Taiwan Veterinary Journal

Enterocytozoon hepatopenaei (EHP) was first described in Thailand in 2009 and has since been identified as a significant threat to the shrimp aquaculture industry. Recently, intracellular microsporidia were identified as a causative agent of hepatopancreatic microsporidiosis (HPM). To date, HPM has been listed as an emerging threat to shrimp farming industries because of reduced shrimp growth and survival rates which are considered to be a wasting disease. This study investigated the outbreaks of HPM in farmed Penaeus vannamei in Taiwan. Sixty-five shrimp samples were collected from Taiwan. The proportion of HPM-positive cases was 48% (31/65). Additionally, the gross signs in infected shrimp were stunted growth, sloughed hepatopancreas (HP), and lethargy. The smear impression on the HP also revealed the existence of large EHP spores. Nested-PCR findings identified that 9 cases were confirmed to be positive for the EhSWP1 gene in the first step and 22 cases tested positive for the second step. Phylogenetic analysis of EHP from Taiwan showed 100% similarity to EHP from Thailand, India, and the United States. Histopathological analysis of the HP revealed haemocyte infiltration and the presence of EHP spores in the hepatopancreatic tubule epithelial cells. These results demonstrated that EHP is the main cause in shrimp farms in Taiwan.

Objective radiographic measurements for determining atlantoaxial instability (AAI) in dogs have been reported. However, choosing a single optimal parameter among different studies is challenging. This study aimed to identify optimal parameters for AAI in small-breed dogs by simultaneously evaluating the flexed and nonflexed lateral radiographs. Moreover, the potential of using serial trichotomization with multiple parameters was investigated. Radiographs of 10 dogs diagnosed with AAI on magnetic resonance imaging (MRI) were compared with 26 control dogs to select parameters with the area under the curve ≥0.9 or ≤0.1. Parameters with outstanding discrimination included cranial border distance and C1–C2 angle on nonflexed radiographs and dens length on ventrodorsal radiographs. Using cutoff values reflecting 100% sensitivity and 100% specificity, the subject was determined into AAI diagnosed, ruled-out or indeterminate. The accuracy rate was 100% for each of the parameters. However, 31–47% of dogs were classified as indeterminate. Serial trichotomization in the order of dens length, cranial border distance, and C1–C2 angle significantly reduced the proportion of dogs in the uncertainty zone while maintaining accuracy. The established method was tested on 19 new subjects. A similar trend of high accuracy (100%) and small uncertainty zone (5%) was observed in the validation cohort. For certain breeds, serial trichotomization with dens length on the ventrodorsal radiograph and cranial border distance and C1–C2 angle on the nonflexed lateral radiograph showed good potential for determining AAI and identifying dogs in which advanced imaging is indicated for diagnosis.

Avian infectious bronchitis virus (IBV) has been reported to acquire haemagglutination (HA) activity after treatment with neuraminidase, which depends on the IBV S1 protein. The purpose of this study was to test the IBV HA activity and its relationship to the S1 sequences. A wild strain of IBV, 2575/98 possessed HA activity after neuraminidase treatment. On the contrary, its attenuated strain through 75 chicken embryo passages did not. The nucleotide sequence differences in S1 genes before and after attenuation were C166A and G280T, resulting in amino acid changes of P56T and A94S. The S1 and S genes of the wild strain were cloned and expressed in a baculovirus (B) expression system. To test the relationship between HA activity and the S sequence changes after attenuation, the two nucleotide residues were mutated. The HA activity of those recombinant baculoviruses (rBs) was tested. The results showed that rB containing S gene from wild strain possesses the HA activity, that containing S gene with C166A mutation shows partial HA but that containing G280T mutation shows no any HA activity. Thus, a Taiwan IBV strain 2575/98 loses its HA activity after attenuation and this loss might be related to amino acid changes of P56T and A94S in the IBV S protein.

The zoonotic illness brucellosis may spread between humans and animals in a variety of ways. The prevention and management of brucellosis depend heavily on the cleanliness of the areas around animals and the effective eradication of infection from animal housing. In our investigation, we tested a variety of disinfectants against Brucella melitensis to see how well they worked and whether they would work in various environmental settings. In addition to three different types of nano-disinfectants (Dettol with Silver-NPs, Glutaraldehyde with Silver-NPs, and Calcium oxide-NPs), our study included various conventional forms of disinfectants and antiseptics (Virkon$Ⓡ$ S, Cidex, Sodium hypochlorite, Betadine, and Dettol). For estimating the effectiveness of various types of applied disinfectants, reduction rate was employed. The findings indicated that the concentration and length of exposure time of the disinfectants employed, particularly Vircon S, had an impact on their ability to kill bacteria. However, the presence of filthy circumstances and low temperatures considerably reduced the effectiveness of disinfectants, particularly Dettol. On the other hand, nano-disinfectants, particularly glutaraldehyde containing silver nanoparticles, showed better effects than conventional ones. Our research indicated that disinfectants used in everyday life had an impact on Brucella melitensis. However, the presence of filthy environments and low temperatures reduced the bactericidal effectiveness. The impact of nano-disinfectants on Brucella was better.

