# Complications of Central Venous Catheterization in Small Animals ## Key Takeaways - Catheter-related bloodstream infections (CR-BSIs), often mediated by biofilm formation from organisms like coagulase-negative staphylococci and *Candida* species, are the most common infectious complication; diagnosis involves paired peripheral and catheter blood cultures, with catheter tip culture upon removal. - Venous thrombosis, frequently subclinical, is the most common noninfectious complication, arising from endothelial injury, venous stasis, and hypercoagulability; diagnosis is confirmed via ultrasound, and management includes catheter removal and anticoagulant therapy based on bleeding risk. - Mechanical complications such as catheter occlusion, breakage, migration, and air embolism present with catheter dysfunction or acute systemic signs; detection involves serial measurement of external catheter length, radiography, and immediate intervention for air embolism. - Prevention hinges on strict aseptic technique during insertion, daily catheter site assessment for signs of infection or thrombosis, and prompt removal when the catheter is no longer clinically indicated to minimize dwell time. - Antimicrobial-impregnated or heparin-bonded catheters may reduce CR-BSI risk, but their efficacy in veterinary medicine is less established than in humans; meticulous aseptic technique remains the cornerstone of infection prevention with standard catheters. - When a patient with a central venous catheter deteriorates, the diagnostic approach must systematically differentiate between infectious (CR-BSI), thrombotic, and mechanical complications based on clinical signs and targeted diagnostics. --- Central venous catheterization is a routine procedure in small animal emergency and critical care practice, yet it carries a distinct set of complications that can escalate quickly if not recognized early. This article addresses the infectious, thrombotic, and mechanical complications that arise after catheter placement in dogs and cats. It is written for the practicing veterinarian who places or manages central lines and needs a practical framework for diagnosis, treatment, and prevention. The focus is on early recognition and management, not on insertion technique or catheter selection. The clinical question this article answers is straightforward: when a patient with a central venous catheter deteriorates, how does the clinician determine whether the catheter is the cause, and what actions should follow? The answer requires familiarity with the pathophysiology of catheter-related infection and thrombosis, the clinical signs that distinguish one complication from another, and the evidence supporting specific interventions. The following sections build that foundation systematically. ## At a Glance | Parameter | Key Information | |---|---| | Most common infectious complication | Catheter-related bloodstream infection (CR-BSI), often biofilm-mediated | | Most common noninfectious complication | Venous thrombosis, frequently subclinical | | Primary biofilm organizms | Coagulase-negative staphylococci, *Staphylococcus aureus*, *Candida* species | | First step in suspected CR-BSI | Remove catheter and culture the tip, obtain peripheral blood cultures | | Catheter salvage option | Antimicrobial lock therapy for uncomplicated infections, with limited evidence in veterinary medicine | | Thrombosis management | Catheter removal, anticoagulant therapy based on patient status, ultrasound monitoring | | Mechanical complications | Catheter occlusion, breakage, migration, and air embolism | | Prevention priorities | Aseptic technique, daily catheter assessment, early removal when no longer needed | ## Pathophysiology of Catheter-Related Complications ### Biofilm Formation and Infection The central venous catheter surface becomes coated with host proteins within hours of insertion. This conditioning film provides a substrate for microbial adhesion and subsequent biofilm formation. Biofilms are structured communities of microorganisms encased in an extracellular polymeric substance that protects them from both host immune responses and systemically administered antimicrobials. Organizms within biofilms exhibit tolerance to antibiotics at concentrations that would be bactericidal in planktonic culture, which explains why systemic therapy alone frequently fails to eradicate catheter-associated infection. The microbiology of catheter-related bloodstream infection is dominated by organizms with a propensity for biofilm formation. Coagulase-negative staphylococci, *Staphylococcus aureus*, and *Candida* species