Disseminated hemangiosarcoma in a horse

A 6.5-year-old horse with a history of exercise-induced pulmonary hemorrhage was admitted because of acute onset of epistaxis, dyspnea, high respiratory rate, pale mucous membranes, and dark feces. There was no clinical or laboratory evidence of a bleeding disorder, and the horse's anemia was considered to be secondary to pulmonary hemorrhage. The cause of the hemorrhage was not found on thoracic sonograms or from cytologic examination of transtracheal aspirates. Despite supportive care, the horse's health deteriorated, and it was euthanatized. Necropsy revealed blood in the thoracic and peritoneal cavities and reddish black masses in many tissues. Histologic examination confirmed a diagnosis of hemangiosarcoma. Hemangiosarcoma is a rare tumor in horses; however, as this case demonstrates, it can cause pulmonary hemorrhage and respiratory distress and may be difficult to diagnose before death.     

An outbreak of eosinophilic bronchitis in horses possibly associated with Dictyocaulus arnfieldi infection.

Eight mature horses which had been affected with a moist cough for six weeks were found to have large numbers of eosinophils in tracheal mucus samples taken by transtracheal washing. These horses were kept on irrigated pasture and fed a hay-free diet. A companion yearling donkey was found to be passing Dictyocaulus arnfieldi larvae in its faeces. Two oral treatments with a dose of thiabendazole (440 mg/kg) resulted in the resolution of the clinical signs and the disappearance of eosinophils from transtracheal washings. The eosinophilic bronchitis seen in these horses was presumed to be a manifestation of prepatent D arnfieldi infestation.     

Cryptococcosis in captive cheetah (Acinonyx jubatus): two cases

Cryptococcus neoformans is a yeast-like organism associated with pulmonary, meningoencephalitic, or systemic disease. This case report documents 2 cases of cryptococcosis with central nervous system involvement in captive cheetah (Acinonyx jubatus). In both cases the predominant post mortal lesions were pulmonary cryptococcomas and extensive meningoencephalomyelitis. Both cheetahs tested negative for feline immunodeficiency virus and feline leukaemia virus. The organism isolated in Case 2 was classified as Cryptococcus neoformans var. gattii, which is mainly associated with disease in immunocompetent hosts.     

Successful treatment of invasive nasal cryptococcosis in a ferret

Invasive cryptococcal rhinitis due to Cryptococcus neoformans var gattii was diagnosed in a castrated, 5-year-old, albino ferret with subcutaneous swelling of the nasal bridge. The diagnosis was based on histology, needle aspirate cytology and positive culture on Sabouraud's dextrose agar and birdseed agar. The ferret was successfully treated using a long course of itraconazole (25 to 33 mg orally once daily with food) subsequent to surgical debulking of the lesion, using sequential cryptococcal antigen titre determinations to guide therapy.     

Detection of PRRSV circulation in herds without clinical signs of PRRS: comparison of five age groups to assess the preferred age group and sample size

The extraordinary ability of Cryptococcus species to cause disease has focused the attention of scientists on finding ways to improve their identification methods. In this study, PCR-REA, manual methods (morphological and biochemical characteristics), API 20C and VITEK 2 were used to test identify a total of 30 Cryptococcus spp. from human and veterinary sources. PCR-REA was performed using the capsular region as amplification target followed by restriction with the enzymes AgeI, BsmFI and HpaII. PCR-REA identified the strains as C. neoformans var. grubii (n=19) and C. gattii (n=8). There was no significant difference between the API 20C AUX and VITEK 2 when compared to manual methods for the identification of Cryptococcus spp. However, none of these non-manual methods were able to detect C. gattii samples. PCR-REA showed a greater level of concordance with the manual method, besides being faster and more sensitive than the other methods. Therefore, it is indicated for routine identification of Cryptococcus spp. strains.     

Anaerobic bacterial pneumonia with septicemia in two racehorses

Anaerobic bacterial pneumonia with septicemia was diagnosed in 2 Thoroughbred racehorses referred with respiratory tract disease that had failed to respond to initial treatment with various antibiotics including penicillin and trimethoprim-sulfamethoxazole. Multiple anaerobic organisms, including Bacteroides spp and Fusobacterium spp, were isolated from blood and transtracheal aspirates obtained from both horses and from aspirates of cutaneous nodules obtained from 1 horse. The latter horse responded to metronidazole treatment followed by procaine penicillin G administration and regained its health over the following 6 months. The other horse did not respond as favorably to a similar antibiotic regimen and died following an acute episode of pulmonary hemorrhage after remaining intermittently febrile for 7 weeks. Although in vitro antimicrobial susceptibility tests indicated that all anaerobic organisms isolated from both horses were susceptible to penicillin, the infection in these horses responded poorly to initial treatments with this drug. We speculated that adequate penicillin concentration was not attained in the deep foci of infection in the lungs. Animals with anaerobic bacterial infections that fail to respond to penicillin or from which penicillin-resistant anaerobes are isolated may benefit from treatment with metronidazole.     

