Longitudinal prevalence of hypertension, proteinuria, and retinopathy in dogs with spontaneous diabetes mellitus

Background

The prevalence and progression of vascular complications of spontaneous diabetes mellitus (DM) in dogs have not been described.

Objectives

To investigate the effects of duration of disease, as estimated by time since DM diagnosis, and glycemic control on prevalence of systemic hypertension, proteinuria, and diabetic retinopathy in dogs with spontaneous DM.

Animals

Seventeen client‐owned dogs with spontaneous DM.

Methods

Prospective, longitudinal observational study. Dogs with DM of less than 1 year's duration were recruited and evaluated once every 6 months for 24 months. Recorded measures included indirect BP, urine albumin, protein and creatinine concentrations, serial blood glucose and serum fructosamine concentrations, ophthalmic examination, and a standardized behavioral questionnaire.

Results

Eleven dogs completed the 2‐year follow‐up period, during which the highest recorded prevalence of systolic and diastolic hypertension was 55 and 64%, respectively. Prevalence of microalbuminuria and elevated urine protein:creatinine ratio (UPC) ranged up to 73 and 55%, respectively. Prevalence of retinopathy ranged up to 20%. No significant effect of time since DM diagnosis or glycemic control was detected for any of the measures examined. Additionally, no significant associations between BP, urine albumin concentration, UPC and retinopathy were detected.

Conclusions and Clinical Relevance

With the exception of proteinuria, which was substantial in some cases, clinically deleterious diabetic vascular complications were not identified in dogs in this study.

Ophthalmic examination findings in a colony of Screech owls (Megascops asio)

OBJECTIVE

To report ophthalmic findings in the Screech owl (Megascops asio). Sample population Twenty-three, apparently healthy adult captive Screech owls in Maryland.

PROCEDURES

OU of all owls underwent complete ophthalmic examination. One randomly assigned eye of each bird was measured by phenol red thread tear test (PRT), and the other eye by Schirmer tear test (STT). TonoVet rebound tonometry and TonoPen-XL applanation tonometry were performed in each eye to measure IOP. Conjunctival swabs were cultured from one eye of 10 birds, corneal diameter was measured in OU of eight birds, and streak retinoscopy was performed on OU of seven birds. Ten birds were anesthetized, and A-scan ultrasonography using a 15-MHz probe was performed to obtain axial intraocular measurements.

RESULTS

Ophthalmic abnormalities were noted in 24/46 (52%) of eyes. Median STT result was < or = 2 mm/min, ranging < or = 2-6 mm/min, and mean +/- SD PRT was 15 +/- 4.3 mm/15 s. Mean +/- SD IOP were 9 +/- 1.8 mmHg TonoVet-P, 14 +/- 2.4 mmHg TonoVet-D, and 11 +/- 1.9 mmHg TonoPen-XL. Coagulase negative staphylococcal organisms were cultured from all conjunctival swabs. Mean +/- SD corneal dimensions were 14.5 +/- 0.5 mm vertically and 15.25 +/- 0.5 mm horizontally. All refracted birds were within one diopter of emmetropia. Mean +/- SD axial distance from the cornea to the anterior lens capsule was 4.03 +/- 0.3 mm, from cornea to the posterior lens capsule was 10.8 +/- 0.5 mm, and from cornea to sclera was 20.33 +/- 0.6 mm.

CONCLUSIONS

This study reports ophthalmic examination findings in Screech owls, and provide means and ranges for various ocular measurements. This is the first report of rebound tonometry and PRT in owls.

Cardiovascular effects of topical ophthalmic 10% phenylephrine in dogs

OBJECTIVE

To evaluate the effect of topical ophthalmic 10% phenylephrine on systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), pulse rate (PR) and electrocardiogram (ECG) in dogs.

ANIMALS STUDIED

Nine clinically normal dogs.

PROCEDURE

Arterial catheters were placed in the dorsal pedal artery of awake dogs and ECG leads were attached. After a 15-min acclimatization period, baseline PR, SAP, DAP and MAP were recorded every 5 min for 20 min. Two treatment groups (eight dogs each) were studied. Group I: one drop of phenylephrine was placed in each eye once. Group II: one drop of phenylephrine was placed in each eye three times at 5-min intervals. Following treatment, PR, SAP, DAP and MAP were recorded every 5 min for 90 min. The mixed procedure of the SAS system was used to perform a repeated measures analysis of variance to test for linear and quadratic trends across time.

