a review of plasma in equine practice 2 · a review of plasma in equine practice the original...
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A Review of Plasma in Equine Practice ................................................................................... 2
SEPTICAEMIA in The Foal and Plasma ..................................................................................... 6
Specific Antibody Transfer
Rhodococcus equi Pneumonia and Hypermune-RE ............................................... 8
Endotoxaemia and Hypermune .............................................................................. 9
Miscellaneous Plasma Use ...................................................................................................... 12
Safety and Quality of Hypermune Products ........................................................................... 15
The purpose of Veterinary Immunogenics Ltd is to promote all the benefits of immunoprophylaxis
and immunotherapy and to be established as the premier producer of the finest animal plasma in
the world.
It succeeds in this by adopting and implementing current best practice, using state of the art
equipment, in the production of blood products in total compliance with the EU regulations for the
manufacture, storage and supply of Veterinary Medicinal Products to the Certificated standard of
Good Manufacturing Practice (GMP). It supports specialist meetings for equine veterinary surgeons
in both the UK and Europe and has formed links with fellow professionals in many countries in
Europe and elsewhere in the world. Above all, it continues to embrace the highest standards of
customer service in product supply and technical advice in product use.
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A Review of Plasma in Equine Practice
The original primary use of equine plasma was to transfer immunity
from adult horses to foals with Failure of Passive Transfer which
became accepted practice following Jeffcott’s work, originally
published in 1974. While this is probably still the main use of plasma in
foals, there are a number of additional indications for plasma to be
considered as part of a preventive or treatment strategy in horses of
different ages:
1. Treatment of FPT 2. Use in septic foals 3. Transfer of specific antibody 4. Miscellaneous:- colic
Colitis intraoperative lavage reproduction.
TREATMENT of FAILURE OF PASSIVE TRANSFER - HYPERMUNE
Introduction
All foals are born with a deficiency of humoral antibody (1). They rely on the adequate intake of good quality colostrum within a few hours of birth to supply significant amounts of IgG and IgG(T) and lesser amounts of IgM and other immunoglobulin classes to provide significant transient protection against infectious agents (2,3,4,6). Unfortunately, this transfer of antibodies from dam to offspring does not always occur successfully due to various factors such as low quantity or poor quality in maiden mares, aged mares losing the ability to concentrate IgG in colostrum or running colostrum before parturition, aggressive mothering and interference with absorption in the foal. This results in “failure of passive transfer” (FPT), as depicted by foal serum gammaglobulin levels (usually specifically IgG) of less than 4g/l. If this deficiency is confirmed before the gut’s ability to absorb antibodies ceases (from 12 hours of age), oral supplementation of good quality colostrum or plasma may well rectify the situation. If, on the other hand, the foal is over 12 hours old when this deficiency is diagnosed, the foal has to be considered at risk to infection, especially in a “high challenge” environment. In such circumstances transfusion of plasma should be considered, the benefits of which are well documented (7,8).
The Practical Use of HYPERMUNE The main use for equine plasma is as a source of equine IgG when used prophylactically in foals with failure of passive transfer or partial failure of passive transfer. The IgG molecule is a Y shaped structure of linked polypeptide chains. Each of the two branches of the Y is the Fab fragment because it has the ability to bind antigen, while the “body” of the Y is called the Fc fragment, which has the ability to bind to receptors on the surface of innate immune cells. This part is crucial in recruiting phagocytes to engulf and kill pathogens, and activating the
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complement cascade, leading to disruption of cell membranes and destruction of invading micro-organisms. It is from this background that Hypermune is harvested and stored to ensure these desirable properties of IgG are preserved. Although there are a number of beneficial proteins in equine plasma, IgG has always been the focus of attention because not only is it of major immune importance but it is also relatively easy to measure semi-quantitatively in foal blood due to the availability of commercial test kits such as Gamma-Check-E or quantitatively using a validated test in an approved laboratory. The veterinary application of equine plasma for the treatment of FPT in foals is not new, having been recommended for over 20 years in text books (12,13,14), conference proceedings (15), satellite article (16), practice tip (13), and a manual of equine neonatal medicine (17). In the United States, where commercial equine plasma usage has been well established for much longer than in the United Kingdom, the whole matter was reviewed in 1994 (18), with the conclusion that the process of plasmapheresis has made the use of equine plasma safe and efficacious. The review states that research with equine plasma has shown that treatment of disease or protection against disease is in proportion to the amount of IgG in the plasma. It also summarises one of the earliest studies on equine plasma in 1984, which saw 119 transfusions being made in a variety of equine disease states including FPT and septicaemia. In the United Kingdom, two publications by Durham (16) and Stoneham (11), advocate that the administration of plasma to a foal can be a life saving procedure and that plasma administration has important applications in the therapeutic and prophylactic management of conditions in equine practice. Indications for Plasma Transfusion Equine plasma transfusion is indicated where a foal of 12-18 hours old or more has been diagnosed as having inadequate circulating gammaglobulin levels. The definition of “inadequate” is open to some degree of interpretation and dependent on several factors (8,9). Generally, veterinary medical standards (and often some insurance company requirements) now dictate that foals be checked for IgG within the first day or so of life and those showing a deficiency given some form of supplementary antibodies. In the treatment of Failure of Passive Transfer, the administration of plasma should be based on the accurate IgG level of the foal. It is, therefore, extremely important to employ a test which provides a meaningful result. On receipt of the result, the following considerations should be borne in mind:
IgG< 2g/l Strong predisposition to development of infection
IgG<2-4g/l Increased risk of developing infection
IgG 4-8g/l Moderate transfer, but risk of developing infection remains especially in a high challenge environment.
