Rational approach to feline medical emergencies: part 1

Abstract

Clinical challenges:

Emergencies cause disruption to the normal flow of the working day in a busy veterinary practice, requiring diversion of resources from routine cases to assist with the medical priority. Assessments and decisions have to be made rapidly, which can be challenging if the particular medical condition is not dealt with on a regular basis.

Aims:

This two-part article series aims to help practitioners feel more confident with the most common types of cases that can present as emergencies and to highlight some of the areas where feline patients require a different approach from their canine counterparts. Part 1 discusses priorities for triage and stabilisation of emergency patients, before addressing the management of shock, dyspnoea, feline aortic thromboembolism and anaemia. The medical emergencies focused on in Part 2 are seizures, urethral obstruction, acute kidney injury and diabetic ketoacidosis.

Audience:

The intended audience is general practitioners who may be confronted with emergency cases on an irregular basis, although clinicians working in out-of-hours services may also find useful details to update their knowledge.

Evidence base:

Although much of the information covered is well established, the article series introduces knowledge and clinical techniques that have emerged in the literature in the past 5 years.

Plain Language Summary

Common feline emergencies not requiring surgery: part 1

This two-part review article covers some of the more common conditions in cats who require emergency treatment. It focuses on medical conditions rather than those requiring surgery. This first instalment starts with the management of shock and breathing problems. It goes on to discuss blood clots related to heart disease before concluding with anaemia.

Keywords

Medical emergencies shock resuscitation respiratory distress

Triage and stabilisation

The sudden presentation of a significantly unwell cat can be a stressful occurrence in a busy practice. However, the experience is far more stressful for the patient and their owner than it should be for the veterinary professional staff. It is, therefore, important to remain calm and utilise the whole team to work in as efficient a manner as possible to maximise the outcomes for the emergency case (see the ‘Roles of the veterinary team’ box).

The patient is likely to require admission to a nonpublic area where oxygen can be supplied and an initial assessment carried out. Ideally, this area should be as quiet as possible to reduce further stress to the cat. Unfortunately, most emergency hospitals, let alone general practices, do not have dedicated feline intensive care units and, therefore, cats may be exposed to a very busy environment in a shared space with dogs. Partitioning of the room with mobile screens may help to reduce visual triggers, but cats will still be able to smell and hear canine patients. It may be possible to find a quieter area in the practice for initial triage, such as an anaesthesia induction room, although this area needs to be large enough to enable two to three people to work comfortably in the space.

General guidelines for feline-friendly practice, such as minimising noise in the area, gentle handling and providing cats with hiding spaces, should be followed (see bit.ly/ JFMSCatFriendly).

During this time, the owners should be escorted into an available consulting room or other private area, rather than being left in the waiting area. Veterinary staff should explain to them what is happening and obtain initial information from the client as to what has happened. Once the patient has undergone an initial assessment and stabilisation, the veterinary surgeon should discuss the findings and plan with the client, obtaining further history and consent for treatment, as required.

Cats who are critically ill can be very fragile, and interventions may result in decompensation, particularly where there is respiratory or circulatory compromise. This may mean certain interventions need to be delayed until the patient is more stable. The physical examination may have to be performed ‘piecemeal’ in a cat with respiratory distress, giving the patient breaks to receive oxygen supplementation. Diagnostic investigations that may require sedation, such as radiography, should be delayed until it is safe to perform them.

A ‘crash box’ containing equipment and drugs for cardiopulmonary resuscitation (CPR) should be available. Updated RECOVER (Reassessment Campaign on Veterinary Resuscitation) CPR guidelines were published in 2024,² with the most significant changes being the description of three compression techniques that can be used in cats (circumferential, one-handed palm or one-handed thumb-to-fingers [Figures 1 –3] – previously just the last of these techniques was advocated), and the recommendations that high-dose adrenaline (epinephrine) should no longer be used and that atropine should only be used once. Drug dosage charts and algorithms from the guidelines should be readily accessible in the practice (eg, laminated copies attached to the wall).

