Metronidazole neurotoxicosis in two cats

Two cats were presented for neurological dysfunction from suspected metronidazole toxicity. One cat was receiving 111 mg/kg body weight per day of metronidazole for 9 weeks. After 9 weeks, the dose was increased to 222 mg/kg body weight per day, and 2 days later the cat began to experience progressive neurological signs that culminated in generalized seizures. The second cat was receiving metronidazole at a total dose of 58 mg/kg body weight per day for 6 months. This cat experienced acute onset of ataxia and alteration in mentation. Laboratory evaluations in both cases were without significant findings. The neurological signs in both cats resolved within days of initiating supportive therapy and withdrawal of the drug. This report describes the two cases and discusses the etiology of metronidazole neurotoxicosis.     

Pulmonary adenocarcinoma with osteoblastic bone metastases in a cat

A 12-year-old male cat with depression and dyspnoea was presented for investigation. Radiography and computed tomography revealed hydrothorax and solid masses involving the sternum, ribs and thoracic vertebrae. The cat died two days after first presentation, and postmortem examination revealed lung masses and proliferative bony lesions. Histologically, a neoplastic proliferation of epithelial cells was seen in the lungs, with a large amount of collagen and deposits of cholesterin. The bone lesions were also composed of neoplastic epithelial cells and abundant calcified osteoid, without atypia. A diagnosis of pulmonary adenocarcinoma with osteoblastic bone metastases was made. This is the first reported case of osteoblastic metastases in the cat.     

Treatment and long-term follow-up of extrahepatic biliary obstruction with bilirubin cholelithiasis in a Somali cat with pyruvate kinase deficiency

A 2-year-old female neutered Somali cat was presented with vomiting and acute onset jaundice 1 year after diagnosis of pyruvate kinase (PK) deficiency. Diagnostic investigations revealed a moderate regenerative haemolytic anaemia, severe hyperbilirubinaemia and elevated liver enzymes. Ultrasonography revealed marked distension of the gall bladder and common bile duct (CBD), consistent with extrahepatic biliary obstruction (EHBO). At cholecystotomy, the gall bladder contained purulent material, and two obstructive choleliths were removed from the CBD by choledochotomy. The cat recovered from surgery uneventfully, and serum liver enzymes and bilirubin normalised within 10 days. Postoperative treatment consisted of cephalexin, metronidazole and ursodeoxycholic acid (UDCA). Bacterial culture of the gall bladder contents yielded a pure growth of an Actinomyces species. Cholelith analysis revealed that they consisted of 100% bilirubin. Antibiotic treatment was stopped 4 weeks after surgery but UDCA was continued indefinitely. The cat remains clinically well with no recurrence of cholelithiasis 20 months after initial presentation. This is the first report of successful treatment and long-term follow-up of a cat with EHBO due to bilirubin cholelithiasis in association with PK deficiency-induced chronic haemolysis.     

Feline giardiasis: observations on natural and induced infections

The excretion of Giardia sp cysts in the feces of naturally and artificially infected cats fluctuated sporadically, and cysts were undetectable several times during 7 weeks of observation. The mean prepatent period for Giardia infection in 7 cats was 9.6 days (range, 5 to 16 days). The amount of the cyst inoculum did not appear to affect the length of the prepatent period. Six of 11 cats had clinical signs consistent with those of giardiasis. Clinical signs and cyst excretion were eliminated after treatment with metronidazole or furazolidone. Moderate oral or parenteral doses of corticosteroids produced little, if any, alteration in the infection. Postmortem examination of 1 inoculated cat revealed Giardia trophozoites in the jejunum and upper portion of the ileum but not in the duodenum, lower portion of the ileum, cecum, or colon. Giardia cysts isolated from cat feces produced infection in Mongolian gerbils but not in C57BL/6J mice.     

Treatment of feline giardiasis with metronidazole

Seven cats from a single household with 17 cats were shedding cysts of Giardia species as detected by a modified zinc sulfate concentration technique. All the cats were housed individually in Horsfal isolation units for the duration of the evaluation, treatment, and follow-up monitoring. Each of the infected cats was treated with metronidazole at a dose of 22 mg per kg of body weight, twice a day, for 5 days. Post-treatment examination of four or five stool samples from each cat during the following 17 days did not reveal the presence of any giardial cysts in the treated cats. After treatment, the diarrhea either ceased or was markedly diminished. Therefore, metronidazole appears to be an effective form of therapy for feline giardiasis.     

