High incidence of the gullet worm, Gongylonema pulchrum, in a squirrel monkey colony in a zoological garden in Japan

Histological examination revealed the gullet worm (Gongylonema pulchrum) embedded in the lingual mucosa of two of four dead Bolivian squirrel monkeys (Saimiri boliviensis) from a zoological garden in Kyushu, Japan. The zoo had kept the monkeys as a colony of approximately 80-100 individuals in a moated, open ground since 1981. To assess the incidence of G. pulchrum infection in this colony, lingual scraping with disposable plastic sticks was conducted in February during 2 consecutive years (2003 and 2004). The oval, thick-shelled egg containing a larva was found in 15 of 27 arbitrarily-chosen adult monkeys (55.5%) in 2003, and 27 of 106 monkeys (25.5%) in 2004. Infection of other zoo-kept mammals with G. pulchrum was not assessed. Since the gullet worm infects a variety of mammals including primates as natural definitive hosts, and dung beetles and cockroaches as intermediate hosts, the zoological garden may provide an ideal environment for the parasite. Zoo veterinarians should be aware of this disease in kept mammals, and should consider in the case of primates, monthly or bimonthly prophylactic anthelmintic treatment.     

Photodynamic therapy as a treatment for esophageal squamous cell carcinoma in a dog

Intrathoracic esophageal squamous cell carcinoma was diagnosed by endoscopy in an 11-year-old, castrated male Labrador retriever with signs of regurgitation and weight loss. Photodynamic therapy with photofrin was administered three times under endoscopic guidance over a two-month period. A partial response to photodynamic therapy was supported by a reduction in tumor size (noted on serial endoscopic examinations) and by a return to oral alimentation. The dog was euthanized due to recurrent regurgitation and aspiration pneumonia nine months after the onset of therapy. Necropsy revealed marked local invasiveness and regional lymph node metastasis of the esophageal squamous cell carcinoma in addition to pneumonia. The application of photodynamic therapy in the treatment of canine esophageal squamous cell carcinoma is discussed and compared with the human literature.     

Squamous cell carcinoma of the vulva in a cow

An 8-year-old Holstein cow was evaluated because of a slowly enlarging vulvar mass that had impaired artificial insemination attempts. Vulvar squamous cell carcinoma was diagnosed. Clinical cases of vulvar squamous cell carcinoma have not been as widely reported as those of ocular squamous cell carcinoma in cattle. Treatment modalities for vulvar squamous cell carcinoma have not been as thoroughly investigated as for those of the ocular condition. Cryosurgery and radio-frequency hyperthermia appear to be the optimal therapeutic modalities, each providing up to 90% tumor remission.     

Efficacy of thiabendazole, mebendazole, levamisole and ivermectin against gullet worm, Gongylonema pulchrum: in vitro and in vivo studies

In vitro and in vivo studies were conducted to evaluate the effects of thiabendazole, mebendazole, levamisole and ivermectin against Gongylonema pulchrum. For in vitro assays, third-stage larvae (L3) incubated with the drugs were administered orally to mice and the ability of larvae to invade the gastric mucosa of the animals was examined. After incubation, only those larvae treated with high concentrations of levamisole (1 and 10 microg/ml) were tightly coiled with intestines exhibiting morphological abnormalities. Good dose-response data for the drugs tested was observed at the time of worm recovery from mice, with no worms recovered at the two highest concentrations of levamisole. In vivo efficacy of the drugs against adult worms was evaluated in six groups of three rabbits, each of which was infected with 30 L3 of G. pulchrum and treated with thiabendazole at 100 mg/kg for 3 days, mebendazole at 70 mg/kg for 3 days, levamisole as a single dose of 8 mg/kg, and subcutaneously injected ivermectin as a single dose of 0.2 mg/kg or vehicles of the drugs (control) at 4 months post-infection. Necropsy 14 days after treatment revealed that levamisole, mebendazole and ivermectin reduced worm burdens by 63.2%, 22.8% and 25.8%, respectively, with no reductions in worms observed with thiabendazole. The surviving worms were principally found in the esophagus with the remainder distributed among the buccal mucosa, the tongue, and/or pharyngeal mucosa in all groups. A number of morphologically abnormal eggs were observed within the uterus and ovijector in female worms recovered from the thiabendazole-treated group. These findings suggest that levamisole exhibits in vivo efficacy against G. pulchrum infection and that the larval invasion tests using mice could be used to screen for anthelmintic susceptibility of nematodes.     