IgG > 8g/l Good to excellent transfer, no action needed
IgG is the immunoglobulin
isotype found in the highest
concentration in blood and
plays a major role in antibody
mediated defence
mechanisms. Because of its
size, it can escape from blood
vessels more easily than
other immunoglobulin
molecules thus readily
participating in the defence
of tissue spaces and body
surfaces. IgG can opsonise,
agglutinate and precipitate
antigen but it can activate the
complement cascade only if
sufficient molecules have
accumulated in a correct
configuration on the antigen
surface.
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A 50kg foal has a plasma volume of approximately four litres and therefore any transfused antibodies will be immediately distributed within this volume. The administration of one litre of plasma containing 24g IgG, Hypermune’s minimum level, will initially raise the recipient’s blood level by 6g/l (24 divided by 4). However, within 24 hours following transfusion there is some movement out of the circulation and only about 50% remains in the vascular system after 24 hours. It is important to wait approximately 24 hours before measuring the IgG level after transfusion. Following transfusion of one litre of plasma containing 24g IgG, the foal’s circulating level will be increased, therefore, by about 3g/l (10). By accurately knowing the initial level and the desired final level the amount of plasma to be administered can be calculated. This may be provided by infusing up to four litres of plasma from a normal resting horse but in a foal this would cause serious volume overload problems. The design of Hypermune equine plasma is to overcome this problem by providing a greater concentration of IgG per litre using hyperimmunised horses. The dose of Hypermune is 20ml/kg body weight. Following plasma transfusion, often a second sample is tested for IgG status. Interpretation of the result depends on a number of factors, such as:
1. How soon the sample is taken following transfusion? 2. Has the foal an active septic process in which IgG is
consumed? 3. The dilution factor effect on the transfused IgG in the foals
circulating blood volume. 4. The speed which IgG leaves the vascular system.
Failure of Passive Transfer may, therefore, also require more than one administration of Hypermune to sustain satisfactory levels of foal serum IgG. The results of a 2003 study (Figure 1) suggest that FPT foals may benefit from a second litre at 3-4 weeks old to close the window of susceptibility to septic challenge, concurring with the literature that foal serum IgG increases naturally only after 8-10 weeks of age (19).
Figure 1: IgG levels of 4 foals pre- and post- Hypermune transfusion; 2003
Field Study.
Any steps which the equine
veterinary surgeon can take
to improve the welfare of
the equine neonate by
decreasing the susceptibility
to painful, debilitating and
potentially fatal infectious
disease such as septicaemia,
joint-ill, navel-ill, diarrhoea
and pneumonia must be
given serious consideration.
Equine plasma provides that
facility for the foal which has
Failure of Passive Transfer of
colostral immunity. The
intravenous administration
of equine plasma produced
and marketed in compliance
with national regulations as
a Veterinary Medicinal
Product is accepted and
utilised in the United
Kingdom and Europe.
Mick, has donated over
2000 litres of Hypermune
since arriving on site in
1992.
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Table 1: Customer feedback
Foal Identity
Before Plasma After Plasma
Dose Age in Hours
IgG level
Age in hours
IgG level
13/6-5 24 4-8 72 > 8 1 litre
6/6 24 <4 72 6-8 1 litre
4/6-2 24 4 96 > 8 1 litre
31/5-5 24 < 4 48 > 8 1 litre
21/5-8 24 < 4 72 8 1 litre
3/5-3 24 4-8 48 8 1 litre
8/3-6 24 < 4 120 8 1 litre
12/2 24-48 4-8 96 > 8 1 litre
References 1. Jeffcott LB. Some practical aspects of the transfer of passive immunity to
new-born foals. Equine Veterinary Journal 1974; 6: 109-115.