Metronidazole for the treatment of feline giardiasis

There are several drugs available for the treatment of giardiasis in cats, including metronidazole. The purpose of this study was to determine whether metronidazole benzoate administered at a dose of 25 mg/kg, orally, twice a day for 7 days lessens or eliminates Giardia cyst shedding in cats with chronic infection. Twenty-six, adult, laboratory-reared cats were used in this study. Sixteen cats had been inoculated orally with cysts of a human Giardia sp. isolate and had completed a Giardia vaccine study in one animal holding room. The other ten cats were infected with the same Giardia sp. presumably by contamination from the adjacent room where the Giardia vaccine study cats were located. From each cat, a fecal sample was collected within 1 week of the start of treatment and then every 2 to 4 days for 15 days after treatment was completed. Fecal samples were analyzed for the presence of Giardia cysts using a commercially available direct immunofluorescence test (IFA). Clinical signs of drug toxicity were not detected during the study.     

Disseminated Mycobacterium avium subspecies infection in a cat

An 18-month-old neutered male domestic shorthair cat, domiciled in the southwest of France, was first presented having suffered for a few days from dysorexia and vomiting. Abdominal palpation revealed lymph node enlargement. Cytological examinations of a fine needle aspirate demonstrated granulomatous inflammation with many non-staining elements consistent with mycobacteria. Diagnosis was confirmed by culture and polymerase chain reaction and Mycobacterium avium subspecies was isolated. Treatment was initiated with marbofloxacin, rifampicin and cefoxitin. There was a rapid clinical improvement. The cat suddenly died 2 months later. The main hypothesis is the administration of an inappropriate combination therapy that leads to the development of mycobacterial resistance. A volvulus and acute peritonitis secondary to the significant enlargement of a mesenteric lymph node were present at necropsy. Histopathological analysis of mesenteric lymph node, liver and spleen revealed multicentric granulomatous and severely necrotic lesions with numerous Ziehl-Neelsen positive intracytoplasmic elements.     

Cerebral Blastomyces dermatitidis infection in a cat

CASE DESCRIPTION: An 8-year-old domestic shorthair cat was evaluated because of signs of depression, circling, and visual deficits. CLINICAL FINDINGS: The cat had no cutaneous lesions, and results of an ophthalmologic examination and thoracic radiography were within reference limits. Computed tomography of the brain revealed a mass lesion involving the right parietal, temporal, and occipital lobes; the mass was in broad-based contact with the skull and smoothly marginated and had strong homogenous enhancement after contrast agent administration. During craniectomy, samples of the mass were collected for cytologic and histopathologic evaluations and microbial culture. A diagnosis of Blastomyces dermatitidis-associated meningoencephalitis with secondary pyogranulomatous inflammation was made. TREATMENT AND OUTCOME: Amphotericin B (0.25 mg/kg [0.11 mg/lb], IV) was administered on alternate days (cumulative dose, 1.75 mg/kg [0.8 mg/lb]). To minimize the risk of nephrotoxicosis, assessments of serum biochemical variables (urea nitrogen and creatinine concentrations) and urinalyses were performed at intervals. The third dose of amphotericin B was postponed 48 hours because the cat became azotemic. The cat subsequently received fluconazole (10 mg/kg [4.5 mg/lb], PO, q 12 h) for 5.5 months. Six months after discontinuation of that treatment, the cat appeared healthy and had no signs of relapse. CLINICAL RELEVANCE: Brain infection with B dermatitidis is typically associated with widespread disseminated disease. The cat of this report had no evidence of systemic disease. Blastomycosis of the CNS should be considered as a differential diagnosis for brain lesions in cats from areas in which B dermatitidis is endemic.     

