Euthanized Research Articles

Effects of flow diversion stents on rabbits' wide necked aneurysms and branches

Objective To observe the effects of flow diversion stents on rabbits' aneurysms and branches.Method 30 New Zealand white rabbits with wide necked aneurysm were randomly divided equally into three groups.In group A and B,flow diversion stents were implanted into parent vessel with metal coverage 30%～35% and 45%～ 50%,respectively.Angiography was performed at 4 weeks after stent implantation.After 3 months all animals were euthanized for pathological examination after angiography.In group C,animals were only performed for angiography without any stent implanted after grouped and at 3 months,and then animals were euthanized for pathological examination after angiography.Results Immediately after stents placement,90% and 70% aneurysms' necks covered by stents successful in group A and B,respectively.The contrast retention in aneurysms were 88.7% and 100%,respectively.intravenous digital subtraction angiography showed that 77.8% and 85.7% aneurysms were completely occluded at 4 weeks fogow -up,respectively.Artery digital subtraction angiography showed that 71.4% and 85.7% aneurysms were occluded at 3 months follow- up,respectively.All branches covered by stents were patency at angiography follow - up.Pathologic analysis showed that the dome of embolized aneurysms was full filled with thrombus and neointimas at neck and parent vessel were found.In group C,mean aneurysm dimensions were not significantly changed in angiography after grouped and before sacrificed at 3 months( P ＞ 0.05).Conclusions The flow diversion stents are effective in the treatment of wide necked aneurysms with preservation of adjacent branch vessels in angiography. Key words: Flow diversion stent; Metal coverage; Intracranial aneurysm; Branch vessel; Rabbit

Value of quantitatively analyzing tissue perfusion parameters of contrast enhanced ultrasound in the evaluation of antiangiogenic therapeutics effect in a mouse hepatoma model

Objective To evaluate the value of quantitatively analyzing tissue perfusion parameters of contrast-enhanced ultrasound in the evaluation of antiangiogenic therapeutics effect. Methods Kun-min mouse were subcutaneously implanted with H22 cells. Ten mouse were treated with thalidomide (200 mg/kg once daily) by intraperitoneal injection over 7 days,starting at day 2 post-implantation. Ten control mouse were treated with an equivalent volume of 0.5 CMC. Contrast-enhanced gray-scale ultrasound was performed on day 8 after bolus injection of SonoVue (0.1 ml) and the imaging was recorded on cine.Regions of interest within tumour were analyzed off-line with the software of SonoLiver to determine the area under the curve (AUC), maximum intensity (Imax), perfusion index (PI), mean transit time (mTT),time to peak (TTP) and quality of fit (QOF). Immediately after imaging, minces were euthanized and tumour tissue removed for fixation in a 10% formalin solution. Microvascular density (MVD) was measured after anti-CD34 staining. Results The body weight and the tumor volume of treated tumors were significant different (lower) than that of control tumors (P ＜0.05). Treatment with thalidomide resulted into a significant decrease in AUC,PI and Imax in comparison with control tumors ( P ＜0.05). There were no significant difference in mTT and TTP between control and treated tumours ( P ＞0.05). Treated tumours were associated with a significantly lower MVD as compared with control tumours( P ＜0.05). ConclusionsQuantitatively analyzing tissue perfusion parameters of contrast enhanced ultrasound shows promise for monitoring tumor response to antiangiogenic therapy. Key words: Ultrasonography; Microbubbles; Liver neoplasms; Angiogenesis inhibitors

A HISTOLOGICAL STUDY ON THE EFFECTS OF AQUEOUS EXTRACT OF ALTHEA OFFICINALIS ON EPITHELIAL AND SUBMUCOSAL MUCOCILLIARY SYSTEM OF RAT TRACHEA FOLLOWING INHALATION OF CIGARETTE SMOKE

