Development of a simple method to measure static body weight distribution in neurologically and orthopedically normal mature small breed dogs.

BACKGROUND: Objective outcome measures capable of tracking different aspects of functional recovery in dogs with acute intervertebral disc herniation are needed to optimize physical rehabilitation protocols. Normal, pre-injury distribution of body weight in this population is unknown. The aims of this study were to quantify static weight distribution (SWD) using digital scales and to establish the feasibility of different scale methods in neurologically normal, mature, chondrodystrophic small breed dogs predisposed to intervertebral disc herniation. RESULTS: Twenty-five healthy, mature dogs were enrolled with a mean age of 4.6 years (SD 2.7) and a mean total body weight of 11.5 kg (SD 3.6). SWD for the thoracic and pelvic limbs and between individual limbs was acquired in triplicate and expressed as a percentage of total body weight using commercially available digital scales in four combinations: two bathroom, two kitchen (with thoracic and pelvic limbs combined), four bathroom and four kitchen (with limbs measured individually). SWD was also obtained using a pressure sensing walkway for comparison to scale data. Feasibility for each method was determined and coefficients of variation were used to calculate inter-trial variability. Mean SWD values were compared between methods using an ANOVA. The two bathroom scales method had the highest feasibility and lowest inter-trial variability and resulted in mean thoracic and pelvic limb SWD of 63 % (SD 3 %) and 37 % (SD 3 %), respectively. Thoracic limb mean SWD was higher for the PSW compared to any of the scale methods (p < 0.0001). CONCLUSIONS: SWD in a population of healthy chondrodystrophic dogs was simple to obtain using inexpensive and readily available digital scales. This study generated SWD data for subsequent comparison to dogs recovering from acute intervertebral disc herniation.

Radiographic indices for the diagnosis of atlantoaxial instability in toy breed dogs [corrected].

Toy breed dogs are overrepresented for atlantoaxial instability. Radiography is a standard diagnostic test, however published toy breed-specific radiographic measurements are lacking and diagnosis remains largely subjective. Aims of this retrospective, diagnostic accuracy study were to describe normal values and determine whether some quantitative radiographic criteria strongly support a diagnosis of atlantoaxial instability specific to toy breed dogs. Neutral lateral and ventrodorsal radiographs of 102 toy breed dogs (92 control, 10 affected) were reviewed. The median C1-C2 overlap (the distance of overlap between the C2 spinous process and the dorsal arch of C1) was +4.65 mm in control dogs and -5.00 mm in atlantoaxial instability cases. A C1-C2 overlap ≤ +1.55 mm was the most sensitive (100%) and specific (94.5%) radiographic measurement in the diagnosis of atlantoaxial instability. Three relative measurements were performed: the ventral atlantodental interval to dorsal atlantodental interval ratio, the dens/C2 ratio, and the C1-C2 angle. These three relative measurements had good specificity (94.5, 86.9, and 98.9%, respectively), lower sensitivity (80.0, 66.7, and 60.0%, respectively), and were not influenced by body weight (P > 0.05). Absolute measurements (including absolute dens length and atlantoaxial distance) were significantly correlated with body weight (P < 0.05) diminishing their utility in the diagnosis of atlantoaxial instability. Decreased C1-C2 overlap strongly supports atlantoaxial instability. The ventral atlantodental interval/dorsal atlantodental interval ratio, dens/C2 ratio, and C1-C2 angle may provide further support but may be normal in individual cases.

Magnetic resonance imaging versus computed tomography to plan hemilaminectomies in chondrodystrophic dogs with intervertebral disc extrusion.