2. Jeffcott LB. The transfer of passive immunity to the foal and its relation to immune status after birth. Journal of Reproduction & Fertility 1975; 23: 727-733. 3. Tizzard I. Immunity in the Fetus and Newborn. Veterinary Immunology, An Introduction, 4th Edition W B Saunders & Co, London 1992: 255. 5. Fenger CK. Neonatal & Perinatal Diseases. Equine Internal Medicine, Reed & Bayly W B Saunders & Co, London 1998: 941. 6. McLure, J.J. The Immune System. Equine Reporduciton. Lea & Febiger, London 1993: 1007 – 1011. 7. Crawford TB, Perryman LE. Diagnosis and treatment of failure of passive
transfer in the foal. Equine Practice 1980; 2,1: 17-23.
8. Rumbaugh GE, Ardens AA, Ginno D, Trommerhausen-Smith. Identification
and treatment of colostrum deficient foals. Journal of the American
Veterinary Medical Association 1979; 174: 273-275.
9. Koterba AM, Brewer B, Drummond WH. Prevention and control of
infection. Veterinary Clinic of North American Equine Practitioners 1985; 1:
41-50.
10. White SL. Exogenous IgG in the treatment of foals with failure of passive
transfer and/or sepsis. Proceedings of the sixth annual veterinary medical
forum. American College of Veterinary Internal Medicine 1988; 145-147.
11. Stoneham S. Collection and Administration of Plasma to a Newborn Foal. In Practice1997; Vol 19, No 7: p 8-12.
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12. Tizzard I. Immunity in the Fetus and Newborn. Veterinary Immunology, An Introduction, 4th Edition W B Saunders & Co, London 1992: 256. 13. Morris D D. Disorders of The Immune System. Equine Internal Medicine, Reed & Bayly 1998: p 48-49. 14 McLure JJ. The Immune System. Equine Reproduction, Lea & Febiger W B Saunders & Co London 1993: p1010.
15. Proceedings of Technical Workshop on Veterinary Transfusion Medicine. American Association of Blood Banks 1989: 1-6.
16. Durham AE. Blood and plasma transfusion in the horse. Equine Veterinary Education 1996; 8 : 8-12.
17. Madigan JE. Plasma Therapy. Manual of Equine Neonatal Medicine – 2nd Edition (revised) 1994: p 39-44.
18. Jones EJ. Hyperimmune plasma therapy: does it have a future in equine practice? Veterinary Review 1994; 14: 581-584. 19. Tizzard I. Immunity in the Fetus and Newborn. Veterinary Immunology, An Introduction, 7th Edition W B Saunders & Co, London 2004: 228.
SEPTICAEMIA in The Foal and Plasma
In the presence of sepsis, immunoglobulins are rapidly consumed whether derived from colostral transfer or plasma, resulting in a shortened half-life. Plasma proteins provided by transfusion normally have a half-life similar to autologous proteins, which in the case of immunoglobulins is about 21 days. In the presence of infection, the half life might be as low as a few hours and a plasma transfusion might not appear to give the expected increase in IgG when given to a sick foal. It needs to be emphasised that the sick foal would have had a lower IgG if plasma had not been given. To keep IgG levels sustained in the face of rapid consumption, severely compromised foals can require a number of litres over a few days to prevent volume overload.
Scientific evidence in recent years supports the use of equine plasma
in the treatment of septic foals (2, 5, 6). The opsonic ability of foal
serum has been found a limiting factor for the phagocytosis of
pathogens in foals up to the age of 3 – 4 weeks (2, 3, 4). Phagocytic
activity has been found to increase when mixed with adult plasma (1,
2). This was associated with greater opsonic factors provided by adult
plasma, with fibronectin and complement being suggested as possible
opsonic contributors. Improved oxidative burst activity of neutrophils
has also been recorded in septic foals post transfusion of plasma (5).
This suggests that specific and non-specific factors in plasma in some
way promote white cell activity.
A retrospective study, covering 65 septicaemia cases, found the
administration of plasma was significantly associated with foal survival
(7). On this evidence, it is recommended that plasma is administered as
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soon as septicaemia is suspected or confirmed in the neonatal foal. At
the Foal Care Course in Newmarket in January 2008, John Madigan
emphasised that in his clinic, all septic foals are given a litre of plasma
at the outset, irrespective of IgG status. Hypermune should therefore
be a prime consideration as part of the treatment protocols when
faced with septicaemia in the foal.
References 1. Grondahl, G., Johanisson, A. and Jensen, W. (1997) Opsonic effect of equine
plasma from different donors. Veterinary Microbiology; 56: 227 – 235.
2. Grondahl, G., Johanisson, A. Demmers, S. and Waern, M.J. (1999) Influence
of age and plasma treatment on neutrophil phagocytosis and CD18 expression
in foals. Veterinary Microbiology; 65: 241 – 254.
3. Demmers, S., Johannisson, A., Grondahl, G. and Jensen-Waern, M. (2001) Neutrophil functions and serum IgG in growing foals. Equine Veterinary Journal; 33: 676 – 680.
