Clinical Salmonellosis in a Closed Colony of Blood Donor Cats.

An adult feline blood donor, group-housed in a closed colony with other blood donor cats in a laboratory animal facility, developed anorexia, abdominal pain, an abdominal mass effect, and hemorrhagic diarrhea. Ultimately Salmonella infection was diagnosed. The index cat and 2 additional cats in the closed colony had clinical signs consistent with Salmonella and yielded Salmonella serotype 4,12:i:- in fecal cultures. An extensive search for the source of Salmonella was unrewarding. With the implementation of individual housing and additional barrier precautions, combined with antibiotic treatment of the index case, all the cats survived and subsequently had multiple, negative Salmonella PCR test results. This case report highlights the potential for unlikely infections to occur, even in a closed colony of research animals, as well as the important role of sanitation in the elimination of this enteric pathogen.

Assessment of Blood Collection from the Lateral Saphenous Vein for Microfilaria Counts in Mongolian Gerbils (Meriones unguiculatus) Infected with Brugia pahangi.

The NIH guidelines for survival bleeding of mice and rats note that using the retroorbital plexus has a greater potential for complications than do other methods of blood collection and that this procedure should be performed on anesthetized animals. Lateral saphenous vein puncture has a low potential for complications and can be performed without anesthesia. Mongolian gerbils (Meriones unguiculatus) are the preferred rodent model for filarial parasite research. To monitor microfilaria counts in the blood, blood sampling from the orbital plexus has been the standard. Our goal was to refine the blood collection technique. To determine whether blood collection from the lateral saphenous vein was a feasible alternative to retroorbital sampling, we compared microfilaria counts in blood samples collected by both methods from 21 gerbils infected with the filarial parasitic worm Brugia pahangi. Lateral saphenous vein counts were equivalent to retroorbital counts at relatively high counts (greater than 50 microfilariae per 20 µL) but were significantly lower than retroorbital counts when microfilarial concentrations were lower. Our results indicate that although retroorbital collection may be preferable when low concentrations of microfilariae need to be enumerated, the lateral saphenous vein is a suitable alternative site for blood sampling to determine microfilaremia and is a feasible refinement that can benefit the wellbeing of gerbils.

Differential Host Immune Responses after Infection with Wild-Type or Lab-Attenuated Rabies Viruses in Dogs.

METHODOLOGY/PRINCIPAL FINDINGS: The experimental infection of dogs with TriGAS induced high levels of VNA in the serum, whereas wt RABV infection did not. Dogs infected with TriGAS developed antibodies against the virus including its glycoprotein, whereas dogs infected with DRV-NG11 only developed rabies antibodies that are presumably specific for the nucleoprotein, (N) and not the glycoprotein (G). We show that infection with TriGAS induces early activation of B cells in the draining lymph nodes and persistent activation of DCs and B cells in the blood. On the other hand, infection with DRV-NG11 fails to induce the activation of DCs and B cells and further reduces CD4 T cell production. Further, we show that intrathecal (IT) immunization of TriGAS not only induced high levels of VNA in the serum but also in the CSF while intramuscular (IM) immunization of TriGAS induced VNA only in the serum. In addition, high levels of total protein and WBC were detected in the CSF of IT immunized dogs, indicating the transient enhancement of blood-brain barrier (BBB) permeability, which is relevant to the passage of immune effectors from periphery into the CNS. CONCLUSIONS/SIGNIFICANCE: IM infection of dogs with TriGAS induced the production of serum VNA whereas, IT immunization of TriGAS in dogs induces high levels of VNA in the periphery as well as in the CSF and transiently enhances BBB permeability. In contrast, infection with wt DRV-NG11 resulted in the production of RABV-reactive antibodies but VNA and antibodies specific for G were absent. As a consequence, all of the dogs infected with wt DRV-NG11 succumbed to rabies. Thus the failure to activate protective immunity is one of the important features of RABV pathogenesis in dogs.

Unassisted blood collection from unanesthetized rats and gerbils.

Blood collection is a common procedure in animal research. This column describes humane methods of collecting blood from the rat and the gerbil that can be carried out by a single person on an awake animal.

Comparison of three clinical techniques for the diagnosis of laryngeal paralysis in dogs.

