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Objective

To evaluate the ability of flumazenil (FLU), butorphanol (BUT), and naloxone (NAL) to reverse the anesthetic effects of oxymorphone-diazepam in dogs.

Animals

6 healthy adult mixed-breed dogs.

Procedure

Dogs were randomly assigned to each of 6 reversal treatment groups. In each experiment, oxymorphone (0.22 mg/kg of body weight, IV) and diazepam (0.22 mg/kg, IV) were given sequentially 15 minutes after glycopyrroiate (0.01 mg/kg, IV) administration. Physiologic saline solution (SAL; 1 ml), FLU (0.01 mg/kg), BUT (0.44 mg/kg), or NAL (0.06 mg/kg) alone, or FLU-BUT or FLU-NAL (same dosages) was given IV as a reversal treatment 15 minutes after oxymorphone-diazepam administration. An individual unaware of the treatment protocol recorded time to extubation, sternal recumbency, and walking.

Results

Time to extubation was significantly (P < 0.05) less with BUT, NAL, FLU-BUT, or FLU-NAL treatment, compared with that for SAL treatment. Time to sternal recumbency was less with BUT, NAL, FLU-BUT, or FLU-NAL treatment, compared with that for SAL treatment. Time to walking was less with FLU-BUT or FLU-NAL treatment, compared with that for SAL treatment.

Clinical Implications

Flumazenil, in combination with BUT or NAL, can be used to reverse the anesthetic effects of oxymorphone-diazepam in dogs. (J Am Vet Med Assoc 1996;209:776–779)

Free access
in Journal of the American Veterinary Medical Association

Summary

Reversal of hemodynamic alterations induced by midazolam maleate (1.0 mg/kg of body weight), xylazine hydrochloride (0.44 mg/kg), and butorphanol tartrate (0.1 mg/kg) with yohimbine (0.1 mg/kg) and flumazenil (0.25 mg/kg) was evaluated in 5 dogs. The dogs were anesthetized with isoflurane for instrumentation. With return to consciousness, baseline values were recorded, and the midazolam/xylazine/butorphanol mixture with glycopyrrolate was administered IV. Hemodynamic data were recorded for 60 minutes, and then a reversal mixture of yohimbine and flumazenil was administered IV. All variables were measured 1 minute from beginning of the reversal injection. Mean arterial pressure, pulmonary arterial pressure, systemic vascular resistance, and right ventricular stroke work index increased significantly (P < 0.05) above baseline at 60 minutes. Cardiac index and central venous pressure significantly decreased below baseline at 60 minutes. After reversal, mean arterial pressure and central venous pressure significantly decreased from baseline, whereas cardiac index, pulmonary arterial pressure, and right ventricular stroke work index increased significantly above baseline. Heart rate, cardiac index, and right ventricular stroke work index increased significantly above the 60-minute value after reversal. Mean arterial pressure and systemic vascular resistance decreased significantly (P < 0.05) below the 60-minute value after reversal. The hemodynamic alterations accompanying midazolam/xylazine/butorphanol sedation-anesthesia may be rapidly reversed with a combination of yohimbine and flumazenil.

Free access
in Journal of the American Veterinary Medical Association

Summary

Plasma catecholamine concentrations in response to onychectomy were examined in 27 cats receiving different anesthetic regimens. Each cat was anesthetized with a dissociative-tranquilizer combination, and onychectomy was performed on 1 forefoot. One week later, each cat was anesthetized with the same dissociative-tranquilizer combination plus either butorphanol or oxymorphone, and onychectomy was performed on the other forefoot. Four treatment groups were studied: tiletamine-zolazepam and tiletamine-zolazepam-butorphanol combinations were administered to group-1 cats, ketamine-acepromazine and ketamine-acepromazine-butorphanol combinations were administered to group-2 cats, tiletamine-zolazepam and tiletamine-zolazepam-oxymorphone combinations were administered to group-3 cats, and ketamine-acepromazine and ketamine-acepromazine-oxymorphone combinations were administered to group-4 cats. All drug combinations were administered im. Central venous blood samples were drawn for catecholamine analysis after injection of drug(s), after onychectomy, and 1, 2, and 4 hours after injection. Tiletamine-zolazepam alone or tiletamine-zolazepam-butorphanol prevented epinephrine release for 2 hours after injection of drug(s). Norepinephrine concentration increased significantly (P < 0.05) from baseline after onychectomy for tiletamine-zolazepam-butorphanol and at 4 hours for tiletamine-zolazepam and tiletamine-zolazepam-butorphanol. After onychectomy, there was no difference in epinephrine values between tiletamine-zolazepam and tiletamine-zolazepam-oxymorphone. Ketamine-acepromazine prevented increases in norepinephrine and epinephrine concentrations for up to 2 hours after surgery. Addition of butorphanol to ketamine-acepromazine decreased norepinephrine values immediately after onychectomy. Addition of oxymorphone to ketamine-acepromazine resulted in lower epinephrine values 4 hours after surgery.