4. McTaggart, C., Yovich, J.V., Penhale. J and Raidal, S.L. (2001) A comparison
of foal and adult horse neutrophil function using flow cytometric techniques.
Research in Veterinary Science; 71: 73 – 79.
5. McTaggart,C., Penhale, J. and Raidal, S.L. (2005) Effect of Plasma
Transfusion on Neutrophil Function in Healthy and Septic Foals. Australian
Veterinary Journal; 83: 499 – 505.
6. Gardner, R.B., Nydam, D.V., Luna, J.A., Bicalho, M.L., Matychak, M.B. and
Flaminio, M.J. (2007) Serum opsonisation capacity, phagocytosis, and
oxidative burst activity in neonatal foals in the intensive care unit. Journal of
Veterinary Internal Medicine; 21: 797 – 805.
7. Gayle, J.M., Cohen, N.D. and Chaffin, M.K. (1997) Factors associated with
survival of septicaemic foals: 65 cases (1988 – 1995). Journal of Veterinary
Internal Medicine; 12: 140 – 146.
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SPECIFIC Antibody Transfer
Rhodococcus equi Pneumonia and Hypermune-RE
R. equi infection represents a significant cause of disease in foals between 1 and 6 months of age producing chronic bronchopneumonia with extensive abscessation, which is often fatal. Much research over the past two decades has focused on immunity to this pathogen (both in the immune adult and susceptible foal), and developing preventive strategies, such as Hyperimmune plasma, to provide passive transfer of specific antibodies. Some researchers have reported a reduction in R. equi related morbidity and mortality as a consequence of plasma administration (1, 2, 3, 4, 5). Currently, development of a protective vaccine has been unsuccessful.
Attendance at the 4th Havemeyer Workshop on R. equi in Edinburgh in July 2008, enhanced Veterinary Immunogenics Ltd’s current knowledge on organismal biology, pathogenesis, immunology, clinical aspects and epidemiology of this disease. A recurrent debate between scientists in the field concerning the age at which young foals are infected with R. equi was apparent. The old, yet accepted paradigm suggests that foals can become infected at anytime throughout the first 1 – 6 months of age, and is often linked to the wane of maternal antibodies. It was argued that this age range is when foals develop clinical signs, not when most infections are initiated. Some researchers have provided evidence that most foals are actually infected within the first few days of life (6), which may mean it will be very difficult to develop a primary vaccination strategy to protect foals within the first week of life from R. equi disease. It was accepted however that some foals can become infected at a more advanced age, as do some adults, which is related to the level of environmental challenge in paddocks, and more likely in the stables and horse walkers of breeding farms in temperate climates such as Ireland and the UK (7, 8, 9, 10).
There was general concern at the meeting on the use of antibiotics, such as Azithromycin and Erythromycin, as a chemoprophylactic tool, for fear of developing multi-drug resistant virulent strains of this pathogen. The use of hyperimmune plasma as an immunoprophylactic tool was still generally supported. Data collected over 4 years from an endemic farm, and presented as a poster at the workshop, clearly showed a reduced incidence of disease in foals that received Hypermune-RE (average 10% with disease), compared to control foals (average 50% with disease) (11).
A further observation made at the workshop was the timing of
transfusing a second litre of hyperimmune plasma. It is current
practise to transfuse a second dose approximately 21 days after the
first, which is administered at birth. Data, also presented by the
previous referenced author, revealed a sharp drop in antibody levels in
foals between 21 and 28 days of age (11). A large field study
conducted on an endemic farm by Veterinary Immunogenics Ltd in
2006 found foals seroconverted at 21 days of age (Figure 2), which was
thought to indicate environmental challenge. It was evident that
Figure: Electron micrograph of R. equi strain 103+ opsonised by Hypermune-RE specific antibodies (black dots on cell surface).
Lung abscesses due to R. equi
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0
5
10
15
20
25
1 1.4 5 21 30 30.4 35
Age (Days)
Me
an
An
ti-R
.eq
ui
An
tib
od
y
(% V
IL S
tan
da
rd)
Group 1: Hypermune-RE
Group 2: Standard Plasma
Group 3: Controls
control foals seroconverted at a faster rate than either of the treatments groups, but an endogenous production of antibodies does not necessarily correlate with clinical infection or indeed protection (22). It was therefore discussed that it may be beneficial to reduce the interval between the first and second transfusion of Hypermune-RE to prevent a sharp drop in antibody and other immune components in the face of environmental challenge.
Figure 2: Mean anti-R. equi antibody levels in foals used in Hypermune-RE
efficacy study 2006, n = 90. Plasma transfused at 1 and 21 days of age (12).