OSTEOGENIC SARCOMA OF THE NASAL CAVITY IN A CAT: POSTOPERATIVE CONTROL WITH HIGH DOSE-PER-FRACTION RADIATION THERAPY AND METRONIDAZOLE

An 11-year-old Siamese cat with an osteogenic sarcoma of the nasal cavity was treated by partial surgical excision followed by a course of high dose-per-fraction radiation therapy in conjuction with metronidazole, a hypoxic cell sensitizer. Four thousand two hundred rads were delivered to the tumor in 7 weekly fractions. Each treatment was preceded by 6 gm/m² oral metronidazole given 3 hours before irradiation. There were no untoward side effects and the cat was in remission 2 years after treatment.     

Abortions in sheep caused by Salmonella Brandenburg: Pathological findings

CASE HISTORY: A 7-year-old cat developed sporadic vomiting, reduced appetite, and weight loss over the previous 3 months.

CLINICAL FINDINGS: Palpation revealed a large mid-abdominal mass and the cat had marked eosinophilia. The cat progressively lost weight over the next 7 weeks when euthanasia was performed.

PATHOLOGICAL FINDINGS: Necropsy revealed a 3?cm diameter firm white intramural mass in the colon and another in the pylorus. Mesenteric and cranial mediastinal lymph nodes were firm, pale, and enlarged. Histopathological examination revealed foci of necrosis surrounded by thick dense collagen trabeculae and predominantly eosinophilic inflammation within the intestine and lymph nodes. Marked eosinophilic infiltration of the liver was also present.

DIAGNOSIS: The lesions were consistent with gastrointestinal eosinophilic sclerosing fibroplasia (FGESF).

CLINICAL RELEVANCE: This is the first report of FGESF in a New Zealand cat and the first time lesions of FGESF have been observed in extra-abdominal tissues. Intestinal neoplasia can be clinically identical to FGESF and histopathology is required for differentiation. Evidence suggests that FGESF has a more favourable prognosis than intestinal neoplasia.     

Late onset and rapid progression of cerebellar abiotrophy in a domestic shorthair cat

A two-year-old male domestic shorthair cat was seen because of sudden onset of incoordination and tremors that had rapidly worsened over five days. Neurological examination revealed severe cerebellar ataxia, intention tremors and bilaterally decreased menace response. Blood work evaluation included a complete cell blood count (CBC), serum biochemistry profile, urinalysis, faecal flotation, cerebrospinal fluid (CSF) analysis and retroviral testing. Except for testing positive for feline immunodeficiency virus (FIV) antibodies, all other results were within the normal range. The patient was euthanased two days later because of progression of clinical signs, and a necropsy was performed. Histologically, lesions were limited to the cerebellum and consistent with cerebellar abiotrophy. No secondary diseases that could explain the rapid development of clinical signs were found. It was considered unlikely that cerebellar degeneration was related to FIV positivity, as virus invasion of the central nervous system (CNS) is mainly limited to the cerebral cortex. This case report is the first to describe late onset and rapid progression cerebellar abiotrophy in a cat.     

A case of diet-related lymphocytic mural folliculitis in a cat

A 5-year-old cat developed a raised hair coat and adherent crusting lesions involving the skin of the head, dorsal neck and abdomen. Erosions were present on the lips and eyelids. The footpads were dry and scaly. Histopathology revealed infiltrative lymphocytic folliculitis, moderate lymphocytic infiltration into the epidermis and apoptotic epidermal cells. A restricted diet as the only therapy resulted in gradual resolution of the skin lesions. Despite an improvement in the dermatological condition, the cat increasingly lost all appetite and marked weight loss occurred. The cat died 4 months after presentation. Post-mortem revealed a perforated gastric ulcer and a mild to moderate inflammatory bowel disease. The clinical course of lesion resolution in this cat suggested a diet-related pathogenesis. The late finding of intestinal disease in a patient with diet-related skin disease is still interesting and needs to be evaluated by further case studies.     

