Xenotransfusion with canine blood in the feline species: review of the literature

Major crossmatch compatibility of rabbit blood with rabbit, canine, and feline blood

OBJECTIVE

To evaluate the major crossmatch compatibility between rabbit recipients, rabbit donors, and the major canine and feline blood types.

DESIGN

Prospective in vitro study in December 2021.

SETTING

Academic veterinary teaching hospital.

ANIMALS

Whole blood samples were collected from 11 healthy New Zealand White rabbits (Oryctolagus cuniculus) with no previous transfusion history. Three pigtail segments were acquired from dog erythrocyte antigen (DEA)-1-positive, DEA-1-negative, and feline type A blood units. Whole blood was collected from a healthy type B blood donor cat.

INTERVENTIONS

Blood from each rabbit recipient underwent a major crossmatch using standard tube crossmatch methodology with itself and the following donor blood types: rabbit, DEA-1-positive, DEA-1-negative, feline type A, and feline type B.

MEASUREMENTS AND MAIN RESULTS

Self-crossmatches and crossmatches between rabbit recipients and conspecific donors were negative for hemolysis and agglutination. Crossmatches between rabbit recipients and canine and feline donors yielded no hemolysis but produced varying degrees of macroscopic and microscopic agglutination. Rabbit recipients had 1.4 (95% confidence interval: 1.1-1.8) times the risk of macroscopic agglutination when major crossmatched with canine blood compared to feline blood. No significant difference in agglutination was found between DEA-1-positive and DEA-1-negative or feline type A and type B donors.

CONCLUSIONS

These findings support allogeneic blood transfusions between rabbits being highly compatible and suggest rabbits have naturally occurring alloantibodies against both canine and feline red blood cells. However, feline red blood cells had a lower rate of in vitro incompatibility on major crossmatch, suggesting potentially higher in vivo compatibility if an emergency xenotransfusion is needed. Further prospective research is needed to determine if xenotransfusion is associated with a higher incidence of acute and delayed transfusion reactions in rabbits than allogeneic transfusions.

Retrospective study of canine blood xenotransfusion compared with type-matched feline blood allotransfusion to cats: indications, effectiveness, limitations and adverse effects

OBJECTIVES

Xenotransfusion is the transfusion of blood from one species to another. With varying availability of allogenic feline blood (AFB) and in emergency conditions, circumstances occur when canine blood is transfused to cats. This study aimed to characterise the indications, effectiveness, limitations, and acute and late transfusion-related adverse effects of canine blood xenotransfusion compared with matched AFB to anaemic cats, and their survival and longer-term outcome.

METHODS

This retrospective study (2013-2020) examined cats receiving canine blood xenotransfusions or AFB.

RESULTS

The study included 311 cats (xenotransfusion [X-group], n = 105; allotransfusion [A-group], n = 206). Xenotransfusion was more frequent among cats sustaining haemorrhage than in those with haemolysis (P <0.01) or hypoproliferative anaemia (P <0.001). Financial constraints were the most common reason to elect xenotransfusion (49%). The post-transfusion mean packed cell volume was higher (P <0.001) in the X-group (22%) compared with the A-group (18%), and also higher (P <0.001) at 48-96 h post-transfusion (23% vs 18%, respectively). Transfusion-related adverse effects (TRAEs) were more frequent (P = 0.001) in the X-group (37.1%) compared with the A-group (19.4%), as were delayed haemolytic transfusion reactions (85% vs 42.5%, respectively; P <0.001). Acute transfusion reactions (ATRs) were more frequent (P <0.001) in the A-group (60%) compared with the X-group (20%). TRAEs were unassociated with survival to discharge. The survival to discharge rate of the X-group (55%) was lower (P = 0.007) than in the A-group (73%), while post-discharge survival rates to 30 days of cats surviving to discharge were 90% and 88%, respectively (P = 0.85).

CONCLUSIONS AND RELEVANCE

Canine blood xenotransfusions to cats might save lives in emergency conditions when AFB is unavailable or blood typing is infeasible. The survival to discharge rate of the X-group was lower than that of the A-group. The longer-term survival rate of cats administered xenotransfusions and surviving to discharge from the hospital was good.

Use of recombinant human factor VIIa in 2 patients with postoperative noncompressible, abdominal hemorrhage

OBJECTIVE

To describe the clinical presentation, clinical course, and successful management of noncompressible, abdominal hemorrhage with recombinant human factor VIIa (rFVIIa) in 2 postoperative patients.

CASE SUMMARY

A 14-year-old neutered female Border Terrier and a 9-year-old neutered male domestic shorthair were treated with rFVIIa to treat noncompressible abdominal hemorrhage in the postoperative period. The dog presented for a septic abdomen following endoscopic intestinal biopsies 10 days prior and was found to have a jejunal perforation along with a fractured liver lobe and hepatic lymphoma at the time of exploratory laparotomy. The cat presented for a spontaneous hemoabdomen associated with hepatic amyloidosis. Clinically significant hemorrhage occurred in the perioperative and postoperative period and both patients received massive transfusions and antifibrinolytic therapy. Despite these interventions, the patients continued to have ongoing abdominal hemorrhage and surgical attempts at hemostasis were not attempted due to the friable nature of the liver at the time of surgery. Both patients received rFVIIa intravenously every 3 hours at a dose between 70 and 90 μg/kg as indicated by the clinical picture, which subsequently decreased transfusion requirements.