OBJECTIVE: To determine the influence of preoperative computed tomography (CT) versus magnetic resonance (MR) on hemilaminectomies planned to treat thoracolumbar (TL) intervertebral disc (IVD) extrusions in chondrodystrophic dogs. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Forty chondrodystrophic dogs with TL IVD extrusion and preoperative CT and MR studies. METHODS: MR and CT images were randomized and reviewed by 4 observers masked to the dog's identity and corresponding imaging studies. Observers planned the location along the spine, side, and extent (number of articular facets to be removed) based on individual reviews of CT and MR studies. Intra-observer agreement was determined between overall surgical plan, location, side, and size of the hemilaminectomy planned on CT versus MR of the same dog. RESULTS: Similar surgical plans were developed based on MR versus CT in 43.5%-66.6% of dogs, depending on the observer. Intra-observer agreement in location, side, and size of the planned hemilaminectomy based on CT versus MR ranged between 48.7%-66.6%, 87%-92%, and 51.2%-71.7% of dogs, respectively. Observers tended to plan larger laminectomy defects based on MR versus CT of the same dog. CONCLUSION: Findings from this study indicated considerable differences in hemilaminectomies planned on preoperative MR versus CT imaging. Surgical location and size varied the most; the side of planned hemilaminectomies was most consistent between imaging modalities.

Inguinal herniation of a mineralized paraprostatic cyst in a dog.

A firm mass was noted in the right inguinal subcutaneous region of an 11-year-old intact male Labrador retriever dog presented for right pelvic limb weakness. Pelvic radiographs showed 2 large ovoid structures with circumferential thin eggshell-like mineralization in the right external inguinal region. The structures were confirmed sonographically, and on magnetic resonance imaging as a large folded herniated mineralized paraprostatic cyst through a defect in the right inguinal wall. To the author's knowledge, this is the first published report of an inguinal herniated mineralized paraprostatic cyst.

Herniation inguinale d'un kyste paraprostatique minéralisé chez un chien. Une masse ferme a été observée dans la région sous-cutanée chez un Labrador retriever mâle intact âgé de 11 ans qui était présenté pour une faiblesse du membre pelvien droit et des radiographies pelviennes ont montré deux grosses structures ovoïdes avec une mince minéralisation circonférencielle semblable à une coquille d'oeuf dans la région inguinale droite. Les structures ont été confirmées par échographie et à l'imagerie par résonance magnétique comme un gros kyste paraprostatique replié minéralisé et hernié via un défaut de la paroi inguinale droite. À la connaissance de l'auteur, il s'agit du premier rapport publié d'un kyste paraprostatique minéralisé hernié inguinal.(Traduit par Isabelle Vallières).

MEDULLOBLASTOMA IN A GRIZZLY BEAR (URSUS ARCTOS HORRIBLIS).

A 3-yr-old female spayed grizzly bear (Ursus arctos horribilis) was evaluated for seizure activity along with lethargy, inappetence, dull mentation, and aggressive behavior. Magnetic resonance (MR) examination of the brain revealed a contrast-enhanced right cerebellar mass with multifocal smaller nodules located in the left cerebellum, thalamus, hippocampus, and cerebrum with resultant obstructive hydrocephalus. Cerebrospinal fluid analysis revealed mild mononuclear pleocytosis, with differentials including inflammatory versus neoplastic processes. Blood and cerebrospinal fluid were also submitted for polymerase chain reaction and agar gel immunodiffusion to rule out infectious causes of meningitis/encephalitis. While awaiting these results, the bear was placed on steroid and antibiotic therapy. Over the next week, the bear deteriorated; she died 1 wk after MR. A complete postmortem examination, including immunohistochemisty, revealed the cerebellar mass to be a medulloblastoma. This is the only case report, to the authors' knowledge, describing a medulloblastoma in a grizzly bear.

Emergency Approach to Acute Seizures in Dogs and Cats.

Seizures are a common presentation seen in small animal practices. Seizures require prompt management including initial interventions for triage, stabilization, and treatment with first-line anticonvulsant (AC) drugs like benzodiazepines. Concurrently, ruling out metabolic or extracranial causes with point-of-care diagnostics can help guide further diagnostics and treatments. Analysis of the history and a physical exam are also necessary to rule out common "look-alikes" that require specific diagnostic workup and treatments. Typically, causes of seizures can be grouped into intracranial and extracranial causes, with the latter being easier to diagnose with commonly available tests. This review presents a systematic approach to the diagnosis and treatment of single seizures, cluster seizures, and status epilepticus in dogs and cats.

