The ulcer developed as an extension of septic uveitis subsequent to submandibular lymphadenopathy. The condition was refractory to therapy and panophthalmitis ensued. The affected eye was enucleated and S. equi was isolated in pure culture from the anterior chamber. S. equi should be considered as an etiologic agent in cases of uveitis in the horse, especially if there is a recent history of strangles.