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Abstract

Objective—To establish the in vitro efficacy of 4 novel drugs (ie, ganciclovir, cidofovir, penciclovir, and foscarnet) against feline herpesvirus type-1 (FHV-1) and compare their antiviral efficacy with that of acyclovir and idoxuridine.

Sample Population—Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727.

Procedure—For each drug, antiviral effect was estimated by use of conventional plaque-reduction assays, and inhibitory concentration 50 (IC50; drug concentration at which plaque numbers were reduced by 50% relative to the number of plaques for nontreated control wells) was calculated. To determine whether observed antiviral effects were related to alterations in the number or viability of CRFK cells, cytotoxicity assays were performed at 1, 2, and 10 times the median IC50 for each antiviral drug.

Results—Median IC50 for each drug was as follows: ganciclovir, 5.2µM; cidofovir, 11.0µM; penciclovir, 13.9µM; foscarnet, 232.9µM; idoxuridine, 4.3µM; and acyclovir, 57.9µM. Obvious changes in morphologic characteristics, confluence, or viability of CRFK cells were not observed at concentrations up to and including 2 times the IC50 for each drug.

Conclusions and Clinical Relevance—In vitro efficacy of idoxuridine and ganciclovir against FHV-1 was approximately equivalent and about twice that of cidofovir and penciclovir. Foscarnet appeared to be comparatively ineffective. Given the reasonable clinical efficacy of idoxuridine in cats infected with FHV-1, clinical trials of ganciclovir, cidofovir, and penciclovir or their prodrug forms appear to be warranted. (Am J Vet Res 2004;65:399–403)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine relative detection rates and detection limits for 6 published polymerase chain reaction (PCR) assays used for detection of feline herpesvirus type 1 (FHV-1) DNA.

Sample Population—5 vaccines licensed for use in preventing FHV-1–associated disease; 15 conjunctival biopsy specimens collected from cats with keratitis, conjunctivitis, or both; and a plaque-purified field isolate of FHV-1 cultured in vitro.

Procedure—Vaccines and clinical samples were assessed for FHV-1 DNA by use of all 6 assays. Detection rates were calculated by assuming that any sample in which FHV-1 DNA was detected was a true-positive result. Detection limits were estimated by use of serial dilutions of DNA extracted from cultured FHV-1 and 1 clinical sample.

Results—Testing by use of all 6 assays resulted in detection of FHV-1 DNA in all 5 vaccines. Testing by use of all 6 assays yielded concordant results for 9 of 15 conjunctival biopsy specimens (8 with negative results and 1 with a positive result). Calculated detection rates for clinical samples ranged from 29% to 86%. Assay sensitivity was ranked similarly by use of detection rate or detection limit.

Conclusions and Clinical Relevance—Testing by use of all assays was equally likely to detect vaccine virus. Therefore, a positive PCR result in a cat may reflect vaccine virus rather than wild-type virus. Test sensitivity as assessed by detection limits and detection rates varied greatly. Because FHV-1 can be shed in clinically normal animals, high detection rate will not necessarily correlate with high diagnostic sensitivity. (Am J Vet Res 2005;66:1550–1555)

Full access
in American Journal of Veterinary Research

Summary

Medical records from 333 cats with diabetes mellitus were studied retrospectively, using epidemiologic methods to determine the incidence of and risk factors for diabetes mellitus in this species. Abstracts were derived, using the Veterinary Medical Data Program with its 17 participating academic institutions in the United States and Canada. A reference population of 135,651 cats was derived from the same hospital population and time span (july 1980 to June 1986).