Neosporosis in cats

Six cats (Nos. 1-6) were inoculated intramuscularly with (1 x 10(6)) and orally (5 x 10(5)) tachyzoites of Neospora caninum. Three (Nos. 1-3) of the six cats were given 40 mg/kg methylprednisolone acetate 7 days before and on the day of inoculation with N. caninum tachyzoites, and three cats (Nos. 4-6) were not given methylprednisolone acetate. Two of the cats (cat Nos. 1 and 2) given methylprednisolone acetate died suddenly. Cat No. 1 died 8 days post-inoculation, and cat No. 2 died 16 days post-inoculation. Cat No. 3 was euthanatized 21 days post-inoculation. Cat No. 1 had lesions of gram-positive bacterial septicemia. Necrotizing encephalitis, myelitis, disseminated skeletal muscle necrosis, hepatic necrosis, interstitial pneumonia, and renal tubular necrosis were the main lesions in cat Nos. 2 and 3. The cats that were not given methylprednisolone acetate remained clinically normal except for slight weight loss in cat No. 6. All three of these cats were euthanatized 55 days post-inoculation. Mild myositis and encephalitis were noted on microscopic examination of tissues from these three cats. Neuromuscular lesions were not seen in six control cats (Nos. 7-12) not inoculated with N. caninum and euthanatized 21 or 22 days after administration of the first two doses of methylprednisolone acetate (40 mg/kg), given at a weekly interval.     

Evaluation of clinical, macroscopic, and histopathologic response to treatment in nonhypoproteinemic dogs with lymphocytic-plasmacytic enteritis

BACKGROUND: Lymphocytic-plasmacytic enteritis (LPE) is a common cause of chronic vomiting and diarrhea in dogs. However, little information is available about endoscopic or histopathologic improvement after therapy in dogs with LPE. HYPOTHESIS: The objective was to study the clinical, endoscopic, and histopathologic evolution of LPE during and after immunosuppressive treatment with prednisone and metronidazole. Most dogs also were treated symptomatically with metoclopramide and cimetidine. ANIMALS: Sixteen dogs with LPE and normal serum protein concentrations diagnosed at the Veterinary Medical Teaching Hospital of the Complutense University of Madrid were monitored during and after drug treatment. The control group consisted of 9 dogs that had no gastrointestinal signs for the preceding 12 months. METHODS: In this prospective clinical treatment trial, clinical, endoscopic, and histopathologic scores were evaluated to describe disease evolution during conventional therapy. Dogs with LPE were monitored for 120 days from the start of treatment. Re-evaluation was performed on post-treatment days 30, 60, 90 (end of treatment), and 120. RESULTS: The average disease activity index observed in our study fell progressively from its initial value, and the decrease between consecutive re-evaluations was statistically significant until day 60 (P = .04). Our results indicate that 75% of the animals revealed improvement of endoscopic gastric lesions (defined as a reduction of the endoscopic score) after treatment, and 75% exhibited improvement of endoscopic duodenal lesions. Statistical analysis of the data revealed significant differences between pre- and post-treatment gastric and duodenal macroscopic endoscopic lesions (P < .05). On the other hand, treatment did not lead to any significant changes in the severity of the gastric and duodenal histopathologic lesions of the affected dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment of nonhypoproteinemic dogs with LPE led to clinical and endoscopic improvement, but histopathologic lesions were unchanged during therapy.     

Pustular calicivirus dermatitis on the abdomen of two cats following routine ovariectomy

An unusual form of calicivirus dermatitis is described in two cats. Two fully vaccinated cats were re-admitted for anorexia and depression following routine ovariectomy. Signs of upper respiratory disease were not present. One cat subsequently showed painful necrosis of the incision wound, the other one developed dyspnoea with pleural effusion and discrete tongue ulcers. Intact pustular lesions confined to the surgically prepared abdomen appeared in both cats, respectively, on days 11 and 9. The histopathological diagnosis was panepidermal pustulosis and necrotizing dermatitis. Positive immunohistochemical staining consistent with feline calicivirus antigen was detected in epithelial cells within pustular lesions. The cats were treated with antibiotics and ketoprofen. The cat with progressive dyspnoea was euthanized. The clinical signs in the other cat rapidly and completely resolved following glucocorticoid therapy. It is hypothesized that the reported cases may represent a distinct calicivirus-induced pustular dermatitis following ovariectomy.     

