An Accessible Alternative to Melarsomine: "Moxi-Doxy" for Treatment of Adult Heartworm Infection in Dogs.

Canine heartworm infection, caused by the filarial parasite Dirofilaria immitis, represents a serious and expanding animal welfare concern that is expected to increase due to the effects of climate change and the COVID-19 pandemic. A body of evidence has emerged to support the use of a non-arsenical adulticide treatment protocol, using moxidectin and doxycycline to kill adult heartworms over a prolonged period. While a three-dose protocol using the arsenical drug melarsomine is currently the safest and most effective treatment for heartworm infection, this drug is not available in some countries and is inaccessible for many owners and animal shelters. Moxidectin-doxycycline (moxi-doxy) provides a viable alternative to no treatment at all, in cases where arsenical treatment is not possible. Based on current evidence, the most effective non-arsenical treatment regimen is doxycycline 10 mg/kg PO q 12 or 24 h for 28 days, combined with topical moxidectin at label dose. Moxidectin is repeated monthly until no antigen detected (NAD) status is confirmed. Sustained release injectable moxidectin, in combination with doxycycline, may provide an alternative in remote regions or in settings where significant compliance or accessibility concerns exist, but more studies are needed. In moxi-doxy protocols, doxycycline should be repeated annually until NAD. This review summarizes the safety and efficacy of moxi-doxy, addresses controversies surrounding this treatment approach, and provides detailed recommendations for treatment regimens and post-treatment testing.

Incidence and Predictors of Canine Parvovirus Diagnoses in Puppies Relocated for Adoption.

Animal relocation programs seek to balance the animal population and resources between source and destination communities to promote positive outcomes, though little objective evidence has been reported on their physical and behavioral implications. The objective of the current report is to describe the incidence and predictors of canine parvovirus (CPV) diagnoses in 8- to 19-week-old puppies reported by destination shelters participating in a large scale, long-distance, structured animal relocation program. The incidence of post-transport CPV diagnoses in the study population of 4088 puppies was 2.3%. The number of pre-transport vaccinations, length of stay at the source shelter, and time between pre-transport vaccination and transport was not associated with the expected difference in count of post-transport CPV diagnoses (p > 0.05), and was lower in those 13-17 weeks of age (IRR = 0.08, 95% CI = 0.02-0.34, p = 0.001), 18-19 weeks of age (IRR = 0.11, 95% CI = 0.02-0.80, p = 0.029), transferred in to the source shelter (IRR = 0.31, 95% CI = 0.10-0.96, p = 0.043), and transported in the summer season (IRR = 0.07, 95% CI = 0.01-0.53, p = 0.010). When basic biosecurity practices and vaccination protocols were in place, post-transport CPV cases in puppies were few, suggesting that the timing of transport should take into account factors other than the number or timing of pre-transport vaccinations.

Impact of surgical preparatory rinses with isopropyl alcohol or water on perioperative body temperature in pediatric female dogs and cats.

OBJECTIVE: To describe the effects of presurgical preparation with an isopropyl alcohol or water rinse on the perioperative rectal temperature (RT) of puppies and kittens. STUDY DESIGN: Randomized clinical trial. ANIMALS: A total of 48 intact female mixed breed puppies and 43 intact female Domestic Short Hair kittens aged 8-18 weeks. METHODS: All animals were premedicated with intramuscular buprenorphine (0.02 mg kg-1) and acepromazine (0.05 mg kg-1). Anesthesia was induced with intravenous propofol (4 mg kg-1 to effect) for puppies or ketamine (5 mg kg-1) and midazolam (0.25 mg kg-1) for kittens. RT was measured every minute for the first 15 minutes at the beginning of hair/fur removal, then every 5 minutes for 45 minutes (dogs) and 35 minutes (cats). All animals were prepared for surgery using a 1.6% chlorhexidine solution, then rinsed with either isopropyl alcohol (group CA) or water (group CW). RESULTS: Mean RT difference between the groups was not significant at any time point. The mean RT at 45 minutes for dogs was 35.9 °C and 36.0 °C in groups CA and CW, respectively (p = 0.74). The mean RT at 35 minutes for cats was 35.1 °C in both groups (p = 0.84). CONCLUSIONS AND CLINICAL RELEVANCE: The use of either water or alcohol as a rinsing agent results in the same degree of perioperative temperature change. Other factors that contribute to perioperative hypothermia should be considered when choosing between these rinsing agents in surgical preparation of pediatric and small animals.

The American Heartworm Society and Association of Shelter Veterinarians' 2019 Shelter Heartworm Management Practices Survey.

