CLINICAL AND MAGNETIC RESONANCE IMAGING FEATURES OF IDIOPATHIC OCULOMOTOR NEUROPATHY IN 14 DOGS

Ophthalmoplegia/ophthalmoparesis (internal, external, or both) has been reported in dogs secondary to neoplasia affecting the oculomotor nerve and is usually given a poor prognosis. The purpose of this retrospective study was to describe the clinical findings, magnetic resonance imaging (MRI) findings, management, outcome, and follow‐up in a group of canine cases with idiopathic oculomotor neuropathy. Inclusion criteria included cases with ophthalmoplegia/ophthalmoparesis (internal, external or both) as sole neuroophthalmologic signs, complete ophthalmic and neurologic examination, head MRI, and a minimum follow‐up period of 1 year. Dogs with progressive neurological signs not related to oculomotor neuropathy were excluded. Fourteen cases met the inclusion criteria. All cases were unilaterally affected. Magnetic resonance imaging showed equivocal enlargement of the oculomotor nerve in three cases, mild enlargement in five, and marked enlargement in six. Contrast enhancement was present in 12 cases, being marked in six. When present, the contrast enhancement was focal in eight cases and diffuse in four. The median follow‐up time was 25 months. External ophthalmoparesis improved in seven cases, five cases under no treatment and two under systemic corticosteroid therapy. The clinical signs in the other seven cases remained unchanged. Idiopathic oculomotor neuropathy should be included as a differential diagnosis in dogs presenting with unilateral ophthalmoplegia/ophthalmoparesis (internal, external, or both) with the absence of other neurologic and ophthalmic signs, and with the MRI findings restricted to the oculomotor nerve. Idiopathic oculomotor neuropathy has a good prognosis as the clinical signs do not deteriorate and they can improve without treatment.     

Safety and efficacy of an ocular insert for apomorphine-induced emesis in dogs

OBJECTIVE: To evaluate the safety and efficacy of an ocular insert designed to provide controlled release of apomorphine for the induction of emesis in dogs. ANIMALS: 5,001 dogs treated with ocular apomorphine inserts and 32 dogs treated with IV administration of apomorphine. PROCEDURES: Data collected on a case report form included breed, body weight, time to emesis after placement of the insert, and any information available regarding the nature of the toxicosis and clinical signs. A list of potential adverse effects was provided, and attending clinicians graded their occurrence by use of a subjective scale. Similar report forms were used for dogs that received apomorphine IV. Treatment was considered successful if emesis occurred within 15 minutes of administration. Safety was assessed by evaluation of the frequency and severity of adverse effects. RESULTS: For the ocular insert and IV injection groups, the success rates were 83.5% and 90.6% respectively, and were not significantly different. Adverse effects were more frequent in the IV group, whereas ocular irritation was most frequent in the insert group. CONCLUSIONS AND CLINICAL RELEVANCE: Overall, the ocular inserts provided an alternative to parenteral administration of apomorphine with comparable efficacy and a lower prevalence of adverse effects.     

Chaotic Dynamics in an Insect Population

A nonlinear demographic model was used to predict the population dynamics of the flour beetle Tribolium under laboratory conditions and to establish the experimental protocol that would reveal chaotic behavior. With the adult mortality rate experimentally set high, the dynamics of animal abundance changed from equilibrium to quasiperiodic cycles to chaos as adult-stage recruitment rates were experimentally manipulated. These transitions in dynamics corresponded to those predicted by the mathematical model. Phase-space graphs of the data together with the deterministic model attractors provide convincing evidence of transitions to chaos.     

The effects of lifetime food restriction on the development of osteoarthritis in the canine shoulder

Objective— To report effects of age and lifetime food restriction on development and progression of shoulder joint osteoarthritis (OA) in Labrador retriever dogs.
Study Design— Longitudinal life-span, cohort study.
Animals— Labrador retriever dogs (n=48).
Methods— Littermates were paired (gender, weight) to make 24 pairs of genetically similar dogs. Each diet-restricted (DR) pair-mate was fed daily 75% of the same diet consumed by its control-fed (CF) pair-mate for life. Shoulders were evaluated radiographically at years 6, 8, and end of life (EOL). At EOL shoulders were evaluated grossly and by histopathology for OA.
Results— Radiographic evidence of shoulder OA was identified in 78% of dogs. Severity of radiographic shoulder OA at 6 ( P <.03) and 8 years ( P <.02) was significantly lower among DR dogs compared with CF dogs. Pooled gross evaluation results revealed 40 of 46 dogs had cartilage erosion on the caudal aspect of the humeral head. By EOL, 91% of dogs had histopathologic changes consistent with OA.
Conclusion— There was a high overall prevalence of radiographic, gross, and histologic OA among dogs. Substantial disparity was found between radiographic evidence of OA (at EOL) and characteristic changes visible by gross and histologic examination.
Clinical Relevance— Radiographic evaluation correlates poorly with severity of shoulder joint pathology. The benefits of DR on shoulder OA are consistent with the demonstrated effect of DR in delaying species- and strain-specific diseases of aging.     

