Serological evidence of antibodies to Neospora caninum in stray and owned Grenadian dogs.

Neospora caninum causes abortion in cattle and neuromuscular disease in dogs, world wide. Cattle become infected by ingesting oocysts voided by dogs. The aim of this study was to estimate the seroprevalence of Neospora caninum in two populations of dogs (stray and owned) in Grenada, West Indies. Sera were collected from 625 dogs from all parishes in Grenada. Three hundred and sixty eight dogs were stray, while 257 dogs were owned. Sera were tested for the presence of antibodies against N. caninum using an indirect enzyme linked immunosorbant assay (ELISA) IDvet, France. Antibodies to N. caninum were found in 6 (1.6%) (95% confidence interval (CI): 0.32% to 2.88%) of the stray dogs and in 3 (1.2%, 95% CI: 0.13% to 2.53%) of the owned dogs. Seroprevalence did not differ significantly between the two populations (p=0.74) and between the males and females (p=1). These results suggest that the prevalence of N. caninum infection in dogs in Grenada is low.

Retrospective study of canine heartworm disease with caval syndrome in Grenada, West Indies.

Canine heartworm disease caused by Dirofilaria immitis is an important disease of dogs. The aim of this retrospective study was to estimate the prevalence of canine heartworm disease and evaluate cases of caval syndrome in dogs submitted for necropsy in Grenada. Out of 1617 dogs necropsied over a period of 13 years (2001-2013), 249 were found to be infected with D. immitis; giving an overall prevalence of 15.4% (95% confidence interval, 13.6% to 17.1%). There was no significant difference between male and female dogs with respect to canine heartworm infection (p = 0.3). During this period, the annual prevalence of canine heartworm disease was 22% in 2001 before slightly declining to an average of 18% in 2002-2003 and peaking at 26.8% in 2004-2005. From 2006 onwards, annual prevalence rates have steadily been decreasing; reaching the lowest (9%) in 2013. Among the 249 positive cases, 33 (13.2%) of the dogs had caval syndrome. Caval syndrome cases presented with concurrent clinical signs and were associated with cardio-pulmonary and hepatic gross lesions at necropsy. Aberrant migration of D. immitis was also noted in 2 dogs with caval syndrome. This is the first report which presents the findings of canine heartworm disease with caval syndrome in Grenada.

Spirocercosis in owned and stray dogs in Grenada.

The aim of this retrospective study was to estimate the prevalence of Spirocerca lupi and its associated lesions in owned and stray dogs in Grenada. During 2001-2011 necropsies were carried out on 1022 owned and 450 stray dogs at the pathology diagnostic laboratory, School of Veterinary Medicine, St. George's University, Grenada. Lesions due to S. lupi characterized by focal to multifocal granulomatous esophagitis with aneurysms, mineralized plaques and nodules in the adjacent thoracic aorta were found in 90 (8.8%; 95% confidence interval, 7.1-10.5%) of owned dogs and 64 (14.2%; 95% CI, 11.2-17.6%) of stray dogs. Stray dogs were significantly more affected by spirocercosis than owned dogs (p=0.0022). Of the 90 owned dogs with spirocercosis, 3 dogs had aberrant migration to the thoracic vertebral column with resultant spondylitis; 1 dog each had aberrant migration involving the stomach and the lung. Two dogs had ruptured aorta with hemothorax. Among the 64 stray dogs with spirocercosis, one dog had an esophageal granuloma that transformed into a fibroblastic osteosarcoma; spondylitis due to aberrant migration of S. lupi and hypertrophic osteopathy. We report spirocercosis for the first time in the dogs from a tropical island of Grenada.

Neoplastic and nonneoplastic cutaneous tumors of dogs in grenada, west indies.

This retrospective survey was undertaken between 2002 and 2007 on samples from dogs residing in Grenada. The objectives of the study were to identify the most common histologic types of canine cutaneous tumors, determine the relative frequency of each tumor type, and compare results to reports from other regions. In a series of 225 skin masses examined, the proportion of neoplasms was 72% whereas nonneoplastic tumors accounted for 15.6%, and inflammatory conditions constituted 12.4%. There were 10 types of nonneoplastic tumors with hamartomas being the most common (28.5%), followed by sebaceous hyperplasia (25.7%) and fibroepithelial polyps (22.8%). The 10 most common cutaneous neoplasms were hemangiosarcomas (19.1%), histiocytomas (8.6%), melanocytomas (8%), mast cell tumors (6.8%), lipomas (6.8%), hemangiopericytomas (6.2%), papillomas (5.6%), fibrosarcomas (5.6%), hemangiomas (4.9%), and squamous cell carcinomas (4.3%). Tumors of vascular origin and transmissible venereal tumors were more common in dogs in our study than reported from other regions.

Preliminary molecular characterization of a fowl poxvirus isolate in Grenada.

