Transseptal puncture in the dog utilizing three-dimensional transesophageal echocardiographic guidance.

Transseptal puncture is necessary to access the left atrium and mitral valve from a transvenous approach but is poorly described in veterinary medicine. The procedure is generally regarded as difficult and dangerous, particularly given the size of most small animal patients. Precise imaging is paramount to the procedure to ensure that puncture occurs within the desired location and to monitor for potential complications. Transesophageal echocardiography, including biplanar two-dimensional and particularly three-dimensional modalities, has great potential to improve the success and safety of transseptal puncture due to superior visualization of the fossa ovalis and other intracardiac structures. Here, we describe the use of transesophageal echocardiography to guide transseptal puncture based on our experience in 159 dogs, with an emphasis on three-dimensional echocardiography. We also detail how to perform transseptal puncture from a jugular approach, which we consider preferable in most patients. Complications from transseptal puncture are discussed, along with ways to limit those complications.

A case of a dog with mandibular extraskeletal osteosarcoma after long-term puncture extirpation of the salivary gland cyst in the mandible.

Background: Extraskeletal osteosarcoma, unlike skeletal osteosarcoma, is a rare malignant mesenchymal tumor with a soft tissue primary that has been reported to occur in a variety of soft tissues. Case Description: The case is a 14-year-old, unneutered male Miniature Pinscher, weighing 6.7 kg, who had been treated medically for more than 5 years with a management strategy of puncture extirpation of a salivary gland cyst in the mandible; 1 month earlier, the fluid retention could not be removed, and after a computerized tomography scan showed no lesion in the mandible adjacent to the mass lesion, surgical resection was performed. Conclusion: Previous reports of extraskeletal osteosarcoma from the salivary glands in dogs have been rare. However, treatment of a salivary gland cyst in the mandible by long-term puncture extirpation may be a potential predisposing factor for the development of extraskeletal osteosarcoma around the mandible.

Feasibility and safety of three-dimensional electroanatomical cardiac mapping, mapping-guided biopsy and transseptal puncture in dogs.

Three-dimensional electroanatomical mapping (3D EAM) has expanded radiofrequency catheter ablation applications in humans to almost all complex arrhythmias and has drastically reduced fluoroscopy use, yet its potential in dogs is poorly investigated. The objectives of the current study were to assess the feasibility and safety of 3D EAM of all four heart chambers, 3D EAM-guided biopsies and transseptal puncture in dogs. Eight healthy purpose-bred Beagle dogs. Electroanatomical mapping was performed under general anaesthesia during sinus rhythm using a 22-electrode mapping catheter. Left heart catheterisation was achieved by either retrograde transaortic access (n = 4) or transseptal puncture (n = 4). Successful 3D EAM of the right atrium and ventricle was achieved in all dogs at a median time of 33 (13-40) min and 17 (3-52) min, respectively. Left atrial and ventricular 3D EAM was successful in six and seven dogs, at a median time of 17 (4-27) min and 8 min (4-19 min), respectively. Complications requiring intervention occurred in one dog only and were a transient third degree atrioventricular block and pericardial effusion following transseptal puncture, which was treated by pericardiocentesis. All dogs recovered uneventfully. Fluoroscopy time was limited to a median of 7 min (0-45 min) and almost exclusively associated with transseptal puncture. Three-dimensional EAM of all cardiac chambers, including mapping-guided biopsy and transseptal puncture is feasible in small dogs. Complications are similar to those reported in human patients. This suggests a potential added value of 3D EAM to conventional electrophysiology in dogs with arrhythmias.

Incidence of dural sac puncture during neuraxial anesthesia in cats: an observational, retrospective study.