The primary objective of the 2019 Shelter Heartworm Management Practices Survey was to identify the current practices employed for the prevention, diagnosis, and management of heartworm disease in animal shelters. Survey questions were developed to collect the information of interest for dogs, cats, and ferrets under the care of sheltering organizations along with demographic information about these organizations. An electronic survey was distributed to the American Heartworm Society and Association of Shelter Veterinarians' mailing lists in February-March 2019. Cross-posting of the survey on relevant lists was encouraged. The survey invitation was directed toward veterinarians delivering care in an animal shelter and excluded practitioners providing services for shelters, shelter animals, or recently adopted animals within a private practice setting. A total of 242 survey responses were received representing private humane societies/societies for the prevention of cruelty to animals (39.7%), municipal animal control facilities (24.9%), traditional (public-private partnership) shelters (21.7%), foster-based organizations (7.9%), sanctuaries (2.6%), and breed/species-specific rescues (2.1%). The largest proportion of respondent shelters were from the southeastern United States (36.9%) and over two-thirds of the shelters had full-time shelter veterinarians (69.0%). Most respondents provided monthly heartworm preventives for dogs (81.1%) and used oral ivermectin products per product labels (67.2%) to do so. Extralabel use of preventives was reported by 21.3% of respondents. Most respondents tested all dogs >6 months of age for heartworm infection (81.9%) and did so during the intake examination (56.6%) with antigen tests (92.2%). At least some heartworm positive dogs were treated by most respondents (93.1%) using a 3-dose (42.5%) or 2-dose (37.9%) melarsomine protocol. Non-arsenical treatment protocols were utilized by 16.8% of respondents. Protocols typically included adjunctive treatment with doxycycline or minocycline (92.3%), prednisone (71.3%), and macrocyclic lactones (58.6%). Nearly two-thirds of respondents housed dogs within foster homes after treatment (65.1%). Heartworm prevention was provided by 29.9% of respondents that admitted cats and 9.9% of those that admitted ferrets. These results can be used to identify challenges to meeting recommended practices regarding prevention, diagnosis, and treatment of heartworm disease in the animal shelter setting and to target operational and educational resources toward the areas of greatest need.

Assessment of body weight for age determination in kittens.

OBJECTIVES: The objective of this study was to assess the utility of using body weight for age determination in kittens. METHODS: Medical records were reviewed for serial body weight measurements collected from neonatal kittens (up to 8 weeks of age) from a breeding colony of specific pathogen-free domestic shorthair cats and for single-point body weight measurements of privately owned pediatric kittens (6-20 weeks of age) presenting for elective sterilization. Body weights were compared with known dates of birth and age assessed by dental eruption in combination with developmental characteristics. RESULTS: The coefficient of determination (R2) between age and body weight in longitudinally sampled neonatal kittens was 0.88, while that for pediatric kittens sampled at a single time point was 0.54. Among neonatal kittens, predicted age based on the 1 lb (0.45 kg) of body weight gain per month of age guideline corresponded to within 1 week of actual age for 243 (98.8%), 234 (95.1%), 203 (82.5%) and 191 (77.6%) kittens at 2, 4, 6 and 8 weeks of age, respectively. Among pediatric kittens, predicted age based on this guideline corresponded to within 1 week of actual age for 24 (77.4%), 411 (67.5%), 170 (57.0%), 96 (46.6%), 23 (28.8%), 15 (27.8%), one (25%) and five (17.9%) kittens at 6, 8, 10, 12, 14, 16, 18 and 20 weeks, respectively. CONCLUSIONS AND RELEVANCE: Body weight was an effective means of predicting age in kittens through 10 weeks of age. Factors other than body weight should be considered when estimating kitten age beyond that time point.

Prevalence and risk factors for the presence of serum antibodies against canine distemper, canine parvovirus, and canine adenovirus in communities in mainland Ecuador.

The purpose of this study was to estimate the apparent prevalence and identify risk factors for antibody levels (AL) against canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) in three communities in the metropolitan area of Quito, Ecuador that have limited access to regular veterinary care. Whole blood samples were collected from 154 dogs presenting to three veterinary field clinics in mainland Ecuador and tested for AL against CDV, CPV, and CAV by a commercially available point-of-care ELISA. Potential risk factors for the presence of AL were analyzed. A majority of dogs had AL against CDV (66%, 95% CI = 58-73%), CPV (95%, 95% CI = 91-98%) and CAV (60%, 95% CI = 52-67%). Dogs had significantly greater odds of AL against CDV if they were >2 years of age, from an urban community, and had previously received veterinary care. Dogs had significantly greater odds of AL against CAV if they were male, >2 years of age, and had previously received veterinary care. Results provide baseline estimates of AL within each community and allow for the targeting of future veterinary services to communities and dogs most at risk.

