Magnet-assisted endoscopic removal of ferromagnetic metallic gastric foreign bodies in 4 dogs

OBJECTIVE

Describe presenting signs, diagnostic findings, and magnet-assisted endoscopic removal method of ferromagnetic gastric foreign bodies (FBs) in dogs.

CLINICAL PRESENTATION

Four dogs presented with ingestion of sharp metallic FBs. The presence of gastric FBs was confirmed by abdominal radiography.

RESULTS

In 3 cases, initial attempts at endoscopic removal were unsuccessful because of ingesta and fluid in the stomach. A magnet contained within a Roth net was introduced endoscopically. Magnet and attached objects were successfully removed from the stomach. In the fourth case, removal with a magnet was judged to be the most expedient method of removal because multiple metallic objects were present.

CLINICAL RELEVANCE

An endoscopic technique was used for the removal of difficult-to-visualize or multiple metallic FBs. The use of this technique allows the removal of ferromagnetic gastric FBs without surgery or risk of complications associated with the passage of sharp material through the gastrointestinal (GI) tract.

Correlation between urine anion gap and urine ammonia-creatinine ratio in healthy cats and cats with kidney disease

BACKGROUND

Ammonium excretion decreases as kidney function decreases in several species, including cats, and may have predictive or prognostic value in patients with chronic kidney disease (CKD). Urine ammonia measurement is not readily available in clinical practice, and urine anion gap (UAG) has been proposed as a surrogate test.

OBJECTIVES

Evaluate the correlation between urine ammonia-to-creatinine ratio (UACR) and UAG in healthy cats and those with CKD and determine if a significant difference exists between UAG of healthy cats and cats with CKD.

ANIMALS

Urine samples collected from healthy client-owned cats (n = 59) and those with stable CKD (n = 17).

METHODS

Urine electrolyte concentrations were measured using a commercial chemistry analyzer and UAG was calculated as ([sodium] + [potassium]) - [chloride]. Urine ammonia and creatinine concentrations had been measured previously using commercially available enzymatic assays and used to calculate UACR. Spearman's rank correlation coefficient between UAG and UACR was calculated for both groups. The UAG values of healthy cats and cats with CKD were assessed using the Mann-Whitney test (P < .05).

RESULTS

The UAG was inversely correlated with UACR in healthy cats (P < .002, r0  = -0.40) but not in cats with CKD (P = .55; r0  = -0.15). A significant difference was found between UAG in healthy cats and those with CKD (P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The UAG calculation cannot be used as a substitute for UACR in cats. The clinical relevance of UAG differences between healthy cats and those with CKD remains unknown.

Development of a reference interval for urinary ammonia-to-creatinine ratio in feline patients

BACKGROUND

Disruption of acid-base homeostasis can lead to many clinical problems. Ammonia excretion by the kidneys is critical to maintaining acid-base homeostasis through bicarbonate production. Measurement of ammonia excretion may help determine if the kidneys are properly functioning in maintaining acid-base balance. Reference intervals are essential tools for clinical decision-making but do not currently exist for urinary ammonia-to-creatinine ratio (UACR) in feline patients.

OBJECTIVE

This study aimed to generate a reference interval (RI) for UACR in healthy adult cats.

METHODS

The study used samples from client-owned adult healthy cats that presented to the University of Florida Primary Care and Dentistry service (n = 92). Physical examination, serum biochemistry, urinalysis, urine ammonia, and creatinine concentrations were measured. Cats were excluded if there were significant abnormalities in their urinalysis or biochemistry panel. The RI for UACR was calculated according to the recommendation of the American Society for Veterinary Clinical Pathology. The UACR was evaluated for correlation with serum bicarbonate, weight, age, and sex.

RESULTS

The RI for UACR was 3.4-20.7 with 90% confidence intervals for the lower and upper limits of (3.0-3.7) and (16.0-23.7), respectively. No significant correlation with age, sex, or weight was found. There was no discernable relationship between serum bicarbonate and UACR.

CONCLUSIONS

Establishing an RI for UACR in healthy adult cats will allow further studies to determine if changes in UACR are observed during specific disease states.

Gastroduodenal ulceration in dogs with liver disease

Background

Liver disease is frequently cited as a cause of gastroduodenal ulceration (GDU) in dogs but studies regarding GDU and liver disease are limited.