Endotoxaemia and Hypermune
Endotoxaemia is a life-threatening condition that is associated with
many gastrointestinal diseases in adult horses and septicaemia in
foals. Successful treatment of endotoxaemia relies on preventing
movement of gram-negative endotoxins into general circulation,
neutralising endotoxins before they react with inflammatory cells, and
preventing synthesis and release of inflammatory mediators (13). The
neutralisation of endotoxins through the use of anti-endotoxin
(lipopolysaccharide, LPS) antibodies in equine plasma has been found
successful, relating to an increased survival rate and reduction in time
to recovery (14, 15, 16, 17). Since circulating endotoxins and infectious
agents are an important risk factor for the development of laminitis,
the use of hyperimmune plasma for treatment of endotoxaemia and
septicaemia is advised to help prevent laminitis in horses during
hospitalisation (18).
Veterinary Immunogenics Ltd produced a plasma product called
Hypermune-J from donors hyperimmunised with a gram-negative core
antigen vaccine for treatment of endotoxaemia. A specific ELISA was
used to assess the level of gram negative endotoxin antibodies in
Hypermune products and the general adult UK horse population.
Clinical signs of
endotoxaemia are related to
the levels of circulating
endotoxin. Low levels
(0.03ug/kg) produce
symptoms such as mild
depression with clinical
"silence" but changes in the
blood, medium levels (10
ug/kg) are clinically "noisy"
and high levels (125ug/kg)
will cause death.
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Group Mean: Comparison @ 1/300
Hypermune-J Hypermune Hypermune-RE General Horse0
1
2
3
4
Group
Ab
so
rban
ce (
450n
m)
Figure 3 demonstrates the comparable level of anti-endotoxin
antibodies in all Hypermune products, which is significantly greater
than levels found within the general horse population (P=<0.001).
Recent publications have reported that ordinary equine plasma
provides a measurable benefit in terms of prolonged opsonisation and
improved neutrophil function when given to septic foals (19, 20). In
addition, this was endorsed at Rossdales Foal Care Course in January
2008 when it was stated that all septic foals are given 1 litre of plasma
irrespective of IgG status (21). On the basis of evidence supporting the
use of existing licensed Hypermune products and the difficulties in
complying with current regulatory demands to license additional
Hypermune products as “new” Veterinary Medicinal Products,
reluctantly the production of Hypermune-J was ceased. Veterinary
Immunogenics Ltd now advocates the use of Hypermune or
Hypermune-RE for endotoxaemia as part of an overall treatment
strategy.
Figure 3: Comparison of anti-endotoxin antibodies in Hypermune products and the general UK adult horse population at 1/300 plasma dilution.
References 1. Martens, R.J., Martens, J.G., Fiske, R.A. and Hietala, S.K. (1989) Rhodococcus equi foal pneumonia: Protective Effects of Immune Plasma in Experimentally Infected Foals. Equine Vet. J. 21, 249–255.
2. Madigan, J.E., Hietala, S. and Muller, N. (1991) Protection against naturally acquired Rhodococcus equi pneumonia in foals by administration of Hyperimmune plasma. J. Reprod. Fertil. Suppl. 44, 571–578.
3. Becu, T., Polledo, G. and Gaskin, J.M. (1997) Immunoprophylaxis of Rhodococcus equi pneumonia in foals. Vet. Microbiol. 56, 193-204.
4. Higuchi, T., Arakawa, T., Hashikura, S., Inui, T. and Takai, S. (1999) Effect of prophylactic administration of hyperimmune plasma to prevent Rhodococcus equi infection on foals from endemically affected farms. J. Vet. Med. B Infect. Dis. Vet. Public Health. 46, 641-648.
The treatment of
endotoxaemia should be
prompt, aggressive and
complete, as there is such a
narrow therapeutic window
through which to achieve
success. In the neonate
especially, clinical signs can
be very subtle. If there is a
hint of septicaemia the
assumption should be that it
is endotoxic and treatment
started.
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5. Caston, S.S., McClure, S.R., Martens, R.J., Chaffin, M.K., Miles, K.G., Griffith, R.W. and Cohen, N.D. (2006) Effect of hyperimmune plasma on the severity of pneumonia caused by Rhodococcus equi in experimentally infected foals. Vet. Ther. 7, 361–375.
6. Horowitz, M.L., Cohen, N.D., Takai, S., Becu, T., Chaffin, K.M., Chu, K.K., Magdesian, K.G. and Martens R.J. (2001) Application of Sartwell’s model (lognormal distribution of incubation periods) to age at onset and age at death of foals with Rhodococcus equi pneumonia as evidence of perinatal infection. J. Vet. Intern. Med. 15, 171-175.
7. Muscatello, G., Gerbaud, S., Kennedy, C., Gilkerson, J.R., Buckley, T., Klay, M., Leadon, D.P. and Browning, G.F. (2006a) Comparison of concentrations of Rhodococcus equi and virulent R. equi in air of stables and paddocks on horse breeding farms in a temperate climate. Equine Vet. J. 38, 263-265
8. Muscatello, G., Anderson, G.A., Gilkerson, J.R. and Browning, G.F. (2006b) Associations between the ecology of virulent Rhodococcus equi and the epidemiology of R. equi pneumonia on Australian Thoroughbred farms. Appl. Environ. Microbiol. 72, 6152-6160.