Clinical Findings and Outcome in 30 Dogs with Presumptive or Confirmed Nerve Sheath Tumors.

Nerve sheath tumors (NSTs) are well-recognized primary nervous system tumors, but there is relatively limited information in dogs including comparison of NSTs in different anatomical locations. This retrospective study describes the clinical features and outcomes in a group of dogs with NSTs affecting the cranial nerves or spinal nerves. Thirty dogs were included, 25 with a presumptive diagnosis and five confirmed by histopathologic analysis. Seven dogs also had cytology of tumor samples, which were supportive of the NST diagnosis in four. Eight dogs had cranial nerve-associated NSTs, with six involving the trigeminal nerve. Twenty-two dogs had spinal nerve-associated NSTs including 13 invading the spinal canal and nine peripheral to the spinal canal, with the majority affecting nerves or nerve roots of the brachial plexus. The prognosis was poor, with dogs being euthanized eventually because of disease progression. Among dogs alive 1 week after diagnosis, the median survival time was 4 months but ranged from 2 weeks to >2 years. While there was a broad overlap between NST locations, survival was generally longer for dogs without spinal canal or intracranial involvement. The results expand available information on NSTs in dogs but should be interpreted with caution given the small number of dogs with a definitive diagnosis. Further investigation is warranted to determine how tumor location, invasiveness, and treatments pursued impact outcome.

Creatine kinase and its isoenzymes in the serum and cerebrospinal fluid of healthy canines.

BACKGROUND: Creatine kinase (CK) exists as three isoenzymes (CK-MM, CK-MB, and CK-BB) that are predominantly expressed in specific tissues and can be detected in both the serum and cerebrospinal fluid (CSF). CSF CK has been relatively unstudied in veterinary medicine, although studies in human medicine have demonstrated that changes in total CSF CK activity can indicate neurologic abnormalities. OBJECTIVES: The purpose of this study was to establish reference intervals for CK and its three major isoenzymes in the serum and CSF of clinically healthy dogs. By establishing a definitive reference interval for this enzyme in healthy canines, the diagnostic use and possible significance of CK in clinical disease can be studied. METHODS: Serum and/or CSF were collected from healthy dogs. Total CK activity was measured spectrophotometrically, and isoenzyme distributions were determined using the QuickGel CK Vis Isoenzyme Kit and a densitometric scanner. Total CK and CK isoenzyme activities were determined within 8 h of collection. RESULTS: The median serum total CK in healthy canines was 159.0 U/L (range: 53.0-539.0 U/L), while the median CSF total CK was 3.7 U/L (range: 2.0-84.0 U/L). CK-BB and CK-MM were approximately equal in the serum, while CK-MM was the predominant isoenzyme in the CSF. CONCLUSIONS: Knowledge of the normal distribution and concentration of CK in canine serum and CSF will set the foundation for future studies of canine CK as a potentially clinically useful biomarker.

Canine intervertebral disc fenestration using a vacuum-assisted tissue resection device.

OBJECTIVE: Describe the use and feasibility of a novel vacuum-assisted tissue resection device (VRD) for canine intervertebral disc fenestration, and compare the effectiveness of manual fenestration to the VRD. STUDY DESIGN: Randomized prospective study. ANIMALS: Canine cadavers (n = 15). METHODS: A cadaveric lumbar spine study was performed to compare the use of manual fenestration to a novel VRD for intervertebral disc fenestration. Both fenestration groups were compared to a control group. Effectiveness of fenestration was assessed by calculating a ratio of remaining nuclear weight postfenestration to total nuclear volume. Fenestrated discs with lower ratios were indicative of greater removal of nucleus pulposus. RESULTS: There was a statistically significant reduction in mean ratio (±SD) of remaining nuclear weight to volume with both fenestration groups compared to controls (0.39 ± 0.07; P < .001). There was an improved ratio using the VRD (0.23 ± 0.09) compared to manual fenestration (0.30 ± 0.10); this was not statistically significant (P = .069). It was technically difficult to fenestrate the disc spaces at L5-L6 and L6-L7 because of location and anatomy, resulting in a statistically significant increase in the median ratio of nuclear weight-to-volume ratios in both manual and VRD fenestration groups when compared to the more cranial L4-L5 disc spaces, 0.32 ± 0.08, and 0.35 ± 0.08 versus 0.25 ± 0.13 at L4-L5 (P = .026 and P = .004, respectively). CONCLUSIONS: The VRD is a feasible instrument for canine intervertebral disc fenestration. It is at least as effective as manual fenestration, and provides additional safety features.

