Field safety and efficacy of a unique live virus vaccine for controlling avian encephalomyelitis and fowlpox in poultry

Research (Published online: 23-08-2019)

17. Field safety and efficacy of a unique live virus vaccine for controlling avian encephalomyelitis and fowlpox in poultry

Girish Sarma, Barry A. Kersting and Gary Spina

Veterinary World, 12(8): 1291-1298

ABSTRACT

Background and Aim: Infection of commercial poultry with avian encephalomyelitis (AE) and fowlpox (FP) virus causes heavy economic loss in endemic areas. Although vaccines are routinely used to control these two diseases, the problem still persists almost all over the world. This study aimed to evaluate safety and efficacy of a unique AE + FP + pigeon pox (PP) live virus vaccine in layer-type chickens under both laboratory and field conditions.

Materials and Methods: The study was conducted using 289 specific-pathogen-free (SPF) chickens under the laboratory conditions and 185,648 commercial layer-type chickens under field conditions. In two consecutive laboratory trials, 8-week-old SPF chickens were vaccinated with the AE + FP + PP live virus vaccine through wing web route and challenged against virulent strains of FP and AE viruses at 3-week post-vaccination (WPV). Challenged chickens were observed for disease protection for 10-21 days. For field safety trials, commercial layer-type chickens in three different geographical areas in the USA were vaccinated with the AE + FP + PP vaccine and observed daily up to 21 days for vaccine "take". adverse reactions, and mortality.

Results: The vaccine was found safe and efficacious under both laboratory and field conditions. Vaccine "take" and protection against FP challenge were 100%. Average protection against AE challenge was 97%. Mean AE enzyme-linked immunosorbent assay (ELISA) antibody titer in the field vaccinated chickens was >1200 at 10 WPV. Average daily post-vaccination mortality in the field vaccinated chickens was 0.04%. So far, more than 400 million chickens in the USA have been vaccinated with this vaccine. No vaccine-associated adverse reactions, other safety issues, or immunity breakdown cases in the vaccinated flocks due to field virus infection have been reported.

Conclusion: This unique vaccine containing AE, FP, and PP viruses in a single preparation was found to be safe and efficacious in controlling the diseases caused by the virulent field strains of AE and FP. Besides being safe and efficacious, this vaccine also offered distinct advantages over the traditional vaccination practices in controlling these two diseases in poultry.

Keywords: avian encephalomyelitis, efficacy, field safety, fowlpox, live virus vaccine, pigeon pox, protection.

Knowledge and behavior of cattle and sheep owners and herders regarding foot-and-mouth disease in Northern Algeria

Research (Published online: 21-08-2019)

16. Knowledge and behavior of cattle and sheep owners and herders regarding foot-and-mouth disease in Northern Algeria

Ratiba Baazizi, Nora Mimoune, M'Hamed El Mokhefi, Muslim Raza, Amina Chahed and Tanveer Hussain

Veterinary World, 12(8): 1285-1290

ABSTRACT

Background and Aim: Foot-and-mouth disease (FMD) has been occurring in Algeria since 2014, when an outbreak was announced in Setif, a district in the eastern region of the country. The problem was apparently resolved with the help of vaccination. However, in 2015, 2016, and 2018, FMD recurred. The veterinary authorities and media educated breeders on how to recognize the clinical signs and how to report the disease. This study aimed to evaluate the knowledge and recognition of FMD by farmers and breeders. Moreover, an assessment of the behavior of cattle and sheep owners and herders following FMD cases is examined.

Materials and Methods: A cross-sectional survey was conducted from June to October 2018 to evaluate the perception of cattle and sheep owners and breeders regarding FMD in the Northern regions of Algeria, using questionnaires.

Results: One hundred questionnaires were distributed; 71 were collected. Data showed that all the responders claimed to know about the disease, while more than half of the owners/herders claimed that they knew the clinical symptoms of FMD and mentioned fever, hypersalivation, lameness, and vesicles. Fewer than half (42%) (30/71) took some measures to prevent the disease, while more than half (58%) (41/71) did not take any measures in 2018. No one claimed to have reported the disease to authorities in 2018, while more than half had done so in 2014.

Conclusion: It appears that experienced farmers recognized the clinical signs of FMD, while an academic background was not conclusively necessary for the identification of the clinical signs of the disease. Concerning the assessment of risk-associated behavior in the event of FMD occurrence, the responses of the breeders were not significantly different from those of risk-associated behaviors in the event of an epidemic. Farmers and breeders expressed similarity in terms of communicating the appearance of the disease in their livestock; the majority of them seemed to be aware of the importance of reporting the disease to local authorities, especially in 2014, when the disease first occurred. This behavior is encouraged by refund and technical assistance policies by the veterinary authorities, but in 2018, no disease was reported due to fear of slaughtering and economic loss.