Figure 1

Circumferential: the fingers are placed below the thorax and both thumbs used to apply compressions

Figure 2

One-handed palm: the palm of the dominant hand applies compressions over the heart, while the non-dominant hand applies pressure along the spine to prevent movement

Figure 3

One-handed thumb-to-fingers: the palm of the dominant hand is placed under the thorax and the thumb on top of the thorax. Compressions are applied by squeezing thumb and fingers together. The non-dominant hand prevents movement

Shock

Shock is defined as tissue hypoxia, which results from an imbalance between oxygen delivery and tissue consumption.³ It may be the consequence of reduced perfusion (hypovolaemic, cardiogenic, obstructive or distributive) or may be metabolic or hypoxaemic in origin (Figure 4). Unlike canine patients, feline patients often do not show the hyperdynamic stage of compensatory shock, when tachycardia and a brisk capillary refill time may be noted. Instead, bradycardia (<160 beats per min [bpm]), hypothermia (<37.8°C; <100°F) and hypotension (systolic arterial pressure <90 mmHg) are more commonly seen, alongside obtunded mentation, pale mucous membranes and a prolonged capillary refill time.⁴ Lactate is typically increased (>2.5 mmol/l), but this finding is not specific for shock, and studies have produced conflicting results regarding the use of lactate measurement as a prognostic indicator in cats.^4,5

Oxygen will be beneficial for all patients, regardless of the underlying cause. Fluid therapy will be beneficial for most types of shock but can be detrimental if cardiogenic shock is present (see ‘Ruling cardiac disease in or out’ box). Thoracocentesis and frusemide therapy may be indicated.

If cardiogenic shock is excluded, fluid boluses of a crystalloid solution should be administered (10–15 ml/kg over 15 mins). Boluses can be repeated two or three times, with reassessment of heart rate, blood pressure and mentation after every bolus. Usually, a response will be seen after 20–30 ml/kg has been given. Where head trauma is present, use of hypertonic (7.5%) sodium chloride given once at 2–4 ml/kg over 10 mins can reduce cerebral swelling and reduce intracranial pressure.⁷ Where intravenous access is challenging due to hypotension, especially in paediatric patients, an intraosseous catheter can be placed (following aseptic preparation) into the femoral or humeral diaphysis. If an intraosseous needle is not available, a 19 G hypodermic needle can be used for kittens, in particular.

Figure 4

Classification and causes of shock. This simplistic representation of the underlying mechanisms of shock is intended to provide practical guidance. More common conditions are indicated in bold. GI = gastrointestinal

Although maximal doses of 40–60 ml/kg (equivalent to blood volume) can theoretically be given, if there has been minimal response to 30 ml/kg, further fluid administration is unlikely to be successful. This is often seen with distributive shock or sepsis (Table 1).^8,9 Cats with sepsis may have signs of organ dysfunction (elevated bilirubin, increased creatinine, decreased myocardial contractility, decreased SpO₂ or evidence of reduced coag-ulation).¹⁰ Vasopressor therapy or inotropic drugs to improve cardiac output need to be considered to address the hypotension and improve perfusion.

Table 1

Signs of sepsis in feline patients

Parameter*	Less than	Greater than
Temperature	37.8°C; 100°F	39.7°C; 103.5°F
Heart rate	140 bpm	225 bpm
Respiratory rate		40 breaths/min
Systolic blood pressure	90 mmHg
White blood cell count	5.0 x 10⁹/l	19.0 x 10⁹/l
Band neutrophils		5%

Alterations in more than two of the above parameters plus evidence of infection is consistent with a diagnosis of sepsis

bpm = beats per min

Noradrenaline is considered the first-line drug for vasopressor therapy.^11,12 It stimulates predominantly alpha (α)₁- and α₂-adrenergic receptors, with less beta (β)-adrenergic effect, and is, therefore, less arrhythmogenic than other vasopressor drugs. It is typically administered intravenously as a constant rate infusion (CRI) at 0.1–2.0 µg/kg/min. If this is unsuccessful, a second-line vasopressor (dopamine, vasopressin) can be considered, although cost and availability of vasopressin may limit this as a choice.

Cats with poor cardiac contractility due to congestive heart failure (CHF) may require an inotropic agent to improve cardiac output and consequently blood pressure. Dobuta-mine, which has predominantly β-adrenergic effects, can improve cardiac output by increasing contractility. This can be started at 1 µg/kg/min, titrating up to 5 µg/kg/min. Dosages higher than 5 µg/kg/min can be associated with neurological side effects.