Spinal cord compression in two related Ursus arctos horribilis.

Two 15-yr-old grizzly bear littermates were evaluated within 9 mo of each other with the symptom of acute onset of progressive paraparesis and proprioceptive ataxia. The most significant clinical examination finding was pelvic limb paresis in both bears. Magnetic resonance examinations of both bears showed cranial thoracic spinal cord compression. The first bear had left-sided extradural, dorsolateral spinal cord compression at T3-T4. Vertebral canal stenosis was also observed at T2-T3. Images of the second bear showed lateral spinal cord compression from T2-T3 to T4-T5. Intervertebral disk disease and associated spinal cord compression was also observed at T2-T3 and T3-T4. One grizzly bear continued to deteriorate despite reduced exercise, steroid, and antibiotic therapy. The bear was euthanized, and a necropsy was performed. The postmortem showed a spinal ganglion cyst that caused spinal cord compression at the level of T3-T4. Wallerian-like degeneration was observed from C3-T6. The second bear was prescribed treatment that consisted of a combination of reduced exercise and steroid therapy. He continued to deteriorate with these medical therapies and was euthanized 4 mo after diagnosis. A necropsy showed hypertrophy and protrusion of the dorsal longitudinal ligament at T2-T3 and T3-T4, with resulting spinal cord compression in this region. Wallerian-like degeneration was observed from C2-L1. This is one of few case reports that describes paresis in bears. It is the only case report, to the authors' knowledge, that describes spinal magnetic resonance imaging findings in a grizzly bear and also the only report that describes a cranial thoracic myelopathy in two related grizzly bears with neurologic signs.

Case Report: Recurrence of an Extradural Spinal Epidermoid Cyst Following Surgical Excision in a Dog.

Congenital epidermoid cysts are slow-growing, mass lesions caused by the abnormal inclusion of neuroectodermal tissue within the developing central nervous system. Subtotal excision of epidermoid cysts increases the risk of early recurrence of clinical signs. A 4-year-old female spayed boxer was presented with a 4-month history of ambulatory paraparesis and proprioceptive ataxia. Neurological examination localized a T3-L3 myelopathy. MRI revealed a T1 iso- to hypointense, T2 and FLAIR hyperintense, rim-enhancing mass at the level of the T9-T10 vertebrae resulting in extradural compression of the spinal cord. This was histopathologically confirmed as an extradural epidermoid cyst following subtotal excision. MRI performed 2 months post-operatively revealed a significant decrease of the lesion volume. The dog was neurologically normal following the surgery however re-presented 28 months later with recurrence of clinical signs. A 28-month post-operative MRI revealed substantial enlargement of the epidermoid cyst. The dog was subsequently taken for repeat decompressive surgery. At 6 months from the repeat surgery, the dog was neurologically static with mild proprioceptive deficits. The case report highlights the clinical and MRI features of a recurrent extradural spinal epidermoid cyst treated by subtotal excision.

Pilot Study on Feasibility of Sensory-Enhanced Rehabilitation in Canine Spinal Cord Injury.