Objectives

To document the presence of GDU in dogs with liver disease.

Animals

Forty dogs that underwent liver biopsy, computed tomographic (CT) angiography or both at the University of Florida Small Animal Hospital to diagnose congenital or acquired liver disease.

Methods

Cross‐sectional study. Dogs had gastroduodenoscopy performed with photographic and video documentation in a standardized fashion. Lesions (hemorrhage, erosions, ulcers) in the esophagus, stomach, and duodenum were scored based on a grading scale. Presence of esophageal varices was recorded. Dogs were categorized into 4 groups according to cause of liver disease (inflammatory disease, cirrhosis, congenital, other). Presence or absence of ulcers, erosions or both as well as total endoscopic scores were compared among groups.

Results

Forty dogs were enrolled with the following distribution: 13 congenital, 13 inflammatory, 3 cirrhosis, and 11 other. Four dogs had GDU (10%; 95% confidence interval [CI], 3%‐24%) and 6 dogs had erosions (15%; 95% CI, 6%‐30%). No difference was found in total endoscopic score (P = .21) or in the proportion of dogs with ulcers, erosions or both versus those without (P = .25) among the groups.

Conclusions and Clinical Importance

Gastroduodenal ulceration was found in 10% of dogs with liver disease in this population. Additional studies are warranted to confirm these findings in larger numbers of dogs with specific disease etiologies.

Evaluation of a novel technique involving ultrasound-guided, temporary, percutaneous gastropexy and gastrostomy catheter placement for providing sustained gastric decompression in dogs with gastric dilatation-volvulus

OBJECTIVE

To evaluate the feasibility of ultrasound-guided, temporary, percutaneous T-fastener gastropexy (TG) and gastrostomy catheter (GC) placement for providing sustained gastric decompression in dogs with acute gastric dilatation-volvulus (GDV) and to compare findings with those of trocarization.

ANIMALS

16 dogs with GDV.

PROCEDURES

Dogs were randomly assigned to undergo gastric decompression by means of percutaneous trocarization (trocar group; n = 8) or temporary TG and GC placement (TTG+GC group; 8) with ultrasound guidance. The gastric volvulus was then surgically corrected, and the decompression sites were examined. Outcomes were compared between groups.

RESULTS

The proportion of dogs with successful decompression did not differ significantly between the TTG+GC (6/8) and trocar (7/8) groups; median procedure duration was 3.3 and 3.7 minutes, respectively. After the failed attempts in the TTG+GC group, the procedure was modified to include ultrasound guidance during T-fastener placement. The decrease in intragastric pressure by 5 minutes after trocar or GC insertion was similar between groups. For dogs in the TTG+GC group, no significant difference in intragastric pressure was identified between 5 and 60 minutes after GC insertion. Complications included inadvertent splenic or jejunal placement in 2 dogs (TTG+GC group) and malpositioned and ineffective trocar placement in 1 dog (trocar group). All dogs survived for at least 2 weeks.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasound-guided, temporary, percutaneous TG and GC placement was safe and effective at providing sustained gastric decompression in dogs with GDV, suggesting that this technique would be ideal for dogs in which surgical delays are anticipated or unavoidable.

Rapid Diagnosis of Babesia gibsoni by Point-of-Need Testing by Insulated Isothermal PCR in Dogs at High Risk of Infection

Background

Dogs seized by law enforcement agencies during dogfighting investigations are at increased risk of Babesia gibsoni infection. A rapid and cost‐effective diagnostic test would increase the feasibility of mass screening of dogs for infection and monitoring treatment efficacy in B. gibsoni‐infected dogs.

Objective

To determine the performance of a point‐of‐need insulated isothermal PCR (iiPCR) test for diagnosis of B. gibsoni in dogs rescued in dogfighting investigations.

Animals

Two hundred and thirty‐three dogs seized in dogfighting investigations.

Methods

Cross‐sectional study. Whole blood samples were tested for B. gibsoni and Babesia spp. by iiPCR. Results were compared to a reference standard comprised of concordant results from real‐time PCR in a commercial diagnostic laboratory and antibody titers.