OBJECTIVES: To evaluate laryngeal function using 3 diagnostic techniques: echolaryngography (EL), transnasal laryngoscopy (TNL), and laryngoscopy per os (LPO). STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs with laryngeal paralysis (n=5) and control dogs (n=10); 5 age- and breed-matched dogs and 5 young, breed-matched dogs. METHODS: Laryngeal function was evaluated in conscious dogs using EL. All examinations were recorded and evaluated by separate, blinded observers upon completion of the study. The methods were compared with a standard evaluation incorporating all clinical knowledge of the case (STD) using sensitivity, specificity, positive, and negative predictive values. RESULTS: Three dogs with bilateral laryngeal paralysis requiring surgery were diagnosed as unilaterally affected or normal on EL. Three dogs had paradoxic motion on TNL and LPO, 2 of those were considered normal on EL, and 1 had no motion on EL. Paralysis was diagnosed in 1 age-matched and 3 young control dogs on EL. LPO and TNL falsely diagnosed lack of arytenoid movement in 2 age-matched controls and 1 young control. Two age-matched and 1 young control dog were misdiagnosed as paralyzed with TNL and LPO. DISCUSSION: Direct observation of the larynx allowed better evaluation of laryngeal function compared with EL. TNL did not require induction of anesthesia, but did not improve the ability to assess laryngeal function compared with LPO. CONCLUSIONS: EL was not as effective as direct observation of the larynx. TNL did not improve the evaluation of laryngeal function compared with LPO. CLINICAL RELEVANCE: We use LPO combined with knowledge of the clinical history and physical examination to diagnose laryngeal paralysis in preference to EL and TNL.

Comparison between CO2 laser and 4.0 MHz radiosurgery for incising skin in white Carneau pigeons (Columba livia).

To objectively evaluate the collateral damage associated with radiosurgical and carbon dioxide (CO2) laser devices, a comparative surgical and histologic study was undertaken in white Carneau pigeons (Columba livia). Ten pigeons were anesthetized, and a series of 3 skin incisions were made in the pectoral region by using a 4.0-MHz radiosurgical unit, a CO2 laser, and a scalpel blade (control). A total of 90 skin incisions were microscopically evaluated, and their associated mechanical- and thermal-induced tissue lesions were measured in micrometers. Scalpel incisions invariably resulted in hemorrhage, whereas all laser and radiosurgical skin incisions were essentially bloodless. Scalpel blade incisions were least traumatic (mean [SD] 18 +/- 15 microm) followed by incisions created with radiosurgery (mean [SD] 94 +/- 60 microm) and CO2 laser (mean [SD] 150 +/- 64 microm). Radiosurgery was significantly less traumatic than CO2 laser (P = .003). Radiosurgery appears to offer significant benefits over CO2 laser for avian surgery.

Evaluation of transcutaneous pulmonoscopy for examination and biopsy of the lungs of ball pythons and determination of preferred biopsy specimen handling and fixation procedures.

OBJECTIVE: To establish a safe and effective technique for the endoscopic examination and biopsy of snake lungs by use of a 2.7-mm rigid endoscope system. DESIGN: Clinical trial. ANIMALS: 17 adult ball pythons (Python regius). PROCEDURES: The right lung of each anesthetized snake was transcutaneously penetrated at a predetermined site. Endoscopic lung examination was objectively scored, and 3 lung biopsies were performed. Tissue samples were evaluated histologically for diagnostic quality. One year later, 11 of the 17 snakes again underwent pulmonoscopy and biopsy; specimens were placed in various fixatives to compare preservation quality. All 17 snakes were euthanatized and necropsied. RESULTS: No major anesthetic, surgical, or biopsy-associated complications were detected in any snake. In 16 of 17 pythons, ease of right lung entry was satisfactory to excellent, and views of the distal portion of the trachea; primary bronchus; intrapulmonary bronchus; cranial lung lobe; and faveolar, semisaccular, and saccular lung regions were considered excellent. In 1 snake, mild hemorrhage caused minor procedural difficulties. After 1 year, pulmonoscopy revealed healing of the previous transcutaneous lung entry and biopsy sites. Important procedure-induced abnormalities were not detected at necropsy. Diagnostic quality of specimens that were shaken from biopsy forceps into physiologic saline (0.9% NaCl) solution before fixation in 2% glutaraldehyde or neutral-buffered 10% formalin was considered good to excellent. CONCLUSIONS AND CLINICAL RELEVANCE: By use of a 2.7-mm rigid endoscope, lung examination and biopsy can be performed safely, swiftly, and with ease in ball pythons. Biopsy specimens obtained during this procedure are suitable for histologic examination.

Endoscopic orchidectomy and salpingohysterectomy of pigeons (Columba livia): an avian model for minimally invasive endosurgery.