The incidence of diabetes mellitus in cats was determined to be 2.45 cases/1,000 cat-years-of-risk during the 6-year study period. Breed had no detectable effect on risk for diabetes mellitus. In contrast, body weight, age, gender, and neutering had a significant (P ≤ 0.01) effect. Body weight of cats was categorized as being < or ≥ 6.8 kg. The higher body weight, probably indicating obesity, contributed a 2.2-fold increase in risk, even after adjustment for age and gender (adjusted odds ratio). The etiologic fraction for high body weight was 3.8%, suggesting that an estimated 3.8% of cases of diabetes mellitus was attributable to this factor alone. Over 50% of diabetic cats were > 10 years old, and the etiologic fraction for age > 7 years alone was 73.5%. Age was a significant (P < 0.001) and the most important single risk factor for development of the disease in cats, with adjusted odds ratios of 8.3 and 14.4 for age 7 to 10 years and > 10 years, respectively. Unlike human beings and dogs, male cats were at 1.5 times greater risk for developing diabetes mellitus than were females, and neutered cats were at nearly twice the risk as sexually intact cats. The adjusted odds-risk ratio for neutered males, sexually intact males, spayed females, and sexually intact females was 2.8, 2.1, 1.9, and 1, respectively.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

The effects of treatment with l-thyroxine (1 mg/m2 of body surface/d, po, for 8 weeks) on the thyroxine (T4) and triiodothyronine (T3) responses to thyrotropin (tsh) and thyrotropin-releasing hormone (trh) administration were determined in 10 euthyroid Beagles; 4 other dogs acted as controls. The tsh response test was performed before treatment and at weeks 2, 4, and 8 of treatment in all dogs and at 2 and 4 weeks after cessation of treatment in 6 dogs. The trh response test was performed before treatment and at week 6 of treatment in all dogs and at 5 weeks after cessation of treatment in 6 dogs.

Suppression of the T3 response to tsh was evident at treatment week 2, whereas the T4 response was suppressed at week 4 and remained suppressed for the duration of the study. Four weeks after l-thyroxine treatment was stopped, T3 response to tsh had returned to pretreatment values. Four weeks after stopping treatment, T4 and T3 responses to tsh in 2 dogs were within the hypothyroid range. The T4 response to trh was completely suppressed after 6 weeks of thyroxine treatment, but returned to pretreatment values by 5 weeks after cessation of treatment. Suppression of thyroid and pituitary function is evident after administration of a replacement dose of l-thyroxine to euthyroid dogs.

Free access
in American Journal of Veterinary Research

SUMMARY

To determine the effects of long-term thyroxine treatment, histomorphometric analysis was performed on the pituitary and thyroid glands of healthy dogs, dogs treated for 9 weeks with a replacement dose of l-thyroxine, and dogs at 6 weeks after cessation of thyroxine treatment. In treated dogs, the volume density of thyrotropes decreased during thyroxine treatment and increased 6 weeks after cessation of treatment, compared with thyrotropes of healthy nontreated dogs. The activity of the thyroid gland was decreased in dogs during thyroxine treatment, as evidenced by decreases in epithelial volume density, epithelial height, and follicular area, and increase in colloid volume density, compared with thyroid gland activity in nontreated dogs. After cessation of thyroxine treatment, the thyroid gland had decreased colloid area, follicular area, and epithelial volume density, and increased interstitial volume density, compared with the thyroid gland of healthy nontreated dogs. Thyroxine treatment resulted in suppression of pituitary thyrotropes and thyroid follicular activity.

Free access
in American Journal of Veterinary Research

Abstract

Objective–To determine detection rates for feline herpesvirus type 1 (FHV-1), Mycoplasma spp, fungi, and bacteria in flush samples and biopsy specimens from the nasal cavities of cats with and without chronic rhinosinusitis (CRS).

Design–Prospective study.

Animals–10 CRS-affected cats and 7 cats without signs of respiratory tract disease.

Procedures–Nasal flush samples and biopsy specimens were collected from all cats for bacterial (aerobic and anaerobic), fungal, and mycoplasmal cultures; additional biopsy specimens were collected for virus isolation and polymerase chain reaction (PCR) assay (to detect FHV-1 DNA).