NEW OR UNIQUE INFORMATION PROVIDED

This case report describes the use of rFVIIa in a cat and a dog with severe, noncompressible abdominal hemorrhage in combination with standard hemostatic interventions.

Case report: Xenotransfusion of canine lyophilized platelets for hemostasis in a feline patient with post-operative abdominal hemorrhage

Objective

To describe the management of post-operative abdominal hemorrhage with a xenotransfusion of canine lyophilized platelets in a feline patient.

Case summary

A 9-year-old male castrated domestic shorthair presented for a spontaneous hemoabdomen secondary to hepatic amyloidosis. Clinically significant hemorrhage occurred in the perioperative and post-operative period and the patient received a massive transfusion and anti-fibrinolytic therapy in combination with a xenotransfusion of canine lyophilized platelets at 0.9 × 10⁹ particles/kg and recombinant human factor VIIa (rhFVIIa). The combination of these interventions decreased transfusion requirements in this patient and the xenotransfusion was well tolerated with no acute or immediate transfusion reactions noted.

New or unique information provided

This case report describes the xenotransfusion of canine lyophilized platelets in a feline patient with severe, non-compressible abdominal hemorrhage.

Incidence of acute haemolysis in cats receiving canine packed red blood cells (xenotransfusions)

OBJECTIVES

The aim of this study was to report the incidence of transfusion reactions in cats, including acute haemolysis (AH), occurring within 24 h of receiving a xenotransfusion. An additional aim was to determine whether cases with AH could be classified as having an acute haemolytic transfusion reaction (AHTR) as per the definition provided by the Association of Veterinary Haematology and Transfusion Medicine's Transfusion Reaction Small Animal Consensus Statement.

METHODS

Medical records of cats that received canine packed red blood cells (PRBCs) between July 2018 and September 2020 at a veterinary hospital were reviewed. The incidence of AH, AHTRs, febrile non-haemolytic transfusion reactions (FNHTRs), transfusion-associated circulatory overload and septic transfusion reactions were recorded.

RESULTS

The medical records of 53 cats were retrospectively evaluated. Twenty-three (43%) cats had transfusion reactions. Thirteen (25%) cats had AH; however, only four (8%) met the definition of an AHTR. Ten (19%) cats were determined to have FNHTRs. Survival to discharge of cats affected by AH was 50% (25% for cases that met the definition of an AHTR). Survival to discharge of cats not suffering from AHTR was 40%.

CONCLUSIONS AND RELEVANCE

This report indicates that a higher proportion of cats undergo AH (25%) when administered canine PRBCs than previously reported, although many could not be classed as having an AHTR due to an apparently adequate packed cell volume rise. Challenges with sourcing feline blood in emergency situations occasionally necessitates the use of xenotransfusion in transfusion medicine. Clinicians should be aware that haemolysis after xenotransfusion can occur within 24 h and that a repeat feline transfusion may be required sooner than anticipated in some cases.

Xenotransfusion of Blood from Dog to Cat: Should Canine Blood Be Our First Choice for Feline Transfusion in Emergency Situations?

Despite the ability to determine feline blood types, the transfusion of canine blood to cats is still practiced in some countries. Xenotransfusion is effective—even if its effects only last for a few days—and is not associated with serious adverse effects. It avoids the need for blood typing, and most importantly, it avoids the transmission of intraspecific infectious agents, notably the feline leukemia virus (FeLV). Transfusion with canine blood is easier, quicker and less costly than transfusion with feline blood; it is less disagreeable for the donor. In the light of these arguments, when feline blood collected according to current guidelines is not available, in particular when the donor is not confirmed to be negative for the FeLV provirus, the authors consider it to be judicious to use canine blood for feline transfusion in emergency situations; this practice is preferable to inaction and to the inoculation of an infectious agent. Allotransfusion remains preferable in non-emergency situations as a treatment of chronic compensated anaemiae or if an appropriate donor (negative for FeLV provirus) is available. However, 2–4 days after a xenotransfusion, if a clinical alteration and a significant decrease in haematocrit are observed, a transfusion with cat’s blood confirmed to be negative for FeLV provirus should be performed. Xenotransfusion should never be used twice.