Evaluating the use of plasma hematocrit samples to detect ketones utilizing urine dipstick colorimetric methodology in diabetic dogs and cats

Objective: To determine whether plasma from a heparinized hematocrit tube placed on a urine dipstick would accurately reflect (positive or negative) urine ketone results in diabetic dogs and cats. Design: Prospective study, 37 dogs and 43 cats, with a known history of diabetes or hyperglycemia, glucosuria, and symptoms of undiagnosed diabetes mellitus were tested. Setting: Veterinary Referral Hospital. Animals: Client owned dogs and cats. Interventions: None. Measurement and main results: Heparinized plasma and urine ketone results were recorded using urine reagent strips. Plasma dipstick results were compared to urine dipstick results as the standard. Results were recorded based on the color chart provided by the manufacturer. Two individuals were responsible for verifying the results of the colorimetric test. Test efficiency was 97% (sensitivity = 96%, specificity = 100%) for the canine population, 93% (sensitivity = 100%, specificity = 83%) for the feline population, and 95% (sensitivity = 98%, specificity = 91%) for the total population. Four of 80 animals were found to have discordant results (1 dog and 3 cats). Conclusion: Plasma from heparinized hematocrit tubes is clinically useful for detecting the presence or absence of ketonuria, and therefore ketosis, in diabetic dogs and cats using urine dipstick colorimetric methodology.     

Moorland restoration aids the reassembly of associated phytophagous insects

A change in the vegetation of UK moorland from Calluna vulgaris-dominated heath to Molinia caerulea- or Nardus stricta-dominated grassland is frequently deemed undesirable on economic and biodiversity grounds. Moorland vegetation restoration is an increasingly practiced management option. However there has been little research on the effectiveness of such management for aiding the restoration of other aspects of moorland biodiversity such as associated insect populations.We sampled Hemiptera and Lepidoptera assemblages from restored, degraded and C. vulgaris-dominated (target) moorland at eight restoration sites in England and Scotland. Vegetation assemblages and additional environmental variables were sampled at the same locations.Vegetation restoration aided the reassembly of moorland insects to a variable extent. Hemiptera restoration success was greatest at mechanically restored sites dominated by C. vulgaris. In addition to treatment, latitude best explained variation in the Hemiptera assemblage. A range of plant species, all either dwarf shrubs or graminoids, acted as further determinants. Lepidoptera restoration success was correlated most closely with the success of restoring the full diversity of the vegetation assemblage and was highest at sites restored by grazing control.The results demonstrate that vegetation restoration brings wider biodiversity benefits and that the form these take may depend on the restoration method used and consequent characteristics of the resultant vegetation assemblage.     

The association of water chemistry variables and fish condition in streams of Shenandoah National Park (USA)

As part of the Shenandoah National Park: Fish in Sensitive Habitats (SNP:FISH) project, the blacknose dace (Rhinichthys atratulus) was utilized as an indicator species to assess the susceptibility of the ichthyofaunal community of Shenandoah National Park (USA) to acidification. Water chemistry (ANC, conductivity, pH, and concentrations of Ca²⁺, Mg²⁺, Na⁺, K⁺, Cl^–, NO₃ ^–, SO₄ ^2–, and SiO₂) was sampled every three months over the course of 3 1/4 years which represents the probable maximum lifetime of R atratulus. Condition factors (K=[g/mm³]^*10⁶) were calculated for samples of fish (age class 2+ yr; n=370) from nine montane, second/third order streams representing a range of ANCs. A principle components regression was performed on factor scores from a principle components analysis of the water chemistry variables and fish condition factor. Two factors, one associated with stream water ANC and ion concentrations, and another associated with SO₄ ^2– concentration, collectively explained 84% of the variance in condition factor. The influence of variables other than water chemistry upon R atratulus K is addressed. The results show that environmental chemistry is highly associated with the K of R atratulus.