Physical rehabilitation is frequently recommended in dogs recovering from acute thoracolumbar intervertebral disc extrusion (TL-IVDE), but protocols vary widely. The objective of this study was to evaluate the feasibility of incorporating sensory-integrated neurorehabilitation strategies into a post-operative rehabilitation protocol in dogs with TL-IVDE. Non-ambulatory dogs with acute TL-IVDE managed surgically were prospectively recruited to this unblinded cross-over feasibility study. Eligible dogs were randomized to start with tactile-enhanced (artificial grass) or auditory-enhanced (floor piano) basic rehabilitation exercises performed twice daily for the first 4 weeks before switching to the opposite surface for the subsequent 4 weeks. Neurologic examination, open field gait scoring, girth measurements and an owner-completed feasibility questionnaire were performed at baseline and 2, 4, 6, and 8 weeks post-operatively. Twenty-four dogs were enrolled, 12 randomized to each order of exercises. Gait scores did not differ between the two groups at baseline, 4 or 8 week visits. All modified exercises could be performed and compliance was high. Adverse events potentially attributable to the study surface were mild, self-limiting and occurred in 2/24 dogs. The most common surface-related limitations were that the piano was slippery and that both surfaces were too short. The artificial grass was preferred by owners and dogs compared to the floor piano surface, but this was influenced by which surface was utilized first. Auditory and tactile modifications were feasible and safe to incorporate into a standardized rehabilitation protocol. This pilot study could prompt larger efficacy studies investigating the benefit of sensory-integrated rehabilitation in dogs with TL-IVDE.

Static Body Weight Distribution and Girth Measurements Over Time in Dogs After Acute Thoracolumbar Intervertebral Disc Extrusion.

Dogs with thoracolumbar intervertebral disc extrusion (TL-IVDE) can exhibit variable neurologic deficits after decompressive surgery. The objectives of this study were to quantify changes in static weight distribution (SWD) and limb and body circumference over time in dogs recovering from surgery for TL-IVDE. Dogs with acute TL-IVDE were prospectively evaluated at baseline (48-72 h post-operatively), 2, 4, 8, and 12 weeks post-operatively. Commercially-available digital scales were used to measure weight distributed to the pelvic limbs (PL%) and asymmetry between left and right pelvic limbs (LRA), each expressed as a percentage of total body weight. Trunk and thigh circumference measurements were performed using a spring-loaded tape measurement device. Measurements were performed in triplicate, compared to neurologically normal small breed control dogs and analyzed for changes over time. P <0.05 was significant. Twenty-one dogs were enrolled; 18 regained ambulation and 3 did not by study completion. PL% increased from 27.6% at baseline to 30.7% at 12 weeks but remained lower than in control dogs (37%) at all time points (p < 0.0001), even excluding dogs still non-ambulatory at 12 weeks (p < 0.025). LRA was similar to the control dogs, and did not have an association with surgical side. Caudal trunk girth decreased over time to 95% of baseline (p = 0.0002), but this was no longer significant after accounting for reductions in body weight (p = 0.30). Forward shifting of body weight persisted in dogs with TL-IVDE 12 weeks after surgery even among ambulatory dogs. SWD and circumference measurements could provide additional objective measures to monitor recovery.

Congenital muscular dystrophy in a dog with a LAMA2 gene deletion.

A 2-year-old female spayed dog was presented with a chronic history of short-strided gait and inability to completely open the jaw. Clinical signs were present since the dog was adopted from a humane society at a few months of age. Serum creatine kinase activity was abnormally high. Neurological examination, electromyography, muscle biopsies with immunofluorescent staining, and whole genome sequencing (WGS) were performed. A dystrophic phenotype was identified histologically in muscle biopsies, deficiency of laminin α2 protein was confirmed by immunofluorescent staining, and a deletion in the LAMA2 gene was identified by analysis of the WGS data. Congenital muscular dystrophy associated with a disease variant in LAMA2 was identified.

The Physiology Associated With "Bed Rest" and Inactivity and How It May Relate to the Veterinary Patient With Spinal Cord Injury and Physical Rehabilitation.