Wild Felids Blood Group System

Wild felids and domestic cats share the AB blood group. However, there have been few studies regarding the characterization and prevalence of the different blood types in wild animals. The erythrocyte membrane glycolipids of the wild cats correspond to the major disialoganglioside patterns observed in domestic cats. Like in domestic cats, type A blood seems to be the most common, although wild felid species seem to exhibit one single blood type. Of the species studied, the wild domestic cats, and the Panthera and ocelot lineages, all had type A blood; the Puma lineage showed almost exclusively type B blood. The prevalence of wild felids blood types show that there seems to be variation between species, but not within species, and no evidence of geographical variation has yet been found, showing apparently no genetic variability. The presence of alloantibodies has also been demonstrated, so the risk of life-threatening transfusion reactions due to mismatched transfusions and neonatal isoerythrolysis is a possibility. Like in other species, the recognition of wild felids blood groups is clinically relevant, as it can also be important in establishing phylogenetic relationships within the Felidae family. We will review the current knowledge on this topic and give insights into the wild felids blood groups potential for zoo transfusion medicine and phylogenetic studies in order to help support reintroduction projects and to preserve genetic diversity.

In vitro compatibility testing of canine and rabbit blood

OBJECTIVE

To determine the in vitro compatibility of rabbit and canine blood using both a tube and slide agglutination crossmatch technique and to compare the results obtained from these 2 methods.

DESIGN

Prospective observational laboratory study from January to March 2020.

SETTING

University veterinary teaching hospital.

ANIMALS

Six client-owned rabbits ≥3.5 kg undergoing phlebotomy for a clinical reason. "Pigtail" blood samples from 3 dog erythrocyte antigen (DEA) 1-positive and 3 DEA 1-negative canine packed red blood cell units.

INTERVENTIONS

Blood from each rabbit was crossmatched with a single unit of canine blood using both a standard laboratory tube agglutination technique and a simple slide agglutination method with each rabbit/canine unit serving as its own intraassay control. Tube crossmatches were evaluated for agglutination both macro- and microscopically and assessed for hemolysis. Slide crossmatches were assessed for the presence of agglutination both macro- and microscopically.  MEASUREMENTS AND MAIN RESULTS: All crossmatches were incompatible. Varying degrees of agglutination were seen for all crossmatches. Hemolysis was observed with all minor tube crossmatches. Results of both crossmatch techniques were in close agreement.  CONCLUSIONS: The crossmatch results in this present study strongly demonstrate in vitro incompatibility between canine and rabbit blood. Agreement between the 2 techniques in this study indicates that the slide agglutination technique may be quicker, require less blood, and provide reliable results in exclusively assessing the compatibility of canine and rabbit blood. Based on the results of this study, emergency xenotransfusion of canine blood to rabbits cannot be recommended.

Gallbladder and Liver Lobe Torsion in a Young Cat Presented with Hemoabdomen

An 11 mo old domestic shorthair presented with acute lethargy. The cat was hypothermic and bradycardic and had pale pink mucous membranes, poor pulses, and a distended abdomen. Point-of-care ultrasound identified significant abdominal effusion, which was diagnosed to be a hemoabdomen. Bloodwork revealed hyperlactatemia, regenerative anemia, neutrophilia, hypoproteinemia, hypoalbuminemia, and increased alanine aminotransferase. The cat received an allotransfusion and a subsequent canine xenotransfusion and received further supportive therapy. After stabilization, abdominal ultrasonography diagnosed a gallbladder and liver lobe torsion with hemoabdomen. Exploratory laparotomy confirmed the torsion of the right medial and quadrate hepatic lobes together with the gallbladder. Cholecystectomy and lobectomy of the affected lobes were performed using a surgical stapler. The cat was discharged after 4 days. Histopathology confirmed hemorrhagic infarction of the liver lobes and gallbladder, consistent with the described torsion, and the hepatic pseudocyst. It also demonstrated a mucocele in the gallbladder. One month postoperatively, the cat had totally recovered. Hepatic lobe torsion without neoplasia is a rare disease in cats, with variable clinical signs. Gallbladder torsion is a hitherto unreported condition in cats. This is the first report of gallbladder and liver lobe torsion with secondary hemoabdomen in a cat, successfully treated by one-stage surgery.

2021 ISFM Consensus Guidelines on the Collection and Administration of Blood and Blood Products in Cats

PRACTICAL RELEVANCE

Blood and blood products are increasingly available for practitioners to use in the management of haematological conditions, and can be lifesaving and therapeutically useful for patients with anaemia and/or coagulopathies. It is important for feline healthcare that donors are selected appropriately, and transfusions of blood or blood products are given to recipients that will benefit from them. Complications can occur, but can be largely avoided with careful donor management and recipient selection, understanding of blood type compatibility, and transfusion monitoring.

CLINICAL CHALLENGES

Feline blood transfusion, while potentially a lifesaving procedure, can also be detrimental to donor and recipient without precautions. Cats have naturally occurring alloantibodies to red cell antigens and severe reactions can occur with type-mismatched transfusions. Blood transfusions can also transmit infectious agents to the recipient, so donor testing is essential. Finally, donors must be in good health, and sedated as appropriate, with blood collected in a safe and sterile fashion to optimise the benefit to recipients. Transfusion reactions are possible and can be mild to severe in nature. Autologous blood transfusions and xenotransfusions may be considered in certain situations.