OBJECTIVES: The aim of this study was to determine the occurrence of dural puncture, indicated by cerebrospinal fluid (CSF) outflow, in cats receiving neuraxial anesthesia through a lumbosacral injection guided by a pop sensation method. METHODS: This was an observational, retrospective study. Cats that were scheduled for lumbosacral neuraxial anesthesia were included. Medical records were analyzed to investigate: (1) demographic data; (2) neuraxial anesthesia performed (epidural/spinal); (3) type of needle used, including gauge and length; (4) presence of CSF (yes/no) and/or blood (yes/no) in the hub of the needle; and (5) flicking of the tail during needle advancement (yes/no). RESULTS: A total of 94 medical records were analyzed. A 22 G 50 mm Tuohy needle was used in all cats scheduled for an epidural injection (n = 60), whereas a 22 G 40 mm Quincke needle was used in all cats scheduled for an intrathecal injection (n = 34). CSF outflow was detected in 55/60 (91.7%) cats in which a Tuohy needle was used, and 34/34 (100%) of the cats in which a Quincke needle was used (P = 0.15). Flicking of the tail was detected in 41/60 (68.3%) and in 24/34 (70.6%) injections with Tuohy and Quincke needles, respectively (P >0.99). Traces of blood, but not active blood outflow, were detected via staining of the first drops of CSF in 2/34 cats in which Quincke needles were used and in none of the cats in which Tuohy needles were used (P = 0.12). CONCLUSIONS AND RELEVANCE: This study shows that the lumbosacral approach for neuraxial anesthesia in cats may result in a dural sac puncture when 22 G Quincke or Tuohy needles are used. The pop sensation method should be deemed effective in predicting intrathecal but not epidural needle placement.

Dural sac localization using myelography and its application to the lumbosacral epidural in dogs.

Background: The techniques described for the identification of the lumbosacral (LS) epidural space in dogs do not guarantee the needle position or an accidental subarachnoid puncture, especially in small size dogs. Aim: To determine the relationship between body weight and the location of the dural sac (DS) using myelography in dogs, and to determine the possibility of subarachnoid puncture during LS epidural based on the position of the DS. Methods: Four masked observers evaluated 70 myelographic studies of dogs, annotating the vertebrae where the DS ended, if it was localized before or after the LS space, and if accidental subarachnoid puncture during LS epidural injection was possible (yes/no). Body weight (kg) was categorized into: less than 10 kg, between 10 and 20 kg, and more than 20 kg and was also converted to body surface area (BSA) as a continuous variable. Results: The DS ended at the LS space or caudally in 50% of dogs. There was a statistically significant difference between the position of the DS and the dog's BSA (p = 0.001). The DS ended caudal to the LS space in 72.7% of dogs weighing <10 kg, in 25% of dogs between 10 and 20 kg and in 15% of dogs in the >20 kg category. The observers considered a possible subarachnoid puncture during LS epidural in 69.7% of patients <10 kg, 16.6% on those between 10 and 20 kg, and in 11.7% of the dogs >20 kg. Conclusion: The DS ended caudal to the LS space in almost 3/4 dogs in the <10 kg category, so accidental subarachnoid puncture during LS epidural is highly possible in this weight range.

Puncture of the Equine Embryonic Capsule and Its Repair In Vivo and In Vitro.

Vitrification of embryos >300 µm in diameter requires puncture of the glycoprotein capsule, although the size of the hole compatible with embryo survival is unknown. Forty-five day-7 or -8 embryos were punctured using a 30-µm glass biopsy pipette mounted on a micromanipulator (n = 20) or manually with either an acupuncture needle (∼100-µm diameter -hole; n = 10) or a microneedle with a <1 µm tip to produce a ∼30-µm diameter hole (n = 15) before transferring to recipient mares; further 12 embryos were punctured with either the acupuncture needle or microneedle before being cultured in vitro for 48 hrs (n = 3 per puncture group) or transferred to recipient mares and recovered 48 hrs later (n = 3 per puncture group). No pregnancies resulted from the 10 embryos punctured with the acupuncture needle, whereas 15 of 20 (75%) and 10 of 15 (67%) punctured on the micromanipulator or manually with the microneedle resulted pregnancies. Neither acupunctured nor microneedle-punctured embryos repaired their capsules in vitro. The acupunctured embryos also failed to repair their capsule after 48 hrs in vivo and subsequent uterine flushing yielded numerous capsular vesicles. The microneedle-punctured embryos did repair their capsule in vivo. Puncture with the microneedle opens the way for development of a manual method to vitrify equine embryos.