In the twentieth century, bed rest was commonly prescribed by human healthcare professionals as a treatment for a variety of ailments including spinal cord injury and disease. With time, the negative impact of bed rest was recognized as a source of slow and even reduced patient healing. As treatment paradigms shifted, the utility and importance of physical rehabilitation (PR) as a critical adjunctive treatment for human patients with spinal cord injury became fully recognized. Today, standardized PR protocols exist for humans with the spinal cord disease, but the same cannot be said for our veterinary patients with spinal cord injury. The purpose of this manuscript is to discuss the effects of inactivity on the musculoskeletal system and to explore how and why PR can play a critical role in improved mobility and overall health in the veterinary patient with spinal cord injury. Research with a focus on the effects of inactivity, in the form of cage rest, for the veterinary patient with spinal cord injury is lacking.

A Canine's Behavior and Cognitive State as It Relates to Immobility and the Success of Physical Rehabilitation in the Non-ambulatory Spinal Cord Patient.

Physical rehabilitation (PR) is recommended following spinal cord injury to help improve and maintain muscle elasticity, joint mobility, and nerve health. It can also be used to relieve pain and improve cardiopulmonary fitness in an immobile patient. There is evidence, in human medicine, that PR plays a critical role in mental health and the psychological state of the patient. As part of the assessment phase, human physical therapists often identify psychosocial symptoms and barriers at the start of PR that ultimately may affect improvement in human patients suffering from injury and the loss of mobility. Patient psychological state plays an integral role in healing and outcome during treatment and rehabilitation. Specific interventions set to address these symptoms can better outcome. Arguably, one of the most emotionally traumatizing injuries suffered by a canine patient can be immobility secondary to spinal cord injury. Poorly understood is the role the canine cognitive state plays in the success of rehabilitation following spinal cord injury. Should breed, age, sex, physical fitness, personality, previous experiences and history or home lifestyle, affect the PR assessment of these patients? Do these factors affect eventual outcome following PR? The purpose of this manuscript is to explore psychosocial barriers encountered during injury rehabilitation in humans and determine if the similar barriers need to be considered when assessing a canine patient for spinal cord injury rehabilitation.

Case Report: Suspected Solitary Osseous Plasmacytoma in a Cat: Use of Magnetic Resonance Imaging to Diagnose and Confirm Resolution of Disease Following Chemotherapy.

A 9-year-old female spayed Domestic Shorthair cat presented for pain, reluctance to jump, and hyporexia of 14 days duration. Neurologic examination was consistent with C6-T2 myelopathy. Magnetic resonance imaging (MRI) revealed a solitary, contrast-enhancing lesion within the T2 vertebral body. Solitary osseous plasmacytoma was diagnosed based on neurologic examination, advanced imaging, and clinicopathologic findings. Melphalan and prednisolone therapy were initiated. Complete resolution of clinical signs and the vertebral lesion were documented at a 2-year follow up examination with neurologic examination and repeat spinal MRI, respectively. Solitary osseous plasmacytoma are rare neoplasms in humans and domestic animals. As such, there is a paucity of published information regarding diagnostic criteria, MRI findings, treatment modalities, progression, and remission of disease in the feline patient. Most data are extrapolated from human medicine. The purpose of this report is to document neurologic exam and MR findings at the time of diagnosis and complete resolution of a solitary osseous vertebral plasmacytoma following melphalan and prednisolone therapy.

Development of an In Vitro Hemorrhagic Hydrocephalus Model for Functional Evaluation of Magnetic Microactuators Against Shunt Obstructions.