Results

The iiPCR system was quick to learn, portable, and had a short processing time of <2 hours. Sensitivity and specificity of the iiPCR assay for B. gibsoni were 90% (95% confidence interval [CI] 81–95%) and 99% (CI, 95–100%), respectively. Sensitivity and specificity of the iiPCR assay for Babesia spp. were 87% (CI, 78–93%) and 98% (CI, 0.94–99%), respectively.

Conclusions and Clinical Importance

The iiPCR system produced few false‐positive results, indicating that positive results are likely to represent true infections when used in high‐risk animals. The iiPCR system can fail to identify 10–15% of truly infected dogs. However, the portability, speed, and economy of the iiPCR system compared to testing through a reference laboratory can allow rescue groups to screen and identify infection in more dogs.

Temporary percutaneous T-fastener gastropexy and continuous decompressive gastrostomy in dogs with experimentally induced gastric dilatation

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

Dynamic exophthalmos and lateral strabismus in a dog caused by masticatory muscle myositis

CASE DESCRIPTION

A 5.5-year-old neutered male mixed-breed dog was presented for evaluation of a 5-month history of deviation of the right globe upon opening the mouth and a 1-month history of conjunctivitis in the same eye. Clinical findings, diagnostic imaging results, treatment and follow-up are described.

CLINICAL FINDINGS

When the mouth was opened, the right globe deviated rostrally and laterally. There was no pain or resistance to opening the mouth, or resistance to retropulsion of the globe. No other abnormalities were observed. Computed tomography was performed, revealing a contrast-enhancing region associated with the right masseter muscle impinging into the right orbit; this was more pronounced with the mouth open. Cytology revealed a small number of mildly to moderately atypical mesenchymal cells. Histopathology was consistent with polyphasic myositis, with a predominance of lymphocytes and plasma cells. No infectious agents were identified. Serum antibody titers for Toxoplasma gondii and Neospora caninum were negative. Serum titers for 2 M antibody were positive at 1:500, consistent with a diagnosis of masticatory muscle myositis.

TREATMENT AND OUTCOME

Therapy with prednisone was initiated. During a follow-up period of 5 months, there was no recurrence of clinical signs, and the dose of prednisone was reduced by 25%.

CLINICAL SIGNIFICANCE

To the authors' knowledge, this is the first reported case of masticatory muscle myositis causing dynamic exophthalmos and strabismus in a dog.

Chromobacterium violaceum infection in two dogs

Chromobacterium violaceum is a saprophyte of soil and water in tropical and subtropical environments that is associated with rare but highly fatal infections in animals and humans. Systemic infection was diagnosed in two critically ill dogs from Florida. Fever was absent in both dogs. Both dogs were treated surgically and provided with intensive care, but only one survived. The identification of characteristic, violet-pigmented bacterial colonies on routine microbial cultures should alert microbiologists and clinicians to the likelihood of this dangerous pathogen. Because of the rapidly progressive nature of this infection, empirical antibiotic administration with fluoroquinolones should be employed pending susceptibility testing.

Electrocardiographic findings in dogs with motor vehicle-related trauma

Motor vehicle-related injury is the most common form of trauma incurred by dogs, and cardiac arrhythmias are a well-recognized complication. Although posttraumatic arrhythmias are often observed, little is known regarding their frequency. This study utilized continuous ambulatory electrocardiography (i.e., Holter monitoring) to describe the cardiac rhythm disturbances in 30 dogs sustaining trauma in motor vehicle accidents. Ventricular ectopy was identified by Holter monitoring in 29 of 30 dogs, although the initial electrocardiogram (EKG) only documented ventricular ectopic complexes (VECs) in four dogs. Ventricular ectopy was infrequent in most dogs (i.e., 62% of the dogs had less than 100 VECs per day for the entire study), but 16% developed frequent arrhythmias (greater than 4,000 VECs per day). In all cases, the VECs were observed within 24 hours of injury. Forty-three percent of dogs had at least one episode of ventricular tachycardia, including several dogs that had an overall infrequent rate of VECs (i.e., less than 100 or 100 to 1,000 VECs per day). Although baseline EKGs are useful in identifying arrhythmias in most dogs, the length of the recording should be increased to improve the likelihood of observing an abnormal EKG event. Most importantly, additional EKGs should be obtained or continuous EKG monitoring should be performed in dogs that display clinical signs that could be attributed to ventricular arrhythmias.