Local interleukin-2 and interleukin-12 therapy of bovine ocular squamous cell carcinomas

Interleukin-2 and interleukin-12 have been used independently to successfully treat the induced and the spontaneous tumours in animals. This trial was done to determine if a combination of IL-2 and IL-12 in the treatment of spontaneous bovine ocular squamous cell carcinomas (BOSCC) would be more successful than IL-2 or IL-12 therapy by themselves. For this trial, we selected 25 BOSCC tumours seen on Holstein Fresian cows in Beatrice, Zimbabwe. The cows were randomly assigned to a treatment group of 5 days of IL-2 (200,000 U/day), 5 days of IL-12 (0.5 microg/day) or 5 days of IL-2 (200,000 U/day) and IL-12 (0.5 microg/day). At 20 months after treatment, the IL-2 therapy group had 63% complete regressions; the combination group had 38% complete regressions, which were significantly higher than the IL-12 group, which had 0% complete regressions at 20 months, despite having 29% complete regressions at 6 months. These results show that IL-2 therapy by itself and in combination with IL-12 is more successful than IL-12 by itself. However, combination therapy does not improve the outcome in comparison to IL-2 as a single therapy. It also proves that IL-2 is consistently successful in the therapy of BOSCC with over 60% complete regression, which corresponds to a number of other studies we have done on IL-2 therapy of BOSCC [Rutten, V.P.M.G., Klein, W.R., De Jong, W.A., Misdorp, W., Den Otter, W., Steerenberg, P.A., De Jong, W.H., Ruitenberg, E.J., 1989. Local interleukin-2 therapy in bovine ocular squamous cell carcinoma. A pilot study. Cancer Immunol. Immunother. 30, 165--169; Stewart, R.J.E., Hill, F.W.G., Masztalerz, A., Jacobs, J.J.L., Koten, J.W., Den Otter, W., 2003. Local low dose interleukin-2 therapy of bovine ocular squamous cell carcinomas in cattle in Zimbabwe, submitted for publication; Den Otter, W., Hill, F.W.G., Klein, W.R., Koten, J.W., Steerenberg, P.A., De Mulder, P.H.M., Rutten, V.P.M.G., Ruitenberg, E.J., 1993. Low doses of interleukin-2 can cure large bovine ocular squamous cell carcinoma. Anticancer Res. 13, 2453-2455; Den Otter, W., Hill, F.W.G., Klein, W.R., Koten, J.W., Steerenberg, P.A., De Mulder, P.H., Rhode, C., Stewart, R., Faber, J.A., Ruitenberg, E.J., 1995. Therapy of bovine ocular squamous cell carcinoma with local doses of interleukin-2: 67% complete regressions after 20 months of follow-up. Cancer Immunol. Immunother. 41, 10-14].     

RADIOGRAPHIC APPEARANCE OF PRIMARY LUNG TUMORS IN CATS

The radiographic findings in 41 feline primary lung tumors are reported. Case material includes 29 adenocarcinomas, six bronchiolog-alveolar carcinomas, and six squamous cell carcinomas. Adenocarcinomas tended to occur as focal, solitary, well-circumscribed masses (eight cats), as localized consolidations (six cats), or as multiple, poorly circumscribed masses (five cats). Bronchiolo-alveolar cell carcinomas and squamous cell carcinomas were radiographically pleomorphic. Calcification was recognized in only five cats, four with adenocarcinomas and one with bronchiolo-alveolar carcinoma. Cavitation was identified in seven adenocarcinomas, one squamous cell carcinoma, and one bronchiolo-alveolar carcinoma. Nearly 50% (20 cats) of the patients had radiographic evidence of pleural involvement. Fifteen cats had evidence of regional lymph node involvement.     

COMPARISON BETWEEN CLINICAL,ULTRASOUND, CT,MRI, AND PATHOLOGY FINDINGS IN DOGS PRESENTED FOR SUSPECTED THYROID CARCINOMA

This study compares clinical, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and pathology findings in 16 prospectively, and seven retrospectively recruited dogs presented for suspected thyroid carcinoma. Of these, 17 were confirmed thyroid carcinoma, while six were initially misdiagnosed. These included four carotid body tumors, one para‐esophageal abscess, and one undifferentiated squamous cell carcinoma. Thyroid carcinomas occurred in older dogs without evidence of sex predilection, and were more often unilateral. All were large, heterogeneous, moderately to strongly vascularized, and most commonly contained areas of dystrophic mineralization and/or fluid accumulations. On MRI, thyroid carcinomas appeared hyperintense compared to surrounding musculature in all imaging sequences used, while on CT they had a lower attenuation value than normal thyroid gland tissue. Histologically confirmed tumor capsule disruption with invasion of the surrounding structures was most commonly detected with MRI. Palpation was not an accurate predictor of locally invasive vs. well‐encapsulated masses. Computed tomography had the highest specificity (100%) and MRI had the highest sensitivity (93%) in diagnosing thyroid carcinoma, while ultrasound had considerably lower results. We conclude that ultrasound is adequate for use as a screening tool for dogs with suspected thyroid carcinoma, but recommend either CT or MRI for preoperative diagnosis and staging.     