The effect of prior thecal puncture on cerebrospinal fluid analytes in normal adult horses.

BACKGROUND: Serial cerebrospinal fluid (CSF) analysis might be required in clinical neurologic disease. The effect of lumbosacral (LS) or cervical (C1-C2) centesis on subsequent CSF cytologic analyses has not been investigated in horses. OBJECTIVE: To evaluate the effect of thecal puncture on subsequent CSF analyses ANIMALS: Ten healthy adult horses. METHODS: Prospective study. Horses were randomly assigned to undergo CSF collection twice, 14 days apart, from either the C1-C2 or LS space. After a 4-month washout period, CSF collection was repeated from the alternate site. Continuous data were analyzed using linear mixed-effects models and count data using mixed-effects negative binomial regression. Statistical significance was set at P < .05. RESULTS: There was no significant effect of collection day (day 0 or day 14) for any CSF analytes, including protein concentration (C1-C2: 45 [95% CI: 33-57] mg/dL day 0 vs 49 [95% CI: 39-62] mg/dL day 14, P = .12; LS: 64 [95% CI: 41-100] mg/dL day 0 vs 83 [95% CI: 53-129] mg/dL day 14, P = .37), or nucleated cell count (C1-C2: 2 [95% CI: 1-4] cells/µL day 0 vs 3 [95% CI: 1-4] cells/µL day 14, P = .65; LS: 3 [95% CI: 2-5] cells/µL day 0 vs 5 [95% CI: 3-8] cells/µL day 14, P = .10). There was no significant difference in EPM titer or EPM serum : CSF ratio between days 0 and 14. CONCLUSIONS AND CLINICAL IMPORTANCE: Repeat thecal puncture from the LS or C1-C2 space 2 weeks apart does not appear to impact CSF analytes.

Development and Validation of a Feline Medial Saphenous Venipuncture Model and Rubric.

Cats are extremely popular pets with the reputation of being uncooperative for even common procedures, such as venipuncture. In this study, we sought to create and validate a cat medial saphenous venipuncture model and rubric for use in veterinary training. The validation framework consisted of content evidence, internal structure evidence, and relationship with other variables. Eleven veterinarians and veterinary technicians who were experienced with the procedure evaluated the model by means of a survey. These experienced participants, along with 25 veterinary students who were novices at the skill, performed venipuncture on the model while being digitally recorded. One hundred percent of the experienced participants and 88% of the novices reported that the model was helpful for teaching feline medial saphenous venipuncture. They identified a few areas for continued improvement, including increasing the blood flow rate and decreasing the vessel wall rigidity. Experienced users' rubric scores were significantly higher than novice students' (experienced, M = 13.4; novice M = 16.5; p = .05), suggesting that the model's features were adequate to differentiate the performances of various users. Internal consistency of the eight-item rubric was acceptable at .74. These results supported validation of the cat medial saphenous model and rubric for use in veterinary education.

Effects of follicular ablation and induced luteolysis on LH and follicular fluid factors during the periovulatory period in mares.