are the most frequently implicated pathogens in human medicine, and the same organizms are recovered from infected veterinary catheters. *Candida tropicalis* deserves specific mention because it adheres readily to silicone surfaces and forms robust biofilms, making it a particularly challenging pathogen once established. Fungal biofilms are more difficult to eradicate with antimicrobial lock therapy than bacterial biofilms, and catheter removal is often required for cure. ### Thrombosis and the Infection-Thrombosis Axis Venous thrombosis associated with central venous catheters arises from endothelial injury at the insertion site, venous stasis caused by the catheter lumen occupying space within the vessel, and the hypercoagulable state of the underlying critical illness. Catheter-related thrombi can be asymptomatic, can cause ipsilateral limb swelling, or can serve as a nidus for infection. The relationship between thrombosis and infection is bidirectional: thrombus formation provides a surface for microbial adherence, and microbial biofilms in turn promote local coagulation. Experimental work in rabbit models has demonstrated that catheters designed to release nitric oxide, an endogenous inhibitor of platelet adhesion and activation, produce significantly smaller thrombus areas and reduce bacterial adhesion by 95% compared with standard catheters. These findings support the concept that preventing thrombosis may simultaneously reduce infection risk, although such dual-function catheters are not yet available in veterinary clinical practice. ## Classification of Complications Complications of central venous catheterization are best classified by mechanism because the diagnostic approach and management differ substantially across categories. The three principal categories are infectious, thrombotic, and mechanical. Infectious complications range from localized insertion-site infection to catheter-related bloodstream infection with systemic signs. Thrombotic complications include catheter-associated venous thrombosis, which may be occlusive or nonocclusive, and catheter lumen occlusion from thrombus or precipitate. Mechanical complications include catheter fracture, migration, dislodgement, and air embolism. This classification is clinically useful because it directs the initial diagnostic steps. A patient with fever and leukocytosis requires evaluation for CR-BSI, whereas a patient with ipsilateral facial or limb swelling requires vascular imaging. Mechanical complications often present with catheter dysfunction, such as inability to aspirate blood or resistance to fluid administration, before systemic signs develop. ## Host and Catheter Factors That Modify Risk ### Patient-Related Risk Factors Critically ill patients carry the highest risk of catheter complications because they frequently have compromised immune function, coagulopathies, and prolonged catheter dwell times. Hypoalbuminemia, systemic inflammatory response syndrome, and concurrent bacterial infections at other sites all increase susceptibility to catheter-related infection. Patients with hypercoagulable disorders, including those with immune-mediated hemolytic anemia, protein-losing nephropathy, or neoplasia, are at increased risk for catheter-associated thrombosis. ### Catheter Material and Design Catheter material influences both thrombogenicity and microbial adherence. Silicone and polyurethane catheters are the most commonly used materials in veterinary practice. Antimicrobial-impregnated and heparin-bonded catheters have been shown in human meta-analyzes to reduce catheter-related bloodstream infections compared with standard catheters, but these products have not been evaluated rigorously in dogs and cats. The decision to use specialized catheters in veterinary patients should be based on individual patient risk assessment and availability. ## Principles of Prevention Prevention of catheter complications begins before insertion and continues until the moment of removal. Strict aseptic technique during placement, including maximal barrier precautions, is the single most effective intervention for reducing infection risk. The insertion site should be clipped and prepared with chlorhexidine, and the catheter should be secured to minimize movement at the skin entry point, as motion promotes both microbial ingress and endothelial injury. Daily catheter assessment is mandatory. The clinician should evaluate the insertion site for erythema, swelling, discharge, or pain, and should assess the catheter for patency and function. The [AAHA and AAFP fluid therapy