ABSTRACT

The purpose was to determine the safety and achievable serum concentrations of transdermally administered phenobarbital in healthy cats. The hypothesis was that transdermal phenobarbital would achieve therapeutic serum concentrations (15–45 µg/mL) with minimal short-term adverse effects. Enrolled cats had normal physical and neurologic exams and unremarkable bloodwork. Transdermal phenobarbital in a pluronic lecithin organogel–based vehicle was administered at a dosage of 3.0–3.1 mg/kg per ear pinna (total of 6.0–6.2 mg/kg) every 12 hr for 14 days. Serum phenobarbital concentrations were measured 3–6 hr after dosing at seven different times over 15 days. The mean and median serum concentration of phenobarbital at study completion were 5.57 and 4.08 µg/mL, respectively. Mean peak concentration and mean time to peak concentration were 5.94 µg/mL and 13.3 days, respectively. Mild adverse effects were observed. Potency was analyzed in three replicates of the transdermal phenobarbital gel administered; potencies ranged from 62.98 to 82.02%. Transdermal application of phenobarbital in healthy cats achieves a detectable, but subtherapeutic, serum concentration and appears safe in the short term. The use of therapeutic drug monitoring is recommended when this formulation of phenobarbital is used to ensure therapeutic serum concentrations are achieved.

ABSTRACT

Special staining and grading of canine liver cytology samples aids in detection of increased copper content. The prevalence of copper in routine diagnostic liver cytology samples, clinical findings associated with high cytologic copper (cCu) grade, and the correlation between cCu grade and histologic findings, including histologic copper (hCu) grade, are unknown. This data may be helpful in ascertaining when to determine a cCu grade and when interpreting cCu grade.

Clinical data and available archived hepatic histologic and cytologic samples from 198 dogs were collected, evaluated, rhodanine stained, and graded for copper. Prevalence of increased cCu >5 in a randomly collected group of 163 individuals, and the correlation between cCu and clinical data (n = 198), hCu grade (n = 37), or findings on hematoxylin and eosin–stained hepatic sections (n = 32) were evaluated. The observed prevalence was 1.23%. Dogs with elevated alanine transaminase >180 IU/L or aspartate transaminase >90 IU/L and patients who subsequently had hepatic copper quantification were statistically more likely to have pathologic levels of copper detected by cytology. There was significant and modest correlation between cCu and hCu, interface hepatitis, portal inflammation, and fibrosis. Evidence of hepatocellular leakage may be indications for determination of cCu.

ABSTRACT

The use of human generic amoxicillin–clavulanic acid formulations in veterinary medicine is currently lacking supportive evidence. This pilot study was conducted to determine preliminary pharmacokinetic parameters and relative oral bioavailability of a human generic and veterinary proprietary 4:1 amoxicillin–clavulanic acid formulation in healthy dogs to evaluate whether drug exposure was similar and to determine if further comparative investigation is warranted. Each dog received a single oral dose of each formulation containing 500:125 mg of amoxicillin–clavulanic acid at two separate instances with a 2 wk washout period between product administration. Following drug administration, blood was collected at fixed times over 24 hr to measure plasma amoxicillin and clavulanic acid concentrations using liquid chromatography–mass spectrometry. There were no statistically significant differences between pharmacokinetic parameters of either formulation. Clavulanic acid showed greater between-dog variation in drug exposure between formulations compared with amoxicillin and was also observed to be more variable within the veterinary proprietary formulation. The average relative oral bioavailability was 98.2% (23.6% coefficient of variation) for amoxicillin and 152.6% (64.3% coefficient of variation) for clavulanic acid between formulations. This pilot investigation supports the need for further bioequivalence studies regarding these formulations before commenting on product interchangeability.

ABSTRACT

Twenty-five cats at a private animal sanctuary received multiple nonimmunosuppressive doses of parenteral methylprednisolone acetate for at least 3 yr. Complete blood count, chemistry, and T4 results from these cats were examined to look for statistically significant changes. Results found significant changes in triglycerides, amylase, and monocytes. However, these changes remained within the reference interval. All other values showed no significant changes. These results suggest that after 3 yr of chronic parenteral administration of nonimmunosuppressive doses of methylprednisolone acetate, the complete blood count, chemistry, and T4 values in 25 cats were not significantly affected and did not result in abnormal laboratory values.

ABSTRACT

This study described the rate of vaccine reactions in a population of dogs receiving vaccines after diagnosis of primary immune-mediated hemolytic anemia (IMHA). A secondary objective was to describe the time elapsed between vaccination and initial diagnosis of IMHA. A medical record search identified cases meeting criteria for primary IMHA. Owners and referring veterinarians were surveyed regarding vaccination of the dog following diagnosis. Referring veterinarians were surveyed regarding vaccination prior to diagnosis of IMHA. A completed survey was returned in 44 cases. Twenty-two dogs received vaccinations after diagnosis, and 22 dogs did not. The median time elapsed between vaccination and initial diagnosis was 280 days. No dog was vaccinated within 30 days of diagnosis. Two of the following possible reactions were noted out of 22 dogs vaccinated: vomiting and urticarial eruption in a dog administered a rabies and canine distemper vaccine, and recurrent anemia in a dog administered a rabies vaccine. The rate of vaccine reactions was higher than previously reported, although the time period evaluated was longer than in previous studies. The relationship between initial vaccination and development of IMHA, and between vaccination and vaccine reaction, in this population is uncertain and may reflect coincidence or differences in susceptibility.

