Posterior capsular opacification in diabetic and nondiabetic canine patients following cataract surgery

Posterior capsular opacification (PCO) is the most common postoperative complication of contemporary cataract surgery. Limited information is available regarding PCO formation and factors that influence PCO development in the dog. Two hundred sixty-five eyes (144 from diabetic dogs and 121 from dogs with breed-related cataracts) were prospectively evaluated for PCO formation for up to 12 months postoperatively. The mean age of all dogs in the study was 7.77 years and diabetic dogs were significantly older than dogs with breed-related cataracts. There were 73 males (61 neutered, 12 intact) and 74 females (70 neutered, 4 intact) in the study. Statistical analysis was performed based on age, breed/size, gender, stage of cataract at the time of surgery, PCO score at each time point, breed-related vs. diabetic cataract, right eyes compared to left eyes, and presence/absence of uveitis. Age and gender did not significantly influence PCO formation. Small and medium-sized breeds developed significantly more PCO in comparison to the large/giant breeds at 2 weeks and 2-4 months postoperatively, but the differences were not significant at later time points. There was an overall significant increase in PCO formation in eyes with early immature cataracts when compared to other stages of cataract up to 4 months postoperatively but not at later time points. There were no statistical differences in PCO score at 6 months or at 1 year postoperatively in eyes with breed-related and diabetic cataracts. Right eyes did not differ from left eyes in PCO score. PCO score significantly increased over time in breed-related and diabetic groups and in the overall population. No difference was found in the degree of PCO formation in eyes with inflammation prior to or after surgery compared with those without inflammation. In summary, age, gender, presence of inflammation, and cause of cataract (breed-related vs. diabetes mellitus) do not influence the development of PCO in canine cataract dogs. Small and medium-sized breeds develop significant PCO earlier than larger breeds. It is important to note that all eyes from all dogs in this study developed PCO in a time dependent manner.     

Unusual “erythroid loops” in canine blood smears after viper‐bite envenomation

Abstract: Northern Italy is a habitat for many species of viper; Vipera aspis is responsible for most reported bites of humans and animals. Five dogs of different breeds and ages were presented by their owners to a veterinary clinic in northern Italy between September 2004 and August 2007 with a history of being bitten by a viper within the past 2 hours. On physical examination, all of the dogs were depressed, had pale mucous membranes, and had a painful area consistent with a recent viper bite wound on the nose (2), distal front leg (2), or lip (1). Hemoglobinemia and hemoglobinuria were observed in plasma and urine from all dogs. CBCs were done at the time of presentation, daily for 4 days, and 10 days after presentation in all dogs with the exception of one dog that died after 2 days. All dogs had an acute decrease in HCT within 24 hours of presentation; all dogs had neutrophilia, 3/5 had a mildly toxic left shift, and 4/5 had thrombocytopenia. On Diff‐Quik‐stained blood smears, moderate numbers of echinocytes, spherocytes, and erythrocyte ghosts were observed. In addition, moderate numbers of unusual erythrocyte membrane‐like structures (“erythroid loops”) were observed. The loops were annular in shape and sometimes disrupted, appearing as thin pale blue bands. Erythrocyte morphologic abnormalities decreased by day 3 and were no longer observed on day 10. The unique appearance of the erythroid loops together with evidence for intravascular hemolysis and other erythrocyte morphologic changes suggest they may be a consequence of erythrocyte lysis. Echinocytes, spherocytes, and erythrocyte ghosts are known to result from the action of phospholipase in viper venom; however, erythroid loops have not been reported previously and their exact mechanism of formation is unknown.     

Prevalence of canine cataract: preliminary results of a cross-sectional study

Objective In this study 2000 dogs were examined ophthalmoscopically to determine presence of cataract. Materials and methods The dogs examined were predominantly from veterinary hospital populations but also from the Waltham Center For Pet Nutrition, rehoming charities and breeding kennels. Prevalence of cataract was thus determined for different age groups (year cohorts). The age at which prevalence of cataract was 50% (C₅₀) was determined indirectly from a fitted prevalence curve. Results The mean ± standard deviation of C₅₀ for all dogs in the study was 9.4 ± 3.3 years. All dogs over 13.5 years were affected by some degree of lens opacity. C₅₀ was determined for animals of different genders and different breeds. For dogs of six breeds sufficient data were available for calculation of breed‐specific C₅₀. In these dogs C₅₀ was positively correlated with longevity with a least squares correlation coefficient of 0.74. Conclusion The study yields novel findings regarding the prevalence and incidence of cataract in the dog and forms the basis for considerable further work on the epidemiology and pathophysiology of age‐related cataract in the dog.     