Keywords: cattle and sheep farmers, clinical signs, foot-and-mouth disease, knowledge and seniority, survey.

Risk factors associated with viral nervous necrosis in hybrid groupers in Malaysia and the high similarity of its causative agent nervous necrosis virus to reassortant red-spotted grouper nervous necrosis virus/striped jack nervous necrosis virus strains

Research (Published online: 21-08-2019)

15. Risk factors associated with viral nervous necrosis in hybrid groupers in Malaysia and the high similarity of its causative agent nervous necrosis virus to reassortant red-spotted grouper nervous necrosis virus/striped jack nervous necrosis virus strains

Nurshuhada Ariff, Azila Abdullah, Mohamed Noor Amal Azmai, Najiah Musa and Sandra Catherine Zainathan

Veterinary World, 12(8): 1273-1284

ABSTRACT

Background and Aim: Viral nervous necrosis (VNN) is a serious disease of several marine fish species. VNN causes 100% mortality in the larval stages, while lower losses have been reported in juvenile and adult fish. This study aimed to detect the occurrence of VNN while identifying its associated risk factors and the genotypes of its causative agent in a hybrid grouper hatchery in Malaysia.

Materials and Methods: A batch of newly hatched hybrid grouper fry (Epinephelus fuscoguttatus X Epinephelus lanceolatus) were followed from the larval stage to market size. Samples of the hybrid groupers, water, live feed, and artificial fish pellets were collected periodically from day 0 to 180 in the hybrid grouper hatchery. Reverse transcription-polymerase chain reaction (RT-PCR) and nested PCR amplifications were carried out on VNN-related sequences. The phylogenetic tree including the sampled causative agent of VNN was inferred from the coat protein genes from all known Betanodavirus species using Molecular Evolutionary Genetics Analysis (MEGA). Pearson's correlation coefficient values were calculated to determine the strength of the correlation between the presence of VNN in hybrid grouper samples and its associated risk factors.

Results: A total of 113 out of 146 pooled and individual samples, including hybrid grouper, water, and artificial fish pellet samples, demonstrated positive results in tests for the presence of VNN-associated viruses. The clinical signs of infection observed in the samples included darkened skin, deformation of the backbone, abdominal distension, skin lesions, and fin erosion. VNN was present throughout the life stages of the hybrid groupers, with the first detection occurring at day 10. VNN-associated risk factors included water temperature, dissolved oxygen content, salinity, ammonia level, fish size (adults more at risk than younger stages), and life stage (age). Detection of VNN-associated viruses in water samples demonstrated evidence of horizontal transmission of the disease. All the nucleotide sequences found in this study had high nucleotide identities of 88% to 100% to each other, striped jack nervous necrosis virus (SJNNV), and the reassortant strain red-spotted grouper NNV/SJNNV (RGNNV/SJNNV) isolate 430.2004 (GenBank accession number JN189932.1) (n=26). The phylogenetic analysis showed that quasispecies was present in each VNN-causing virus-positive sample, which differed based on the type of sample and life stage.

Conclusion: This study was the first to confirm the existence of a reassortant strain (RGNNV/SJNNV) in hybrid groupers from Malaysia and Southeast Asia. However, the association between the mode of transmission and the risk factors of this virus needs to be investigated further to understand the evolution and potential new host species of the reassortant strain.

Keywords: epidemiology, quasispecies, reassortant, red-spotted grouper nervous necrosis virus-striped jack nervous necrosis virus, viral nervous necrosis.

Evaluation of hepatobiliary ultrasound scores in healthy dogs and dogs with liver diseases

Research (Published online: 17-08-2019)

14. Evaluation of hepatobiliary ultrasound scores in healthy dogs and dogs with liver diseases

Sathidpak Nantasanti Assawarachan, Piyathip Chuchalermporn, Phudit Maneesaay and Naris Thengchaisri

Veterinary World, 12(8): 1266-1272

ABSTRACT

Background and Aim: Ultrasonography is the first-line method for examining the canine liver. Hepatic ultrasound scoring systems are widely described in human medicine, yet there is no information on the use of semi-quantitative ultrasound scoring systems in canine liver diseases. This study aimed to evaluate the hepatobiliary ultrasound scores between physically healthy dogs and dogs with primary liver diseases confirmed by clinical, biochemical, and histological parameters. We also evaluated the putative correlations between ultrasound scores and ALT or ALP levels. Moreover, the severity of ultrasound scoring and fold changes in liver enzymes was also evaluated.