Primary and metastatic carcinomas in the digits of cats

In the period 1993-1998, digital carcinomas in 64 cats were examined. In all animals primary complaints were painful digit(s). Eight cats had a primary squamous cell carcinoma which involved one digit or two adjacent digits of one leg. Fifty-six cats had metastases of a pulmonary carcinoma in the digits, and in general multiple digits of different legs were involved. In many of these cats metastases also occurred in other organs, including the skin and muscles. No primary sweat gland carcinomas of the digits were seen. Primary squamous cell carcinomas of the digits were characterized by cornification and the absence of PAS-positive cells, PAS-positive secretory material. Immunohistochemically, these neoplasms stained negative with the monoclonal antibody CAM 5.2 directed against Keratin 8 (K 8). The metastases of pulmonary carcinomas to the digits showed one or more of the following histological features: goblet cells, ciliated epithelial cells, PAS-positive cells or lakes, and/or a PAS-positive lining of luminal membranes and no cornification. Immunohistochemically, they showed positive staining for CAM 5.2 (K8). Thoracic radiographs from three cats with a primary squamous cell carcinoma showed no abnormalities, whereas all cases of metastases from a pulmonary carcinoma to the digits available for follow-up showed evidence of a primary pulmonary carcinoma on radiography and/or postmortem examination (25 out of 56). The conclusion of this study was that most carcinomas in the digits of cats were metastases of a primary pulmonary carcinoma (87.5%). Primary squamous cell carcinomas occurred infrequently. The prognosis of metastases of a pulmonary carcinoma in the digits is poor with an average survival time of 4.9 weeks, in contrast to 29.5 weeks in cats with a squamous cell carcinoma. These data stress the importance of taking thoracic radiographs of cats with digital tumours before surgical intervention.     

Helminth parasitisms among intermingling insular populations of white-tailed deer, feral cattle, and feral swine.

Helminth infections among free-ranging, intermingling populations of white-tailed deer (Odocoileus virginianus), cattle (Bos taurus), and swine (Sus scrofa) on an island off the Georgia coast were studied. Of 39 species of helminths collected, 19 were found in deer, 17 in cattle, and 13 in swine. Of 28 species of helminths recovered from ruminants, 8, viz, Capillaria bovis, Cooperia punctata, Dictyocaulus viviparus, Gongylonema pulchrum, G verrucosum, Haemonchus contortus, Moniezia benedeni, and Trichostrongylus axei, occurred in both deer and cattle. Common liver flukes (Fasciola hepatica) infected cattle and swine but not deer. Only 1 helminth, G pulchrum, infected deer, cattle, and swine. The findings suggested that helminths harbored by the host species are distinct, with little exchange occurring.     

Oral and peripheral vestibular signs in a cat with squamous cell carcinoma

A 13-year-old female, spayed cat had oral and vestibular signs resulting from a 3-cm mass extending from the tympanic membrane to the nasopharynx. Radiography revealed a soft-tissue density in the tympanic bulla. Cytologic examination and biopsy confirmed the presence of a squamous cell carcinoma. Squamous cell carcinoma causes vestibular signs in the cat. In this cat, squamous cell carcinoma, involving the middle and inner ear, resulted in oral and vestibular signs.     

Evaluation of piroxicam for the treatment of oral squamous cell carcinoma in dogs

OBJECTIVE: To evaluate the use of piroxicam for the treatment of oral squamous cell carcinoma in dogs. DESIGN: Prospective case series. ANIMALS: 17 dogs with measurable oral squamous cell carcinoma. PROCEDURE: Dogs were treated with piroxicam at a dosage of 0.3 mg/kg (0.14 mg/lb) of body weight, PO, every 24 hours until progressive disease or unacceptable signs of toxicosis developed or the dog died. RESULTS: One dog had a complete remission (maxillary tumor), and 2 dogs had partial remissions (lingual tumor and tonsillar tumor). An additional 5 dogs had stable disease, including 1 with a maxillary tumor, 2 with mandibular tumors, and 2 with tonsillar tumors. Variables associated with tumor response were not identified. Median and mean times to failure for the 3 dogs that had a remission were 180 and 223 days, respectively. Median and mean times to failure for the 5 dogs with stable disease were 102 and 223 days, respectively. Time to failure was positively associated with tumor response and negatively associated with tumor size. One dog had mild adverse gastrointestinal tract effects that resolved with the addition of misoprostol to the treatment regimen. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that piroxicam may be useful in the treatment of dogs with oral squamous cell carcinoma; response rate was similar to that reported for other cytotoxic treatments. Larger-scale studies are warranted to determine what role piroxicam may have, alone or in combination with other treatments, for the treatment of dogs with oral squamous cell carcinoma.     