The contents of cigarette smoke (gaseous and solid phases) have been attributed to a variety of diseases in the respiratory and cardiovascular systems and have been associated with development of different types of cancers. In respiratory system, these compounds specially cause epithelial cell injury, and interfere with mucocilliary transport (MTC). Various parts of Althea officinalis (family Malvaeceae), known as Khatmi (in Persian), are commonly used in Iranian traditional medicine in treatment of acute bronchitis, pneumonia etc. Thus, we conducted a study to evaluate the effectiveness of the aqueous extract of flower part of this plant in the treatment of epithelial and submucosal cell injuries produced following experimental exposure to cigarette smoke in an experimental setting in rat. In this study the rats of either sexes were divided into 4 groups (n=5). First group (control group) received 1 ml normal saline every 12 hours. Second group was nebulized by 1 ml of Althea extract (100 mg/ml) twice daily. Third group was exposed to smoke of four cigarettes in a chamber for 1 hour. Fourth group was nebulized with 1 ml Althea extract as the second group but after the first dose of extract, animals were exposed to cigarette smoke for 1 hour. After 10 days, the animals were euthanized through IP injection of sodium thiopental (200 mg/kg) then trachea was removed and prepared for histological examination, using H&E and PAS staining. The results of this study revealed that (1) the group receiving cigarette smoke had a significant increase in occurrence of metaplasia in comparison to other groups (p

Should There Be a Legal Right to Die?

Imagine a society in which patients are routinely euthanized—whether they want their lives to end or not—if their suffering cannot be alleviated without dulling their consciousness, eliminating their in-dependence, or threatening their dignity.[...]

Deterioration and Metastasis of a Canine Transmissible Venereal Tumor in a Dog Associated with a CPV-2

Virus infection has been documented to be associated with tumor progression. A 2- year-old female beagle was inoculated in the dorsal flank with viable canine transmissible venereal tumor (CTVT) cells for routine laboratory tumor passage. Tumor masses were palpable 2 weeks after inoculation, then grew progressively, and the tumor size remained stable. Parvovirus (CPV-2) infection was diagnosed by RT-PCR at week 11 after tumor inoculation and, 2 weeks later, the primary tumors began to grow again. Besides, palpable tumor masses were found scattered around the primary tumor sites. Because of the deteriorating condition of the animal and the dramatic increase in tumor size and number, the dog was euthanized and venous blood collected for a complete blood count and serum chemistry analysis. Postmortem examination revealed a disseminated CTVT involving the subcutaneous tissue, spleen, liver, lung, and multiple lymph nodes, which was confirmed by histopathological examination and the presence of LINE gene insertion in the 5 end of c-myc gene, a characteristic of CTVT cells, shown using RT-PCR. Lymphoid cell depletion in the spleen and lymph nodes, and focal micro-necrosis of the cryptic epithelium of the small intestine were also seen. Blood analysis showed decreased levels of albumin and total blood protein and an extremely low lymphocyte count. Here, we report a rare case in which a stable CTVT became a devastating metastatic CTVT after a CPV-2 infection. The immunosuppressive effects of CPV-2 might account for the breakdown in the symbiotic balance between the CTVT and host that caused the stable tumor to develop into a metastatic cancer. The correlation between parvovirus infection and aggravated CTVT progression is worthy of further investigation.