RESULTS

Group I: There was a significant quadratic decrease in PR across time (P = 0.0051). Systolic arterial pressure increased linearly with time (P = 0.0002), MAP increased linearly with time (P = 0.0131), and DAP increased linearly with time (P = 0.0001). Group II: There was a significant quadratic decrease in PR across time (P = 0.0023). There was a significant quadratic increase in SAP (P = 0.0324), MAP (P = 0.0103) and DAP (P = 0.0131) across time.

CONCLUSIONS

Topical ophthalmic application of 10% phenylephrine in normal dogs results in elevation of arterial blood pressure and reflex bradycardia.

Detection of feline leukaemia virus in blood and bone marrow of cats with varying suspicion of latent infection

The purpose of this study was to determine if polymerase chain reaction (PCR) could be used to detect FeLV proviral DNA in bone marrow samples of cats with varying suspicion of latent infection. Blood and bone marrow samples from 50 cats and bone marrow from one fetus were collected, including 16 cats with diseases suspected to be FeLV-associated. Serum enzyme-linked immunosorbent assay (ELISA), blood and bone marrow immunofluorescent antibody test (IFA), and blood and bone marrow PCR were performed on each cat, and IFA and PCR on bone marrow of the fetus. Forty-one cats were FeLV negative. Five cats and one fetus were persistently infected with FeLV. Four cats had discordant test results. No cats were positive on bone marrow PCR only. It appears persistent or latent FeLV infection is not always present in conditions classically associated with FeLV.

Feline leukemia virus detection in corneal tissues of cats by polymerase chain reaction and immunohistochemistry

OBJECTIVES

To determine the presence of feline leukemia virus (FeLV) in the corneas of FeLV-infected cats.

ANIMALS STUDIED

Thirty-four random source cats.

PROCEDURES

Seventeen cats were found positive for FeLV serum p27 antigen by enzyme-linked immunosorbent assay (ELISA). Twelve ELISA positive cats were also positive on peripheral blood samples by immunofluorescent antibody (IFA) testing. Seventeen ELISA negative cats served as negative controls. Full thickness corneal specimens were collected from the left cornea of all cats and analyzed for FeLV proviral DNA and gp70 antigen by polymerase chain reaction (PCR) and immunohistochemical (IHC) testing, respectively.

RESULTS

Eleven (64.7%) positive corneal PCR results were obtained from 17 ELISA positive cats. Of 12 cats that were both ELISA and IFA positive on peripheral blood, 10 (83.3%) had positive corneal PCR results. All corneal tissues from ELISA negative cats were PCR negative. IHC staining of corneal sections revealed the presence of FeLV gp70 in corneal tissues of nine (52.9%) ELISA positive cats. Of the 12 cats that were both ELISA and IFA positive on peripheral blood, eight (66.7%) had positive corneal IHC results. Positive IHC staining was localized to the corneal epithelium. Corneal tissues of all ELISA negative cats and all IFA negative cats were negative on IHC testing.

CONCLUSIONS

FeLV antigens and proviral DNA are present in corneal tissues of some FeLV-infected cats. Screening corneal donors for FeLV infection is warranted.

Evaluation of aqueous tear production in dogs following general anesthesia

Pre- and postanesthetic Schirmer tear test (STT) values were measured in 46 dogs. All subjects had normal preanesthetic STT values (18.3 +/- 2.8 mm per min in the left eye [OS] and 18.3 +/- 3.0 mm per min in the right eye [OD]). Significant differences were found between pre- and postanesthetic STT values. Significant decreases in tear production were evident for up to 24 hours following the anesthetic event. Subject age did not significantly influence the results. Duration of anesthesia significantly affected the rate of return to preanesthetic STT values, with anesthetic events greater than two hours in duration having a prolonged effect as compared to anesthetic events less than two hours in duration. Anticholinergic administration prior to or during anesthesia further lowered postanesthetic STT values.