Free access
in American Journal of Veterinary Research

SUMMARY

Six healthy Holstein calves were anesthetized with isoflurane in O2 and instrumented for hemodynamic studies. A saphenous artery was catheterized for measurement of blood pressure and withdrawal of blood for determination of the partial pressure of carbon dioxide (PaCO2 ), oxygen (PaO2 ), and arterial pH (pHa). Respiration was controlled throughout the study. The ecg and eeg were monitored continuously. A thermodilution catheter was passed via the right jugular vein into the pulmonary artery for determination of cardiac output and measurement of central venous pressure, pulmonary arterial pressure, and pulmonary capillary wedge pressure. Baseline values (time 0) were recorded following recovery from isoflurane. Tiletamine-zolazepam (4 mg/kg)-xylazine (0.1 mg/kg) were administered iv immediately after recording baseline values. Values were again recorded at 5, 10, 20, 30, 40, 50, and 60 minutes after injection. Changes in left ventricular stroke work index, Paco2 , and pHa were insignificant. Arterial blood pressure and systemic vascular resistance increased above baseline at 5 minutes and then gradually decreased below baseline at 40 minutes, demonstrating a biphasic response. Values for pulmonary capillary wedge pressure, pulmonary arterial pressure, central venous pressure, and Pao2 were increased above baseline from 5 to 60 minutes. Stroke volume, stroke index, and right ventricular stroke work index were increased from 20 or 30 minutes to 60 minutes. Pulmonary vascular resistance increased at 10 minutes, returned to baseline at 20 minutes, and was increased again at 60 minutes. Heart rate, cardiac output, cardiac index, and rate pressure product were decreased at 5 minutes, and with the exception of cardiac output, remained so for 60 minutes. Cardiac output returned to the baseline value at 30 minutes. All calves recovered without complications. We concluded that tiletamine-zolazepam (4 mg/kg iv)-xylazine (0.1 mg/kg iv) is a safe and useful anesthetic regimen for use in calves.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To examine the effects of giardiasis on production and carcass quality, using growing lambs as a domestic ruminant model.

Design

Randomized block.

Animals

Giardia-free lambs: 23 in infected group, 24 in control group.

Procedure

Six-week-old, specific-pathogen-free lambs were infected with Giardia trophozoites; control lambs received saline solution. Clinical signs of infection, body weight, and feed intake were determined for 10 weeks. Carcass weight and quality were determined at slaughter weight of 45 kg.

Results

Giardia infection persisted from weeks 7 to 16. For 5 weeks after challenge exposure, abnormal feces were more frequently observed in infected lambs. Giardia infection was associated with a decrease in rate of weight gain and impairment in feed efficiency. Time to reach slaughter weight was extended in infected lambs, and the carcass weight of Giardia-infected lambs was lower than that of control lambs.

Conclusion

Giardiasis has a negative effect on domestic ruminant production.

Clinical Relevance

Giardiasis in domestic ruminants is an economically important disease, thus necessitating control or elimination of the infection.

Free access
in American Journal of Veterinary Research

Objective

To determine duration of infection and association of infection with diarrhea for dairy calves with naturally acquired cryptosporidiosis and giardiosis.

Design

Cohort study.

