Comparison of ophthalmic loteprednol etabonate and prednisolone acetate effects on adrenocortical response to ACTH in dogs.

OBJECTIVE: This study served to compare the degree of adrenocortical suppression following a 2-week administration of loteprednol etabonate (LE) and prednisolone acetate (PA) ophthalmic drops. PROCEDURES: In this prospective double-masked triple-crossover study, 21 clinically healthy dogs were randomized to receive loteprednol etabonate ophthalmic suspension 0.5%, prednisolone acetate ophthalmic suspension 1%, or artificial tears (AT). Each group (LE, PA, and AT) received one drop in each eye every 12 h for 2 weeks, followed by a 3-week washout period between treatment blocks. ACTH stimulation tests were performed before and after each treatment block. Serum cortisol samples were drawn before and 60 min after administration of 1 µg/kg cosyntropin IV. Repeated-measurement ANOVA followed by a Tukey's multiple comparisons test (or a Friedman test followed by a Dunn's multiple comparisons test) were used to compare pre- and post-treatment cortisol values between each group. A p-value of ≤.05 was considered significant. RESULTS: A total of 18 dogs completed the study. Prestimulation cortisol values were lower in the PA group compared to the LE (p = .0106), but not AT (p = .0589) groups, and post-stimulation cortisol values were lower in the PA group than either LE (p = .0005) or AT (p = .0002) groups. There was no significant difference detected in pre- or post-stimulation cortisol values after the treatment periods between LE and AT. CONCLUSIONS: Based on the reduced suppression of cortisol values, LE caused significantly less hypothalamic-pituitary-adrenal axis suppression than PA. A topical steroid with minimal adrenocortical suppression, such as LE, may be favorable in patients where systemic glucocorticoid effects should be avoided.

Severe meningoencephalitis secondary to calvarial invasion of Lagenidium giganteum forma caninum in a dog.

Background: The oomycete Lagenidiumgiganteum forma caninum is an uncommon cause of severe dermal and subcutaneous infections in dogs with possible vascular invasion and other fatal sequelae. Infection within the central nervous system of affected dogs has not been previously reported. Case Description: A 6-year-old spayed female mixed-breed dog was evaluated at a referral institution with a 2-month history of suspected fungal infection in the region of the right mandibular lymph node that was refractory to surgical resection and empiric medical therapy. Physical examination identified a 6-cm fluctuant subcutaneous mass caudoventral to the ramus of the right mandible and a second firm mass in the region of the right caudal maxilla. Lesional punch biopsies were submitted for fungal culture and polymerase chain reaction (PCR), which subsequently identified L. giganteum forma caninum infection. Initial treatment consisted of anti-inflammatory doses of prednisone and hyperbaric oxygen therapy. Four weeks following initial evaluation, the patient was presented with progressive neurological signs consistent with a forebrain lesion. Magnetic resonance imaging revealed soft-tissue, contrast-enhancing lesions ventral to the calvarium adjacent to the site of original surgical resection and throughout the brain. Humane euthanasia was elected, and postmortem examination was consistent with the extension of local disease from the right masseter muscle into the right ventral calvarium. Postmortem DNA sequencing confirmed the identity of the organism as L. giganteum forma caninum. Conclusion: This is the first reported case of intracranial lagenidiosis in the dog. PCR distinguished this species from other Lagenidium species and from oomycetes of other genera, such as Pythiuminsidiosum and Paralagenidium karlingii. Regional extension of cutaneous lagenidiosis should therefore be considered in cases with concurrent or spontaneous neurologic disease.

Erysipeloid lesions caused by Erysipelothrix rhusiopathiae in a dog: clinical and histopathological findings, molecular diagnosis and treatment.