Two 1-mo-old local breed chickens, with gross lesions in the skin of the head region suspected to be fowl poxvirus infection, were submitted to the Diagnostic Laboratory of the School of Veterinary Medicine, Grenada, West Indies. Cutaneous lesions were collected from these birds for virus isolation, histopathologic diagnosis, and molecular analysis. Fowl poxvirus infection was confirmed by virus isolation in chicken embryo and by histopathology. Molecular characterization of the fowl poxvirus was conducted by PCR amplification of selected genomic fragments and by nucleotide sequencing. Integration of reticuloendotheliosis virus fragments into the fowl poxvirus genome was confirmed by PCR and DNA sequencing. This is the first report from the Caribbean region on the preliminary molecular characterization of a fowl poxvirus isolate.

Existence of Angiostrongylus cantonensis in rats (Rattus norvegicus) in Grenada, West Indies.

The zoonotic rat lung worm, Angiostrongylus cantonensis is endemic to Asia, North America, Africa and Australia. The parasite is expanding geographically and has recently been recorded in some of the Greater Antilles in the northern part of the Caribbean. In this study A. cantonensis is reported for the first time in the Lesser Antilles in one of the southernmost islands, Grenada. Between September 2005 and September 2006, 192 rats (Rattus norvegicus) were trapped throughout the island. The rats were anesthetized, exsanguinated, necropsied and the lungs were fixed whole in 10% buffered formalin, trimmed, processed, cut at 3microm, stained with hematoxylin and eosin and examined microscopically. A total of 45 (23.4%) of the 192 rats examined were found to be infected with A. cantonensis and adult worms were found in the cardiopulmonary system of one of the rats. Microscopically, pulmonic lesions, consisting of pulmonary thrombosis, hypertrophy of pulmonary arteries and granulomatous pneumonia were associated with intralesional adults, larvae and embryonated eggs of A. cantonensis. An incidental finding of variably sized (2-7mm) solitary to multiple cysts containing larvae of Taenia taeniaformis were seen in the livers of 57 rats. This report of A. cantonensis in Grenada provides evidence of the further global expansion of this important zoonotic parasite and the public health implications of this discovery is discussed.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Prevalence of gastrointestinal parasites in free-range poultry in Grenada, West Indies.

Rural poultry production systems in Grenada are based on the scavenging indigenous domestic fowl (Gallus domesticus), the predominant species in the poultry sector. This study was done to establish the species and frequency of gastrointestinal parasites in 106 free-ranges chickens ages between 1-2 years, and collected from 13 households. Three nematodes and one tapeworm were identified: Gongylonema ingluvicola (29.2%); Ascaridia galli (10.3%); Heterakis gallinarum (4.7%); Capillaria contorta (2.83%); Railietina tertagona (38.6%). Helminth infections in free-range chickens, even when they occur in low numbers, may result in subclinical disease. High numbers can produce clinical disease. Further studies may be required to devise appropriate prevention and control methods, with improved management systems. This is the first report of gastrointestinal parasites of free-ranging poultry in Grenada.

Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies.

Cats are important in the natural epidemiology of Toxoplasma gondii, because they are the only hosts that can excrete environmentally resistant oocysts. Cats are infected with T. gondii via predation on infected birds and rodents. During 2005, 238 rats (Rattus norvegicus) were trapped in Grenada, West Indies, and their sera along with tissue samples from their hearts and brains were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, titer 1:40 or higher); only 2 (0.8%) of 238 rats were found to be infected. Brains and hearts of all rats were bioassayed in mice. Toxoplasma gondii was isolated from the brain and the heart of only 1 rat, which had a MAT titer of 1:320. All of 5 mice inoculated with the heart tissue, and the 5 mice inoculated with the brain tissue of the infected rat remained asymptomatic, even though tissue cysts were found in their brains. Genetically, the isolates of T. gondii from the heart and the brain were identical and had genotype III by using the SAG1, SAG2, SAG3, BTUB, and GRA6 gene markers. These data indicate that rats are not important in the natural history of T. gondii in Grenada.

Case Report: A four footed broiler chicken with duplication of cloaca.

An 8-week old male broiler chicken (Gallus domesticus) with four feet was presented for examination. At necropsy and extra vestigial pelvis was attched to the normal synsacrum by fibrocartiliginous tissue. The vestigial pelvis had a single femur attached to which were two feet, one with three digits and the other with two digits. By radiography, components of the extraneous feet were abnormal. There were two functional cloacae. The lesions were diagnosed as supernumery feet and duplication of cloaca.

Case Report: A four footed broiler chicken with duplication of cloaca.

An 8-week old male broiler chicken (Gallus domesticus) with four feet was presented for examination. At necropsy and extra vestigial pelvis was attched to the normal synsacrum by fibrocartiliginous tissue. The vestigial pelvis had a single femur attached to which were two feet, one with three digits and the other with two digits. By radiography, components of the extraneous feet were abnormal. There were two functional cloacae. The lesions were diagnosed as supernumery feet and duplication of cloaca.

Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from chickens in Grenada, West Indies.

The prevalence of Toxoplasma gondii in free-range chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 102 free-range chickens (Gallus domesticus) from Grenada was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 53 (52%) chickens with titers of 1:5 in 6, 1:10 in 4, 1:20 in 4, 1:40 in 4, 1:80 in 15, 1:160 in 9, 1: 320 in 5, 1:640 in 4, and 1:1,280 or greater in 2. Hearts, pectoral muscles, and brains of 43 seropositive chickens with MAT titers of 1:20 or greater were bioassayed individually in mice. Tissues of each of 10 chickens with titers of 1:5 and 1:10 were pooled and bioassayed in mice. Tissues from the remaining 49 seronegative chickens were pooled and fed to 4 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. T. gondii was isolated from 35 of 43 chickens with MAT titers of 1:20 or greater; from the hearts, brains, and pectoral muscles of 2, hearts and brains of 20, from the hearts alone of 11, and brains alone of 2. T. gondii was isolated from 1 of 10 chickens with titers of 1:5 or 1:10. All 36 T. gondii isolates were avirulent for mice. Genotyping of these 36 isolates using polymorphisms at the SAG2 locus indicated that 29 were Type III, 5 were Type I, 1 was Type II, and 1 had both Type I and Type III. Genetically, the isolates from Grenada were different from those from the United States; Type II was the predominant type from the United States. Phenotypically, all isolates from Grenada were avirulent for mice, whereas those from Brazil were mouse-virulent. This is the first report of isolation of T. gondii from chickens from Grenada, West Indies.

Ultrasonographic findings of an ovarian abscess in a cow.

Ultrasonographic examination was carried out in a cow with an ovarian abscess. Real time ultrasound scanning using a 7.5 MHz linear probe per rectum revealed an active left ovary with follicles of up to 11 mm in diameter and an enlarged right ovary measuring 6 x 6 cm, with a mass of 4 x 3 cm. The mass had varied echotexture, a thick hyperechoic boundary and a hypoechoic centre with echoic foci. It was tentatively diagnosed as an ovarian tumour or abscess. After ovariectomy, grossly the right ovary measured 6 x 6 x 5 cm and on cutting cheesy pus oozed out. The abscess was completely localised within the ovary, 4 cm in diameter and encapsulated thickly. On bacteriological examination Staphylococcus spp. was isolated. This is a rare case of ovarian abscess.

Brain lesions in chickens experimentally infected with a neuroadapted strain of mesogenic Newcastle disease virus.

Neuroadapted Newcastle disease virus (Q10) was selected by tenth serial passage, in the chicken brain of a mesogenic strain (Q0) originally isolated from quails. Specific pathogen-free birds were inoculated intranasally with one of these viruses. At daily intervals for 7 days and then at 10, 14, and 21 days post-inoculation (PI), two birds from each group were killed and samples of the brain were collected for histopathological and virological examination. Q10 caused severe nonsuppurative encephalitis with nervous signs and high mortality. Lesions characterized by neuronal degeneration and necrosis, perivascular lymphocytic infiltration, and focal or diffuse astrogliosis occurred mainly in the parahippocampal cortex, hippocampus, hyperstriatum, neostriatum, subleptomeningeal and periventricular regions of the cerebrum. Spongy changes with neuronal degeneration and axonal spheroids were also observed in the brain stem of a few cases. The amount of virus in the brain reached a peak on day 4 PI and virus could not be recovered from the brain after 6 days PI. In contrast, Q0 caused nonfatal asymptomatic disease and virus could not be isolated from the brain, sections of which showed only minimal inflammatory changes. This difference in the lesions of the brain might be related to neurovirulence and, neuroadaptation by serial passage may occur by increased efficiency of viral replication in neurons.

Brain lesions in young broiler chickens naturally infected with a mesogenic strain of Newcastle disease virus.

Thirty-nine 4- to 5-week-old broiler chickens from an outbreak of Newcastle disease (ND) in Japan were examined pathologically. The causative agent was identified as a mesogenic strain of ND virus. Predominant gross lesions included haemorrhage in the lungs, congestion of the trachea, splenomegaly, atrophy of the thymus and bursa of Fabricius, and whitish discolouration of the brain. Microscopically, there was mild haemorrhagic pneumonia, catarrhal tracheitis, lymphoid necrosis in the spleen, thymus, bursa of Fabricius and caecum and diffuse non-suppurative encephalitis. Lesions associated with encephalitis were characterized by multifocal perivascular cuffing, malacia, demyelination and proliferative vasculitis. Malacic lesions occurred in the hyperstriatum, neostriatum, subleptomeningeal and periventricular regions of the cerebrum, whereas demyelination was seen mainly in the brain stem. The morphological changes that occurred in the brain in these cases were distinctive and the lesions in the lymphoid tissues were related to concurrent infection with infectious bursal disease virus.