guidelines](https://www.aaha.org/resources/2024-aaha-fluid-therapy-guidelines-for-dogs-and-cats/) emphasize that catheters should be removed as soon as they are no longer needed, because the risk of both infection and thrombosis increases with dwell time. There is no evidence that routine catheter replacement at fixed intervals reduces complication rates, and replacement at a new site may actually increase risk compared with leaving a well-functioning catheter in place. The [RECOVER Initiative veterinary CPR guidelines](https://recoverinitiative.org/) note that central venous access is valuable during cardiopulmonary resuscitation, but they also underscore that the urgency of the resuscitation setting should not compromise aseptic technique. A catheter placed under emergency conditions should be replaced electively once the patient is stabilized if aseptic placement could not be assured. ## Clinical Recognition and Diagnostic Approach Early recognition of catheter complications depends on systematic daily assessment instead of waiting for overt clinical deterioration. Examine the insertion site at least twice daily for swelling, erythema, discharge, or pain. Palpate the catheter tract gently and compare jugular vein filling and pulse quality with the contralateral side. Document catheter length at the skin surface to detect migration. Systemic signs mandate immediate evaluation. Fever, lethargy, tachycardia, or unexplained hypotension in a patient with an indwelling central line should raise suspicion for catheter-related bloodstream infection until proven otherwise. In cats, subtle signs such as decreased grooming or reduced appetite may precede overt pyrexia. ### Complication Recognition Table | Complication | Clinical Signs | Immediate Actions | |---|---|---| | Catheter-related bloodstream infection | Fever, chills, lethargy, tachycardia, hypotension, leukocytosis or leukopenia | Draw blood cultures from catheter and peripheral vein, remove catheter if unstable or if purulent site discharge present, submit catheter tip for culture | | Venous thrombosis | Facial or cervical swelling, jugular distension, dysphagia, Horner syndrome (cats), ipsilateral forelimb edema | Stop infusion through catheter, obtain vascular ultrasound, consider anticoagulant therapy after bleeding risk assessment | | Catheter occlusion | Inability to aspirate blood, increased resistance to flushing, infusion pump alarms | Do not force flush, assess for kinks or migration, consider thrombolytic lock if thrombus confirmed | | Catheter migration or dislodgement | Increased external catheter length, infusion leakage, subcutaneous fluid accumulation | Measure exposed length, obtain thoracic radiograph to confirm tip position, remove and replace if migrated | | Air embolism | Acute dyspnea, cyanosis, collapse, cardiac arrest | Occlude catheter hub immediately, place patient in left lateral recumbency with head down, administer oxygen, initiate CPR per RECOVER guidelines if arrest occurs | | Catheter-related pneumothorax or hemothorax | Acute respiratory distress, muffled heart sounds, tachypnea after placement | Obtain thoracic radiographs, perform thoracocentesis if tension pneumothorax suspected, provide supplemental oxygen | The [RECOVER veterinary CPR guidelines](https://recoverinitiative.org/) provide the resuscitation algorithm for patients that progress to cardiopulmonary arrest from any catheter complication. ## Catheter-Related Bloodstream Infection Bloodstream infection represents the most consequential infectious complication of central venous catheterization. Organizms gain access through the insertion site, the catheter hub, or contaminated infusate. Biofilm formation on the catheter surface protects organizms from systemic antimicrobial concentrations and host immune responses. [Biofilm research in central venous catheters](https://pubmed.ncbi.nlm.nih.gov/18453275/) demonstrates that eradication of established biofilms is difficult, and the tolerance of biofilm organizms to systemic therapy explains why catheter removal is often required for cure. ### Diagnostic Sequence When infection is suspected, obtain paired blood cultures. Collect one sample through the catheter and one from a peripheral vein. Growth of the same organizm from both samples with a differential time to positivity favoring the catheter sample supports a catheter source. Submit the catheter tip for semiquantitative culture when the catheter is removed. Growth of greater than 15 colony-forming units by the roll-plate method indicates colonization. Candida species deserve particular attention. [Candida tropicalis bloodstream