Evaluation of nasotracheal aspiration as a diagnostic tool for Rhodococcus equi pneumonia in foals

The reliability of preparing bacteriological cultures from nasotracheal aspirates of foals routinely in order to diagnose R. equi pneumonia in foals was studied by isolating Rhodococcus equi from specimens obtained from 96 foals by nasotracheal aspiration with a silicon catheter. Results were compared with specimens obtained from 21 foals by transtracheal aspiration (percutaneous tracheal puncture). These 117 foals showed clinical signs of respiratory tract infection at sampling. R. equi was isolated from 14 of 21 (66.7%) specimens by transtracheal aspiration and from 59 of 96 (61.4%) specimens by nasotracheal aspiration, 649 of 655 isolates (99.1%) from the 73 positive specimens were virulent R. equi, and the culture-positive foals were diagnosed as having R. equi pneumonia. To assess the contamination of aspirates by organisms from the nasopharynx, the results of R. equi isolation from nasal swabs obtained from 56 of the 96 foals were compared to those obtained by nasotracheal aspiration from the same foals. R. equi was isolated from 2 of the 56 nasal swabs: one from a tracheal aspirate was positive, and the other was not. These results suggest that the nasotracheal aspiration technique, which is noninvasive and not associated with complications, could be used as an alternative to the transtracheal aspiration method, especially for the diagnosis of R. equi pneumonia in foals.     

Chronic bronchitis, cardiomegaly and medial hypertrophy of small pulmonary arteries in a dog

A 10-year-old male Labrador Retriever had a history of chronic cough which was refractory to antibiotic and steroid therapy. Cytologic and bacteriologic examinations of transtracheal washings were unremarkable. Thickening of the bronchial mucosa was observed by bronchoscopy. Routine thoracic radiographs were interpreted as indicative of thickening of the bronchial walls and mild cardiomegaly. The dog was killed 2 years later at the owner's request. Chronic bronchitis and medial hypertrophy of the small muscular pulmonary arteries were observed on histopathologic examination.     

Cryptococcosis in Gilbert's and long-nosed potoroo

Two cases of fatal cryptococcosis are described, one of Cryptococcus neoformans infection in a Gilbert's potoroo (Potorous gilbertii) and one of Cryptococcus gattii infection in a long-nosed potoroo (Potorous tridactylus). The diagnoses were confirmed by culture and specific immunohistochemistry, respectively. The long-nosed potoroo tested positive using the latex cryptococcal antigen test (LCAT), whereas the Gilbert's potoroo had a negative LCAT result despite having advanced disease of some duration. In both cases, the clinical presentation was a progressive neurologic disease associated with a central nervous system infection. Pulmonary infection was also observed in the long-nosed potoroo. Specific treatment with antifungal agents was unsuccessful in the long-nosed potoroo.     

Study of efficacy of miltefosine and allopurinol in dogs with leishmaniosis

Visceral leishmaniosis is a life-threatening disease of medical, social and economic importance in endemic areas. It is an opportunistic infection in immunocompromised patients, including human immunodeficiency virus-positive subjects. Dogs are the main reservoir of Leishmania infantum. The aim of this study was to evaluate the efficacy of miltefosine and allopurinol for the control of human leishmaniosis using the dog as a model. The study included 28 sick dogs treated with miltefosine (2 mg/kg/day PO) administered concurrently with allopurinol (10 mg/kg/day, PO) for 30 days, and then with allopurinol alone, at the same dosage, for 1 year. Eight dogs (four of which relapsed) received a second cycle of miltefosine within 6 months of the first cycle. Efficacy was measured by real-time polymerase chain reaction assay on whole blood samples and lymph node aspirates, collected at baseline and every 3 months for 12 months. Of the total number of animals (28), two showed renal insufficiency and died after the start of therapy with miltefosine. Two other dogs presented some side effects to treatment, such as nausea, vomiting and reduction in white and red blood cell counts, and these animals were excluded from the follow-up. The results showed that the first cycle of therapy with miltefosine and allopurinol induced a drastic and progressive reduction of L. infantum load in lymph node aspirates but the second cycle did not eliminate the parasite.     