A study of the morphology of canine eyes enucleated or eviscerated due to complications following phacoemulsification

This study was undertaken to describe the histopathologic abnormalities observed in canine eyes enucleated or eviscerated due to complications following phacoemulsification; to correlate these findings with the clinical abnormalities reported, and to suggest, if apparent, likely causes and effects of these abnormalities. Sixty-six canine globes or evisceration samples received for histopathologic interpretation over a 10-year period (1990-2000) were studied. All globes and evisceration samples were obtained from clinical patients examined by board-certified ophthalmologists. Hematoxylin and eosin (H&E) and alcian blue/periodic acid Schiff (PAS) stained sections were examined by light microscopy in every case. A tissue Gram stain was used when indicated. Clinical information obtained from the pathology submission form was reviewed in all cases, and obtained from questionnaires completed and returned by an ophthalmologist for 51 cases (77%). The most frequent histopathologic diagnoses were glaucoma (76%) and retinal detachment (64%). The most frequently reported clinical abnormalities in this series were glaucoma (86%) and uveitis (82%). Five problem areas were identified that appear to make a significant contribution to the failure of canine cataract surgery and merit further investigation: pre-iridal fibrovascular membranes; lens fiber regrowth; lens epithelial membranes; endophthalmitis, and the health of the corneal surgical incision.     

Immunopathology of the eye: Purification of canine retinal “S” antigen

Canine retinal S antigen has been purified to study the retinal progressive atrophy of the dog. The purified antigen will be used to detect, by the ELISA technique, specific autoantibody in dogs with ocular diseases.     

IMAGING DIAGNOSIS —ANTEMORTEM DETECTION OF OLIGODENDROGLIOMA “CEREBROSPINAL FLUID DROP METASTASES” IN A DOG BY SERIAL MAGNETIC RESONANCE IMAGING

An English Bulldog underwent radiation therapy of an intracranial, left lateral ventricle mass. Following resolution of the primary mass, an intraventricular fourth ventricle lesion developed. Subsequently, multiple lesions developed from the cervical central canal and leptomeninges. Serial magnetic resonance imaging documented the propagation of lesions along the cerebrospinal fluid (CSF) pathways, known as “CSF drop metastasis.” Histopathology confirmed multifocal intraventricular and leptomeningeal oligodendroglioma. Oligodendroglioma should be included in the differential diagnosis for an intraventricular tumor exhibiting apparent CSF drop metastasis.     

Intraocular pressure development after cataract surgery: a prospective study in 50 dogs (1998-2000)

Objective To study the course of intraocular pressure (IOP) after cataract surgery in 50 dogs. Design Prospective study. Animals Fifty dogs without preoperative ocular hypertension were selected for cataract surgery. Methods All dogs underwent cataract surgery: 25 by manual extracapsular extraction and 25 by phacoemulsification. For each dog, intraocular pressure was measured before surgery, and 1, 3, 5, 18 h, 1 week and 1 month post surgery. Results No significant difference of mean intraocular pressure between the two surgical methods was observed for each time measurement. Nine dogs had postoperative hypertension (IOP > 25 mmHg) during the first 5 hours post surgery. Incidence of postoperative hypertension was not significantly different with manual extracapsular extraction (16%) vs. phacoemulsification (20%). A decrease of mean IOP was observed 1 h after surgery (8.49 mmHg vs. 10.91 mmHg), then an increase 3 and 5 h post surgery (12.3 and 13.32 mmHg, respectively). At 18 h, 1 week and 1 month post surgery, mean IOP decreased. Mean IOP was 10.38, 10.38 and 8.84 mmHg, respectively. Conclusion In this study incidence of POH is not high. However, a follow‐up of IOP in the first hours after cataract surgery is required to avoid complications of the retina and optic nerve and to administer hypotensive treatment if necessary.     

A comparison of anesthetic complications between diabetic and nondiabetic dogs undergoing phacoemulsification cataract surgery: a retrospective study

Objective To compare the incidence of anesthetic complications in diabetic and nondiabetic dogs undergoing general anesthesia and phacoemulsification cataract surgery. Procedure The medical and anesthetic records of all dogs undergoing phacoemulsification cataract surgery at Davies Veterinary Specialists between 2005 and 2008 were reviewed. Anesthetic records were evaluated by an ECVAA Diplomate. Dogs for which records were incomplete were excluded. The anesthetic technique, including all drugs administered in the perioperative period, was recorded. The anesthetic complications investigated included hypotension (MAP (mmHg): ≥55 none/mild; ≤54 moderate/severe), bradycardia (<60 bpm associated with hypotension) and hypothermia (esophageal temperature <36.7 °C). Where hypotension was present, the method of and response to treatment was recorded. The incidence of severe hyperglycemia (blood glucose >13.75 mmol/L (250 mg/dL)) in the diabetic group was also assessed. Results 66 diabetic and 64 nondiabetic dogs were included in the study. Diabetic dogs were more likely to develop moderate and severe intraoperative hypotension than nondiabetic dogs. Forty‐four percent of diabetic dogs had at least one episode of severe hyperglycemia whilst anesthetized. Conclusions Diabetic dogs undergoing phacoemulsification are more likely to suffer the anesthetic complications of moderate and severe hypotension than nondiabetic dogs. The increased incidence and severity of hypotension in diabetic dogs may be explained by hypovolemia secondary to hyperglycemia and resultant osmotic diuresis.     

A “taxonomic affidavit”: Why it is needed?

Imprecise and faulty taxonomic identification of the biological objects of many ecological and experimental studies renders these studies irreproducible. Incomplete identification to the species level and excessive use of vernacular species names are additional problems. Good science must be able to be falsified. I recommend that publications and granting agencies use and mention the names of the zoologists or botanists who identified the species. Voucher specimens should be marked and deposited in scientific museums for future checking.