EVIDENCE BASE

These Guidelines have been created by a panel of authors convened by the International Society of Feline Medicine (ISFM), based on available literature. They are aimed at general practitioners to provide a practical guide to blood typing, cross-matching, and blood collection and administration.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS). Part 1: Definitions and clinical signs

OBJECTIVE

To use a systematic, evidence-based consensus process to develop definitions for transfusion reactions in dogs and cats.

DESIGN

Evidence evaluation of the literature was carried out for identified transfusion reaction types in dogs and cats. Reaction definitions were generated based on synthesis of human and veterinary literature. Consensus on the definitions was achieved through Delphi-style surveys. Draft recommendations were made available through industry specialty listservs and comments were incorporated.

RESULTS

Definitions with imputability criteria were developed for 14 types of transfusion reactions.

CONCLUSIONS

The evidence review and consensus process resulted in definitions that can be used to facilitate future veterinary transfusion reaction research.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Preliminary Investigation of Bovine Whole Blood Xenotransfusion as a Therapeutic Modality for the Treatment of Anemia in Goats

Anemia requiring whole blood transfusion for appropriate treatment is a common clinical presentation of caprine patients to veterinary practitioners; however, identifying suitable blood donors in goat herds can be challenging. In other veterinary species, the practice of xenotransfusion, where blood from 1 species is transfused to another, is used in emergency settings. Due to their ability to donate large volumes of whole blood, cattle could be an ideal source for xenotransfusion of goats. In this study 2 healthy goats were transfused with bovine whole blood. The goats were then monitored for adverse effects and the presence of bovine erythrocyte post-xenotransfusion. Afterward, 15 caprine–bovine combinations were evaluated for compatibility via cross-matching. Both goats tolerated xenotransfusion, although transient reactions were observed. Of the 15 cross-match combinations, 11 of the major cross matches were compatible, and all minor cross matches were also compatible. While future work is necessary to refine this technique, xenotransfusion of goats with cattle blood may be a therapeutic modality for the treatment of caprine anemia.

The dog erythrocyte antigen 1 blood group in nondomesticated canids and compatibility testing between domestic dog and nondomesticated canid blood

Background

The dog erythrocyte antigen (DEA) 1 blood group is considered as the most immunogenic and clinically important in dogs. Little is known in nondomesticated canids.

Objectives

To type DEA 1 in nondomesticated captive canids and to evaluate potential interspecific blood transfusions between domestic and nondomestic canids.

Animals

One hundred forty captive nondomesticated canids belonging to 13 species from 19 French zoos, and 63 domestic dogs.

Methods

Prospective study. Blood samples were typed for DEA 1 using immunochromatographic and flow cytometric techniques. A neutral gel column test was used for crossmatching.

Results

Of 140 nondomesticated canids, 72.9% were DEA 1+ and 27.1% were DEA 1− using immunochromatographic technique and 74.3% were DEA 1+ and 25.7% were DEA 1− by flow cytometric technique.

Crossmatch (XM) between 140 nondomesticated canid red blood cells (RBCs) and plasma from a previously DEA 1+ sensitized DEA 1− dog revealed 112 incompatibilities (80%). Crossmatches between 130 nondomesticated canid serum and 1 or up to 8 donor dogs' RBCs revealed 99 of 130 (76%) compatibilities. Crossmatches between 115 nondomesticated canid RBCs and donor dogs' serum revealed 59 of 115 (51%) compatibilities.

Conclusions and Clinical Importance

Dog erythrocyte antigen 1 blood type is present in nondomesticated canids with variable prevalence depending on species. The majority of tested nondomesticated canids appear to have no naturally occurring alloantibodies against domestic dogs' RBCs. Therefore xenotransfusion of blood from domestic dogs can be considered when species specific blood is not available. Cross matching is essential before xenotransfusion.

Small Animal Transfusion Medicine

Transfusion medicine can be a lifesaving intervention. Component therapy has expanded the availability and blood products available. Patient safety and minimizing risk is important and can be accomplished through proper donor screening, collection, storage, compatibility testing, administration, and monitoring. The pros and cons of available products must be considered and tailored to each individual patient. Recent discoveries include new antigens and blood types, microbial effects on blood type, and the association between blood type and disease prevalence.

Cryopreservation of feline red blood cells in liquid nitrogen using glycerol and hydroxyethyl starch

OBJECTIVES

The objective of this study was to evaluate the techniques and short-term effects of cryopreservation of feline red blood cells (RBCs) in liquid nitrogen using glycerol or hydroxyethyl starch (HES) as a cryoprotectant.

METHODS

Feline RBCs were manually mixed with either 20% glycerol or 12.5% HES and frozen for 24 h in liquid nitrogen. The samples were thawed and glycerolized samples were manually washed. Success of the freeze/thaw process was determined by recovery rate of RBCs and evaluation of morphological changes using scanning electron microscopy (SEM). A unit of canine packed RBCs was also subjected to the same methodology to evaluate the cryopreservation handling technique.