Pimobendan is also an inotropic agent that can be considered (see ‘Approach to respiratory distress (cardiac in origin)’ section).

Warming of patients with hypothermia will better enable assessment of perfusion parameters such as pulse quality and mucous membrane colour. Ideally, a warm air blanket should be used; if using heat pads or hot water balloons, care should be taken not to induce thermal burns. Bleeding should be controlled, where possible, by use of bandaging, with blood products given to restore circulation, where available. Intravenous broad-spectrum antimicrobials should be started in cats with evidence of sepsis; where possible, samples should be obtained for culture prior to administering these drugs.

Many conditions associated with shock will be painful, and analgesia will be required. Opioids such as morphine and methadone provide good levels of analgesia but can cause respiratory depression at higher doses. In patients with increased intracranial pressure, caution is warranted, as opioids could make assessment of clinical signs harder to gauge. Multimodal therapy may allow reduced doses of opioids to be used. Non-steroidal anti-inflammatory drugs are not recommended in patients who may have sustained acute kidney injury subsequent to hypotension. A CRI of ketamine can provide useful adjunctive analgesia.

Respiratory distress

Respiratory distress may be caused by upper airway obstruction, lower airway disease, pulmonary parenchymal disease, pleural space disease, cardiac disease or neurogenic disease. Tachypnoea or open-mouth breathing can be seen with anaemia, pain and metabolic conditions such as hyperthyroidism. Localisation of the problem by means of history, observation and clinical examination will enable diagnostic investigations to be targeted appropriately.

Cats with respiratory distress are anxious and susceptible to developing cardiopulmonary arrest (Figure 5). Therefore, a quiet and methodical approach, with minimal intervention, is required. Consideration should be given to the use of butorphanol (Table 2) for sedation to reduce stress, and oxygen supplementation should be provided throughout.

Figure 5

Cat with respiratory distress showing an anxious facial expression, open-mouth breathing, and orthopnoeic posture with extended neck and abducted elbows

Table 2

Emergency drugs for feline respiratory distress

Drug	Dose	Route(s) of administration	Frequency	Indication
Frusemide	1–2 mg/kg	IV, IM, SC	q0.5–4h Up to 12 mg/kg q24h	Cardiogenic pulmonary oedema
Terbutaline*	0.01 mg/kg	IV, IM, SC	q4h	Bronchospasm
Salbutamol (albuterol) 100 μg MDI*	1–2 puffs	Via spacer device or endotracheal tube	q4h	Bronchospasm
Dexamethasone	0.1 mg/kg	IV, IM, SC	q24h	Inflammation
Butorphanol	0.2–0.4 mg/kg	IV, IM, SC	q4h	Anxiolysis

Not licensed for veterinary use

IM = intramuscular; IV = intravenous; MDI = metered-dose inhaler; SC = subcutaneous

Upper airway obstruction is typically accompanied by a prolonged inspiratory phase and inspiratory noise. Owners may report snoring or snuffy respiration. Nasal discharge may or may not be present. Cyanosis is seen less commonly in cats than dogs (see ‘Cyanosis’ box). Wheezing may be heard in association with laryngeal/tracheal diseases, but these are relatively uncommon in cats; bronchoconstriction associated with feline asthma is the most common cause of wheezing. If anaesthetising these patients for further investigations, consideration should be given to the possibility of upper airway obstruction, which may require placement of a tracheostomy tube.¹³ Administration of an anti-inflammatory dose of dexamethasone (Table 2) may partially reduce an obstruction if there is an inflammatory component present.

Respiratory distress due to pulmonary parenchymal or pleural space disease is more common than upper airway obstruction. Cats with both pleural space disease and lung parenchymal disease will exhibit a restrictive respiratory pattern (ie, rapid shallow breathing with loss of the expiratory pause). Three studies of feline dyspnoea indicated four common underlying categories of disease for dyspnoea – cardiac, respiratory, neoplasia and trauma.^14–16 Younger cats were affected more commonly by trauma (median age 2.0–3.83 years), whereas those with cardiac disease and neoplastic disease were older (median age 6.4–11.6 years and 10.17–11.8 years, respectively). Cardiac disease was the most common cause in two of these studies, based in the UK,^14,15 but the third study, based in France,¹⁶ indicated respiratory diseases to be the most common category. There may, therefore, be regional variation in why cats present in respiratory distress.