Haemorrhagic anovulatory follicles (HAFs) are the most common pathological anovulatory condition in the mare. To enhance understanding of the physiopathology of HAFs, the aim of the present study was to determine the effects of an induced-follicular wave on LH concentrations and follicular fluid factors relevant to the ovulatory process. Mares were allocated to treatment or control groups (n = 7/group) in a crossed over design during 14 oestrous cycles with a period of one cycle occurring when there were no treatments between the times when treatments were administered. In the treatment group, all antral follicles ≥8 mm were ablated on Day 10 after ovulation followed by administration of a luteolytic dose of PGF2α. All mares of both groups were treated with 1500 IU of hCG when a follicle ≥32 mm was detected (Hour 0), and follicular fluid was aspirated 35 h later. Blood samples were collected every 48 h from Day 10 until Hour 0 from all mares. Follicular fluid was assayed for PGE2, estradiol and progesterone. Plasma was assayed for LH concentrations. A follicular wave followed follicle ablation in the treated mares. Concentrations of LH were greater (P = 0.05) in mares ot the treatment compared with control group. Concentrations of PGE2, estradiol and progesterone in follicular fluid did not differ between groups (P > 0.05). Treatment resulted in an earlier increase in circulating LH, however, there was no effect on concentrations of intra-follicular PGE2, estradiol or progesterone in hCG-stimulated preovulatory follicles.

Percutaneous posterolateral approach for the simulation of a far-lateral disc herniation in an ovine model.

PURPOSE: This work describes a minimally invasive damage model for ovine lumbar discs via partial nucleotomy using a posterolateral approach. METHODS: Two cadavers were dissected to analyze the percutaneous corridor. Subsequently, 28 ovine had their annulus fibrosus punctured via awl penetration under fluoroscopic control and nucleus pulposus tissue removed via rongeur. Efficacy was assessed by animal morbidity, ease of access to T12-S1 disc spaces, and production of a mechanical injury as verified by discography, radiography, and histology. RESULTS: T12-S1 were accessible with minimal nerve damage morbidity. Scar tissue sealed the disc puncture site in all animals within 6 weeks, withstanding 1 MP of intradiscal pressure. Partial nucleotomy led to a significant reduction in intervertebral disk height and an increased histological degeneration score. CONCLUSION: Inducing a reproducible injury pattern of disc degeneration required minimal time, effort, and equipment. The posterolateral approach allows operation on several discs within a single surgery and multiple animal surgeries within a single day.

Short communication: Repeatability of ß-hydroxybutyrate measurements in capillary blood obtained from the external vulvar skin.

The primary objective of this study was to evaluate the repeatability of measurements of ß-hydroxybutyrate (BHB) concentrations in capillary blood obtained from minimal-invasive puncturing of different sites at the external vulva skin of dairy cows. A total of 240 multiparous cows sampled once within 21 d in milk were enrolled in the study. Capillary blood samples were obtained from the right and left labium of the external vulva skin and additionally from a site close to the first puncture. Samples were analyzed by using an electronic hand-held device [FreeStyle Precison Neo (FSP-Neo), Abbott GmbH & Co., Wiesbaden, Germany)]. Additionally, samples from a coccygeal vessel were analyzed as reference in a laboratory. Mean deviations (± standard deviation) between the 3 capillary sampling sites ranged from 0.01 ± 0.14 (left vs. right labium) to 0.02 ± 0.13 mmol/L (left or right labium vs. additional site). The BHB concentrations in capillary blood compared with the reference showed a mean deviation of 0.14 ± 0.18 mmol/L. The Spearman correlation coefficient between BHB concentrations in capillary blood and coccygeal blood was 85.4%. Mixed model analyses showed no significant effect of sampling site or squeezing the skin during sampling procedures on the differences toward the reference. Based on laboratory BHB concentrations of ≥1.2 and ≥1.4 mmol/L, respectively, the prevalence of hyperketonemia was 10.4 (n = 25) and 5.0% (n = 12). Thresholds to detect hyperketonemia with the FSP-Neo were optimized by receiver operating characteristic analyses. Based on a laboratory BHB concentration of ≥1.2 mmol/L thresholds were determined as 1.1 (left labium, 2nd puncture) and 1.0 mmol/L (right labium), with sensitivities between 94 and 99% and specificities between 89 and 97%. Based on a serum BHB concentration of 1.4 mmol/L, receiver operating characteristic analyses resulted in optimized cutoffs of 1.4 mmol/L for all sampling sites at the vulva, with sensitivities of 100% and specificities between 96 and 99%. In conclusion, vulvar capillary blood is suitable for accurate measuring of BHB concentrations by using the FSP-Neo. After adjusting the thresholds, the FSP-Neo provides very good test characteristics independent of the capillary sampling site or squeezing the skin and allows a practical and reliable screening tool for dairy cows.