ABSTRACT

Six dogs with massive hepatocellular carcinoma that was not amenable to surgery were treated by oral administration of single-agent toceranib at a dose of 2.0–3.0 mg/kg every other day for a minimum of 60 days. Partial response was achieved in three dogs, stable disease was achieved in one dog, and progressive disease occurred in two dogs, according to the canine Response Evaluation Criteria in Solid Tumors v1.0. Observed adverse events were mild to moderate in severity and reported in accordance with the Veterinary Cooperative Oncology Group’s common terminology criteria for adverse events v1.1. Activities of alanine aminotransferase and alkaline phosphatase decreased in the cases that were sensitive to treatment with toceranib, whereas the activities remained high in resistant cases. Additionally, the level of phospho-vascular endothelial growth factor receptor 2 was found to be increased in a resistant case. Single-agent toceranib might prove to be an effective treatment for canine hepatocellular carcinoma pending further validation.

ABSTRACT

In dogs with leptospirosis, doxycycline therapy is recommended as the preferred therapy for its ability to eliminate the organism from all tissues, including the renal tubules. Elimination of organisms from the renal tubules terminates leptospiruria and prevents transmission of the organism. This report describes the discovery of persistent leptospiruria in the face of therapy with doxycycline in four dogs and enrofloxacin in one dog. Leptospiruria was confirmed by polymerase chain reaction testing for pathogenic leptospires in all five dogs. In two dogs, leptospiruria resolved after a change in therapy to enrofloxacin. In three dogs, doxycycline and/or enrofloxacin were ineffective at eliminating leptospiruria, which then resolved after therapy with clarithromycin. Pet owners could be at risk as persistent leptospiruria poses a potential zoonotic risk. The potential reasons for persistent leptospiruria as demonstrated by polymerase chain reaction testing are discussed.

ABSTRACT

A 1.5 yr old spayed female mixed-breed dog and a 3 yr old spayed female Labrador retriever were evaluated for suspected esophageal fishhook foreign bodies. Radiographs yielded fishhook foreign bodies present caudal to the cardiac silhouette. Endoscopic retrieval for suspected caudal esophageal foreign body was attempted and aborted due to inadequate visualization of the entire fishhooks within the lumen of the esophagus. At surgery, the fishhooks were seen within the caudal mediastinum, and were engaging the left caudal pulmonary artery. Manual fishhook extraction was performed successfully with minimal hemorrhage. Fishhook foreign bodies caudal to the cardiac silhouette may have vascular involvement. Clinicians should exercise caution when attempting endoscopic retrieval of fishhooks in this location.

ABSTRACT

A 1 yr old castrated male American Staffordshire terrier mix was treated for Scopulariopsis brevicaulis that was discovered during an evaluation of chronic rhinosinusitis. A sinusotomy was performed, with intraoperative infusion of amikacin-impregnated gel and systemic administration of postoperative amikacin. Antibiotic therapy was initially chosen because of historic culture of Mycoplasma. Fungal culture of the frontal sinus identified S. brevicaulis by combined phenotypic characterization and DNA sequencing after morphologic analysis failed to identify the organism. Systemic terbinafine therapy was instituted after fungal culture results were available. The patient recovered well and has had no clinical relapse of disease 3 yr after treatment. This is the first reported case of a fungal rhinosinusitis caused by S. brevicaulis in a dog. Reports of Scopulariopsis infections in humans indicate that treatment of S. brevicaulis infection is hampered by multidrug resistance; prognosis may be poor in people with invasive infections and is currently unknown in dogs. Multimodal therapy, including concurrent surgical and systemic intervention, may be necessary to optimize treatment success.

ABSTRACT

A 10 yr old spayed female toy poodle was presented to a tertiary referral center for a 10 day history of waxing and waning lethargy, vomiting, diarrhea, and anorexia. An immune-mediated neutropenia (IMN) was suspected to be the underlying cause of her clinical signs. A bone marrow aspirate was obtained from the chostochondral junction of the 11th and 12th ribs on the right side and provided a definitive diagnosis of IMN. A positive response to therapy and repeat blood work further confirmed the diagnosis. Obtaining bone marrow aspirates from the chostochondral junction is a safe, cheap, and reliable method of diagnosing IMN and can be performed in the private practice setting with light sedation and minimal need for specialized equipment.

ABSTRACT

Clinically relevant hypocalcemia is a well-documented complication of glucocorticoid administration in people with hypoparathyroidism. The current report describes the phenomenon in a dog. A 7 yr old neutered male Pomeranian was diagnosed with immune-mediated thrombocytopenia, immune-mediated hemolytic anemia, and primary hypoparathyroidism. This dog required long-term parenteral calcium gluconate to prevent clinical hypocalcemia despite appropriate doses of oral calcitriol and calcium carbonate. This is the first description of clinically significant presumptive glucocorticoid induced hypocalcemia in a dog with primary hypoparathyroidism.

ABSTRACT

Canine insulinoma is a highly metastatic neoplasm that is associated with a guarded to poor prognosis in dogs with distant metastases. A median survival of 6 mo has been reported for dogs with metastatic insulinoma. The dog in this report, diagnosed with stage III pancreatic insulinoma, had long-term glycemic control with survival of over 24 mo while receiving prednisone and toceranib phosphate after partial pancreatectomy. Toceranib phosphate has been shown to be an efficacious therapy for canine mast cell tumors with increasing evidence that it may be beneficial in the medical management of neuroendocrine tumors.