POCUS is very useful for gaining further information about the underlying cause of respiratory distress without causing the patient undue stress. POCUS can be used to readily assess for the presence of pleural effusions, and left atrial enlargement will become familiar with practice. However, pneumonia (shred signs), pneumothorax (absence of glide signs) and pulmonary oedema (increased number of B-lines) can be harder to detect.^17–19 Currently, there is no standardised POCUS technique that is universally recommended, and further investigations may still be required to obtain a definitive diagnosis for the respiratory distress.

Thoracocentesis should be performed if pneumothorax or pleural effusion is identified (Figures 6 –10). This can substantially improve respiration and enable samples to be obtained for further testing. Thoracocentesis should always be conducted prior to radiography. Not only is the presence of pleural effusion likely to mask underlying pathology such as neoplastic masses or cardiomegaly, but the patient will also be able to better tolerate radiography if they are less dyspnoeic.

Figure 6

Equipment required for thoracocentesis comprises a 19–21 G butterfly catheter and extension tubing, three-way tap and syringe as well as sample pots. If a butterfly catheter is not available, a 21 G hypodermic needle can be used

Figure 7

The area from the fourth to tenth rib should be clipped and aseptically prepared while the cat receives flow-by oxygen. Sedation (eg, with butorphanol) may be required. Local anaesthetic may be used if desired but can lead to a delay in performing thoracocentesis

Figure 8

The extension tubing, three-way tap and syringe are connected to the butterfly catheter, with the three-way tap closed towards the needle. The needle is inserted between the seventh and ninth intercostal spaces, cranial to the rib, to avoid the neurovascular bundle that runs on the caudal border. The bevel should be directed cranially on insertion; then, once within the pleural space, the needle can be directed caudally so that it lies parallel to the thoracic wall. This reduces the risk of iatrogenic lung injury

Figure 9

The three-way tap is opened so that fluid (or air) can be aspirated. When emptying the syringe, the three-way tap is closed to the patient, and this allows the syringe to be emptied without disconnecting it. Maintaining a closed system reduces the chance of air being introduced and causing iatrogenic pneumothorax

Figure 10

Samples should be placed into an EDTA tube for cytology and a plain tube for fluid analysis (protein, specific gravity, triglycerides, cholesterol) and culture. Ideally, the plain sample tube should be completely filled (or a Vacutainer [BD] used) to increase the chance of recovering anaerobes

Determining whether a cat’s respiratory distress is cardiac or non-cardiac in origin – and, in turn, appropriate emergency therapy – can be achieved in a number of ways (see ‘Differentiating cardiac disease from respiratory disease’ box).

Approach to respiratory distress (cardiac in origin)

If cardiac disease is considered the likely aetiology of respiratory distress, then frusemide (Table 2) should be administered. If intravenous access is available, a bolus of 1–2 mg/kg might be expected to take effect within 30 mins. Where intravenous access is not available, the intramuscular route can be used, with a slower onset of action of 1–2 h.²⁴ If there is a response to frusemide, the dose can be repeated every 30 mins to 4 h, depending on effect, but should not exceed 12 mg/kg in 24 h. The aim of initial treatment is to reduce the respiratory rate to <40 breaths/ min. Treatment should be switched to oral therapy when the cat is eating.

Electrolytes, particularly potassium, should be monitored, as well as creatinine and urea, as these cats may become azotaemic. Consideration can be given to administering frusemide as a CRI. Following administration of an initial bolus of 1–4 mg/kg, frusemide was given at 0.5–1.0 mg/kg/h, diluted in dextrose in water, in one study that included 24 cats.²⁵ Although the results suggested greater diuresis (increases in creatinine and total benefit), the clinical benefit of administering frusemide in this way was not convincingly demonstrated, although the number of cats in the study was quite small.²⁵ Some cats may require potassi-um-supplemented fluids at a low rate (0.5–1.0 ml/kg/h) to mitigate the effects of frusemide, especially if the respiratory distress has improved but azotaemia is worsening.