Accuracy of a point-of-care luteinizing hormone test for help in distinguishing between sexually intact and ovariectomized or castrated domestic cats.

Objectives The aim of this study was to determine the accuracy of a commercial luteinizing hormone (LH) test as an aid in distinguishing between sexually intact and ovariectomized or castrated domestic cats. Methods Convenience serum samples collected from sexually intact female and male cats (n = 67) undergoing elective sterilization surgery and archived sera from ovariectomized and castrated cats (n = 54) were tested for LH using a commercial diagnostic assay. Test results were compared with the known reproductive status of the cats. Additionally, sera from sexually intact (n = 54) and ovariectomized (n = 94) queens were collected at specific times of the year to evaluate possible seasonal effects on test results. Results Overall test sensitivity was 89.3% (95% confidence interval [CI] 82.3-94.2%), specificity was 92.6% (95% CI 87.1-96.2%) and accuracy was 91.1%. Analysis of results of female cats (n = 216) - sexually intact (n = 87) and ovariectomized (n = 129) - yielded a test sensitivity of 90.8% (95% CI 82.7-96.0%), a specificity of 92.3% (95% CI 86.2-96.2%) and accuracy of 91.7%. Analysis of the results of male cats (n = 53) - sexually intact (n = 19) and neutered (n = 34) - yielded test a sensitivity of 85.3% (95% CI 68.9-95.1%), a specificity of 94.7% (95% CI 74.0-99.9%) and accuracy of 88.7%. The sera of 10 intact queens unexpectedly yielded positive LH results; two of these cats were in estrus, based on visual inspection at the time of ovariohysterectomy. Test accuracy was 94.6% for those 148 samples collected at specific times of the year, with two samples each over three, 3 month periods yielding false-positive results. Conclusions and relevance The commercial point-of-care LH test is a useful adjunct to historical and physical examination findings for determination of reproductive status in domestic cats. Repeat testing 24 h later should be considered for those female cats with signs of estrus and initial positive test results.

Impact of heat treatment on Dirofilaria immitis antigen detection in shelter dogs.

BACKGROUND: The diagnosis and management of canine heartworm disease is a growing concern for shelter veterinarians. Although the accuracy of commercial antigen test kits has been widely studied, recent reports have renewed interest in antigen blocking as a causative factor for false "no antigen detected" results. The objectives of this study were to determine the prevalence of false "no antigen detected" results in adult dogs entering shelters in northern, southern, and western regions of the country and to identify historical and clinical risk factors for such results. METHODS: Serum samples were evaluated for Dirofilaria immitis antigen using a commercially available point-of-care ELISA; samples in which no antigen was detected underwent a heat treatment protocol and repeat antigen testing. Whole blood samples underwent Knott testing to identify the presence of microfilariae. Historical and clinical findings were analyzed using exact logistic regression. RESULTS: A total of 616 samples were analyzed. Overall prevalence of positive antigen test results (prior to heat treatment) was 7.3% and frequency of false "no antigen detected" results due to antigen blocking (ie, samples with no antigen detected prior to heat treatment and positive after heat treatment) was 5.2%. Among dogs that had no detectable antigen on the initial tests, dogs that had microfilariae detected via modified Knott testing (OR = 32.30, p-value = 0.013) and dogs that previously received a heartworm preventive (OR = 3.81, p-value = 0.016) had greater odds of antigen blocking than dogs without these factors. Among dogs that were heartworm positive, those without microfilariae detected had greater odds of antigen blocking than dogs with this factor (OR = 11.84, p-value = 0.0005). Geographic region of origin was significantly associated with occurrence of antigen blocking (p = 0.0036); however, blocking occurred in all regions sizably contributing to heartworm diagnoses. Of the 74 dogs found to be infected with heartworms in this study, 39.2% (29) had no detectable antigen prior to heat treatment. CONCLUSIONS: Heat treatment of serum samples should be considered to improve diagnostic test accuracy, particularly in dogs that reportedly received a heartworm preventive prior to antigen testing regardless of region of origin.

Post-operative outcomes of surgical and chemical castration with zinc gluconate in dogs presenting to veterinary field clinics.