Electrochemotherapy treatment for bilateral pleomorphic rhabdomyosarcoma in a cat

A 13-year-old male neutered cat was presented for the sudden growth of two nodular lesions close to the upper eyelid of both eyes. Fine-needle aspiration cytology was suggestive of mesenchymal neoplasia. The cat had conservative surgical excision in order to preserve the eyelids’ functionality; however, the histopathological report came with a diagnosis of incompletely excised bilateral pleomorphic rhabdomyosarcoma. Due to the local aggressiveness of this neoplasm, the cat was treated with two sessions of cisplatin-based electrochemotherapy, delivered 14 days apart. Systemic or local toxicities were not detected during the whole course of therapy. The cat is still in complete remission after 12 months. Electrochemotherapy is a safe and efficacious adjuvant therapy for aggressive sarcomas and warrants further investigations in order to standardise its protocols.     

Utility of 5-aminolaevulinic acid fluorescence-guided endoscopic biopsy for malignant mesothelioma in a cat and dog

Malignant mesothelioma (MM) is uncommon in cats and dogs and can be challenging to diagnose. Adequate tissue sampling is required for superior diagnostic accuracy. Protoporphyrin IX, a metabolite of 5-aminolaevulinic acid (5-ALA), is a photosensitiser for photodynamic diagnosis (PDD). To the best of our knowledge, no study has reported the use of 5-ALA-PDD to detect MM in veterinary medicine. The present study describes the use of 5-ALA-PDD for MM diagnosis in a cat and dog, as well as the effectiveness of intracavitary chemotherapy. We evaluated the use of PDD with 5-ALA hydrochloride (5-ALA-PDD) in two cases of MM. A 12-year-old cat presented with a 1-month history of respiratory distress, and a 9-year-old dog presented with a 3-month history of mild abdominal distention. We endoscopically biopsied lesions in both the cases using 5-ALA-PDD. Histopathological examination revealed mesothelioma, and immunohistochemical staining was positive for calretinin. Both patients were treated with carboplatin. The cat died of respiratory failure. Although, the dog's condition improved 21 days after the first chemotherapeutic drug administration, the dog died on day 684 owing to cardiac-related issues. 5-ALA-PDD is thus, safe and feasible for the diagnosis of MM in veterinary medicine.     

Efficacy of ronidazole for treatment of feline Tritrichomonas foetus infection

OBJECTIVES: To determine the efficacy of ronidazole (RDZ), tinidazole (TDZ), and metronidazole (MDZ) against Tritrichomonas foetus in vitro and of RDZ for treatment of feline naturally occurring or experimentally induced T. foetus infection. ANIMALS: A cat naturally infected with T. foetus infection and diarrhea. Ten specific-pathogen-free (SPF) kittens. PROCEDURE: RDZ, TDZ, and MDZ were tested for activity against 3 different feline isolates of T. foetus in vitro. RDZ then was administered to a naturally infected cat at 10 mg/kg PO q24h for 10 days. SPF kittens were infected orogastrically with feline T. foetus and treated with either placebo or RDZ (10 mg/kg PO q12h for 14 days). Cats with relapsing infection or those receiving placebo were treated subsequently with RDZ (either 30 or 50 mg/kg PO q12h for 14 days). Feces were examined for T. foetus by direct microscopy, culture, and polymerase chain reaction (PCR) testing weekly. RESULTS: Both RDZ and TDZ killed T. foetus at concentrations >0.1 microg/mL in vitro. In the naturally infected cat, RDZ abolished diarrhea and T. foetus infection for 85 days after treatment, at which time infection and diarrhea relapsed. Retreatment with RDZ eradicated diarrhea and T. foetus infection for over 407 days. In experimentally induced infection, RDZ at 10 mg/kg caused initial improvement, but infection relapsed in all 5 cats 2 to 20 weeks after treatment. At 30 or 50 mg/kg, 10/10 cats were negative for T. foetus infection for follow-up durations of 21 to 30 weeks after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of RDZ at 30 to 50 mg/kg q12h for 14 days resolved diarrhea and eradicated infection (on the basis of polymerase chain reaction [PCR] testing) in 1 naturally infected cat and 10 experimentally inoculated cats receiving a different isolate of T. foetus.     

An unusual species of demodex mite in a cat

Skin scrapings taken from an adult neutered female cat were found to contain demodicid mites. These differed morphologically from Demodex cati but resembled a currently unnamed species which has recently been reported from the cat. Measurements of this parasite are given for the first time. The skin lesions were treated with rotenone, but the animal died within a few days of this treatment.