Equine penile squamous cell carcinomas are associated with the presence of equine papillomavirus type 2 DNA sequences

Forty cases of equine penile disease were screened with polymerase chain reaction for the presence of papillomaviral DNA. Cases consisted of 20 squamous cell carcinomas (average age of horse, 23.9 years) and 20 non-squamous cell carcinoma diseases (average age of horse, 13.3 years). All horses but one originated from the Northeastern United States. Breeds were not recorded. As based on MY09/MY11 consensus primers, DNA sequences from equine papillomavirus type 2 were amplified from 9 of 20 horses (45%) with penile squamous cell carcinoma and only 1 of 20 horses (5%) with non-squamous cell carcinoma penile disease. Equine papillomavirus type 2 DNA was the only papillomaviral DNA amplified from any of the 40 horses. Tissues from the 10 horses in which papillomaviral DNA was detected by polymerase chain reaction were also screened with in situ hybridization and immunohistochemistry. The presence of papillomavirus was demonstrated in a subset of these by in situ hybridization (6 of 10) and immunohistochemistry (1 of 10). This report describes a possible association between equine penile squamous cell carcinomas and equine papillomavirus type 2. This study is also the first report of equine papillomavirus type 2 infection in North American horses.     

Multisite integumentary squamous cell carcinoma in an African grey parrot (Psittacus erithacus erithacus)

A 22-year-old male African grey parrot (Psittacus erithacus erithacus) had had episodes of chronic feather picking and self-mutilation for 10 years; it had a 5 cm diameter right axillary wound and a 2 cm left dorsal patagial wound. Initial treatment with azithromycin and wound management was unsuccessful. Biopsies of both masses indicated squamous cell carcinoma. The left patagial tumour was removed completely by electrocautery. Cisplatin was administered weekly into multiple sites on the right axillary tumour and it initially appeared to regress; however, the bird's condition deteriorated after a month of treatment, and it was euthanased. The tumour was confirmed postmortem to be squamous cell carcinoma, which had invaded local tissues. The aetiology of the carcinoma may have been secondary to chronic focal trauma.     

Multiple skeletal metastases from a penile squamous cell carcinoma in a horse

A 21‐year‐old gelding with ventral abdominal and preputial oedema was evaluated for right hindlimb lameness. Partial phallectomy had been performed 3 years prior for treatment of squamous cell carcinoma. Regional analgesia did not localise the source of lameness and nuclear scintigraphy was recommended. The results of the scan revealed severe increased radiopharmaceutical uptake in the proximal femur. Radiographic and ultrasound examinations were inconclusive. The horse was discharged with recommendations of stall confinement and a 2 week course of nonsteroidal anti‐inflammatory drugs. Four weeks later the horse presented for an inability to elevate his neck and persistent hindlimb lameness. The owner elected humane euthanasia. Post mortem examination revealed metastatic squamous cell carcinoma in the proximal femur and fifth cervical vertebrae consistent with metastasis from the penile squamous cell carcinoma. To the authors’ knowledge, multiple site bone metastasis of squamous cell carcinoma has not been reported previously in the horse.     

Carcinoma in the urinary bladder of a cat: cytologic findings and a review of the literature

Percutaneous fine needle aspiration biopsy (FNAB) was used to diagnose a urinary bladder carcinoma in an aged cat. The cytologic appearance of specimens collected initially was similar to that reported for canine transitional cell carcinoma. However, impression smears of the tumor made at necropsy 7 weeks later consisted predominantly of atypical squamous epithelial cells compatible with squamous cell carcinoma. Histologically, the malignancy was noted to have intermixed areas of abnormal squamous and transitional cell proliferation. The neoplasia was interpreted as a transitional cell carcinoma with extensive transformation to squamous cell carcinoma. This report examines the use and limitations of FNAB in the diagnosis of feline urinary bladder carcinoma and the incidence and behavior of these tumors in the cat.     

Survey of equine cutaneous neoplasia in the Pacific Northwest.