A modified method for elastase -induced aneurysm model in rabbits

Objective To create an animal model to simulate human aneurysms, we modified the elastase - induced aneurysm model by application of a simple surgical technique in rabbits. Methods 33New Zealand white rabbits were divided into three groups: In group 1 ( n = 23 ), a temporary arcuated aneurysm clip was placed at the origin of the right common carotid artery and part of right subclavian artery,and the pancreatic elastase induced aneurysm procedure was undertaken;In group 2 ( n = 5 ), elastase was replaced by saline;And in group 3 ( n = 5 ) , the temporary arcuated aneurysm clip was located 3 mm above the location of the clip in group 1. Intravenous digital subtraction angiography was performed at 3 weeks, 8weeks, 4 months, and 6 months after the procedures, and two animals from group 1, and one each from groups 2 and 3, were euthanized for pathology after angiography. In group 1, aneurysm sizes were compared over time by analysis of variance. Results At every time point, saccular aneurysms were displayed in animals of group 1, but retrograde residuals were displayed in all remaining animals of the other 2 groups.Pathologic analysis showed that aneurysms had a thin wall and absence of elastin in group 1. There was no aneurysm and retrograde thrombosis in group 2. Aneurysms with thrombosis at 3 weeks were absorbed after 2months in group 3. In group 1, the mean aneurysm dimension and diameter of parent vessel were not significantly changed over time ( P ＞ 0. 05 ). Conclusions Elastase and location of the temporary arcuated aneurysm clip are important to the success of this aneurysm model. Key words: Aneurysm; Models, Animal; Pancreatic elastase; Rabbits

Epidemiologia de problemas comportamentais em cães no Brasil: inquérito entre médicos veterinários de pequenos animais

Problemas de comportamento afetam diretamente a qualidade de vida dos animais e das pessoas que com eles convivem. Em alguns países, os problemas de comportamento são as principais causas de abandono e eutanásia de animais de companhia. O presente estudo objetivou avaliar a prevalência dos problemas de comportamento dos cães na rotina clínica dos médicos veterinários brasileiros por meio do envio de questionários às faculdades de Medicina Veterinária do Brasil, para serem respondidos pelos profissionais responsáveis pelo atendimento clínico a cães e gatos. No total de 101 questionários respondidos, 91,1% dos participantes afirmaram ser consultados sobre problemas de comportamento e 82,2% afirmaram que a maior frequência das queixas comportamentais foi relacionada à espécie canina. Os respondentes, em sua maioria (56,7%), relataram que tentaram resolver sozinhos alguns casos ou encaminharam o caso para um veterinário especializado. Dentre os respondentes, 89,1% afirmaram não realizar eutanásia em razão de problemas de comportamento. O problema de comportamento citado como o mais frequente foi a destrutividade e, em seguida, as agressões. O tratamento mais recomendado, tanto para agressões quanto para eliminações inapropriadas de urina, foi a terapia comportamental.

Veterinary surgeons and suicide: a structured review of possible influences on increased risk

Veterinary surgeons are known to be at a higher risk of suicide compared with the general population. There has been much speculation regarding possible mechanisms underlying the increased suicide risk...

Influence of ingaalp laser (660nm) on the healing of skin wounds in diabetic rats

To determine the influence of low-power laser (660 nm) on the collagen percentage and macrophages in skin wounds in diabetic rats. 30 male Wistar rats were used, distributed in two groups: laser treated diabetic (n= 15); untreated diabetic (n = 15). The diabetes was induced by intravenous injection of alloxan into the dorsal vein of the penis, at a rate of 0.1 ml of solution per 100 g of body weight. A wound was made on the back of all the animals. Groups 2 were treated with Aluminium Gallium Indium Phosphide - InGaAlP type diode laser (Photon Laser III DMC) with a continuous output power of 100 mW and wavelength (lambda) of 660 nm (4 J/cm(2)) for 24 s. five animal from each group was sacrificed on the 3rd, 7th and 14th days after wounding. Samples were taken, embedded in paraffin, stained with hematoxylin-eosin, Masson's trichrome, and immunohistochemical macrophage. morphometrically analyzed using the Image Pro Plus 4.5 software. The percentages of collagen fibers and macrophages were determined from the samples from the euthanasia animals. The data were treated statistically using analysis of variance (ANOVA) and the Post-hocTukey test. The significance level was set at 0.05 or 5%. The low-power laser (660 nm) was shown to be capable of influencing the collagen percentage in skin wounds by increasing the mean quantity of collagen fibers and macrophages.