Animals

20 Holstein calves on a single dairy farm.

Procedure

Fecal samples were collected 3 times/wk for the first 45 days after birth, then weekly until calves were 120 days old and examined for Giardia duodenalis cysts and Cryptosporidium parvum oocysts. Calves were monitored for diarrhea during the first 45 days after birth; during each episode of diarrhea, fecal samples were examined for parasitic, bacterial, and viral pathogens.

Results

All 20 calves shed Giardia cysts and Cryptosporidium oocysts at some time during the study. Mean ages at which Giardia cysts and Cryptosporidium oocysts were first detected were 31.5 and 16.3 days, respectively. Mean number of Giardia cysts in feces remained high throughout the study, whereas Cryptosporidium oocysts decreased to low or undetectable numbers 2 weeks after infection. Eighteen calves had a total of 38 episodes of diarrhea during the first 45 days after birth. Giardia duodenalis was the only pathogen identified during 6 (16%) episodes, C parvum was the only pathogen identified during 9 (24%) episodes, and G duodenalis and C parvum were identified together during 10 (26%) episodes.

Conclusions

Prevalences of giardiosis and cryptosporidiosis were high in these calves, and both parasites were associated with development of diarrhea. Cryptosporidium parvum was an important pathogen when calves were < 1 month old, but G duodenalis was more important when calves were older. Calves cleared C parvum infections within 2 weeks; however, G duodenalis infections became chronic in these calves. (J Am Vet Med Assoc 1999;214:391–396)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine efficacy of fenbendazole for treatment of giardiasis in calves.

Animals

Twenty male and 15 female Holstein calves (100 to 180 kg), naturally infected with Giardia sp.

Procedure

In vitro fenbendazole susceptibility and resistance development was determined for a ruminant Giardia isolate by use of an adherence assay. Calves were treated as follows: group 1, a single administration of 5 mg of fenbendazole/kg of body weight; group 2, a single administration of 10 mg of fenbendazole/kg; group 3, 5 mg of fenbendazole/kg, every 24 hours for 3 days; group 4, 10 mg of fenbendazole/kg, every 24 hours for 3 days; group 5, 20 mg of fenbendazole/kg, every 24 hours for 3 days; group 6, 0.833 mg of fenbendazole/kg, every 24 hours for 6 days; and group 7, saline solution, Fecal Giardia cysts were counted on days −3 through −1 and 1 through 7, 9, 11, 13, 21, and 28 by use of sucrose gradient concentration and staining with a fluorescent monoclonal antibody.

Results

The 50% adherence inhibition concentration was 0.024 ± 0.002 μg/ml, and resistance could not be detected after 5 weeks of continuous culture at sublethal concentration of fenbendazole (0.01 μg/kg). Fenbendazole was 100% effective in eliminating cysts from the feces within 6 days for calves in treatment groups 2–6. Reinfection was observed in some calves within the 28-day study period.

Conclusions

Fenbendazole is effective in the elimination of Giardia infections in calves, but repeat treatments may be required in reinfected animals.

Clinical Relevance

Fenbendazole is an effective and economical treatment for Giardia-associated diarrhea and growth rate reduction in calves. (Am J Vet Res 1997;58:384–388)

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To determine whether tilmicosin alters neutrophil infiltration or function, induces neutrophil apoptosis, and affects accumulation of leukotriene B4 (LTB4) or tumor necrosis factor-alpha (TNF-α) in lungs of calves experimentally infected with Pasteurella haemolytica.

Animals

12 weight-ranked Holstein calves.

Procedure

Calves were given 25% propylene glycol vehicle (n = 5) or tilmicosin (10 mg/kg of body weight; n = 6) subcutaneously, 18 hours and 15 minutes before intratracheal infection with 2 × 108 P haemolytica organisms. Two unmanipulated calves served as controls in some experiments. Rectal temperatures were recorded 15 minutes before, and at 3- hour intervals after infection for 24 hours. Samples obtained from bronchoalveolar lavage performed 3 and 24 hours after infection were used to assess colonization by P haemolytica, and neutrophil infiltration. Neutrophil phagocytosis of P haemolytica, membrane leakage as determined by trypan blue exclusion, oxidative function as determined by nitro blue tetrazolium reduction, and apoptosis, using electron microscopy and DNA fragmentation ELISA, were determined. Soluble TNF-α and LTB4 were measured from supernatants from bronchoalveolar lavage samples, using ELISA.