To evaluate a minimally invasive endosurgical system in birds, endoscopic orchidectomy and salpingohysterectomy were evaluated in 11 male and 14 female pigeons (Columba livia). Anesthesia was maintained by using isoflurane delivered by a pressure-cycle ventilator and produced good to excellent anesthesia during 96% of procedures. Endosurgery was performed with a 2.7-mm telescope system, 3-mm human pediatric laparoscopy instruments, and a 4.0-MHz radiofrequency device. Mean +/- SD surgery times for bilateral orchidectomy and salpingohysterectomy procedures were 39 +/- 18 minutes and 34 +/- 15 minutes, respectively. Procedures were generally straightforward, with any minor complications easily overcome. Surgical complications were generally minor, with mild hemorrhage and focal coagulative damage to the kidney being most common. All pigeons recovered quickly (20 +/- 11 minutes), with 95% displaying good to excellent recoveries. No birds exhibited any clinically apparent morbidity or mortality associated with endosurgery. At least 1 male and 1 female bird were subjected to elective euthanasia and necropsy on postoperative days 1, 3, 5, 10, 20, and 90 to determine the success and side effects of surgery. Gross and histologic abnormalities, when observed, were generally mild, with hemorrhage and partial necrosis of the cranial kidney present in 27% of males. Mild damage or hematoma associated with the left kidney was also reported in 28% of females. The surgical objectives were achieved in 23 of 25 pigeons. The 2 surgical failures (regenerated testes in a male and large oviductal remnant in a female) were attributed to endosurgical inexperience and occurred during the first procedures. Salpingohysterectomy does not appear to prevent ovarian development and ovulation in the pigeon, at least not during the first 3 postoperative months. Orchidectomy and salpingohysterectomy appear to be safe procedures when performed using appropriate equipment and techniques. Endosurgery offers a valuable, minimally invasive alternative to the standard coeliotomy techniques commonly used in birds.

Effects of topical 2% dorzolamide hydrochloride alone and in combination with 0.5% timolol maleate on intraocular pressure in normal feline eyes.

OBJECTIVE: To evaluate the effect of topical 2% dorzolamide alone, and in combination with topical 0.5% timolol, on intraocular pressure (IOP) in normal cats. ANIMALS: Twenty-four healthy Domestic Short-haired cats. PROCEDURE: Baseline values of IOP were established at 7 am, 10 am, 1 pm, 5 pm and 9 pm during pretreatment phase (days 1-2). During treatment phase (days 3-10) cats received 2% dorzolamide HCl q 12 h in group A (n = 6), q 8 h in group B (n = 6), and combined with 0.5% timolol maleate q 12 h in group C (n = 6). Cats in control group D (n = 6) received artificial tears q 8 h. During treatment phase IOP measurements were continued at the same time-points as in the pretreatment phase. RESULTS: Mean pretreatment IOP in all cats was 18.46 +/- 2.99 mmHg. Mean IOP decreased significantly (P < 0.0086) in all treatment groups compared to pretreatment values (group A: 16.40 +/- 0.49 mmHg, group B: 16.04 +/- 0.49 mmHg, group C: 17.76 +/- 0.49 mmHg). IOP did not decrease in control group D (18.55 +/- 0.49 mmHg). The difference in IOP between treatment groups (A, B, C) was not statistically significant, but comparison of IOP between each treatment group and the control group was statistically significant (A-D; P = 0.0057; B-D, P = 0.0012; C-D, P = 0.0212). CONCLUSION: Topical 2% dorzolamide significantly lowers IOP in normal cats but the effect is mild. Concomitant application of 2% dorzolamide and 0.5% timolol does significantly decrease IOP, but the effect is not significantly greater than q 8 h administration of dorzolamide alone.

Evaluation of the effects of inhibition of angiotensin converting enzyme with enalapril in dogs with induced chronic renal insufficiency.

OBJECTIVE: To determine whether the angiotensin converting enzyme inhibitor enalapril would lower systemic arterial and glomerular capillary pressure and reduce the magnitude of renal injury in a canine model of renal insufficiency. ANIMALS: 18 adult dogs that had renal mass reduced by partial nephrectomy. PROCEDURE: After surgical reduction of renal mass and baseline measurements, dogs in 2 equal groups received either placebo (group 1) or enalapril (0.5 mg/kg, PO, q 12 h; group 2) for 6 months. RESULTS: Values for systemic mean arterial blood pressure determined by indirect and direct measurement after 3 and 6 months of treatment, respectively, were significantly lower in group 2 than in group 1. During treatment, monthly urine protein-to-creatinine ratios were consistently lower in group 2 than in group 1, although values were significantly different only at 3 months. At 6 months, significant reduction in glomerular capillary pressure in group 2 was detected, compared with group 1, but glomerular filtration rate in group 2 was not compromised. Glomerular hypertrophy, assessed by measurement of planar surface area of glomeruli, was similar in both groups. Glomerular and tubulointerstitial lesions were significantly less in group 2, compared with group 1. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that inhibition of angiotensin converting enzyme was effective in modulating progressive renal injury, which was associated with reduction of glomerular and systemic hypertension and proteinuria but not glomerular hypertrophy. Inhibition of angiotensin converting enzyme may be effective for modulating progression of renal disease in dogs.