Although not licensed in cats, pimobendan has been investigated for use in patients with CHF.^26–28 Pimobendan is a positive inotropic agent that has traditionally been considered contraindicated in cats with hypertrophic obstructive cardiomyopathy (HOCM) due to the reduction in afterload and subsequent hypotension it can cause. One study involving

54 cats with hypertrophic cardiomyopathy (HCM) or HOCM showed improved survival in the 27 cats receiving pimobendan (median 625 days compared with 103 days for control cats).²⁶ However, a more recent, prospective study failed to show a significantly improved outcome for cats receiving pimobendan, although there was no worsening of dynamic outflow obstruction with use of this drug.²⁷ These cats were not in heart failure at the time of the study but had been treated for CHF in the preceding 60 days.²⁷ A third study included 119 cats with CHF at the time of initiation of treatment with pimobendan; the drug was well tolerated in these cats but the study did not assess the survival benefits.²⁸

Taken together, there is a low level of evidence to support the use of pimobendan. However, in cases where cardiac output is considered to be reduced (bradycardia, hypotension, hypothermia), pimobendan can be considered, and may be more readily available, as a positive inotrope than dobutamine.²⁹

Approach to respiratory distress (non-cardiac in origin)

Non-cardiac causes of respiratory distress may or may not result in the formation of pleural effusion. Where pleural effusion has been removed by thoracocentesis, in-house analysis can help to narrow down the differential diagnoses (Table 3). Radiography following drainage of pleural effusion may also help to establish a diagnosis. The dorsoventral view should be obtained first, to minimise respiratory compromise and prevent atelectasis. Consideration should be given to obtaining radiographs under general anaesthesia to optimise control of respiration, improve ventilation and enable inspiratory films to be acquired.

Table 3

Classification and causes of pleural effusion

	Transudate	Modified transudate	Exudate	Chyle	Blood
Protein (g/dl)	<2.5	2.5–5.0	>3.0
Specific gravity	<1.015	1.015–1.030	>1.030
Total nucleated cell count (/μl)	<1500	1000–7000	>5000
Appearance	Clear	Clear	Turbid	Lactescent	Sanguineous
Comments			Neutrophils and bacteria, if septic	Predominantly lymphocytes Measure triglycerides and cholesterol in fluid and blood	Check PCV Ensure not iatrogenic
Aetiology	Hypoalbuminaemia Neoplasia CHF		Septic: pyothorax Non-septic: FIP	CHF Idiopathic Neoplasia Diaphragmatic hernia	Trauma Coagulopathy Neoplasia

CHF = congestive heart failure; FIP = feline infectious peritonitis; PCV = packed cell volume

Where lower airway disease (asthma) is suspected to be the cause of respiratory distress (wheezing on auscultation, increased expiratory effort and/or history of cough), a combination of a bronchodilator to reduce bronchospasm and a steroid to reduce inflammation should be given (Table 2). If terbutaline injection is not available, then salbutamol (albuterol) can be administered via a metered-dose inhaler using a spacer device (Figure 11). In cats who are anaesthetised, the spacer device can be attached to the endotracheal tube. Cats with severe asthma can develop spontaneous pneumo-thorax,^30–32 and this should be assessed for if signs are not improving following treatment.

Figure 11

Inhaler therapy. A metered-dose inhaler attached to a spacer device. The spacer device can be attached to a face mask for administration of the inhaler to a conscious cat or to an endotracheal tube in an anaesthetised patient

If pulmonary parenchymal disease is present, primary differential diagnoses would be pneumonia (bacterial, viral or parasitic) or neoplasia. More rarely, idiopathic pulmonary fibrosis and inhalation of irritant toxins (acrid smoke, chemicals) can also lead to respiratory distress. In addition to thoracic imaging (radiography or CT scan), further diagnostic testing may comprise faecal analysis (Baermann flotation for lungworm), heartworm antigen testing in endemic countries, Toxoplasma gondii serology, bronchoalveolar lavage and lung lobe aspir-ate/thoracoscopic biopsy. More invasive testing is likely to have to be deferred until the patient is more stable. Therefore, antibacterials and antiparasitic treatments are sometimes given empirically in the absence of a diagnosis.