Influence of transvaginal ultrasound-guided follicular punctures in the mare on heart rate, respiratory rate, facial expression changes, and salivary cortisol as pain scoring.

Transvaginal ultrasound-guided follicular punctures are widely used in the mare for diagnosis, research, and commercial applications. The objective of our study was to determine their influence on pain, stress, and well-being in the mare, by evaluating heart rate, breath rate, facial expression changes, and salivary cortisol before, during, and after puncture. For this experiment, 21 pony mares were used. Transvaginal ultrasound-guided aspirations were performed on 11 mares. After injections for sedation, analgesia, and antispasmodia, the follicles from both ovaries were aspirated with a needle introduced through the vagina wall into the ovary. In the control group, 10 mares underwent similar treatments and injections, but no follicular aspiration. Along the session, heart rate and breath rate were evaluated by a trained veterinarian, ears position, eyelid closure, and contraction of facial muscles were evaluated, and salivary samples were taken for evaluation of cortisol concentration. A significant relaxation was observed after sedative injection in the punctured and control mares, according to ear position, eyelid closure, and contraction of facial muscles, but no difference between punctured and control animals was recorded. No significant modification of salivary cortisol concentration during puncture and no difference between punctured and control mares at any time were observed. No significant modification of the breath rate was observed along the procedure for the punctured and the control mares. Heart rate increased significantly but transiently when the needle was introduced in the ovary and was significantly higher at that time for the punctured mares than that for control mares. None of the other investigated parameters were affected at that time, suggesting discomfort is minimal and transient. Improving analgesia, e.g., through a multimodal approach, during that possibly more sensitive step could be recommended. The evaluation of facial expression changes and heart rate is easy-to-use and accurate tools to evaluate pain and well-being of the mare.

Clinical Practice of Epidural Puncture in Dogs and Cats Assisted by a Commercial Acoustic Puncture Assist Device-Epidural Locator: Preliminary Results.

The objective of this study was to compare an Acoustic Puncture Assist Device-Epidural Locator (APAD-EL) with the "pop sensation" (POP) and "lack of resistance" (LOR) commonly used to confirm penetration of the ligamentum flavum and to ensure correct epidural placement in dogs and cats. We recruited 38 dogs and cats undergoing surgery and receiving epidural analgesia. Two anesthetists performed epidural puncture using the POP and LOR signs. Simultaneously, APAD-EL was used to collect visual and acoustic confirmation during advancement and placement of the needle tip for post hoc evaluation. A positive APAD-EL sign consists of a sudden pressure drop at the needle tip visible on a display and a concomitant pitch change of an acoustic signal. Failure to record a sudden pressure drop is considered a negative APAD sign. Descriptive statistics were used. In 32 patients with positive POP and LOR, the APAD was also positive. In one patient, POP was positive with a negative LOR and APAD result. Five patients had negative POP but positive LOR. Four patients had APAD positive and one (a dog) APAD negative. The study results showed that the APAD-EL information supports the subjective signs of correct needle placement suggested by positive POP and LOR experienced by trained anesthetists. The technique can be useful to assist difficult epidural puncture and as a training and teaching tool.

Description and evaluation of four ultrasound-guided approaches to aid spinal canal puncture in dogs.