isolates](https://pubmed.ncbi.nlm.nih.gov/19851885/) demonstrate strong biofilm-forming capacity and expression of virulence factors including hemolysins and proteases. Fungal catheter infections are difficult to clear with systemic therapy alone, and catheter removal is usually necessary. ### Management Decisions Catheter removal is indicated for hemodynamic instability, septic shock, suppurative thrombophlebitis, or persistent bacteremia beyond 48 to 72 hours of appropriate antimicrobial therapy. In stable patients with uncomplicated infection, some clinicians attempt catheter salvage with systemic antimicrobials and antimicrobial lock therapy. [Antimicrobial lock therapy for catheter infections](https://pubmed.ncbi.nlm.nih.gov/23070153/) involves instilling high concentrations of an antimicrobial agent into the catheter lumen for a dwell period. The evidence for lock therapy derives largely from human medicine, and veterinary data remain limited. Fungal infections respond poorly to lock therapy, and catheter removal is the preferred approach. Antimicrobial selection should follow culture and susceptibility results. Empirical therapy, when required before results return, should cover common nosocomial pathogens including staphylococci, Enterobacteriaceae, and Pseudomonas species. The [MSD Veterinary Manual](https://www.msdvetmanual.com/) provides species-specific guidance on antimicrobial selection and dosing considerations. ## Venous Thrombosis and Occlusion Thrombosis develops from endothelial injury at the catheter tip, venous stasis around the catheter, and the thrombogenic surface of the catheter itself. Experimental work in a rabbit model demonstrated that [nitric oxide releasing catheter materials](https://pubmed.ncbi.nlm.nih.gov/27506125/) reduce thrombus area and bacterial adhesion simultaneously, confirming the close relationship between the coagulation and infection pathways. Standard catheters remain thrombogenic, and clinical thrombosis occurs despite routine flushing protocols. ### Recognizing Thrombosis Clinical signs depend on the affected vessel. Jugular catheter thrombosis produces cervical swelling, facial edema, and visible distension of collateral veins. Cats may develop Horner syndrome due to involvement of the sympathetic trunk adjacent to the jugular vein. Bilateral jugular thrombosis causes severe facial and laryngeal edema with potential upper airway obstruction. Ultrasound is the preferred diagnostic modality. B-mode imaging reveals echogenic material within the vessel lumen, absent compressibility, and reduced or absent flow on color Doppler. In patients where ultrasound is unavailable, venography can confirm the diagnosis, though this requires catheter manipulation and contrast administration. ### Management of Thrombosis Anticoagulant therapy is indicated for confirmed thrombosis, but bleeding risk must be assessed first. Patients with recent surgery, thrombocytopenia, or concurrent coagulopathy require cautious dose adjustment. The [AAHA/AAFP fluid therapy guidelines](https://www.aaha.org/resources/2024-aaha-fluid-therapy-guidelines-for-dogs-and-cats/) emphasize individualized patient assessment for any intervention affecting hemostasis. Consult current formulary references for dosing, as protocols vary by species and clinical context. Catheter removal is generally recommended once thrombosis is confirmed, unless the catheter is essential and the thrombus is non-occlusive. Removing the catheter eliminates the nidus for continued thrombus propagation. Anticoagulant therapy should continue for 1 to 3 weeks after removal, guided by repeat ultrasound assessment. ### Catheter Occlusion Without Clinical Thrombosis Occlusion may result from a fibrin sheath, a thrombus at the catheter tip, or mechanical factors such as kinking or malposition. Attempt aspiration first. If aspiration fails, do not force flush, as this may dislodge a thrombus or rupture the catheter. Assess the external catheter for kinks, verify the catheter position radiographically, and confirm that the catheter has not migrated. When mechanical causes are excluded, a thrombolytic lock may be considered. Instill a thrombolytic agent into the catheter lumen and allow a dwell time of 30 to 60 minutes before attempting aspiration. This approach is extrapolated from human protocols, and veterinary outcome data are limited. If patency is not restored, remove the catheter. ## Mechanical Complications ### Catheter Migration and Dislodgement Catheters secured with sutures or adhesive devices can still migrate, particularly in active patients. Jugular catheters may advance into the right atrium or