Materials and Methods: A cross-sectional study design was conducted to compare the results of the six different parameters (liver surface, echogenicity of parenchyma, nodularity of parenchyma, gallbladder wall thickness, amount of gall sludge, and visibility of bile duct) of ultrasound scores between dogs with and without liver disease.

Results: Our results showed that 17.4%, 88.2%, and 100% of dogs with liver diseases were identified according to the ultrasound severity classified as mild (total score 0-2), moderate (total score 3-5), and severe (total score 6-12). Approximately 30% of patients with chronic hepatitis, the most common canine liver disease, presented with normal or mild ultrasound score category, whereas most of the patients with vacuolar hepatopathy and steroid-induced hepatopathy due to secondary reactive changes had moderate-to-severe ultrasound score category. There were 75% of patients with tumor and 80% of patients with hepatic fibrosis that were identified with severe ultrasound score category. Dogs with moderate-to-severe ultrasound scores had significant liver enzyme elevation (both alanine aminotransferase [ALT] and alkaline phosphatase [ALP]) compared to those of dogs with mild ultrasound scores. Ultrasound score was moderately associated with ALT and highly associated with ALP levels (p=0.553 and p=0.730, respectively).

Conclusion: Our semi-quantitative, simplified ultrasonographic scoring system may have potential to be used as a screening tool to detect some groups of liver diseases.

Keywords: diagnosis, dogs, hepatic disease, ultrasound score.

Effects of a standardized 40% ellagic acid pomegranate (Punica granatum L.) extract on seminiferous tubule histopathology, diameter, and epithelium thickness in albino Wistar rats after heat exposure

Research (Published online: 17-08-2019)

13. Effects of a standardized 40% ellagic acid pomegranate (Punica granatum L.) extract on seminiferous tubule histopathology, diameter, and epithelium thickness in albino Wistar rats after heat exposure

Budi Utomo, Nurfitri Rahmah Daningtia, Gandul Atik Yuliani and Wiwik Misaco Yuniarti

Veterinary World, 12(8): 1261-1265

ABSTRACT

Background and Aim: It has long been known that the spermatogenic tissue is very sensitive to temperatures higher than its physiologic temperature and causing cessation of activity and resulting in sterility. This study investigated the effect of a standardized 40% ellagic acid extract of pomegranate on the histopathology, diameter, and epithelial thickness of seminiferous tubules in albino rats exposed to heat.

Materials and Methods: Twenty-five male albino Wistar rats were randomized at 7-8 months of age to five treatment groups. Group C was not treated; Group T0 was treated with 0.5% of Na carboxymethyl cellulose (CMC) 2 ml/day and exposed to heat. T1, T2, and T3 were treated with 75, 150, and 300 mg/kg/day of a standardized 40% ellagic acid extract of pomegranate (Punica granatum L.), respectively. The animals were orally administered Na CMC or pomegranate extract and were exposed to sunlight for 15 min at 40°C-42°C for 14 days. The animals were sacrificed on day 15 and the testes were removed for histological evaluation and measurement of seminiferous tubule diameter and epithelium thickness.

Results: Our results showed that 17.4%, 88.2%, and 100% of dogs with liver diseases were identified according to the ultrasound severity classified as mild (total score 0-2), moderate (total score 3-5), and severe (total score 6-12). Approximately 30% of patients with chronic hepatitis, the most common canine liver disease, presented with normal or mild ultrasound score category, whereas most of the patients with vacuolar hepatopathy and steroid-induced hepatopathy due to secondary reactive changes had moderate-to-severe ultrasound score category. There were 75% of patients with tumor and 80% of patients with hepatic fibrosis that were identified with severe ultrasound score category. Dogs with moderate-to-severe ultrasound scores had significant liver enzyme elevation (both alanine aminotransferase [ALT] and alkaline phosphatase [ALP]) compared to those of dogs with mild ultrasound scores. Ultrasound score was moderately associated with ALT and highly associated with ALP levels (p=0.553 and p=0.730, respectively).

Conclusion: Compared with controls, administration of 300 mg/kg/day of a standardized 40% ellagic acid extract of P. granatum L. for 14 days increased seminiferous tubule diameter and epithelium thickness in albino Wistar rats exposed to heat.

Keywords: diameter, epithelium thickness, heat, pomegranate extract, seminiferous tubule.