OBJECTIVE: To describe four ultrasound-guided approaches to the lumbar and thoracic spine to aid spinal canal puncture in the dog and to evaluate the feasibility of the technique. STUDY DESIGN: Prospective experimental study. ANIMAL POPULATION: Two canine cadavers. METHODS: In the first part of the study, the ultrasonographic appearance of the interlaminar space in the lumbosacral, lumbar and thoracic regions was described. In the second part of the study, four operators attempted a real-time, ultrasound-guided approach to the vertebral canal. Each operator performed the technique 20 times in total: five times at the lumbosacral junction, five in the thoracic region, five in the lumbar region with an in-plane approach, and five in the lumbar region with an out-of-plane approach. Computed tomography (CT) was used to confirm the position of the needle. The procedure was considered successful when the tip of the needle was observed within the vertebral canal. The success rate was calculated for each approach and operator. Fisher's exact test was used to compare differences between approaches and operators. RESULTS: In all cases, visualization of a ventral, parallel and straight hyperechoic line (floor of the vertebral canal) was considered a necessary prerequisite for successful positioning of the needle within the vertebral canal. A straight hyperechoic line (ligamentum flavum or dura mater) closer to the ultrasound probe was visualized in both the median lumbosacral approach and the transverse lumbar approach. The success rate overall was 81%; for the lumbosacral approach, 100%; for the thoracic approach, 80%; for the in-plane lumbar approach 95%; and for the out-of-plane lumbar approach, 45%. These differences were statistically significant (p < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: The sonographic description of these approaches was considered adequate for performing spinal canal puncture. In-plane techniques achieved a higher success rate than out-of-plane ones. Further studies are needed to evaluate them in a clinical setting.

Chitosan hemostatic dressing for control of hemorrhage from femoral arterial puncture site in dogs.

Removal of an introducer-sheath from a femoral artery after completing transarterial embolization of a patent ductus arteriosus can cause life-threatening hemorrhage in dogs. In the present study, the effectiveness of chitosan acetate dressing in 10 experimental dogs was tested. Under general anesthesia, an introducer-sheath was placed into the femoral artery with percutaneous puncture using Seldinger's technique. The outer diameter of the introducer-sheaths varied from 3.0 to 4.0 mm with an introducer/artery ratio of 80 to 123%. The artery's diameter was measured using ultrasonography. Following removal of the introducer-sheath, a chitosan acetate dressing was applied to the wound and held in place with manual compression for 10 min. Successful hemostasis was reached on 12 arteries. However, on two arteries, hemorrhage was uncontrollable and led to a hypovolemic shock during 10 min of manual compression. Possible causes of the negative outcome in two dogs were their old age and an introducer-sheath with a too large diameter. The chitosan acetate dressing was easy to use and the artery remained patent. Dogs could walk directly after recovery from anesthesia and their femoral arteries were saved. In conclusion, the outer diameter of the introducer-sheath should not exceed 3 mm or the inner diameter of the artery.

Ultrasonographic percutaneous anatomy of the atlanto-occipital region and indirect ultrasound-guided cisternal puncture in the dog and the cat.

Cisternal puncture in dogs and cats is commonly carried out. This article describes the percutaneous ultrasound anatomy of the cisternal region in the dog and the cat and an indirect technique for ultrasound-guided cisternal puncture. Ultrasound images obtained ex vivo and in vivo were compared with anatomic sections and used to identify the landmarks for ultrasound-guided cisternal puncture. The ultrasound-guided procedure was established in cadavers and then applied in vivo in seven dogs and two cats. The anatomic landmarks for the ultrasound-guided puncture are the cisterna magna, the spinal cord, the two occipital condyles on transverse images, the external occipital crest and the dorsal arch of the first cervical vertebra on longitudinal images. Using these ultrasound anatomic landmarks, an indirect ultrasound-guided technique for cisternal puncture is applicable in the dog and the cat.

Evaluation of transabdominal ultrasound as a tool for predicting the success of abdominocentesis in horses.