retract into the subcutaneous tissues. Cardiac arrhythmias, tricuspid regurgitation, or endocardial irritation may result from excessive advancement. Retraction causes perivascular infusion and subcutaneous swelling. Measure the external catheter length at placement and record it in the medical record. Recheck the measurement at each assessment. Any change greater than 1 cm warrants radiographic confirmation of tip position. The tip should lie within the cranial vena cava, proximal to the right atrium. ### Catheter Fracture and Embolization Catheter fracture is rare but serious. Shearing by the stylet during placement, repeated clamping, or aggressive flushing can weaken the catheter wall. A fractured catheter fragment may embolize to the right heart or pulmonary circulation. Suspect fracture if resistance to flushing develops suddenly or if blood cannot be aspirated despite normal external appearance. Thoracic radiography may identify the fragment. Retrieval requires interventional or surgical approaches. ### Air Embolism Air embolism occurs when the catheter hub is open to atmospheric pressure during inspiration. Negative intrathoracic pressure draws air into the venous system. Small volumes may be tolerated, but larger volumes can obstruct right ventricular outflow. Clinical signs include acute respiratory distress, cyanosis, and cardiovascular collapse. The [RECOVER guidelines](https://recoverinitiative.org/) provide the resuscitation framework for patients that arrest. Immediate management consists of occluding the catheter hub, placing the patient in left lateral recumbency with the head lowered to trap air in the right atrium, and administering oxygen. Aspiration of air through the catheter may be attempted if the catheter remains in place. ## Documentation and Monitoring Protocols Standardized documentation supports early recognition and defensible medical records. Record the following at placement: catheter type, gauge, length, insertion site, tip position confirmed radiographically, number of attempts, and any complications encountered. Record the external catheter length and mark the catheter at the skin surface. Daily monitoring should include: - Insertion site inspection for swelling, erythema, discharge, or pain - External catheter length measurement - Catheter patency assessment by aspiration and flushing - Infusion site assessment for subcutaneous leakage - Patient temperature and attitude assessment - White blood cell count trends in patients with prolonged catheterization Document all findings in the medical record, including negative assessments. A structured catheter care checklist reduces omission errors and supports consistent evaluation across shifts. The [AVMA practice resources](https://www.avma.org/resources-tools) offer guidance on medical record standards and documentation practices for veterinary practice. Catheter removal should be considered when the catheter is no longer essential, when complications develop, or after 5 to 7 days of use in patients with ongoing infection risk. Prolonged catheterization increases infection and thrombosis risk, and daily review of catheter necessity is a core preventive practice. ## Recognized Complications and Early Detection Central venous catheterization in small animals carries a defined set of failure modes that can be grouped by mechanism and time course. Early recognition depends on systematic observation instead of reliance on any single clinical sign. Catheter-related bloodstream infection typically presents with fever, lethargy, or unexplained deterioration in a patient with an indwelling line. Local signs at the insertion site, including erythema, swelling, or exudate, may precede systemic illness but are absent in a substantial proportion of cases. Daily inspection with gentle palpation of the site and surrounding tissues should be paired with regular review of the patient's temperature curve and attitude. Blood cultures drawn through the catheter and from a peripheral vein simultaneously help distinguish catheter infection from other sources. The diagnostic sequence matters: culture both sites before removing the line, because catheter removal eliminates the opportunity to confirm the diagnosis. Venous thrombosis may be silent until it causes facial or limb edema, jugular vein distension, or resistance to infusion. In dogs, unilateral jugular catheterization can produce ipsilateral facial swelling that is subtle at first. Serial measurement of neck circumference at a marked skin tattoo or suture provides an objective trend. Ultrasonography with color Doppler remains the most reliable