Pulling the Plug on Anthrax Research: Wild Horses and “The Doctor's Dilemma”

Pulling the Plug on Anthrax Research: Wild Horses and “The Doctor's Dilemma”

Assessment of antiangiogenic therapeutics effect in a mouse hepatoma model using contrast-enhanced gray-scale ultrasound

Objective To evaluate antiangiogenic therapeutics effect with contrast-enhanced gray-scale ultrasound.Methods Kun-min mouse with subcutaneously implanted H22 mice hepatoma were treated with thalidomide or placebo by oral gavage over 7 days, starting at clay 2 post-implantation.Contrast-enhanced gray-scale ultrasound was performed on day 8.The tumor maximum cross-sectional area and non-enhanced area in ultrasound imaging were measured on the ultrasound machine.The percent of non-enhanced area from contrast-enhanced gray-scale ultrasound was calculated.Immediately after imaging, minces were euthanized and tumor tissue removed for fixation in a 10% formalin solution.The section equivalent to ultrasound imaging plane was stained with Hematoxylin and Eosin(HE) to allow for assessment of maximum cross-section area and necrotic area.The percent of necrotic area from HE stained section was calculated.Results The difference of maximum cross-sectional area measured in ultrasound and pathology slice was not significant between control and treated tumors (P >0.05).Ultrasound measurement of the tumor non-enhanced area and the percent of non-enhanced area were significantly larger in treated tumors than in control tumors (P <0.001).The necrotic area and the percent of necrotic area measured from HE stained section were also significantly larger in treated tumors than in control tumors (P < 0.001).The maximum cross-sectional area determined by the two methods was well corrected (r = 0.815, P < 0.001).There was good correlation between the non-enhanced area in contrast-enhanced gray-scale ultrasound and the necrotic area in pathology slides (r = 0.909, P <0.001).The percent of non - enhanced area calculated from ultrasound highly correlated with necrotic area estimated by pathology slides (r = 0.910, P <0.001).Conclusions Contrast-enhanced gray-scale ultrasound can detect the intratumoral necrosis and changes of tumor perfusion caused by antiangiogenic treatment before apparent change in tumor volume. Key words: Ultrasonography; Microbubbles; Liver neoplasms,experimental; Angiogenesis inhibitors

Superovulatory Response, Oocyte Spontaneous Activation, and Embryo Development in WMN/Nrs Inbred Rats

WMN/Nrs inbred rats have been widely used in radiation biology for years. However, their reproductive profile has never been examined. We examined various reproductive characteristics of WMN/Nrs inbred rats such as superovulatory response, oocytes spontaneous activation (OSA), and embryo development in vitro and in vivo. Superovulation was induced in 3- to 9-week-old females by injection of 150 IU/kg PMSG and 150 IU/Kg hCG by 48 h apart. Only 8- and 9-week-old animals superovulated averaging 31.4 and 43.9 oocytes, respectively, and superovulation did not depend on estrous cycle. Animals 3-7 weeks of age did not superovulate. Because Wistar strains have been known to show a high incidence of OSA, factors expected to affect OSA in WMN/Nrs, including the time interval of various steps from euthanasia to oocyte recovery, incubation media, estrous cycle, and anesthetic treatments, were examined. The time from animal euthanasia to oviduct excision was the only factor shown to affect OSA. We also compared in vitro and in vivo embryo developmental competence between embryos obtained by natural ovulation and superovulation. Although percent in vitro development of 2-cell embryos to blastocysts was similar for embryos obtained by natural ovulation (63.7%) and superovulation (69.7%), fetus development after oviductal transfer of 2-cell embryos was significantly lower in embryos obtained by superovulation than in those obtained by natural ovulation (60.2% vs. 87.5%, P=0.02). Our results provide important normative data regarding future applications of rat assisted reproductive technologies (ARTs) such as in vitro fertilization and cryopreservation in WMN/Nrs strain and may be applicable to other strains of laboratory rats.