Calcium channel blockers in veterinary medicine

Calcium channel blockers are becoming increasingly popular in veterinary medicine for the treatment of systemic hypertension, cardiac arrhythmias, and hypertrophic cardiomyopathy. Calcium is vital to many cellular functions and thus stringent regulation of intracellular calcium concentrations is required. Pharmacologic manipulation of the regulatory mechanisms has the potential to alter cellular function in all body systems. In human medicine, calcium channel blockers are being evaluated for, among other things, use in treating glaucoma, deep vein thrombosis, and pulmonary hypertension, in renal transplantation, and for prevention of reperfusion injury. The potentially beneficial effects of these drugs have often been overshadowed by adverse effects including hypotension, inappetence, bradycardia, conduction abnormalities, and decreased cardiac output. With the introduction of sustained-release formulations (diltiazem) and 2nd generation calcium channel blockers (amlodipine) many of these effects have been attenuated or eliminated. This paper will review the functions of calcium and the calcium channels as well as discussing the classes and current and potential uses of the various calcium channel blockers.

Fluid therapy in the cardiac patient

Correcting fluid deficits and preventing fluid overload in patients with cardiac disease can be challenging. The purpose of the fluid therapy, the projected duration of the therapy, and the type of heart disease affecting the patient play important roles in the decision-making process. In addition, the distinction between patients who are not symptomatic (NYHA Class I) and those who are symptomatic (NYHA Classes II to IV) for their cardiac disease should be made early in fluid therapy planning.

Analysis of an SEIRS epidemic model with two delays

A disease transmission model of SEIRS type with exponential demographic structure is formulated. All newborns are assumed susceptible, there is a natural death rate constant, and an excess death rate constant for infective individuals. Latent and immune periods are assumed to be constants, and the force of infection is assumed to be of the standard form, namely proportional to I(t)/N(t) where N(t) is the total (variable) population size and I(t) is the size of the infective population. The model consists of a set of integro-differential equations. Stability of the disease free proportion equilibrium, and existence, uniqueness, and stability of an endemic proportion equilibrium, are investigated. The stability results are stated in terms of a key threshold parameter. More detailed analyses are given for two cases, the SEIS model (with no immune period), and the SIRS model (with no latent period). Several threshold parameters quantify the two ways that the disease can be controlled, by forcing the number or the proportion of infectives to zero.

The population dynamics of two vertically transmitted infections

The transmission of Keystone virus in the mosquito Aedes atlanticus and of Rickettsia rickettsii in the tick Dermacentor andersoni is modeled and analyzed. Both of these infections can be transmitted vertically from an infective parent to newborn offspring as well as horizontally via direct or indirect contacts with infected individuals. The vertical transmission mechanism plays a major role in the maintenance of these infections and its effects are analyzed in detail. This same mechanism can act as a means for controlling the size of the infected host population and an analysis of this effect is also provided. The sensitivity of the threshold parameters and the endemic prevalence rates of the disease to variations in the basic infection transmission components are investigated. The transmission components that are considered include the ability to transmit the pathogen vertically as well as horizontally, the size of the host population, and survival probabilities of the hosts.

Analysis of the complicated dynamics of some harvesting models

In this paper we will study in a qualitative way discrete single species population models including harvesting. The class of models under consideration is quite general. In fact, we will study models with fixed parameter values. However, the obtained results do have implications for the models if one varies the parameters slightly. The models with so-called "Allee-effect", i.e. the population will die out whenever the size of the population is below some threshold, are included in the class of models we studied.

Analysis of a model of a vertically transmitted disease

A model is presented of a disease that can be transmitted directly from parent to offspring (vertical transmission) as well as through contact with infectives. A global stability analysis is given for the basic model and the epidemiological effects of vertical transmission are discussed. The effects of the addition of maturation and incubation delays as well as spatial diffusion are analyzed in some special cases.

The effect of integral conditions in certain equations modelling epidemics and population growth

Models of epidemics that lead to delay differential equations often have subsidiary integral conditions that are imposed by the interpretation of these models. The neglect of these conditions may lead to solutions that behave in a radically different manner from solutions restricted to obey them. Examples are given of such behavior, including cases where periodic solutions may occur off the natural set defined by these conditions but not on it. A complete stability analysis is also given of a new model of a disease propagated by a vector where these integral conditions play an important role.