The objective of this study was to characterize post-operative outcomes of chemical castration as compared to surgical castration performed by existing municipal field clinics. Fifty-four healthy adult male dogs underwent chemical castration with zinc gluconate solution and 55 healthy adult male dogs underwent surgical castration in veterinary field clinics. Dogs in each group were evaluated for swelling, inflammation, and ulceration (chemical castration) or dehiscence (surgical castration) at Days 3, 7, and 14 following castration. More surgically castrated dogs required medical intervention than chemically castrated dogs (P=0.0328); the number of dogs requiring surgical repair within each group did not differ (P=0.3421). Seven chemically castrated dogs and 22 surgically castrated dogs experienced swelling, inflammation, and/or ulceration; all were managed medically. Two chemically castrated dogs experienced scrotal ulceration requiring surgical castration at Days 3 and 7. One surgically castrated dog experienced partial incisional dehiscence requiring surgical repair at Day 3. Our results suggest that chemical castration of dogs in field clinics is a feasible alternative to surgical castration, but proper follow-up care should be ensured for at least 7days post-procedurally.

Effects of anesthetic induction with a benzodiazepine plus ketamine hydrochloride or propofol on hypothermia in dogs undergoing ovariohysterectomy.

OBJECTIVE: To assess the effect of anesthetic induction with a benzodiazepine plus ketamine or propofol on hypothermia in dogs undergoing ovariohysterectomy without heat support. ANIMALS: 23 adult sexually intact female dogs undergoing ovariohysterectomy. PROCEDURES: Baseline rectal temperature, heart rate, and respiratory rate were recorded prior to premedication with buprenorphine (0.02 mg/kg, IM) and acepromazine (0.05 mg/kg, IM). Anesthesia was induced with midazolam or diazepam (0.25 mg/kg, IV) plus ketamine (5 mg/kg, IV; n = 11) or propofol (4 mg/kg, IV; 12) and maintained with isoflurane in oxygen. Rectal temperature was measured at hospital intake, prior to premedication, immediately after anesthetic induction, and every 5 minutes after anesthetic induction. Esophageal temperature was measured every 5 minutes during anesthesia, beginning 30 minutes after anesthetic induction. After anesthesia, dogs were covered with a warm-air blanket and rectal temperature was measured every 10 minutes until normothermia (37°C) was achieved. RESULTS: Dogs in both treatment groups had lower rectal temperatures within 5 minutes after anesthetic induction and throughout anesthesia. Compared with dogs that received a benzodiazepine plus ketamine, dogs that received a benzodiazepine plus propofol had significantly lower rectal temperatures and the interval from discontinuation of anesthesia to achievement of normothermia was significantly longer. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs in which anesthesia was induced with a benzodiazepine plus propofol or ketamine became hypothermic; the extent of hypothermia was more profound for the propofol combination. Dogs should be provided with adequate heat support after induction of anesthesia, particularly when a propofol-benzodiazepine combination is administered.

Prevalence of serum antibody titers against feline panleukopenia virus, feline herpesvirus 1, and feline calicivirus in cats entering a Florida animal shelter.

OBJECTIVE: To determine the proportion of cats entering a Florida animal shelter with serum antibody titers against feline panleukopenia virus (FPV), feline herpesvirus 1 (FHV1), and feline calicivirus (FCV) and to identify factors associated with seropositivity. DESIGN: Cross-sectional study. ANIMALS: 347 cats admitted to a Florida animal shelter. PROCEDURES: Within 24 hours after admission to the animal shelter, blood samples were collected from all cats ≥ 8 weeks of age. Serum antibody titers against FPV were determined via a hemagglutination inhibition assay, and those against FHV1 and FCV were determined via virus neutralization assays. Age, sex, environment (urban or rural), source (stray or previously owned), evidence of previous caregiving, health status (healthy or not healthy), and outcome (adoption, transfer, return to owner, or euthanasia) were evaluated as potential factors associated with antibody seropositivity. RESULTS: Of 347 cats, 138 (39.8%), 38 (11.0%), and 127 (36.6%) had antibody titers ≥ 40, ≥ 8, and ≥ 32 (ie, seropositive) against FPV, FHV1, and FCV, respectively. Factors associated with seropositivity included being neutered, age ≥ 6 months, and being relinquished by an owner. On multivariable analysis, health status at shelter admission, environment, vaccination at shelter admission, and outcome were not associated with seropositivity. CONCLUSIONS AND CLINICAL RELEVANCE: Most cats were seronegative for antibodies against FPV, FHV1, and FCV at the time of admission to an animal shelter. These findings supported current guidelines that recommend vaccination of all cats immediately after admission to animal shelters, regardless of the source or physical condition.