RESULTS

Feline RBCs preserved with 20% glycerol had a high recovery rate (94.23 ± 1.25%) immediately after thawing. However, the majority of the cells were lost during the washing process, with a final packed cell volume of <1%. A recovery rate was unable to be assessed for samples preserved with HES owing to the high viscosity of the mixture. SEM revealed significant morphological changes after glycerol was added to the feline RBCs. Although these morphological changes were partially reversed after thawing, the majority of the RBCs were lost during the washing process. Minimal morphological changes were noted in the HES sample. Similar results were noted with the canine RBCs.

CONCLUSIONS AND RELEVANCE

The described manual technique for cryopreservation using glycerol was not able to successfully preserve feline or canine RBCs. In the present study, it was difficult to make conclusions about the efficacy of HES. Further studies evaluating HES as a cryoprotectant are warranted.

Life-Threatening Hemorrhage During Patent Ductus Arteriosus Ligation in a Cat: Xenotransfusion With Canine Blood

A 13-month-old Sphynx cat was referred for patent ductus arteriosus (PDA) ligation. A left thoracotomy was performed and the PDA was efficiently ligated. Immediately after chest tube placement, it presented extensive intrathoracic bleeding from the caudal intercostal artery. In view of the absolute necessity of a blood transfusion and given that compatible feline blood was not available, xenotransfusion of canine blood was administered to the cat and resulted in a positive outcome.

Acute hemolytic reaction due to A-B mismatched transfusion in a cat with transient AB blood type

OBJECTIVE

To document a case of transient AB blood type indicated by immunochromatography in a type B cat following administration of an incompatible type A transfusion.

CASE SUMMARY

A 7-month-old neutered male domestic longhair cat was evaluted for anemia, pigmenturia, and intravascular hemolysis 1 day after receiving a feline whole blood transfusion. Neither blood donor nor patient had been blood-typed or crossmatched. The cat presented in shock with a severe non-regenerative anemia, hyperlactatemia, hyperbilirubinemia, hemoglobinemia, hemoglobinuria, and a positive saline slide agglutination test. Immunochromatographic blood typing tests initially indicated the cat had type AB blood, but crossmatch tests with blood from type A and type B donors suggested that the cat was type B. The cat was transfused with type B packed red blood cells without apparent complications and clinically improved. The cat's blood type reverted to type B once all the previously transfused type A cells were cleared from circulation. Furthermore, the original donor was subsequently identified as a Siamese cat and confirmed to have type A blood. While the cause of the original anemia remained unknown, the cat completely recovered and regained a normal hematocrit.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first documented report of transient AB blood type diagnosed using immunochromatography after a transfusion mismatch and shows the utility of crossmatching or back-typing to identify the cat's correct blood type during the hemolytic transfusion reaction.

Successful xenotransfusion in a domestic ferret with spontaneous hemoperitoneum using feline packed red blood cells

OBJECTIVE

To describe the diagnosis, management, and outcome of a ferret with spontaneous hemoperitoneum with surgical intervention and xenotransfusion of type A feline packed red blood cells (pRBCs).

CASE SUMMARY

A domestic ferret diagnosed with a spontaneous hemoperitoneum secondary to a hepatic mass received isotonic crystalloids, hypertonic saline, and an allogenic blood transfusion perioperatively. Postoperatively, the ferret developed progressive anemia and tachycardia refractory to fluid therapy and, given a lack of additional allogenic blood sources, received a xenotransfusion of feline pRBCs. The ferret was hospitalized for 4 days postoperatively and developed a presumed delayed transfusion reaction characterized by transient hyperbilirubinemia. At a 6-month recheck, the ferret was doing well clinically.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first reported case of successful xenotransfusion of feline pRBCs in a ferret. Although xenotransfusion of ferrets with feline blood products is not recommended as a routine procedure, it remains a viable option in critical situations in which ferret blood is unavailable.

Xenotransfusion of canine blood to cats: a review of 49 cases and their outcome

OBJECTIVES

To describe the use of a xenotransfusion protocol, the outcome of xenotransfusion in recipient cats and to assess owner memory of the xenotransfusion.

MATERIALS AND METHODS

Cats administered xenotransfusions in two hospitals between January 2016 and July 2018 were included. Adherence to xenotransfusion protocol, cause of anaemia, blood type, packed cell volume (PCV), transfusion volume, transfusion reactions, PCV 12 hours after transfusion and survival to discharge were recorded. Owners of surviving cats were questioned to assess if they remembered that a xenotransfusion had been performed.

RESULTS

Forty-nine cats underwent the xenotransfusion protocol. The most common causes of anaemia were surgical blood loss (n = 17), immune-mediated haemolytic anaemia (n = 14) and neoplasia (n = 14). Median PCV before transfusion was 10%. Six cats (12%) had febrile non-haemolytic transfusion reactions. Median PCV 12 hours after transfusion was 25%. Ten cats (20%) died or were euthanased within 24 hours of xenotransfusion. A delayed haemolytic transfusion reaction occurred in 25 of 39 (64%) cats manifesting as icterus in 15 cats after a median of 1.9 days and haemolytic serum in 19 cats after a median of 2 days. Of the 18 cats alive at 1 week after discharge, 15 (83%) were still alive at a median of 173 days after xenotransfusion. All owners contacted remembered that their cats had received a xenotransfusion.