Feline aortic thromboembolism

Feline aortic thromboembolism (FATE) has been reported to affect approximately 0.2% of cats in the general UK population.³³ Cats with FATE typically present as having ‘gone off their legs’, with hindlimb paresis, acute pain, absence of femoral pulses, cold extremities and digital pads that may be pale, purple or cyanotic. In 10–15% of cases, only one hindlimb may be affected;³⁴ alternatively, the thrombus may be present in a foreleg rather than the more classic ‘saddle thrombus’ at the aortic trifurcation.

On clinical examination, signs relating to underlying cardiomyopathy, such as a heart murmur, gallop rhythm or pleural effusion, may also be present, and cats are frequently hypothermic.

Outcomes for cats treated for FATE are improving – 30–40% survival was reported in a 2024 publication³⁴ compared with 25% survival in studies around 10 and 20 years prior.^33,35 However, owners still need to be aware of the guarded prognosis and requirement for ongoing medication due to underlying heart disease before embarking on potentially expensive treatment.

Analgesia with an opioid is recommended. Options include methadone, morphine or fentanyl. Buprenorphine is unlikely to provide sufficient analgesia but can be considered if other options are not available. Management of CHF (discussed in the earlier section on ‘Shock’) with oxygen and diuretics may also be required.

Thrombolytic agents (tissue plasminogen activator) are most beneficial if administered within 6 h of the embolic event.³⁶ Cost, availability and appropriate timing limit use of this therapy in general practice and, therefore, thromboprophylactic therapy is often instigated to reduce progression of the thrombus, while collateral circulation develops and intrinsic thrombolysis reduces the size of the clot. Clopidogrel (18.75 mg PO q24h) and rivaroxaban (2.5 mg PO q24h) can be given concurrently and appear to reduce recurrence rates.³⁷

Heparin can be used, but monitoring (activated partial thromboplastin time for unfractionated heparin and anti-factor Xa for low-molecular weight heparin) is recommended due to individual variation in dose requirements. Restricted availability of antifactor Xa testing makes monitoring low-molecular weight heparins challenging.

Cats with FATE also require supportive nursing care to ensure adequate nutrition and physiotherapy to prevent contraction of the gastrocnemius muscle. Reperfusion injury can result in the development of marked hyperkalaemia.

Improvement may take 48 h to be seen; however, ischaemic necrosis of the distal extremities can become apparent even after several weeks. Further information regarding FATE is available in a recent review article by Julien Guillaumin, ‘Feline aortic thromboembolism: recent advances and future prospects’.³⁴

Anaemia

Anaemia is a reduction in red blood cell numbers or haemoglobin within the blood. This is most commonly assessed rapidly by measurement of packed cell volume (PCV) following centrifugation of blood in a microhaematocrit tube, or by calculation of haematocrit (Hct) using automated analysers that multiply red blood cell count by mean cell volume.

Cats with anaemia typically present as emergencies when there has been acute blood loss. In this situation, the PCV/Hct may not be particularly low, as they have lost plasma at the same rate as red blood cells. Thus, signs initially may be attributable to hypovolaemia rather than anaemia. Alternatively, cats who have developed anaemia more chronically can compensate quite well for falling haemoglobin levels and then suddenly decompensate, and will present with profoundly low PCV/Hct values (often <10%).

When presented with a cat with anaemia from blood loss, it is important to stabilise the patient and control the blood loss. Stabilisation will initially consist of volume resuscitation, oxygen support and analgesia (discussed in the earlier section on ‘Shock’). It is only after appropriate fluid resuscitation that the true extent of the anaemia will be known. Blood loss is most commonly due to trauma, in which case the source of bleeding may be relatively easy to identify if it is external. Pressure bandaging may enable control of external bleeding until the patient is stabilised for surgical repair. The hard palate should be assessed for evidence of ulceration (Menrath ulcer), as blood that is haemorrhaging at this location may be swallowed and thus will not be externally visible.^38,39

POCUS of the thorax and abdomen should be used to evaluate for cavitary bleeds (Figure 12). If there is no sign of external trauma, then coagulopathy due to vitamin K deficiency (rodenticide poisoning, biliary tract obstruction or exocrine pancreatic insufficiency), thrombocytopenia, bleeding neoplasms or amyloidosis need to be considered. If there has been extensive gastrointestinal tract bleeding, then barrier nursing should be implemented until parvoviral infection has been excluded. Consideration can be given to the use of antifibrinolytic agents such as tranexamic acid (10 mg/kg q8–12h) or epsilon aminocaproic acid (50 mg/kg q6–8h), if available, although there has been minimal use of these therapies in this species.^40,41 If given by the intravenous route, these drugs should be administered slowly, and can be diluted in water for injection to facilitate this slower administration.⁴¹