Hesperidin, a natural citrus flavanone, alleviates hyperglycaemic state and attenuates embryopathies in pregnant diabetic mice

In this study, we attempted to investigate the effect of hesperidin, a natural antioxidant citrus flavanone, on diabetes-induced embryopathies in mice. Streptozotocin (STZ) was injected intraperitoneally in 60 mg/kg bw/day for 3 consecutive days to induce diabetes in virgin females. 72 h later, mating was applied and hesperidin was orally given to pregnant diabetic mice in 20 ppm from the 1st to the 18th day of approximately 19 days-gestational length. Maternal body weight and glycaemia were measured throughout pregnancy. Mice were euthanized on day 18 in order to evaluate the teratological parameters. The results showed a considerable decrease of maternal body weight at the last week of pregnancy in hesperidin-treated diabetic mice. Maternal glycaemia was slowly attenuated by hesperidin with a significantly manifest effect on days 11 and 18. This flavanone enhanced the number of implantations per litter, the overall number of foetuses and the absolute and relative foetal weights while reducing malformations and resorptions rates. The red alizarin-staining procedure for foetal skeleton demonstrated a full protective role of hesperidin since, as in controls, no skeletal defects were found in treated diabetic group. These findings suggest that hesperidin may have a prophylactic effect against diabetic embryopathies in mice. Key words: Hesperidin, citrus fruits, diabetic embryopathy, mice.

Neuroprotective effects of NAAG peptidase inhibition on the treatment of traumatic brain injury

Objective To explore the neuroprotective effects of NAAG peptidase inhibition on the treatment of traumatic brain injury.Method A total of 20 male Sprague-Dawley rats were divided into 4 groups,then sustained to moderate lateral fluid percussion TBI.A novel NAAG peptidase inhibitor,ZJ-43,was used in4 different doses (0,50,100,or 150 mg/kg).Each dose was repeatedly administered i.p.(n=5/group) by multiple injections at 3 times (0 h,8 h,16 h) after TBI.Rats were euthanized at 24 hrs after TBI and brains were processed and stained according to the Fluoro-Jade B Histofluorescence and GFAP Immunohistochemistry protocols,lpsilateral neuronal degeneration and bilateral astrocyte loss in the CA2/3 regions of the hippocampus were quantified using stereological techniques.Results Compared with vehicle,ZJ-43 significantly reduced the number of the ipsilateral degenerating neurons (P＜0.01) with the greatest neuroprotection at the 50 mg/kg dose.Moreover,50 mg/kg of ZJ-43 also significantly reduced the ipsilateral astrocyte loss (P＜0.05 ).Conclusions Blockade of NAAG peptidases may augment an endogenous neuroprotective mechanism in the brain and limit glutamate excitotoxicity.The strategy may represent a new therapeutic approach to secondary brain damage after traumatic brain injury. Key words: Traumatic brain injury; N-acetylaspartylglutamatc (NAAG); Glutamate; Excitotoxicity; Neuroprotection

Euthanasia-related strain and coping strategies in animal shelter employees

To identify and evaluate coping strategies advocated by experienced animal shelter workers who directly engaged in euthanizing animals. Cross-sectional study. Animal shelters across the United States in which euthanasia was conducted (5 to 100 employees/shelter). With the assistance of experts associated with the Humane Society of the United States, the authors identified 88 animal shelters throughout the United States in which animal euthanasia was actively conducted and for which contact information regarding the shelter director was available. Staff at 62 animal shelters agreed to participate in the survey. Survey packets were mailed to the 62 shelter directors, who then distributed them to employees. The survey included questions regarding respondent age, level of education, and role and asked those directly involved in the euthanasia of animals to provide advice on strategies for new euthanasia technicians to deal with the related stress. Employees completed the survey and returned it by mail. Content analysis techniques were used to summarize survey responses. Coping strategies suggested by 242 euthanasia technicians were summarized into 26 distinct coping recommendations in 8 categories: competence or skills strategies, euthanasia behavioral strategies, cognitive or self-talk strategies, emotional regulation strategies, separation strategies, get-help strategies, seek long-term solution strategies, and withdrawal strategies. Euthanizing animals is a major stressor for many animal shelter workers. Information regarding the coping strategies identified in this study may be useful for training new euthanasia technicians.