Results–Aerobic bacteria were detected in flush samples from 5 of 7 control cats; culture of flush samples from CRS-affected cats yielded aerobic bacteria (9/10 cats), anaerobic bacteria (3/10), and Mycoplasma spp (2/10). No fungal organisms were isolated from any cat. Potential pathogens were isolated significantly more often from CRS-affected cats than from control cats. Bacterial culture of biopsy specimens yielded aerobic bacteria (2/7 control cats and 4/10 CRS-affected cats) and anaerobic bacteria (2/10 CRS-affected cats). Although FHV-1 was not detected in nasal biopsy specimens from control or CRS-affected cats, FHV-1 DNA was detected via PCR assay in specimens from 4 of 7 control cats and 3 of 10 CRS-affected cats.

Conclusions and Clinical Relevance–Compared with findings in control cats, anaerobic bacteria, Mycoplasma spp, and a variety of potentially pathogenic organisms were detected more commonly in samples from cats with CRS. In both groups, FHV-1 was detected via PCR assay as a nonviable organism or in noncultivable amounts. (J Am Vet Med Assoc 2005;227:579–585)

Full access
in Journal of the American Veterinary Medical Association

Abstract

This article describes the core competencies recommended for inclusion in the veterinary curriculum for all veterinary graduates based on the American Association of Veterinary Medical Colleges Competency-Based Veterinary Education document. General practice companion animal veterinarians are frequently presented with patients having dental, oral, or maxillofacial pathology, and veterinary graduates will be relied upon for recommendations for the maintenance of oral health, including the prevention of periodontal disease, identification of endodontic disease, and knowledge of developmental defects. These recommendations should be made for all veterinary patients starting at a young age. These core competencies can apply to many companion species, but mainly are focused on the dog and cat.

Because periodontal disease is the most common abnormality observed in dogs and cats, the first key step is taking a few seconds during examination of every patient of any age presented for any reason to examine the oral cavity. Although dental, oral, and maxillofacial pathology is often diagnosed after imaging and evaluation under anesthesia, the first step is observation of dentition and gingivae during the conscious exam to assess periodontal health status. The physical exam of the oral cavity may reveal oral behavior (eg, observation of uncomplicated crown fractures due to chewing on hard objects), which will permit recommendations for enhanced prevention by daily oral hygiene or professional treatment.

There are now many involved dental and surgical treatments available, some of which require specialist-level instrumentation and expertise. General practitioners should be able to competently perform the following immediately upon graduation from veterinary school:

  • For patients for whom the owner’s reason for the veterinary visit is not dental, oral, or maxillofacial disease, obtain a brief (1 or 2 questions) history of the oral health of the patient.

  • On lifting the lip of every patient, recognize presence or absence of accumulated dental plaque or calculus on the crowns of the teeth, presence or absence of gingival inflammation or ulceration, and presence or absence of other dental, oral, and maxillofacial pathology.

  • On anesthetized patients that have dental, oral, and maxillofacial pathology for which professional treatment is indicated, be able to obtain and interpret appropriately positioned and exposed dental radiographs.

  • When the presence of dental, oral, and maxillofacial pathology is recognized, determine whether each tooth present in the mouth does or does not require professional treatment beyond dental subgingival and supragingival scaling and polishing.

  • List the indications for tooth extraction, know indications for potential oral/dental treatments beyond subgingival and supragingival scaling and polishing or extraction, and determine whether the professional treatment that may be indicated, such as root canal treatment or mass resection of oral tissues, requires referral for specialist-level expertise and instrumentation.

  • Complete a thorough periodontal evaluation and therapy with periodontal probing, including professional subgingival and supragingival ultrasonic scaling with polishing under anesthesia.

  • Demonstrate the ability to extract teeth indicated for extraction, using gentle and appropriate techniques that will risk minimal injury to the jaws and oral soft tissues and reduce postoperative patient pain.

  • Provide appropriate postoperative care, including recognition of when postoperative analgesia and possibly antibiotic administration are indicated.

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