Muhammad Iqbal Bhaiyat

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.

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.

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. Georges 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.

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.

Isolation of Coagulase-Negative Staphylococcus Spp. and Kocuria Varians in Pure Culture from Tissues of Cases of Mortalities in Parrots in Grenada, West Indies

Approximately 30 psittacine birds, including African grey parrots and ring-necked parrots died during a period of 1-2 months in 2012 in the parish of St.David, Grenada. At necropsy, the liver showed swelling with red to tan mottling, and there was diffuse pulmonary congestion. Tissues from 8 birds were examined for bacteria by culture. Pure cultures of coagulase-negative staphylococci in moderate to heavy amounts were isolated from almost all tissues, including liver, lung, and spleen. Only 7 isolates could be identified to species level. Liver, lung and intestines of 2 birds were positive for Staphylococcus lentus, and one spleen sample from a single bird was positive for Kocuria varians. Antimicrobials drug susceptibility tests against 10 drugs showed susceptibility to all drugs except for the tetracycline resistance in one isolate. Significance of these findings is discussed in view of the negative results for Pacheco’s disease which was originally suspected.

Klebsiella Pneumoniae Infection in a Squirrel Monkey (Saimiri Sciureus ) in Grenada, West Indies

An 11 month-old squirrel monkey that died after one week of illness, characterized by anorexia, lethargy, pale mucosae, and dehydration was presented for post-mortem examination. A large retroperitoneal abscess with adhesions to the colon was found on necropsy. Culture of the pus from the abscess on blood agar and MacConkey agar, resulted in heavy growth of Klebsiella Pneumoniae. The significance of this organism as a cause of morbidity and mortality in non-human primates with particular reference to squirrel monkeys is discussed.

Epidemiological Study of Rabies from 2001-2016 in Grenada, West Indies

1DVM Student, School of Veterinary Medicine, St. George’s University, Grand Anse, The Lime, Grenada, West Indies 2Department of Pathobiology, School of Veterinary Medicine, St. George’s University, Grand Anse, The Lime, Grenada, West Indies *Corresponding author Ravindra Nath Sharma, PhD Department of Pathobiology School of Veterinary Medicine St. George’s University Grenada, West Indies Tel. 1 473 444 4175, ext. 3335 E-mail: rsharma@sgu.edu

Multifocal Pulmonary Abscesses due to Trueperella Pyogenes in Sheep

Pneumonia is often diagnosed in adult sheep simply because the animal presents with an increased respiratory rate and breathing effort despite the fact that many infections affecting other organ systems can present with such signs including mastitis, metritis, clostridial diseases, and painful conditions such as lameness. There are three common causes of respiratory disease in sheep: respiratory disease caused by Mannheimia haemolytica, sheep pulmonary adenomatosis, and suppurative pneumonia/lung abscesses. Lung abscesses are not uncommon in adult sheep, but are difficult to diagnose on clinical examination alone. Sheep with lung abscesses generally show poor body condition and are often dull and depressed (NADIS, 2009). Abstract

Pulmonary adenocarcinoma in two dogs in Grenada, West Indies: Case report

Primary lung tumours are uncommon in the dog, whereas pulmonary metastatic neoplastic involvement is common. We report the pathologic features of pulmonary adenocarcinoma in two dogs (case No. 1: 10-year-old castrated male German Shepherd dog; case No. 2: adult intact male pothound stray dog). Case No. 1 presented with left hind limb paralysis and pain upon walking; it was also positive for heart worm disease. There was no history for Case No. 2 which was euthanized and submitted for disposal under the stray dog control program of the Ministry of Health and the Division of Veterinary and Livestock, Ministry of Agriculture, Lands, Forestry, Fisheries & Environment, Grenada. Post-mortem examination revealed a single pulmonary nodule in both cases with metastasis to the liver and pelvic canal in case No. 1. Histopathologically, all the tumour masses consisted of neoplastic, polygonal to cuboidal epithelial cells with moderate amounts of cytoplasm and a large hyperchromatic nucleus arranged in nests and trabeculae. Immunohistochemically, the epithelial cells possessed keratin-cytokeratin in their cytoplasm. The origin of these tumours from bronchiolar epithelial cells or alveolar type I pneumocyte is suggested. Although the incidence of canine primary lung neoplasms is markedly low, this condition must be considered in the differential diagnosis of pulmonary lesions in older dogs.

Meta-Analysis of the Prevalence of Dirofilaria Immitis In Dogs from Grenada, West Indies

A comparison of several individual studies was made in order to determine the statistical significance for the prevalence of Dirofilaria immitis in dogs (n=1245) in Grenada, using necropsy and different ELISA test kits. The overall prevalence was estimated to be 17% in a study of live dogs, 12% in a study of necropsied dogs, and 14% when combining the studies using meta-analysis. There was no evidence of infection in dogs less than 6 months of age and no statistical difference (P>0.50) between male and female dogs. The prevalence reported is the cause for concern particularly since Dirofilaria immitis in dogs were found in all parishes in Grenada, favorable climatic conditions exist for vector-borne transmission, there is only sporadic use of preventatives, and there is an almost complete lack of public knowledge of the zoonotic potential of this filarial parasite in Grenada.