A retrospective study examined data regarding equine cutaneous and mucocutaneous neoplasms submitted to the Veterinary Diagnostic Laboratory at Oregon State University in a 3.5-year period. A total of 536 neoplasms were identified, accounting for 30% of the total equine pathology submissions. Sarcoid, squamous cell carcinoma, melanocytic tumors, papillomas, and mast cell tumors were the most common neoplasms, constituting 87.5% of all cutaneous neoplasms. Sarcoids represented 51.4% of all neoplasms and 15.18% of total equine accessions. Sarcoid was most common in paints, quarter horses, and Arabians, and was the only common tumor in donkeys and mules. Mean age at diagnosis of equine sarcoid was 9 years. Squamous cell carcinoma constituted 18.3% of all neoplasms and 5.41% of total equine accessions. Ocular squamous cell carcinoma was most common in paints and quarter horses, and penile/preputial squamous cell carcinoma was most common in appaloosas and quarter horses. The mean age of horses with ocular squamous cell carcinoma (13 years) and squamous cell carcinoma of the skin (15 years) was significantly less (P < 0.5) than that of horses with squamous cell carcinoma of the penis and prepuce (21 years) or vulva, anal, and perianal skin (19 years). Findings suggest that equine sarcoid and squamous cell carcinoma occur more frequently in the Pacific Northwest than in the northeastern United States.     

家畜的消化系统增生性病变与癌前病变的研究

增生性病变与癌前病变的研究对于肿瘤的早期诊断、早期防治以及认识肿瘤在形态学上的发生发展过程均有重要意义。国内外医学对这一方面的研究日益重视,但在兽医科学领域中,尚未引起注意。本文作者应用病理组织学方法,对家畜和一部分野生动物的食管、胃和大小肠等消化系统组织共1,037例进行了研究,检出了一批增生性病变和癌前病变,它们是:上皮的单纯性增生、上皮的乳头状增生、粘膜白斑、慢性溃疡、上皮的不典型增生、乳头状瘤和腺瘤性息肉。研究中并发现上皮的异型性增生、乳头状瘤癌变为原位癌与浸润癌,以及腺瘤性息肉恶变为腺癌等移行现象。 本文重点描述检出的各种增生性病变与癌前病变的形态学特征,并对某些病变向癌转变的移行现象进行了分析讨论。     

Monoclonal antibodies: cell surface markers for canine keratinocytes

Plasma membranes were isolated from cultured canine keratinocytes by paraformaldehyde-induced membrane vesiculation. The isolated plasma membrane vesicles retained cell surface antigens (eg, a pemphigus vulgaris antigen). These membrane vesicles were used as an antigen source for the production of monoclonal antibodies. Eight antibodies that had specific reactivity to the cytoplasmic membrane of keratinocytes on frozen sections of canine esophagus were identified by use of an indirect immunoperoxidase method. The stratified squamous epithelium of the esophageal mucosa had 4 staining patterns. When applied to frozen sections of canine skin, lip, and tongue, the antibodies had different tissue specificities for differing stratified squamous epithelia. Using sodium dodecyl sulfate polyacrylamide-gel electrophoresis and the western blot technique, one of the antibodies was specific for a 60-kD cell surface molecule. Therefore, such monoclonal antibodies may be useful in defining heterogeneity between different stratified squamous epithelia, in identifying biologically important surface antigens, or in the diagnosis of tumors.     

Treatment by digital amputation of subungual squamous cell carcinoma in dogs: 21 cases (1987-1988)

Malignant digital tumors were diagnosed in 62 dogs during a 1-year period. Twenty-one (33.9%) of the dogs had subungual squamous cell carcinoma. Each of these dogs had involvement of single digits. Sixteen (76.2%) of the dogs with squamous cell carcinoma were large-breed dogs, and 15 (71.4%) had predominantly black coats. Labrador Retrievers (n = 5, 23.8%) and Standard Poodles (n = 3, 14.3%) were the most commonly represented purebreeds. None of the dogs had evidence of metastases prior to treatment. All 21 tumors were treated by amputation of the involved digit. Histologic evidence of neoplastic bone invasion was found in 15 of the 21 amputated digits (71.4%). Local tumor recurrences were not observed. Only 1 dog developed documented metastatic disease; this dog was euthanatized because of pulmonary metastases 5 months after surgery. At the time of this report, 9 dogs (42.9%) were alive with no evidence of disease (median, 26 months after surgery), and 11 dogs (52.4%) had died or were euthanatized (median, 20 months after surgery). The cause of death in 7 dogs was known to be unrelated to squamous cell carcinoma, and the cause of death in 4 dogs was unknown. The 1-year and 2-year survival rates were 76.2% and 42.9%, respectively.