The aim of this study was to evaluate the transabdominal ultrasonography as a tool for predicting the success of abdominocentesis in horses. Patients were included in the study if a complete transabdominal ultrasonography examination and abdominocentesis were performed as part of the clinical work-up. Ultrasonographically, the amount of peritoneal fluid was assessed using a 4-point grading system, as well as the amount of peritoneal fluid collected. A χ(2) or Fischer exact test was performed to test for an association between the ultrasonography findings and fluid retrieved, and between the two grading scales. Interobserver and intraobserver agreement values were calculated using k statistics. Values of P<0.05 were considered significant; 109 horses met the inclusion criteria. Peritoneal fluid was identified ultrasonographically in 72 per cent of horses, and it was collected from 93 per cent of these cases. In horses with no peritoneal fluid identified at ultrasonography (28 per cent), fluid was collected in 70 per cent of cases. There is a significant association between transabdominal ultrasonography detection of peritoneal fluid and the likelihood to obtain a diagnostic amount of peritoneal fluid at abdominocentesis; however, even when peritoneal fluid is not detected during abdominal ultrasonography examination, an amount of peritoneal fluid useful for gross, clinicopathological and cytological evaluation can frequently be obtained.

Influence of tail versus cardiac sampling on blood glucose and lipid profiles in mice.

Blood is collected during animal experimentation to measure haematological and metabolic parameters. It cannot be assumed that circulating blood has the same composition irrespective of its location, and indeed, differences in the composition of blood sampled from the arterial and venous compartments have been reported. Here we investigated whether blood collected by cardiac puncture (CP) versus that collected following removal of the distal 1 mm of the tail tip (TT) differs with respect to glucose and lipid profiles in male C57BL/6J mice at 4, 7, 20 and 28 weeks of age. Blood was first collected from the TT of unanaesthetized mice, which were then immediately anaesthetized using ketamine/xylazine, and a second blood sample was collected by CP. The CP glucose concentration was significantly higher than TT glucose by a positive bias averaging +80% (P < 0.01), irrespective of the age of the mice. Conversely, the concentrations of the CP lipids, including total cholesterol, high-density lipoprotein cholesterol and triglyceride were lower than TT lipids by a negative bias averaging -25% (P < 0.05). These observations highlight the difficulty in measuring and comparing metabolic parameters such as glucose and lipid between one blood compartment and another. They illustrate the need to standardize sampling sites, especially when repeated blood sampling is required.

Impact of fine needle aspiration (FNA) and of the number of punctures on the feline testis: clinical, gross anatomy and histological assessment.

The safety of testicular fine needle aspiration (FNA) has been proven in dogs but has not been fully established in men, while studies in rats have given contradictory results. Furthermore, the extent of damage inflicted by multiple punctures is unknown. The aim of this study was to determine the impact of FNA and of the number of punctures on the feline testis with clinical, gross anatomy and histological examinations. Twenty-seven sexually mature healthy laboratory Domestic Shorthair cats were randomly assigned to two groups: 5 cats in which no FNA was performed (control group), and 22 cats which had their left and right testis punctured with a 26 ga needle towards 3 and 8 directions, respectively (experimental group). Two cats at a time were orchiectomized 5 or 30 min, 1, 2, 4, 7 or 14 days or 1, 2, 3 or 4 mo post-aspiration. The cats of the control group were also orchiectomized. During the first week post-aspiration clinical examination revealed vaginal cavity hematoma (8/44 testes), while the histological findings were focal hemorrhagic areas (20/24 testes), erythrocytes inside the seminiferous tubules' lumen (9/24 testes), and germinal cell degeneration in <1.94% of the seminiferous tubules (15/24 testes). After the first week the histological findings were germinal cell degeneration in <2.14% of the seminiferous tubules (19/20 testes) and enlargement of the lumen of <5.16% of the seminiferous tubules (7/20 testes). The germinal epithelium and interstitium had an overall normal appearance. No significant differences were observed between the left and right testis. The results of the study indicate that testicular FNA should be considered a safe procedure in the cat when up to 8 punctures are performed.