CLINICAL SIGNIFICANCE

Xenotransfusion of canine packed red blood cells to cats is possible but haemolysis should be expected between 1 and 6 days after transfusion.

Twelve autologous blood transfusions in eight cats with haemoperitoneum

OBJECTIVES

The objectives of this study were to describe the clinical use and outcome of autologous transfusions in cats with intracavitary haemorrhage.

METHODS

A retrospective descriptive study was performed. Computerised medical records of a single referral centre were searched for cats receiving an autotransfusion. Medical records were evaluated for underlying disease process, autotransfusion technique, autotransfusion volume, time period over which the autotransfusion was given, packed cell volume (PCV) pre- and post-autotransfusion, percentage rise in PCV, use of other blood products and any complications of the procedure. Survival to discharge and survival at 2 months was documented.

RESULTS

Between July 2012 and March 2018 a total of 12 autotransfusions were performed in eight cats. All patients were diagnosed with haemoperitoneum. Four of the eight cats were diagnosed with abdominal neoplasia, three had postoperative haemorrhage and one had a traumatic haemoperitoneum. Three cats received more than one autotransfusion. Blood was collected using a 23 G butterfly catheter and 20 ml syringe in 7/12 collections, a 23 G needle and 20 ml syringe in 2/12 collections and directly into syringes from the open abdomen at the time of surgery in 3/12 collections. A median volume of 50 ml (range 25-80 ml) was collected and administered, meaning a median volume of 16.5 ml/kg (range 9-26 ml/kg) was administered. The autologous transfusions were given over a median of 3 h (0.25-6 h). Five cats were given another blood product alongside the autotransfusion. Median percentage PCV increase was 5% (range 1-7%). Anticoagulant was used in 5/12 autotransfusions. No clinically relevant adverse effects were reported. Six of the eight cats survived to discharge. Two month survival was 60% (3/5).

CONCLUSIONS AND RELEVANCE

Autologous transfusion appears to be a safe and effective technique for stabilising cats with haemoperitoneum. This technique allows rapid and cheap provision of blood and avoids the need for an allogenic blood donor.

Xenotransfusion with packed bovine red blood cells to a wildebeest calf (Connochaetes taurinus)

A 4-month-old female blue wildebeest (Connochaetes taurinus) was presented for bilateral pelvic limb fracture repair. Clinical examination under anaesthesia revealed a water-hammer pulse and a haematocrit of 0.13. A xenotransfusion was performed using bovine (Bos taurus) erythrocytes because of inability to acquire a wildebeest donor. Clinical parameters improved following transfusion and the post-operative haematocrit value was 0.31. The wildebeest remained physiologically stable with a gradually declining haematocrit for the next three days. On the third post-operative day, the wildebeest refractured its femur and was humanely euthanised because of the poor prognosis for further fracture repair. Xenotransfusion using blood from domestic ruminants represents a life-saving short-term emergency treatment of anaemic hypoxia in wild ungulates. Domestic goats could be used as blood donors for rare ungulates where allodonors are not available.

Naturally occurring antibodies in cats against dog erythrocyte antigens and vice versa

Objectives The aim of this study was to investigate the presence of naturally occurring antibodies against canine erythrocyte antigens in cats and vice versa. The influence of canine and feline blood type on cross-match results was also studied. Methods Blood samples from 34 cats and 42 dogs were used to perform test tube major and minor cross-match tests and blood typing. Blood from each cat was cross-matched with blood from 2-6 dogs, for a total of 111 cross-match tests. Haemolysis, macro- and microagglutination were considered markers of a positive cross-match. Results Eighty-three overall major cross-match tests were positive at 37°C, 86 at room temperature and 90 at 4°C. The minor cross-match tests were positive in all but two cross-matches performed at 37°C, all tests performed at room temperature and all but one test performed at 4°C. No cats tested totally negative at both major and minor cross-matches performed with samples from any single dog. Prevalence of warm natural antibodies against canine erythrocyte antigens was lower in type B cats than in type A cats, regardless of the blood type of donor dogs. Conclusions and relevance This study reveals a high prevalence of naturally occurring antibodies in cats against dog erythrocyte antigens and vice versa, and suggests that transfusion of cats with canine blood is not recommended as a routine procedure owing to the potential high risk of either acute severe or milder transfusion reactions.