confirmatory test, and it can be performed at the bedside in most referral settings. Thrombosis and infection are linked: biofilm formation on the catheter surface promotes both microbial adherence and platelet aggregation, and experimental work in rabbits has shown that catheters designed to reduce thrombus area also reduce bacterial adhesion by a large margin [nitric oxide releasing central venous catheters in a rabbit model](https://pubmed.ncbi.nlm.nih.gov/27506125/). Mechanical complications include catheter migration, dislodgement, fracture, and air embolism. Migration is detected by comparing the external catheter length at placement with daily measurements. A change of more than 1 cm warrants radiographic confirmation of tip position. Catheter fracture is rare but catastrophic, it presents with sudden loss of infusion capability, swelling at the site, or acute respiratory signs if embolisation has occurred. Air embolism presents with acute dyspnoea, collapse, or cardiac arrest, particularly in hypovolemic patients or those breathing spontaneously during line manipulation. ## Common Errors and Corrective Actions Less experienced clinicians frequently misattribute fever to the underlying disease instead of the catheter. The corrective action is to maintain a high index of suspicion in any febrile patient with a central line and to perform paired blood cultures before changing antimicrobial therapy. Another recurring error is flushing an occluded catheter with force. This can dislodge a thrombus or damage the catheter wall. The correct response to resistance on flush is to stop, aspirate gently, and assess for causes such as kinking, malposition, or precipitation before any further manipulation. Clinicians sometimes overlook the insertion site when a patient deteriorates. The site should be examined at least once daily, and the dressing changed using sterile technique. Documentation of site appearance, catheter length, and infusion patency at each shift creates a record that distinguishes new problems from pre-existing ones. ## Troubleshooting Table | Observation | Likely Cause | Discriminating Check | | --- | --- | --- | | Fever without local signs | Catheter-related bloodstream infection | Paired blood cultures from catheter and peripheral vein | | Resistance to flush | Thrombus, kink, or tip against vessel wall | Aspirate gently, radiograph or ultrasound to confirm tip position | | Facial or neck swelling | Venous thrombosis | Ultrasonography with color Doppler, compare serial neck measurements | | Sudden loss of infusion capability | Catheter fracture or migration | Measure external catheter length, radiograph to locate tip | | Acute dyspnoea during line manipulation | Air embolism | Immediate patient assessment, stop manipulation, position patient, aspirate line | | Exudate or erythema at site | Local infection | Swab for culture, consider early catheter removal | ## Limitations of Current Evidence The evidence base for central venous catheter complications in small animals is largely extrapolated from human medicine. Randomised controlled trials in dogs and cats are scarce, and much of the comparative data on catheter materials and antimicrobial coatings comes from human meta-analyzes [antimicrobial-impregnated and heparin-bonded central venous catheters](https://pubmed.ncbi.nlm.nih.gov/11008998/). Whether these findings transfer directly to veterinary patients is uncertain, particularly given differences in skin flora, hair coat, and patient activity levels. Expert opinion differs on several points. The role of antimicrobial lock therapy in veterinary patients remains contested. Human data suggest that biofilm eradication is possible with high-concentration antimicrobial dwells, but fungal biofilms are considerably more difficult to treat, and catheter removal is often required for Candida infections [biofilms on central venous catheters](https://pubmed.ncbi.nlm.nih.gov/18453275/). The optimal dwell time, agent selection, and patient selection criteria have not been established for dogs and cats. There is also disagreement about whether routine catheter replacement at a fixed interval reduces infection risk. Some clinicians advocate scheduled replacement, while others argue that replacement should occur only for clinical indications. The available evidence does not resolve this question for veterinary patients. ## Referral and Escalation Criteria Referral to a specialist or escalation of care is warranted when a patient develops signs of systemic infection with hemodynamic instability, when thrombosis causes significant venous obstruction, or when