Effects of maternally-derived antibodies on serologic responses to vaccination in kittens.

The optimal vaccination protocol to induce immunity in kittens with maternal antibodies is unknown. The objective of this study was to determine the effects of maternally-derived antibody (MDA) on serologic responses to vaccination in kittens. Vaccination with a modified live virus (MLV) product was more effective than an inactivated (IA) product at inducing protective antibody titers (PAT) against feline panleukopenia virus (FPV). IA vaccination against feline herpesvirus-1 (FHV) and feline calicivirus (FCV) was more effective in the presence of low MDA than high MDA. Among kittens with low MDA, MLV vaccination against FCV was more effective than IA vaccination. A total of 15%, 44% and 4% of kittens had insufficient titers against FPV, FHV and FCV, respectively, at 17 weeks of age. Serologic response to vaccination of kittens varies based on vaccination type and MDA level. In most situations, MLV vaccination should be utilized and protocols continued beyond 14 weeks of age to optimize response by all kittens.

Detection of protective antibody titers against feline panleukopenia virus, feline herpesvirus-1, and feline calicivirus in shelter cats using a point-of-care ELISA.

Serum antibody titers are a useful measurement of protection against infection (feline panleukopenia virus [FPV]) or clinical disease (feline herpesvirus-1 [FHV] and feline calicivirus [FCV]), and their determination has been recommended as part of disease outbreak management in animal shelters. The objective of this study was to determine the sensitivity, specificity, and inter-observer and inter-assay agreement of two semi-quantitative point-of-care assays for the detection of protective antibody titers (PAT) against FPV, FHV and FCV in shelter cats. Low sensitivity for FPV antibodies (28%) rendered a canine point-of-care assay inappropriate for use in cats. The feline point-of-care assay also had low sensitivity (49%) and low negative predictive value (74%) for FPV PAT detection, but was highly accurate in the assessment of FHV and FCV PAT. Improvements in accuracy and repeatability of FPV PAT determination could make this tool a valuable component of a disease outbreak response in animal shelters.

Use of a commercially available relaxin test for detection of pregnancy in cats.

OBJECTIVE: To determine the earliest day of gestation at which relaxin could be detected in pregnant queens by use of a commercially available point-of-care test designed for use in dogs, and to calculate sensitivity and specificity of the test for pregnancy detection on any specified day of gestation. DESIGN: Evaluation study. ANIMALS: 162 female cats (24 queens from a breeding colony, 128 stray and feral queens undergoing ovariohysterectomy, and 10 ovariohysterectomized cats). PROCEDURES: 24 queens were monitored for pregnancy. Blood samples were collected daily and tested for relaxin until 2 consecutive positive test results were obtained. The earliest day of pregnancy detection was estimated by counting backward from the day of parturition to the day of the first positive test. The uteri, ovaries, and any fetuses of 128 stray and feral queens undergoing ovariohysterectomy were examined grossly, and gestational day in pregnant queens was determined on the basis of fetal crown-rump length. Blood samples from these queens and from 10 cats ovariohysterectomized prior to the study were collected for relaxin testing. RESULTS: Pregnancy was detected by use of the relaxin test kit as early as gestational day 20; sensitivity of the test was 100% on and after gestational day 29. False-positive results were detected in 3 queens, 2 of which had large (approx 2×3-cm) ovarian cysts, resulting in a specificity of 95.9%. CONCLUSIONS AND CLINICAL RELEVANCE: A commercially available relaxin test kit designed for use in dogs can be used to reliably detect pregnancy in cats.

Outcome of cats adopted from a biomedical research program.

Adoption of companion animals retired from biomedical research projects can provide an alternative, humane method for their disposition. For more than a decade, the University of Florida College of Veterinary Medicine has allowed investigators to arrange for the adoption of nonhuman animals used in their research. This report directed a survey to caregivers (owners) of 458 cats adopted over a 6-year period. The survey determined (a) retention rate of adopted cats in their original homes, (b) characteristics of adopters and cats, (c) adopters' initial expectations and subsequent experiences with the cats, (d) quality of the humananimal bond, and (e) adopters' perceptions of the adoption process. Completed surveys totaled 275 (60.0% response rate) with a median follow-up interval of 38 months. Of cats surveyed, 91.3% were still in their original homes, 91.0% had seen a veterinarian following adoption, and 80.4% were highly valued family members. The procedures followed to place cats in appropriate homes satisfied the vast majority of adopters surveyed. These results suggest that adoption into private homes is a viable alternative for cats who have completed research studies.