Chloral Hydrate Is Not Acceptable for Anesthesia or Euthanasia of Small Animals

Chloral Hydrate Is Not Acceptable for Anesthesia or Euthanasia of Small Animals

Chloral Hydrate Is Not Acceptable for Anesthesia or Euthanasia of Small Animals

We sincerely thank Baxter et al . for their interests in our article and their valuable information about the use of chloral hydrate for rats' anesthesia and euthanasia in our experiment.First, we would like to emphasize that we do not think the reliability of our experimental results was influenced by chloral hydrate. Chloral hydrate was used in all the experimental groups, thus its interpretations were comparable among these groups. Our significant findings could not be simply induced by it. In addition, the mechanisms of most anesthetics, including their effects on Arc expression, are still obscure. Furthermore, sevoflurane has even been proved to inhibit Arc transcription.1Under this condition, choosing any other anesthetic for rat euthanasia may produce the similar unpredicted interpretations. Therefore, we believe that to a great extent, our results and conclusions are reliable.Second, we designed our experiment on the basis of a great deal of published articles on authority journals. The method as intraperitoneal injection of chloral hydrate was wildly used to rats for some kinds of surgeries, particularly with the word as “anesthesia.” For example, Rodríguez Manzanares et al ., Bredeloux et al ., and Sammut et al . all use chloral hydrate to anesthetize rats for stereotaxic neurosurgery to implant cannulae.2–4Actually, in recent years, chloral hydrate is still widely used to anesthetize rats. However, we agree with the view of Baxter et al . that some other anesthetics (like Phenobarbital sodium) may be more suitable in this type of surgery because of the side effects of chloral hydrate illustrated by them. Fortunately, the overwhelming majority of rats in our experiment recovered well from the neurosurgery, with normal appetite and defecation.Third, we admit that we neglect the potential problem of using chloral hydrate for euthanasia of rats. Chloral hydrate is a traditional anesthetic in animal experiments, and before we performed our study we also found that it is used for killing rats by either decapitation or cardiac perfusion in respectable published articles.2,5,6Moreover, our research was approved by the Institutional Animal Care and Use Committee with no questions. Therefore, we never doubted the use of chloral hydrate for rat euthanasia. Now we feel deeply sorry for the possibility of inflicting pain on the animals because of using chloral hydrate.Finally, we would like to extend our sincere gratitude to Baxter et al . for letting us understand animal euthanasia more deeply. We will pay much more attention to the euthanasia issue, adopt proper and scientific animal welfare methods, and try our best to decrease harm to the experimental animals as much as possible in future research.*Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, People's Republic of China. yubuwei@yahoo.com.cn

Local X-irradiation promotes regeneration of spinal cord central nervous system in a rat model

To evaluate the effect of local X-irradiation on spinal cord injury by using physiology, kinology, electrophysiology and histology method. 46 female Sprague-Dawley rats were subjected to spinal cord injury by weight dropping on T(11-12). All animals were divided into 3 groups randomly. One of the animal groups was irradiated with 10 Gy at the lesion site; another was irradiated with 20 Gy, the other without irradiation is regarded as sham-group. The animals were euthanized at different time points at 4 and 12 weeks after irradiation. Spinal cord callus was assessed by using physiology, kinology, and electrophysiology and histology method. In all the groups, the NF at 14 weeks were found higher than that of 6 weeks. Both 10 Gy irradiated and 20 Gy irradiated groups were higher than those of group at each time point (P < 0.05). The MBP decreased at 14 weeks in irradiated groups (P < 0.05), but increased at 14 weeks in sham-group (P < 0.05), the MBP of irradiated groups was lower than that sham-group at 14 weeks (P < 0.05). The GFAP and Nogo-A at 14 weeks were higher than that in 6 weeks in all the groups (P < 0.05), and there was no statistical significance with physiology, kinology, electrophysiology test in all groups. A self-repair mechanism exists after SCI, which will last at least 14 weeks. Local irradiation promotes the regeneration of spinal cord system after injury to some extent.