Cryptococcosis in seven horses

The clinical, radiographic and post-mortem findings in 6 horses with cryptococcal pneumonia and one horse with an abdominal cryptococcal granuloma are described. In pulmonary cryptococcosis, the lesions were either diffuse and multiple, with bilateral lung involvement, or localised mainly to the dorsocaudal region of one lung. The cases of diffuse multiple cryptococcosis were thought to be associated with haematogenous spread of the fungus after gastrointestinal infection and dissemination from regional lymph nodes. The localised form of the disease was thought to have been associated with inhalation of cryptococci. In all cases of pulmonary cryptococcosis, encapsulated yeast-like organisms were demonstrated in Wright's-stained sediment of tracheal washes. In the horse with the abdominal granuloma, cryptococci were present in a fine needle aspirate sample. Isolates of Cryptococcus neoformans var gattii were recovered from 2 of the 5 horses in which cultures were attempted. In addition to a history of previous illness that may have predisposed to infection, most horses in this report had been in areas in which Eucalyptus camaldulensis, or the closely related E rudis, were growing. In humans, an epidemiological relationship between E camaldulensis and infection with C neoformans var gattii has been suggested. Cases of equine cryptococcosis carry a poor prognosis and treatment was not attempted in any of these cases.     

Farnesol inhibits in vitro growth of the Cryptococcus neoformans species complex with no significant changes in virulence-related exoenzymes

Farnesol is a sesquiterpene alcohol that modulates cell-to-cell communication in Candida albicans. In recent years, several studies have shown that this molecule presents inhibitory effects against non-albicans Candida species, Paracoccidioides brasiliensis and bacteria. The present study aimed at determining the effect of farnesol on the growth of strains of the Cryptococcus neoformans species complex, through microdilution assays. In addition, the effect of farnesol on the synthesis of phospholipase and protease - important virulence-associated enzymes - by C. neoformans and Cryptococcus gattii was also investigated. A total of 36 strains were studied, out of which 20 were from veterinary sources, 8 were from human cases and 8 were from a reference collection. The minimum inhibitory concentrations (MICs) were determined in accordance with the M27-A3 protocol as described by the CLSI and farnesol was tested at a concentration range of 0.29-150μM. Phospholipase and protease activities were evaluated through growth on egg yolk agar and spectrophotometry, respectively, after pre-incubating the strains at different farnesol concentrations (MIC/4, MIC/2 and MIC). It was observed that farnesol presents an inhibitory activity against C. neoformans and C. gattii (MIC range: 0.29-75.0μM). Although farnesol did not significantly alter phospholipase activity, a tendency to decrease this activity was observed. Concerning protease, no statistically significant differences were observed when comparing the production before and after pre-incubation at different farnesol concentrations. Based on these findings, it can be concluded that farnesol has in vitro inhibitory activity against C. neoformans and C. gattii, but has little impact on the production of the analyzed virulence factors.     

Real-time PCR assay in Leishmania-infected dogs treated with meglumine antimoniate and allopurinol

A real-time PCR assay was exploited for monitoring the Leishmania DNA load in different tissues from 18 naturally-infected dogs before and after treatment with a combination of meglumine antimoniate (100mg/kg/day, subcutaneously) and allopurinol (10mg/kg/day, orally) for 30 days. After the combined therapy, allopurinol was continued at the same dose until the end of the observation period. Whole blood samples, lymph node aspirates, and skin biopsies were collected at the time of diagnosis, 1 month after starting therapy, and every 3 months for 2 years. In six dogs parasite load assessments continued every 6 months for a further 3 years. At each assessment, the dogs were examined for signs of disease and a clinical score was recorded. At diagnosis, the highest Leishmania DNA load was detected in lymph node aspirates. From 1-6 months post-therapy a general improvement in clinical conditions was recorded in all dogs, which correlated with a decrease in the parasite DNA load in all tested tissues, even though it was less pronounced in lymph node aspirates. In the period from 9-24 months post-therapy, a re-increase in parasite load was observed in the tissues of some dogs, concomitant with a disease relapse. The results show that the combined therapy with meglumine antimoniate and allopurinol promoted a clinical improvement which was accompanied by a reduction in the parasitic load in the blood, skin and lymph nodes but, even after long period of allopurinol administration alone, Leishmania may persist in dog tissues.     