Clinical presentations, treatments and risk factors for mortality in cats with tick paralysis caused by Ixodes holocyclus: 2077 cases (2008-2016)

Objectives The objective of this study was to describe seasonality, demographics, presentations, treatments, complications and outcomes for cats with Ixodes holocyclus causing tick paralysis, and to identify risk factors for mortality. Methods This was a retrospective single cohort study with 2077 cases occurring between 2008 and 2016, and presenting to one of four emergency clinics in south-eastern Queensland, Australia. Case mortality at 5 days post-presentation could be determined for 1742 cases, and potential risk factors for mortality were assessed using random-effects logistic regression. Results Cases occurred all year round, but there was a marked seasonal pattern with more cases presenting in spring than any other season. Overall, 54/1742 cases (3%) died by 5 days after presentation. Five day mortality incidence for cases that received polyclonal canine tick antitoxin serum (TAS) and recommended treatment was 28/1410 (2%) vs 4/52 (8%) for cases that did not receive TAS ( P <0.001). Mechanical ventilation was recommended for 131/2077 cases (6%). Where mechanical ventilation was recommended but not implemented, mortality incidence was 15/17 (88%), whereas 4/22 cases (18%) that received mechanical ventilation died by day 5. From multivariable analyses, initial gait score (overall P = 0.047) and body temperature on presentation (overall P <0.001) were independently associated with mortality; cases with higher gait scores and those with body temperatures <35°C were at greater risk of death. Cases that had an adverse reaction to TAS were also more likely to die ( P = 0.002). Additional ticks were detected at coat clipping for 80/872 (9%) the cases that were clipped, and coat clipping was associated with a reduced risk of mortality ( P = 0.020). Risk of mortality did not differ significantly by time of year, clinic location, breed, sex, neuter status, age, weight, coat length or number of ticks found. Conclusions and relevance The overall mortality risk for cats treated for tick paralysis caused by I holocyclus is low. Risk factors for mortality include advanced gait and respiratory scores, and hypothermia at presentation. Coat clipping and TAS reduce the risk of mortality, whereas the occurrence of a TAS reaction increases the risk. Mechanical ventilation reduces mortality risk in cats with respiratory failure due to tick paralysis.

Comparative serological investigation between cat and tiger blood for transfusion

Evidence suggests that non-domesticated felids inherited the same AB-erythrocyte antigens as domestic cats. To study the possible compatibility of tiger blood with that of other endangered felidae, blood samples from captive tigers and domestic cats were subjected to an in vitro study. The objectives of this study were to (1) identify whether the captive tigers had blood type AB and (2) determine the compatibility between the blood of captive tigers and that of domestic cats with a similar blood type. The anti-coagulated blood with ethylenediaminetetraacetic acid of 30 tigers was examined to determine blood type, and a crossmatching test was performed between tiger and cat blood. All 30 tigers had blood type A. Tube agglutination tests using tiger plasma with cat erythrocytes resulted in 100% agglutination (n=30) with type B cat erythrocytes and 76.7% agglutination (n=23) with type A cat erythrocytes. The 80% of major and 60% of minor compatibilities between blood from 10 tigers and 10 domestic cats with blood type A were found to pass compatibility tests. Interestingly, 3/10 of the tigers’ red blood cell samples were fully compatible with all cat plasmas, and 1/10 of the tiger plasma samples were fully compatible with the type A red cells of domestic cats. Although the result of present findings revealed type-A blood group in the surveyed tigers, the reaction of tiger plasma with Type-A red cell from cats suggested a possibility of other blood type in tigers.

Ultrasound-guided intracardiac xenotransfusion of canine packed red blood cells and epinephrine to the left ventricle of a severely anemic cat during cardiopulmonary resuscitation

OBJECTIVE

To describe the use of an ultrasound-guided intracardiac xenotransfusion of canine packed red blood cells (pRBC) to the left ventricle of a severely anemic cat during cardiopulmonary resuscitation (CPR).

CASE SUMMARY

An 8-year-old previously healthy neutered female cat was presented with severe weakness after she had disappeared for 1 month. On presentation, the cat was in hypovolemic shock, laterally recumbent, and severely anemic with massive flea infestation. Within minutes of admission, the cat became agonal and suffered cardiopulmonary arrest. CPR was immediately initiated; however, attempts to gain IV access during CPR were unsuccessful. As the cat's blood type was yet unknown, 10 mL of canine pRBC was transfused directly into the left ventricular chamber using ultrasound guidance, as well as 0.02 mg/kg of epinephrine using a similar technique. The cat regained cardiac activity and once the jugular vein was cannulated it received 20 additional mL of canine pRBC intravenously. The packed cell volume and total plasma protein following the intracardiac transfusion were 0.09 L/L [9%] and 30 g/L [3.0 g/dL], respectively. Subsequent blood typing revealed the cat had type B blood. The cat was discharged 3 days post-CPR and was alive and doing well 3 months following discharge.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first reported case of ultrasound-guided intracardiac canine-to-feline xenotransfusion during CPR.

XENOTRANSFUSION IN AN ISLAND FOX (UROCYON LITTORALIS CLEMENTAE) USING BLOOD FROM A DOMESTIC DOG (CANIS LUPUS FAMILIARIS)

Successful xenotransfusion in an island fox ( Urocyon littoralis clementae) has not been previously reported but may be necessary in an emergency. An 11-yr-old male, intact, captive island fox was exhibiting clinical signs of rattlesnake envenomation including hypoperfusion, tachypnea, facial edema, and multifocal facial and cervical ecchymosis. Blood work revealed severe thrombocytopenia (18 K/μl) and anemia (Hct 15.8%). A presumptive diagnosis of rattlesnake ( Crotalus sp.) envenomation was made. Initial treatment included oxygen therapy, fluid therapy, antibiotics, antacids, pain medications, and polyvalent crotalid anti-venom. Emergency xenotransfusion using whole blood (45 ml) from a domestic dog was used due to worsening clinical signs from anemia. No acute or delayed transfusion reactions were observed in the fox and the patient made a full recovery 5 days later. Successful xenotransfusion in an island fox using whole blood from a domestic dog ( Canis lupus familiaris) is possible and may be lifesaving.