9. Fogarty, U., McGrath, P. and Buckley, T. (2008) Rhodococcus equi in adult animals. Proceedings of the 4th Havemeyer workshop on Rhodococcus equi, pg 64.
10. Klay, M., Leadon, D., Fogarty, U. and Buckley, T. (2008) R. equi disease in Ireland’s temperature climate – clinical studies 2002 to 2007. Proceedings of the 4th Havemeyer workshop on Rhodococcus equi, pg 58.
11. Palmer, L., Cooke, C.D., Holmes, M.A., Manning, F.M., Challis, M., Cash, R. and Stoneham, S.J. (2008) Studies on the persistence of transfused Rhodococcus equi antibodies in thoroughbred foals. Proceedings of the 4th Havemeyer workshop on Rhodococcus equi, pg 67.
12. Dawson, T.R.M.Y, Carter, N. and Cunningham, A.C. (2008) A double blind study comparing the effect of hyperimmune plasma and standard equine plasma on reducing the incidence of Rhodococcus equi infection and requirement for treatment on an endemic farm. Proceedings of the 4th Havemeyer workshop on Rhodococcus equi, pg 71.
13. Moore, J.N. (2005) An update on Endotoxaemia in horses. Proceedings from the American Association of Equine Practitioners (AAEP), Canada.
14. Wells, M.T., Gaffin, S.L., Gregory, M. and Coovadia, Y. (1987) Properties of equine anti-lipopolysacchairde hyperimmune plasma: binding to lipopolysaccharide and bactericidal activity against gram-negative bacteria. Journal of Medical Microbiology; 24: 187 – 196. 15. Gaffin, S.L. and Wells, M.T. (1987) A morphological study of the action of anti-lipopolysaccharide plasma on gram-negative bacteria. Journal of Medical Microbiology; 24: 165 – 168. 16. Spier, S.J., Lavoie, J.P., Cullor, J.S., Smith, B.P., Synder, J.R. and Sischo, W.M. (1989) Protection against clinical endotoxaemia in horses by using plasma containing antibody to an Rc mutant E. Coli (J5). Circulatory Shock; 28: 235 – 248.
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17. Peek, S.F., Semrad, S. McGuirk, S.M., Riseberg, A., Slack, J.A., Marques, F., Coombs, D., Lien, L., Keuler, N. and Darien, B.J. (2006) Prognostic value of clinicopathologic variables obtained at admission and effect of anti-endotoxin plasma on survival in septic and critically ill foals. Journal of Veterinary Internal Medicine; 20: 569 – 574. 18. Parsons, C.S., Orsini, J.A., Krafty, R., Capewell, L. and Boston, R. (2007) Risk factors for development of acute laminitis in horses during hospitalisation: 73 cases (1997 – 2004). Journal of the American Veterinary Medical Association; 230: 885 – 889.
19. McTaggart, C., Yovich, J.V., Penhale. J and Raidal, S.L. (2001) A comparison of foal
and adult horse neutrophil function using flow cytometric techniques. Research in
Veterinary Science; 71: 73 – 79.
20. Gardner, R.B., Nydam, D.V., Luna, J.A., Bicalho, M.L., Matychak, M.B. and Flaminio,
M.J. (2007) Serum opsonisation capacity, phagocytosis, and oxidative burst activity in
neonatal foals in the intensive care unit. Journal of Veterinary Internal Medicine; 21:
797 – 805.
21. Madigan, J. (2008) Plasma – how and when to use it. Proceedings of the Rossdale and Partners Foal Care Course, British Racing School, Newmarket. pg 131–132.
22. Giguere, S. and Prescott, J.F. (1997) Strategies for the control of Rhodococcus equi infections on enzootic farms. AAEP Proceedings; 43: 65 – 70.
MISCELLANEOUS Plasma Use
Colic
In addition to immunoglobulins, plasma provides a source of many
other non-specific proteins, such as coagulation factors, anti-thrombin
III and albumin to maintain oncotic pressure (1), which is important in
cases of hypoproteinaemia and hypovolaemia. Hyperimmune plasma
has been reported to help reduce abdominal inflammation and
minimise the effects of endotoxaemia associated with gastrointestinal
adhesions (2). Hypermune is frequently used in large equine hospitals
in the UK for post-operative management of colic.