Severe cryptococcal granulomas of the nasopharynx in a horse treated with standing endoscopic laser surgery and oral fluconazole

An Arabian mare was referred due to a 4-month history of bilateral mucopurulent nasal discharge, which was unresponsive to multiple courses of antimicrobials and intravenous sodium iodide. Digital radiographs revealed multiple variably sized nodular opacities within the nasopharynx. Upper airway endoscopy showed multiple, ulcerated granulomatous masses originating from the walls of the nasopharynx. Repeat culture of the exudate and from endoscopic biopsies grew only a mixed bacterial population. Standing endoscopic guided laser excision of two granulomas was performed and histopathology and culture from the center of a surgically excised granuloma identified Cryptococcus terrestris. Treatment with fluconazole (14 mg/kg bwt per os once then 5 mg/kg bwt per os q. 12 h) was administered for a total of 11 weeks. Follow-up endoscopic examination was used to guide therapy duration, and the horse has since returned to competition and remained free of infection for >1.5 years. Establishing a diagnosis of cryptococcal infection was difficult in this horse despite multiple culture attempts. This is the first report of Cryptococcus terrestris infection in a horse and treatment with oral fluconazole after surgical de-bulking was successful.     

Determination of brodifacoum and bromadiolone residues in rodent and canine liver

A method to determine residue concentrations of anti-coagulant rodenticides, brodifacoum (BF) and bromadiolone (BD) in liver was developed, using gas chromatography/mass spectrometry. Nine dogs were given 1.1 mg of BF/kg of body weight, PO, in polyethylene glycol 400, one time. Rats were fed BF or BD (via commercial baits) in amounts from 0.28 to 11.25 mg/kg over 1- to 4-day periods. Fresh liver samples were collected at necropsy from all rats and 3 dogs, ground with Na2SO4, and extracted with CHCl3:MeOH (9:1). After evaporation and silica cartridge purification were performed, residues were oxidized with a 0.16M chromic acid solution, and an oxidation product (4-bromobenzoic acid) was partitioned into CHCl3. The methylated derivative (port derivatization with trimethylanilinium hydroxide) was assayed, using gas chromatography/mass spectrometry. Bromadiolone was detected in livers from rats given greater than 6 mg of BD/kg of body weight, but not in livers of rats given 1.25 mg of BD/kg. In contrast, BF was detected (with one exception) in livers from dogs (given 1.1 mg of BF/kg) and from rats given high (11.25 mg of BF/kg) and low (0.28 mg of BF/kg) doses. This protocol, which does not differentiate between BF and BD because of the formation of a common product after chromic acid oxidation, was used to diagnose anticoagulant toxicosis in 3 dogs, 1 human being and 1 llama naturally poisoned.     

Eprinomectin pour-on for control of Boophilus microplus (Canestrini) ticks (Acari: Ixodidae) on cattle

The efficacy of a commercial pour-on formulation of eprinomectin, a macrocyclic lactone, against experimental infestations of Boophilus microplus (Canestrini) ticks was evaluated in two trials involving 27 Bos taurus calves. The first trial was designed to evaluate the effects of a single treatment at a dose of 0.5 mg/kg of body weight against standard size B. microplus females (4.5-8.0 mm long). A significant reduction in tick numbers (P<0.05, Wilcoxon test) was observed between treated calves as compared to untreated ones from Day 3 (44% efficacy) after treatment to the end of the trial on Day 28 (96.9%), with a peak efficacy of 97.1% on Day 21. In the second trial the effect of eprinomectin on standard size tick numbers, engorgement weight and fertility of female ticks from calves with a single treatment dose of 1 mg/kg on Day 0 and calves treated twice at a dose of 0.5 mg/kg on Days 0 and 4 was evaluated. An efficacy >93% was obtained from Day 2 to Day 28 after treatment in calves treated twice at 0.5 mg/kg, and to the end of the trial (Day 35) in calves treated once with 1 mg/kg. The 1mg/kg treatment provided >98% residual efficacy for at least 7 days. During the first part of the second trial the efficacy of eprinomectin resulted from a dramatic adverse effect on engorgement weight and fertility of female ticks, with 100% control on Day 5 (dosage of 1 mg/kg) and on Days 6 and 7 (two doses of 0.5 mg/kg). Following Day 7, most of the effect was due to reduction in the number of standard size female ticks.     