catheter fracture or embolisation is suspected. These situations require advanced imaging, interventional capability, or intensive monitoring that may not be available in general practice. Laboratory involvement is indicated for blood cultures, catheter tip culture, and antimicrobial susceptibility testing. Suspected fungal infection warrants early laboratory communication because culture and identification of organizms such as Candida tropicalis and Fusarium species require specialised media and longer incubation periods [virulence factors of Candida tropicalis clinical isolates](https://pubmed.ncbi.nlm.nih.gov/19851885/). Fusarium infections in immunocompromised patients carry a poor prognosis, and successful outcome depends on removing the infected catheter and starting appropriate antifungal therapy promptly [clinical aspects of Fusarium species](https://pubmed.ncbi.nlm.nih.gov/7834602/). Regulatory reporting may apply in specific circumstances. Adverse events involving investigational drugs or devices should be reported according to the relevant study protocol. Reportable complications that cause serious harm should be documented in the medical record and, where applicable, reported to the appropriate oversight body. Practitioners should consult their regional professional standards and any applicable institutional policies [AVMA professional practice resources](https://www.avma.org/resources-tools). ## Frequently Asked Questions ### How do I decide between catheter salvage and removal when a patient develops a suspected catheter-related bloodstream infection? Removal is the default when the patient is hemodynamically unstable, has septic shock, or when infection is caused by organizms known to form robust biofilms, such as *Candida* species. For stable patients with no signs of tunnel infection or exit site purulence, salvage with antimicrobial lock therapy may be attempted, but this requires daily reassessment. The evidence for lock therapy is stronger for bacterial biofilms than for fungal ones, and eradication depends on biofilm age and the agent used. If blood cultures remain positive after 48 to 72 hours of appropriate systemic therapy, remove the catheter. Document the decision and the rationale in the medical record. ### What should I do when antimicrobial-impregnated or heparin-bonded catheters are unavailable or unaffordable? Standard polyurethane catheters remain acceptable when enhanced catheters are not available. Meticulous aseptic handling, strict hub hygiene, and daily site inspection are the primary defenses against infection regardless of catheter type. A meta-analysis of human studies showed that antimicrobial-impregnated and heparin-bonded catheters reduced catheter-related bloodstream infections relative to standard catheters, but the effect size varied across studies. In small animal practice, the added cost of specialized catheters must be weighed against the patient's anticipated duration of catheterization and the clinic's infection control infrastructure. When using standard catheters, shorten dwell time where clinically feasible and monitor the insertion site at least twice daily. ### How does the approach to catheter complications differ in cats compared with dogs? Cats have smaller jugular veins and higher risk of vasovagal reactions during catheter manipulation. Thrombosis may present with subtle signs such as facial swelling or dysphagia instead of obvious limb edema. Cats also tolerate prolonged catheterization poorly and are more prone to self-trauma at the insertion site, so secure bandaging and Elizabethan collars are essential. Infection in cats is more likely to involve *Candida* species, which form biofilms that resist systemic therapy and often require catheter removal. The RECOVER guidelines emphasize that cardiopulmonary arrest during catheter placement is a recognized risk in cats, particularly those with preexisting cardiac disease, so preoxygenation and gentle restraint are mandatory. ### What monitoring parameters should I record daily for a patient with a central venous catheter? Record the insertion site appearance, including any erythema, swelling, discharge, or pain on palpation. Document catheter patency by noting the ease of aspiration and flushing, and record the volume of fluid administered and withdrawn. Check for jugular vein distension, facial or limb edema, and changes in central venous pressure readings that might indicate thrombosis. Measure body temperature at least twice daily and note any unexplained fever. Document the catheter dwell time and the date of the last dressing change. The AAHA and AAFP