Results

Treatment with tilmicosin resulted in significant (P< 0.05) clearance of P haemolytica and neutrophil apoptosis at 3 hours, and decreased concentration of LTB4 at 24 hours. Rectal temperatures, neutrophil infiltration, phagocytosis, oxidative functions, membrane leakage, and soluble TNF-α concentrations were not significantly affected by tilmicosin.

Conclusion

Tilmicosin effectively controlled P haemolytica infection, induced neutrophil apoptosis, reduced pulmonary inflammation, and did not affect neutrophil infiltration or function.

Clinical Relevance

By inducing neutrophil apoptosis, tilmicosin prevents further amplification of inflammatory injury in P haemolytica-infected lungs. (Am J Vet Res 1998;59:765-771)

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To describe rabies and rabies-related events occurring during 2018 in the United States.

ANIMALS

All animals submitted for laboratory diagnosis of rabies in the United States during 2018.

PROCEDURES

State and territorial public health departments provided data on animals submitted for rabies testing in 2018. Data were analyzed temporally and geographically to assess trends in domestic animal and wildlife rabies cases.

RESULTS

During 2018, 54 jurisdictions reported 4,951 rabid animals to the CDC, representing an 11.2% increase from the 4,454 rabid animals reported in 2017. Texas (n = 695 [14.0%]), Virginia (382 [7.7%]), Pennsylvania (356 [7.2%]), North Carolina (332 [6.7%]), Colorado (328 [6.6%]), and New York (320 [6.5%]) together accounted for almost half of all rabid animals reported in 2018. Of the total reported rabies cases, 4,589 (92.7%) involved wildlife, with bats (n = 1,635 [33.0%]), raccoons (1,499 [30.3%]), skunks (1,004 [20.3%]), and foxes (357 [7.2%]) being the major species. Rabid cats (n = 241 [4.9%]) and dogs (63 [1.3%]) accounted for > 80% of rabid domestic animals reported in 2018. There was a 4.6% increase in the number of samples submitted for testing in 2018, compared with the number submitted in 2017. Three human rabies deaths were reported in 2018, compared with 2 in 2017.

CONCLUSIONS AND CLINICAL RELEVANCE

The overall number of animal rabies cases increased from 2017 to 2018. Laboratory diagnosis of rabies in animals is critical to ensure that human rabies postexposure prophylaxis is administered judiciously.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To provide epidemiological information on animal and human cases of rabies occurring in the United States during 2019 and summaries of 2019 rabies surveillance for Canada and Mexico.

ANIMALS

All animals submitted for laboratory diagnosis of rabies in the United States during 2019.

PROCEDURES

State and territorial public health departments and USDA Wildlife Services provided data on animals submitted for rabies testing in the United States during 2019. Data were analyzed temporally and geographically to assess trends in domestic and wildlife rabies cases.

RESULTS

During 2019, 53 jurisdictions submitted 97,523 animal samples for rabies testing, of which 94,770 (97.2%) had a conclusive (positive or negative) test result. Of these, 4,690 tested positive for rabies, representing a 5.3% decrease from the 4,951 cases reported in 2018. Texas (n = 565 [12.0%]), New York (391 [8.3%]), Virginia (385 [8.2%]), North Carolina (315 [6.7%]), California (276 [5.9%]), and Maryland (269 [5.7%]) together accounted for almost half of all animal rabies cases reported in 2019. Of the total reported rabid animals, 4,305 (91.8%) were wildlife, with raccoons (n = 1,545 [32.9%]), bats (1,387 [29.6%]), skunks (915 [19.5%]), and foxes (361 [7.7%]) as the primary species confirmed with rabies. Rabid cats (n = 245 [5.2%]) and dogs (66 [1.4%]) accounted for > 80% of rabies cases involving domestic animals in 2019. No human rabies cases were reported in 2019.

CONCLUSIONS AND CLINICAL RELEVANCE

The overall number of animal rabies cases decreased from 2018 to 2019. Laboratory diagnosis of rabies in animals is critical to ensure that human rabies postexposure prophylaxis is administered judiciously.

Full access
in Journal of the American Veterinary Medical Association