Figure 12

Haemoabdomen. Abdominal ultrasound image (a) from an 11-year-old Siamese cat presenting with a packed cell volume (PCV) of 13%. There is echogenic fluid within the abdomen, which was confirmed to be blood (PCV 35%) following abdominocentesis. A haematoma was identified between the right liver lobes and, given the breed, amyloidosis was suspected. The cat was stabilised with a blood transfusion but required a second transfusion 4 weeks later. There was little improvement following the second transfusion and the owner elected euthanasia. The liver was mottled and friable on post-mortem examination (b); peliosis hepatis was confirmed on histopathology

Cats with more chronic signs and profoundly low Hct levels may have either bone marrow disease or haemolytic disease and are, therefore, unlikely to show improvement in heart rate and respiratory rate with fluid resuscitation. Heart murmurs and gallop rhythms are commonly identified in anaemic cats, especially those with a PCV <15%,⁴² and fluid therapy at high rates may lead to volume overload in this group of patients.

Blood transfusion

There is no specific value for PCV/Hct that is, in itself, an indication for blood transfusion (see ‘Interpretation of PCV/Hct in the decision to transfuse’ box). All cats should be blood typed before receiving a transfusion; cross-matching is recommended, and essential if they have previously received blood products. In addition, samples for further diagnostic testing (haematology, blood smear evaluation, in-saline agglutination, feline leukaemia virus, feline immunodeficiency virus, Coombs test, clotting times, D-dimer, fibrinogen, feline infectious anaemia, as indicated) should be taken prior to administering blood products.

Cats who are anaemic from blood loss should ideally receive a whole blood transfusion. Where blood banking is available, transfusion could also comprise packed red cells and plasma. For patients who have haemolysis or a non-regenerative anaemia, packed red cells are the blood product of choice, if available.

Identifying a donor can be challenging, particularly in the emergency situation and/or where the recipient is blood type B or AB. Xenotransfusion of canine blood, either as whole blood or packed red blood cells, can, therefore, be life-saving for these patients.^43,44 The incidence of transfusion reactions may be higher than for allotrans-fusions;^44,45 hence, allotransfusion is preferred for a stable patient. The improvement in red blood cell parameters following a xeno-transfusion may only be sustained for approximately 48–72 h. If ongoing haematological support is envisioned, a feline donor must be identified, as xenotransfusion should not be repeated.

Practical guidance on blood typing, cross-matching, donor selection, xenotrans-fusion, and blood collection and administration is available in the ‘2021 ISFM consensus guidelines on the collection and administration of blood and blood products in cats’.⁴⁶

Key Points

✜ Medical emergencies often present without warning and demand immediate veterinary attention. This, together with the fact that cats who are critically ill can be very fragile, makes these cases challenging to manage in a busy veterinary practice.

✜ This article briefly reviews the importance of an appropriate environment for the initial triage and stabilisation of the feline patient, before discussing current thinking specific to the management of shock, dyspnoea, feline aortic thromboembolism and anaemia.

✜ Some ways in which feline patients differ from their canine counterparts are highlighted. Cats, for example, often do not show the hyperdynamic stage of compensatory shock, and cyanosis is seen less commonly in cats than dogs.

✜ The best patient outcomes are achieved when all members of the veterinary team understand their respective roles and work efficiently together. This also helps to ensure that the client’s experience – from the point of making the initial telephone call to the practice through to being appraised of the treatment plan for their cat – is as least stressful as possible.

Footnotes

Conflict of interest

The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author of this commissioned Clinical Spotlight review received an honorarium; as for all JFMS articles, this Clinical Spotlight article went through peer review.

Ethical approval

This work did not involve the use of animals and therefore ethical approval was not specifically required for publication in JFMS.

Informed consent

This work did not involve the use of animals (including cadavers) and therefore informed consent was not required. For any animals or people identifiable within this publication, additional informed consent for publication was obtained.

ORCID iD

Nicola Reed

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