Colitis and Diarrhoea
Colitis, whether associated with gram-negative bacteria in the large
intestine (Salmonella spp) or gram positive bacteria ( Clostridium spp),
or antibiotic use, is frequently coupled with diarrhoea and subsequent
hypoproteinaemia and hypovolaemia. Plasma provides many benefits,
but is primarily used intravenously for colloidal support. Plasma is also
the treatment of choice if protein loss is accompanied by coagulation
disorders (3). Although intravenous transfusion of plasma is more
commonly used, there is evidence, especially in the human literature,
that oral administration of plasma can effectively minimise causative
agents of colitis and diarrhoea, such as Clostridium spp, Candida spp, E.
Coli and Rotavirus (4). Hyperimmune plasma has also been reported to
decrease the time to resolution of diarrhoea (5).
Intraoperative Lavage
Hyperimmune plasma has
been reported to reduce the
adhesion of bacteria to bone
surfaces, compared to
PlasmalyteTM (6). Hypermune
could therefore be useful as
an Intraoperative lavage
solution to decrease post-op
infections.
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Reproduction
Bacterial infections in the uterus are recognised as a major cause of reproductive failure in mares (7). The use of plasma transfusion therapy to improve fertility has been studied and discussed (13). Intrauterine administration of hyperimmune plasma was found to increase pregnancy rates in susceptible mares by reducing uterine infections caused by common bacterial strains, such as Streptococcus zooepidemicus (8,9,10). The mechanism by which this occurred was associated with plasma enhancing the phagocytic activity of uterine neutrophils (9,14). An earlier study also showed considerable promise of intrauterine infusions of plasma through successfully breeding many barren mares (11), though some authors have suggested that plasma may only be beneficial in mares that do not possess mechanical clearance problems (14,15). Some authors debated whether the efficacy of plasma exceeded the efforts required to collect, store and administer plasma (8), but the availability of commercial Hypermune now provides reliable access to high quality and safe plasma. The use of Hypermune for the management and treatment of endometritis could be considered to try to improve reproductive rates and possibly prevent the development of bacterial resistance associated with repeated antibiotic administration.
A further use for Hypermune in equine breeding is for the prevention of Neonatal Isoerythrolysis. If a mare is at risk of transferring anti-red cell antibodies via colostrum to the foal, hyperimmune plasma should be considered as an immunological passive transfer replacement (12). This method could allow breeders to continue using mares associated with Neonatal Isoerythrolysis.
References
1. Hardy, J. and Rakestraw, P.C. (2002) Postoperative management for colics. Clinic Techniques in Equine Practice; 1: 188 – 197.
2. Eggleston, R.B. and Mueller, P.O. (2003) Prevention and treatment of gastrointestinal adhesions. Veterinary Clinics of North America: Equine Practice; 19: 741 – 763.
3. McConnico, R. (2003) Acute equine colitis. Equine Compendium; 25: 623 – 631.
4. Zeitlin, L., Cone, R.A. and Whaley, K.J. (1999) Using monoclonal antibodies to prevent mucosal transmission of epidemic infectious diseases. Emerging Infectious Diseases; 5: 54 – 64. 5. Atherton, R.P. (2007) Efficacy of hyperimmunised plasma in the treatment of horses with acute diarrhoea. MSc Thesis (unpublished), Faculty of Virginia Polytechnic Institute and State University. 6. Bauer, S.M., Santschi, E.M., Fialkowski, J., Clayton, M.K. and Proctor, R.A. (2004) Quantification of Staphylococcus aureus adhesion to equine bone surfaces passivated with PlasmalyteTM and Hyperimmune Plasma. Veterinary Surgery; 33: 376 – 381.
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7. Reiswig, J.D., Threlfall, W.R. and Rosol, T.J. (1993) A comparison of endometrial biopsy, culture and cytology during oestrus and dioestrus in the horse. Equine Veterinary Journal; 25: 240 – 241.
8. Causey, R.B. (2006) Making sense of equine uterine infections: the many faces of physical clearance. The Veterinary Journal; 172: 405 – 421.
9. Pascoe, D.R. (1995) Effect of adding autologous plasma to an intrauterine antibiotic therapy after breeding on pregnancy rates in mares. Biology of Reproduction Monograph Series; 1: 539 – 543.
10. Watson, E.D. and Stokes, C.R. (1988) Use of hyperimmune serum in treatment of endometritis. Theriogenology; 30: 893 – 899.
11. Asbury, A.C. (1982) Uterine defence mechanisms in the mare: the use of intrauterine plasma in the management of endometritis. Theriogenology; 21: 387 – 393.
12. McClure Blackmer, J., Paccamonti, D., Eilts, B., Costa, L.R.R. and Koch, C. (2002) Strategies for preventing Neonatal Isoerythrolysis. Equine Compendium; 24: 562 – 569.
13. Pycock, J.F. (2007) Therapy for mares with Uterine Fluid. In Samper, J.C., Pycock, J.F. and McKinnon, A.O. (eds) Current Therapy in Equine Reproduction. Saunders (Elsevier), St. Louis, Missouri.