Intestinal and hepatic coccidiosis among rabbits in Yogyakarta, Indonesia

Research (Published online: 15-08-2019)

12. Intestinal and hepatic coccidiosis among rabbits in Yogyakarta, Indonesia

Penny Humaidah Hamid, Sigit Prastowo and Yuli Purwandari Kristianingrum

Veterinary World, 12(8): 1256-1260

ABSTRACT

Background and Aim: The attention to rabbit meat production in Indonesia is comparatively less to other farm animals such as cattle and poultry industries. However, future prospect of rabbit to be seriously industrialized seemed quite promising due to rabbit is highly productive and has short reproduction cycle as well as generation interval. One of the diseases infecting many rabbits is coccidiosis caused by protozoan parasite, Eimeria spp. The infectious stage of Eimeria spp. presents ubiquitously in the environment and increases the risk of parasite transmission. Preventive methods such as vaccination are not yet fully developed, while sporadic treatment is not efficiently reduce the cases. In this study, Eimeria spp. infecting rabbits in Yogyakarta Province, Indonesia, were investigated with the aim for precise diagnosis to determine targeted treatment and as a baseline epidemiological data from rabbit in Indonesia.

Materials and Methods: Sample collection was performed randomly for 3 months, from March 2017 to May 2017 and covered areas in Yogyakarta, Indonesia. A total of 750 samples were collected. Eimeria species identification was determined morphologically from the samples after sporulation in 2.5% potassium dichromate by COCCIMORPH.

Results: Ten species of Eimeria spp. were identified in this study from the positive samples (527/750; 70.3%). Eimeria flavescens was present in 80% of the positive samples, Eimeria coeciola in 78%, Eimeria perforans in 61%, Eimeria exigua in 37%, Eimeria media in 33%, Eimeria stiedae in 31%, Eimeria irresidua in 12%, Eimeria magna in 11%, Eimeria intestinalis in 10%, and Eimeria piriformis in 10%. Coinfection as noted in 80% of the positive samples with 2-6 species in a specimen. E. flavescens and E. coeciola were the most prevalent among all Eimeria spp. (p=0.0001).

Conclusion: Eimeria spp. is detected in high prevalence among rabbit in Yogyakarta, Indonesia, with commonly occurs in mixed infections. In this paper, we describe Eimeria spp. that are circulating in Indonesia and present it as updated information to farmers and veterinarians. To the best of our knowledge, we provided the first information about rabbit coccidiosis in Indonesia.

Keywords: coccidiosis, Indonesia, rabbit.

Studies on immune response to Newcastle disease virus in broiler chickens fed with Lactobacillus reuteri PIA16 isolated from the gut of indigenous chicken of Assam, India

Research (Published online: 15-08-2019)

11. Studies on immune response to Newcastle disease virus in broiler chickens fed with Lactobacillus reuteri PIA16 isolated from the gut of indigenous chicken of Assam, India

Gaichamdinliu Gonmei, Deben Sapcota, Girin Kumar Saikia, Pankaj Deka, Joga Dev Mahanta, Niranjan Kalita, Bibeka Nanda Saikia and Jitendra Kumar Talukdar

Veterinary World, 12(8): 1251-1255

ABSTRACT

Background and Aim: The chicken gut harbors microflora which impacts the health, production performance and immune response against pathogens. Assam local chickens reared under natural conditions are known to possess high immunocompetence which may be attributable to its gut microbiota make-up. This study aimed to investigate the individual effect of two strains of Lactobacillus reuteri PIA16 isolated separately from cecum and jejunum of Assam indigenous chicken on the immunity of broiler chickens against Newcastle disease virus (NDV) when fed singly and in combination with a prebiotic.

Materials and Methods: A total of 240 birds (48 per group) were vaccinated with Lasota strain of NDV on the 5th and 21st day of age. Blood samples were collected before and after immunization against ND for the detection of humoral antibody response by hemagglutination inhibition test. The cell-mediated immune (CMI) response was estimated through response to phytohemagglutinin-P (PHA-P) and expressed as web index.

Results: A significant influence on the immune response to NDV was observed in all the L. reuteri PIA16 as well as mannan oligosaccharide (MOS) supplemented groups revealing higher antibody titer than the control counterpart. The CMI response revealed a better cutaneous basophilic hypersensitivity response to PHA-P in the treated groups than the control.

Conclusion: Enhancement in immunity was perceived in the broilers fed with L. reuteri PIA16 and in combination with MOS due to the stimulation of the host's humoral and CMI response by the probiotics and prebiotics used.

Keywords: hemagglutination inhibition, Lactobacillus reuteri PIA16, mannan oligosaccharide, Newcastle disease, phytohemagglutinin-P, probiotics.