Xenotransfusion of anemic cats with blood compatibility issues: pre- and posttransfusion laboratory diagnostic and crossmatching studies

BACKGROUND

Finding compatible feline blood donors can be challenging. Canine blood has been occasionally used when compatible feline blood was not available in emergency situations.

OBJECTIVES

The study goals were to describe the effects of xenotransfusion in 2 anemic cats receiving canine blood because of discordant blood types and acute transfusion reaction, respectively, and to report in vitro heterotyping and crossmatching results between canine and feline blood samples.

MATERIAL AND METHODS

Blood samples from patients and other cats and dogs were typed, crossmatched, and assessed for alloantibodies using gel, card, and immunochromatographic strip techniques.

RESULTS

Cat 1 was found to have type AB blood. Cat 2, which experienced an acute transfusion reaction, had type A blood. Neither had detectable alloantibodies against feline RBC. Both cats transiently improved after transfusion with canine blood; however, acute intravascular hemolysis occurred and the PCV rapidly declined. Blood typing post xenotransfusion with DEA 1 strips revealed a positive control band that was absent in feline blood, thus allowing for the identification of transfused canine RBC. Longitudinal assessment revealed that canine RBC could no longer be detected 4 days after xenotransfusion. Major crossmatching (feline plasma with canine RBC) resulted in both positive and negative reactions, depending on the cat. Minor crossmatching results showed mostly incompatibility.

CONCLUSION

While both cats survived xenotransfusion, the positive control band on the DEA 1 strip revealed that transfused canine RBC were short-lived and intravascular hemolysis occurred. Crossmatch results between cats and dogs showed varied incompatibilities and may not predict transfusion reactions.

Blood transfusion in cats: ABCD guidelines for minimising risks of infectious iatrogenic complications

OVERVIEW

The availability of blood components has increased the number of indications for transfusing cats, and fresh whole blood is readily accessible to clinicians because it can be taken from in-house donor cats or 'volunteer' feline blood donors. A certain amount of risk remains to the recipient cat, as immediate or delayed adverse reactions can occur during or after transfusion, related to immunemediated mechanisms. This article, however, focuses on adverse events caused by infectious agents, which may originate either from contamination of blood following incorrect collection, storage or transfusion, or from transfusion of contaminated blood obtained from an infected donor.

PREVENTION OF BLOOD CONTAMINATION

In cats, blood cannot be collected through a closed system and, therefore, collection of donor blood requires a multi-step manipulation of syringes and other devices. It is crucial that each step of the procedure is performed under the strictest aseptic conditions and that bacterial contamination of blood bags is prevented, as bacterial endotoxins can cause an immediate febrile reaction or even fatal shock in the recipient cat.

PREVENTION OF DISEASE TRANSMISSION

With a view to preventing transmission of blood-borne infectious diseases, the American College of Veterinary Internal Medicine has adopted basic criteria for selecting pathogens to be tested for in donor pets. The worldwide core screening panel for donor cats includes feline leukaemia virus, feline immunodeficiency virus, Bartonella species and feline haemoplasma. The list should be adapted to the local epidemiological situation concerning other vector-borne feline infections. The most practical, rapid and inexpensive measure to reduce transfusion risk is to check the risk profile of donor cats on the basis of a written questionnaire. Blood transfusion can never, however, be considered entirely safe.

Canine and feline blood transfusions: controversies and recent advances in administration practices

OBJECTIVES

To discuss and review blood transfusion practices in dogs and cats including collection and storage of blood and administration of products. To report new developments, controversial practices, less conventional blood product administration techniques and where applicable, describe the relevance to anaesthetists and anaesthesia.

DATABASES USED

PubMed and Google Scholar using dog, cat, blood transfusion, packed red blood cells and whole blood as keywords.

CONCLUSIONS

Blood transfusions improve oxygen carrying capacity and the clinical signs of anaemia. However there are numerous potential risks and complications possible with transfusions, which may outweigh their benefits. Storage of blood products has improved considerably over time but whilst extended storage times may improve their availability, a phenomenon known as the storage lesion has been identified which affects erythrocyte viability and survival. Leukoreduction involves removing leukocytes and platelets thereby preventing their release of cytokines and bioactive compounds which also contribute to storage lesions and certain transfusion reactions. Newer transfusion techniques are being explored such as cell salvage in surgical patients and subsequent autologous transfusion. Xenotransfusions, using blood and blood products between different species, provide an alternative to conventional blood products.