14. Adams, G.P. and Ginther, O.J. (1989) Efficacy of intrauterine plasma for treatment of infertility and endometritis in mares. Journal of the American Veterinary Medical Association; 194: 372.
15. Umpheneor, N.W., Sprinkle, T.A. and Murphy, H.Q. (1993) Natural Service. In McKinnon, A.O. and Voss, J.L. (eds) Equine Reproduction. Lea & Febiger, Philadelphia.
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Safety and Quality of Hypermune Products
Hypermune equine plasma is designed to be:
Red cell group compatible with recipient horses
Produced by a consistently repeatable process
Free from endotoxins
Free from external contaminants
Free from important named viruses
Free from known pathogens
Consistent with normal fresh equine plasma
More consistent in its immunoglobulin and total protein content than plasma from the foal’s dam or a random donor, specifically IgG ≥ 24g/l
More value in its IgG content due to VIL’s vaccine protocols than plasma from the foal’s dam or a random donor
Immediately available
Free from excess citrate
In addition Hypermune-RE contains high levels of specific antibodies to European strains of pathogenic R. equi.
Avoiding Problems with Frozen Hypermune Products
Plasma Considerations:
Adoption of instructions on product label and package insert
Receiving, CAREFULLY handling and placing in dedicated frozen storage at -25°C (± 5C°).
Selecting, removing from storage and DILIGENTLY thawing at not greater than 40°C.
Slowly warming thoroughly to body temperature.
Using the correct blood giving set with large filter.
Foal Considerations:
Between birth and 1 month the sympathetic nervous system matures
dramatically (Table 3). Until then, the immature baro receptor reflexes
mean that there is an inherent degree of haemodynamic instability and
neonates do not tolerate sudden or large changes in blood pressure or
volume very well. It is therefore essential to evaluate carefully the
physiological state of the foal, in each and every situation, prior to
administration of plasma. Consultation of breeding records together
with a thorough clinical examination is good veterinary practice.
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All the safety studies carried out on Hypermune products relate to the
administration to normal full term foals. Extra care should be taken
when plasma is to be administered to foals out with this category. In
particular it should be assessed:
If the foal is premature <320 days or
Dysmature >320 days with signs of immaturity
Or normal and full term, and that a full term foal is not a miniature adult
Table 2: Physiological Parameters of the Developing Neonatal Foal
RESTRAINT and the SEDATION of FOALS
Foals up to 1 month of age can usually be restrained manually by a
single person. Veterinary Immunogenics Ltd adopts the advice of
leading equine veterinary surgeons and advises that chemical restraint
should be considered only in extreme circumstances and then only
using drugs with minimal side effects on cardiovascular and
respiratory systems.
Chemical Restraint
Alpha 2 adrenoreceptor agonists (Xylazine, Detomidine, Romifidine)
It should be bourne in mind that foals have inherent dynamic
instability and their cardiac output is heart rate dependent. Since
these agents cause marked changes in haemodynamic variables,
including bradycardia and reduced cardiac output, they must be used
with caution especially in neonatal, hypovolaemic or sick foals.
Benzodiazepines (Diazepam – Vallium)
These drugs are particularly useful because of their minimal side
effects on the cardiovascular and respiratory systems.
Age Heart rate (beats/min)
Respiratory Rate
(breaths/min)
Temperature °C
Birth 60-80 Gasping 37-39
0-2 hours 120 – 150 40 – 60 37-39
12 hours 80 – 120 30 - 40 37-39
24 hours 80 – 100 30-35 37-39
PLASMA ADMINISTRATION
Foals 24 hours to 6 days of age
Blood giving set and 16 gauge catheter
Thaw and warm plasma thoroughly 40°C
Dose 20ml/kg or pro rata
Start very slowly & diligently monitor vital signs
Administration should
take at least 15 – 20 minutes
Further dose may be given at not less than 24 hours
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CONTACT DETAILS
VETERINARY IMMUNOGENICS LTD
Carleton Hill, Penrith, Cumbria CA11 8TZ England
+44 (0)1768 863881
+44 (0)1768 891389
+44 (0)7831259539
For further information, updated regularly throughout
the foaling season, please visit:-
www.veterinaryimmunogenics.com
Hypermune Products are
shipped Monday to Thursday
for overnight delivery in
most cases, but national
holidays, weather and traffic
problems may interfere with
this prompt and efficient
service. It is wise, therefore,
to hold some plasma in the
practice freezer especially
during the anticipated period
of use. (Hypermune products
have a proven frozen shelf
life of two years from the
date of production.)
Orders may be placed by fax
using the Faxback order form
which can be downloaded
from the website or by
telephone or by email.
Please note that in order to
comply with Good
Manufacturing Practice,
Veterinary Immunogenics
Ltd has to adopt a NON
RETURNS POLICY, and thus
will NOT accept return of any
unused product under any
circumstances.