OBJECTIVE: Occlusion of ventriculoperitoneal shunts placed after intraventricular hemorrhage occurs frequently. The objective of this study was to develop a hemorrhagic hydrocephalus model to assess the ability of an oscillating microactuator within the ventricular catheter (VC) to prevent shunt obstruction. METHODS: An in vitro hydrocephalus model with extreme risk of shunt obstruction was created. Phosphate-buffered saline, blood, and thrombin were driven through ventriculoperitoneal shunts for 8 hours. Five VCs were fitted with a microactuator and compared with 5 control VCs. The microactuator was actuated by an external magnetic field for 30 minutes. Pressure within the imitation lateral ventricle was measured. RESULTS: In the 5 control shunts, 6 obstructions developed (3 VC, 3 valve-distal catheter) compared with 1 obstruction (VC) in the 5 microactuator shunts. In the control and microactuator groups, the median volume exiting the shunts in 8 hours was 30 mL versus 256 mL. Median time to reach an intraventricular pressure of 40 mm Hg (13.8 minutes vs. >8 hours), median total time >40 mm Hg (6.2 hours vs. 0.0 hours), and median maximum pressure (192 mm Hg vs. 36 mm Hg) were significantly improved in the microactuator group (P < 0.01). CONCLUSIONS: In addition to protecting the VC, the microactuator appeared to prevent hematoma obstructing the valve or distal catheter, resulting in a much longer duration of low intraventricular pressures. A microactuator activated by placing the patient's head in an external magnetic field could reduce shunt obstructions in hemorrhagic hydrocephalus.

Evaluation of the hydroxyethyl starch stabilizing agent, Vetstarch, in the preservation of canine cerebrospinal fluid samples.

BACKGROUND: A challenge of cerebrospinal fluid (CSF) analysis is the time-dependent degradation of nucleated cells, impeding accurate interpretation. CSF additives have been used to delay cell degradation; however, stabilizing agents, including serum, can alter microprotein levels. OBJECTIVES: This study aimed to determine if the hydroxyethyl starch, Vetstarch, is effective at preserving nucleated cell morphology in CSF compared with the saline diluent or serum without altering microprotein levels. METHODS: CSF samples were collected from 26 dogs. Samples were divided into four aliquots. One aliquot was analyzed immediately (control). The remaining three aliquots were mixed with either saline, fetal calf serum, or Vetstarch before storage at 4°C. Nucleated cell differentials, protein concentrations, and cell morphology scores were analyzed 48 hours later. A cell morphology score of 1 indicated no cellular degeneration; a score of 4 indicated severe degeneration. RESULTS: Samples stored in serum, saline, and Vetstarch exhibited poorer mean (±SD) morphology scores (2.4 ± 0.7, 2.6 ± 0.8, and 2.7 ± 0.9, respectively) compared with controls (1.9 ± 0.4). Samples stored in saline and Vetstarch demonstrated higher percentages of unrecognizable cells, with a median of 28 (range 0-100) and 27 (0-100), respectively; samples stored in serum had a median of 14 (range 0-67) unrecognizable. Microprotein levels of samples stored in Vetstarch were dependent on the method of protein analysis. Serum significantly increased microprotein levels. CONCLUSIONS: Vetstarch does not reduce time-dependent cellular degeneration compared with the saline diluent or serum and is, therefore, not recommended as a stabilizing agent for canine cerebrospinal fluid.

Serum Melatonin Values in Normal Dogs and Dogs with Seizures.

Epilepsy, or recurrent seizures, is reported to be the most common neurologic condition in dogs; 20-30% of epileptic dogs are considered to be pharmacoresistent to one medication. The hormone melatonin has been shown to have significant anticonvulsant effects; epileptic humans have lower serum melatonin levels than unaffected individuals. We hypothesize that serum levels of melatonin will be lower in dogs with seizures as compared with normal dogs. Sixty-two dogs were enrolled in the study: 29 normal dogs (Group 1) and 33 dogs with seizures (Group 2). Blood sampling was done at three separate time points (8:00 a.m., 12:00, and 4:00 p.m.). The majority of dogs in Groups 1 (69%) and 2 (76%) had serum melatonin levels <0.5 pg/mL as measured by radioimmunoassay. There were no significant differences in serum melatonin values between the groups or within groups when time of blood draw, length of sample freezing, time of day/year of sampling, or presence of anticonvulsant therapy were compared. There were no notable differences in daytime serum melatonin values in normal dogs versus dogs with seizures. The majority of daytime serum melatonin levels were <0.5 pg/mL in dogs with and without seizures.