BACKGROUND: Erysipelothrix rhusiopathiae is a widespread Gram-positive, nonsporulating rod bacterium predominantly associated with skin disease in swine and cetaceans. Cutaneous lesions have yet to be described in dogs. OBJECTIVE: To describe the clinical presentation, molecular and histopathological diagnosis, and treatment of a case of erysipeloid caused by E. rhusiopathiae in a dog. ANIMALS: A 6-month-old spayed female standard poodle dog presented with lethargy, fever, vomiting and diarrhoea. Skin lesions appeared 20 days post first examination. METHODS AND MATERIALS: Complete blood count, serum chemistry profile, urinalysis, urine culture, blood culture, computed topography, forelimb radiography, joint and cerebrospinal fluid aspiration were performed; samples were collected for skin cytological evaluation, culture and histopathological analysis. RESULTS: Blood cultures yielded Gram-positive, catalase-negative bacilli. Histopathological evaluation of skin biopsies revealed lymphoplasmacytic, neutrophilic and histiocytic perivascular and periadnexal dermatitis, and vasculitis. Cutaneous and blood PCR and sequencing of 16S rRNA identified the bacteria as E. rhusiopathiae. Clinical resolution was observed following the use of of amoxicillin/clavulanic acid and ciprofloxacin therapies. CONCLUSIONS AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first confirmed case of erysipeloid caused by E. rhusiopathiae in a dog. Clinical resolution was attained with the extended use of antibiotics. After 13 months, no clinical signs had returned.

Novel treatment using topical malachite green for nasal phaeohyphomycosis caused by a new Cladophialophora species in a cat.

CASE SUMMARY: A 1.5-year-old castrated male domestic shorthair cat presented with a 2 month history of progressive nasal swelling and hyporexia. Minimal improvement prior to referral was achieved with a course of antibiotics and glucocorticoids. Cytology of an ulcerative lesion on the dorsal aspect of the nose was consistent with a diagnosis of phaeohyphomycosis. The cat achieved static disease for 6 weeks following initiation of itraconazole but developed epistaxis at 9 weeks. CT of the head demonstrated nasal and frontal sinus involvement. Nasal biopsy and culture identified infection with a Cladophialophora species not previously reported to cause disease. Initial response to a combination of itraconazole and terbinafine was noted, but owing to severe thrombocytopenia this combination was discontinued. Voriconazole was used but discontinued because of adverse side effects. Posaconazole treatment was offered throughout the clinical course but rejected owing to financial constraints and an uncertain response to medical therapy. Rhinotomy with debulking of diseased tissue and topical malachite green treatment was performed. Following the procedure itraconazole was continued and the cat has had no recurrence for over 1 year. RELEVANCE AND NOVEL INFORMATION: Infections by Cladophialophora species have been reported in veterinary species, including cats. The specific fungal organism isolated from this cat has not been previously reported to cause disease in humans or animals and has only been described in the mangroves of Brazil. Furthermore, this is the first report to describe the use of topical malachite green as a treatment for refractory phaeohyphomycosis.

Effects of therapeutic plasma exchange on serum immunoglobulin concentrations in a dog with refractory immune-mediated hemolytic anemia.

CASE DESCRIPTION A 9-year-old 8.3-kg (18.3-lb) neutered male Miniature Schnauzer was referred for diagnosis and treatment of a sudden onset of lethargy, anorexia, vomiting, and pallor. CLINICAL FINDINGS On physical examination, the dog was lethargic with pale mucous membranes and a capillary refill time ≥ 2 seconds. Skin and sclera were mildly icteric. Signs of pain were elicited during abdominal palpation, and an enlarged spleen was noted. Results of agglutination testing and cytologic findings were consistent with immune-mediated hemolytic anemia (IMHA). No contributing factors for development of IMHA were identified. TREATMENT AND OUTCOME Initial treatment included management with immunosuppressant medications. Three packed RBC transfusions were administered, but clinical signs continued to progress. Therefore, therapeutic plasma exchange (TPE) was performed 5 and 9 days after admission. Following each TPE procedure, the dog had an appreciable clinical improvement and decrease in RBC autoagglutination, and the Hct stabilized. Serum IgG and IgM concentrations were measured during and after both TPE procedures. Despite anticoagulative treatment, the dog developed a thrombus in the splenic vein, necessitating a splenectomy. CLINICAL RELEVANCE The decrease and rebound in serum IgG and IgM concentrations following TPE provided evidence that TPE may have the same immunomodulatory effects in dogs as have been proposed to occur in people. Further, findings suggested that TPE may be a useful alternative in dogs with refractory IMHA when traditional treatments fail.