In Taiwan, infectious bronchitis virus (IBV) is mainly restricted to two groups Taiwan Group I (TW-I) and Taiwan Group II (TW-II) that are distinct from other countries. To evaluate the reliability of commercial enzyme-linked immunosorbent assay (ELISA) kits, imported commercial test kits (namely, A, B and C) were used to test field samples. The results were further compared with hemagglutination inhibition (HI) test to figure out the consistency. Results showed that the three commercial ELISA kits had only partial consistency with HI results. In fact, testing results of breeders and layers bore resemblance to HI, whereas there were ELISAs negatively detecting results of broilers opposed in HI. The specificities of these ELISA kits were 0.45, 0.86 and 0.77 for kits A, B and C, respectively, and their sensitivities were 0.79, 0.68 and 0.70, respectively. The commercial ELISA kits may not sustainably provide us the whole view of birds infected or vaccinated status. Based on the results of in-house ELISA and western blot, different IBV strains showed different antigen–antibody interaction. Thus, different ELISA coatings with different antigens might result in different antibody titers. Furthermore, according to HI results, 91% (256) and 70% (198) of the 282 tested sera were positive to H120 (as a Massachusetts vaccine) and 3263/04 (as a field strain), respectively. These high positive rates indicate that in spite of popular use of Massachusetts vaccines, the chickens are still commonly infected with field IBVs in Taiwan.

Glaucoma and retinal degenerations are two important ocular diseases that often cause massive impacts to vision in both humans and animals. Rat models are commonly used to explore the complex pathophysiology and potential treatments of these diseases. The models of high intraocular pressure (HIOP)-induced retinal ischemia-reperfusion imply the ischemic outcome weight on the inner retina layers (including the nerve fiber layer, retinal ganglion cell (RGC) layer, inner plexiform layer (IPL), and inner retinal layer (INL)) that eventually progressed to the outer retinal layers. Depending on the duration (cycles) of ischemic treatment, more glaucoma pathological change signs may be exhibited more obviously with time. The model requires a short ischemic treatment and anticipates an adequately long period of disease manifestation. To investigate photoreceptor-led retinal degeneration, rat models for light-induced retinopathy are commonly used and it is predominantly attributed to the photoreceptor cells damage of ONL and OPL loss by high intensity of light exposure. This model unraveled the pathophysiological impairment of phototransduction as well as disease mechanisms involving oxidative stress and inflammatory process of the outer retinal layer. With the knowledge gained from the research using these animal models, better understanding of the disease mechanisms in terms of its pathophysiology and molecular changes can be achieved. Besides, the rat models can serve as the key basis for further investigation into the therapeutic or preventive perspectives of these retinopathies.

Corneal injuries in pets cause severe suffering and vision impairment, creating significant challenges in the field of veterinary medicine. It is important to understand that the cornea lacks the inherent capability to regenerate itself through the administration of substances such as hyaluronic acid or antibiotics, which are commonly utilized by veterinarians for managing edema and infections in animals. It has been shown that platelet rich fibrin extract (PRFE) is effective in healing both deep corneal ulcers and superficial keratitis. In this case report, the use of PRFE in dogs and cats which showed promising results.

A 5-year-old multiparous lactating Holstein cow was reported to have cystic ovarian disease with a history of whitish vaginal discharge on the 80th day postpartum. On the 83rd day postpartum, transrectal ultrasonography revealed a thick-walled cystic structure with visible cobwebs in the cavity, measuring 4.2cm × 3.4cm in diameter on the right ovary. The serum progesterone (P₄) concentration was 6.82ng/mL, leading to a diagnosis of luteinized follicular cyst. Transvaginal aspiration of the cyst was performed to decrease the compression of ovarian stroma by the cyst, followed by intramuscular administrations of cloprostenol and buserelin. A 1.9cm diameter corpus luteum was detected on the right ovary nine days after aspiration, with a serum P₄ concentration of 1.29ng/mL. Continual hormone treatment was followed, consisting of an injection of buserelin and an intravaginal progesterone-releasing device inserted for seven days. After seven days, two corpora lutea were noted on the right ovary with an average diameter of 2.8cm and 1.8cm, respectively. The device was removed and the cow showed a P₄ concentration of 11.22ng/mL on that day. Estrus induction was conducted with two low doses of cloprostenol followed by an injection of gonadorelin, to induce a complete luteolysis and the following ovulation to fit a fixed-timed artificial insemination (AI). Pregnancy was confirmed 33 days after AI. Although the number of days open was 102 in this case, it took a total of 19 days from treatment to pregnancy.

A Holstein dairy cow on a farm located in central Taiwan gave birth after 281 days of gestation; however fetal membranes were not expelled until 12h post-parturition. Preventive antibiotics of ceftiofur (750mg) combined with flunixin (750mg) were administered intramuscularly for three consecutive days. On day 11 postpartum, expulsion of partial fetal membranes and reddish-brown vaginal discharge with an offensive odor were reported. Intrauterine lavage using 800ml of sterile saline and 500ml of 0.2% chlorhexidine solution was performed, followed by intrauterine infusion with 300ml of 0.5% povidone iodine. On day 21 postpartum, a vaginal discharge score (VDS) of 3 was graded by Metricheck${}^{\text{®}}$ and uterine cytology revealed 76.1% polymorphonuclear neutrophils (PMNs), all of which suggested endometritis. An additional intrauterine infusion of 0.5% povidone iodine was subsequently prescribed, followed by two low doses of PGF${}_{2\alpha }$ to control uterine infection. On day 49 postpartum, a VDS of 0 with a proportion of 3.8% PMNs was revealed, indicating available criteria for breeding. Estrus induction and timed artificial insemination were scheduled and pregnancy was confirmed 33 days after artificial insemination. In summary, we have demonstrated a successful two-step treatment for a Holstein having retained fetal membranes (RFMs) combined with puerperal metritis (PM) to have a favorable result of 65 days open.