fluid therapy guidelines recommend that all fluid administration lines be labeled with the date and time of placement, and that catheters be removed as soon as they are no longer needed. ### How do I explain a catheter complication to a concerned owner without causing panic? Use clear, factual language that acknowledges the complication without assigning blame. State what has been observed, what it means for the patient, and what steps are being taken. For example, explain that a small clot has formed around the catheter tip and that the catheter will be removed and the patient monitored for any further signs. Avoid technical jargon and do not speculate about outcomes that are not yet known. Reassure the owner that catheter complications are a recognized risk of this procedure and that the veterinary team is following established protocols. Offer a realistic timeline for the next assessment and provide a direct contact number for questions. Written handouts can reinforce the verbal discussion. ### What documentation is required when a catheter complication occurs? Record the date and time the complication was first observed, the clinical signs, and the person who identified it. Document the diagnostic steps taken, including imaging findings, culture results, and any changes in central venous pressure. Note the treatment administered, the response to treatment, and the date and time of catheter removal if that was required. Include a description of the catheter tip if it was submitted for culture. The AVMA practice resources emphasize that accurate medical records are a professional obligation and serve as the foundation for continuity of care and risk management. If the complication resulted in significant morbidity, consider a team debrief to identify any process improvements. ## Related Clinical & Scientific Guides * [Toxicology in Emergency Practice: Common Poisons and Diagnostic Approach](/knowledge/veterinary-medicine/emergency-critical-care/toxicology-emergency-practice-common-poisons-diagnostic-approach) * [Veterinary Cardiopulmonary Resuscitation: Post-Cardiac Arrest Care](/knowledge/veterinary-medicine/emergency-critical-care/veterinary-cardiopulmonary-resuscitation-post-cardiac-arrest-care) * [Fluid Therapy Guidelines for Dogs and Cats: A Practical Update](/knowledge/veterinary-medicine/emergency-critical-care/fluid-therapy-guidelines-dogs-cats-practical-update) ## References and Further Reading - [Prevention of nosocomial bloodstream infections: effectiveness of antimicrobial-impregnated and heparin-bonded central venous catheters.](https://pubmed.ncbi.nlm.nih.gov/11008998/). 2000. - [Attenuation of thrombosis and bacterial infection using dual function nitric oxide releasing central venous catheters in a 9day rabbit model.](https://pubmed.ncbi.nlm.nih.gov/27506125/). 2016. - [Antifungal lock therapy.](https://pubmed.ncbi.nlm.nih.gov/23070153/). 2013. - [Examination of potential virulence factors of Candida tropicalis clinical isolates from hospitalized patients.](https://pubmed.ncbi.nlm.nih.gov/19851885/). 2010. - [Biofilms on central venous catheters: is eradication possible?](https://pubmed.ncbi.nlm.nih.gov/18453275/). 2008. - [Taxonomy, biology, and clinical aspects of Fusarium species.](https://pubmed.ncbi.nlm.nih.gov/7834602/). 1994. - [RECOVER Initiative Veterinary CPR Guidelines](https://recoverinitiative.org/). Veterinary Emergency and Critical Care Society. - [AAHA/AAFP Fluid Therapy Guidelines for Dogs and Cats](https://www.aaha.org/resources/2024-aaha-fluid-therapy-guidelines-for-dogs-and-cats/). AAHA. - [MSD Veterinary Manual, Professional Edition](https://www.msdvetmanual.com/). MSD Veterinary Manual. ## Related Articles - [Central Venous Pressure Monitoring in Veterinary Critical Care](/knowledge/veterinary-medicine/emergency-critical-care/central-venous-pressure-monitoring-veterinary-critical-care) - [Complications of Oxygen Therapy in Veterinary Patients](/knowledge/veterinary-medicine/emergency-critical-care/complications-oxygen-therapy-veterinary-patients) - [Coagulation Emergencies in Small Animals: Diagnosis and Management](/knowledge/veterinary-medicine/emergency-critical-care/coagulation-emergencies-small-animals-diagnosis-management) - [Trauma Triage and Primary Survey in Small Animals](/knowledge/veterinary-medicine/emergency-critical-care/trauma-triage-primary-survey-small-animals) - [Blood Transfusion in Dogs and Cats: Crossmatching and Compatibility](/knowledge/veterinary-medicine/emergency-critical-care/blood-transfusion-dogs-cats-crossmatching-compatibility) > This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.