Evaluation of dirlotapide for sustained weight loss in overweight Labrador retrievers

The effects of dirlotapide on body weight (BW) reduction were investigated in overweight Labradors in two parallel-design studies. Study A involved 42 dogs randomized to 0.0, 0.025, 0.05, 0.1, 0.2 or 0.4 mg dirlotapide/kg/day orally for 4 weeks. Study B involved 72 dogs randomized to nine treatments: placebo (24 weeks); dirlotapide (24 weeks) followed by placebo (28 weeks); or dirlotapide (52 weeks); on diets containing 5%, 10% or 15% fat. Dirlotapide dose (initially 0.1 mg/kg) was adjusted monthly during 24-week weight-loss and subsequent 28-week weight-stabilization phases. Food was offered above maintenance energy requirements (MER× 1.1–1.2) based on initial BW. Body composition (body fat, lean tissue and bone mineral content) was monitored using dual-energy X-ray absorptiometry. After treatment, dogs that had received dirlotapide for 52 weeks were fed 90% of quantity consumed at week 52. In study A, BW and food intake decreased asymptotically with dose: mean weekly weight loss exceeded 1% at 0.1–0.4 mg/kg. In study B, dirlotapide resulted in significant mean weekly weight loss (>0.8%) and decreased food intake over 24 weeks compared with placebo ( P  = 0.0001) for all diets. Food restriction minimized post-treatment weight rebound. Dirlotapide administered daily to dogs for up to 52 weeks was clinically safe and resulted in sustained weight reduction.     

Cryptococcosis: update and emergence of Cryptococcus gattii

Cryptococcosis is a fungal disease that occurs throughout the world. Recent reclassification of Cryptococcus species along with a change in the distribution pattern has prompted reevaluation of the organism and the diseases caused by this pathogen. This review highlights the emergence of Cryptococcus gattii as a primary pathogen in North America and summarizes our current understanding of the disease in mammals and birds.     

Dexamethasone-induced attenuation of cardiopulmonary dysfunction in endotoxemic calves

Effects of dexamethasone on pulmonary hemodynamics, pulmonary mechanics, and gas exchange were determined in anesthetized (pentobarbital sodium) and paralyzed (pancuronium bromide) calves (9.4 +/- 0.4 weeks old) during 5 hours of endotoxemia. Escherichia coli endotoxin (055-B5) was infused IV at 20 micrograms/kg the 1st hour, followed by a continuous infusion at 10 micrograms/kg/hour for the following 4 hours. Dexamethasone (5 mg/kg) was given IV 18 hours and 1 hour before endotoxin administration, and was also administered IV (1 mg/kg/hr) during endotoxemia. Endotoxin induced large increases in pulmonary artery pressure, pulmonary vascular resistance, alveolar-arterial O2 gradient, alveolar dead-space ventilation, postmortem gravimetric lung weight of bloodless lung, albumin and total protein concentrations in bronchoalveolar lavage fluid, and the number of neutrophils recovered from bronchoalveolar lavage fluid. Endotoxin induced decreases in the cardiac index, dynamic lung compliance, and PaO2. Dexamethasone attenuated most of the cardiopulmonary responses induced by endotoxin, especially during the first 3 hours of endotoxemia. Dexamethasone blocked endotoxin-induced increases in bronchoalveolar lavage albumin, total protein, and neutrophil content. Therefore, glucocorticoids modify endotoxin-induced pulmonary injury in calves, possibly by limiting mobilization of endogenous arachidonic acid.     

Cryptococcus neoformans granuloma in the lung and spinal cord of a free-ranging cheetah (Acinonyx jubatus). A clinical report and literature review

A 6-year-old, male, wild-born, free-ranging cheetah (Acinonyx jubatus) was evaluated for acute onset of progressive lameness in the right hind limb. Survey radiographs were unrewarding and myelography indicated an intramedullary compressive mass at the L3-L4 region. A fine needle aspirate of the lesion indicated the presence of Cryptococcus organisms. Necropsy confirmed the presence of granulomas (cryptococcoma) in the lung and the spinal cord (meningomyelitis) caused by Cryptococcus neoformans var. gattii. Cryptococcus neoformans is a yeast-like organism that is a potential pathogen to many species. Initial infection is thought to be of respiratory origin and then it commonly disseminates systemically from the nasal cavity or lungs to the skin, eyes and central nervous system in particular. The cheetah tested negative for both feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV), as have all the previously reported cheetah cases. C. neoformans is a non-contagious, opportunistic organism and is the most common systemic mycoses in domestic cats and the cheetah.