Enhancing effects of microbubble contrast agent of different dosage on high-intensity focused ultrasound ablation in goat liver in vivo

Objective To investigate the enhancing effect of microbubble contrast agent SonoVue of different dosage on high-intensity focused ultrasound (HIFU) ablation in goat livers in vivo. Methods Twenty goats were divided into 4 groups randomly. Animals in group 1,2 and 3 were bolus-injected of 0.01 ml/kg,0. 03 ml/kg and 0.05 ml/kg of SonoVue intravenously before HIFU exposure, respectively,and those in group 4 were not given injections as control. After injection 20s, the livers were ablated using HIFU performed in the manner of a single dot set by a computer system using a clinical device. The frequency of HIFU was 0.8 MHz,the intensity of HIFU was 19 100 W/cm2 ,the distance from skin to the target liver tissue was 30 mm,the exposure time was set at 15 s for all animals in the four groups. All animals were euthanized 7 days after HIFU, volumes of coagulated necrosis were measured. Pathological examinations were performed to analysis the exposure regions. Results Under the same parameters of exposure, coagulated volumes in group 1,2 and 3 were larger than those in group 4, the difference was significant (P < 0.05),and the coagulated volumes increased gradually with the dosage of SonoVue increasing from group 1 to group 3, the difference was significant (P<0.05). Pathological examinations confirmed that there were no residual unaffected tissues within the exposed volume. Two remarkable changes were observed in one goat in group 37 days after HIFU:the surrounding adjacent tissue outside the reactive zone necrotized and the skin were destroyed. Conclusions The enhancing effects of microbubble contrast agent in HIFU ablation is related with the dosage of the microbubble contrast agent SonoVue. The higher the SonoVue dosage,the larger the volume destroy in the target tissue. Key words: Ultrasonography, Ultrasound, high-intensity focused ; Microbubbles, Liver

ANIMAL RABIES IN MASSACHUSETTS, 1985–2006

In this study, we review annual rabies data from Massachusetts from 1985 to 2006, spanning the introduction of raccoon strain rabies in 1992. Of 52,034 animals tested, 9.7% (5,049/52,034) were rabid, representing 26 of over 67 species submitted. Bats were the most common rabid animals prior to 1992 (50 of 52), but raccoons (Procyon lotor) became the most common rabies-positive species upon arrival of raccoon strain rabies virus (38.2%, 2,728 of 7,138 tested), followed by striped skunks (Mephitis mephitis, 34.4%, 1,489 of 4,332), bats (5.3%, 427 of 8,053), foxes (red fox, Vulpes vulpes, and gray fox, Urocyon cinereoargenteus, 16.3%, 135 of 827), cats (0.8%, 136 of 18,050), and woodchucks (Marmota monax, 5.7%, 82 of 1,446). Cats were the most frequently tested animal (34.7%). Raccoon strain rabies spread from two foci of introduction with an initial epizootic phase of 4 yr, by which time most of the state was affected. In 1992, there was a transition from enzootic bat rabies, with little spillover to other animals, to terrestrial rabies associated with raccoon strain virus. Although raccoons were most affected by the raccoon strain virus, there was spillover to other species, particularly to skunks. The eastern United States raccoon rabies epizootic led to a marked increase in submissions for rabies testing and the number of positive animals detected; however, bat rabies cases remained at their previous levels. Wild animal rabies presents a significant threat to humans and domestic/companion animals and increased costs related to increased demand for rabies testing, postexposure prophylaxis as well as euthanasia of valuable domestic animals.