NEOSPOROSIS IN DOGS by Dr Alastair Smith & Dr Alex Hauler
Dec 29, 2018 19:56:02 GMT 10
Post by Tom Meulman on Dec 29, 2018 19:56:02 GMT 10
NEOSPOROSIS IN DOGS
By Dr. Alastair Smith Sandown Veterinary Clinic
Printed in the August 2002 Edition of the Walk & Talk
Neosporosis is a disease syndrome caused by the protozoa Neospora caninum. A relatively new disease first identified in the USA in 1988. Neospora occurs naturally in cattle, sheep, coats and other large animals and can affect dogs of any breed and of any age including fetuses in pregnant bitches.
The organism usually forms cysts in the muscular tissue and other organs which can produce clinical disease or remain dormant until a period of stress allows their activation. The full
lifecycle has never been determined or documented at this stage.
TRANSMISSION
Neospora can be spread in a number of ways. The form most documented is that of puppies becoming infected in utero by an infected bitch. The number of pups affected can vary from entire litters to only one pup. The ingestion of faecal material or infected tissue eg. Placenta from affected animals and the ingestion of meat from infected cattle are other proposed methods of transmission.
CLINICAL SIGNS
The signs of infection can be divided into 3 main groups.
1. Muscular-skeletal - Shifting lameness, weakness, paralysis, myositis and pain.
2. Neurological - pain and discomfort, paralysis, altered behaviour, proprioceptive defects, seizures, head tilt, blindness and tremors.
3. Reproductive - abortions, still births, infertility in the bitch and muscular problems in newborn pups. In newborn pups the paralysis begins with muscle stiffening, hyperextension and muscular atrophy in the hind limbs and progresses to rigid paralysis at 3-6 weeks of age.
The paralysis can progress to the point that the animals are unable to eat or breath, resulting in euthanasia or death.
Other organs can also be involved. These include the heart, liver, skin and respiratory system.
Subclinical infections are also possible. Allowing the bitch to become a carrier and pass the protozoa to her puppies or presenting later with clinical signs after a period of stress or immunosuppression., eg., racing, pregnancy or lactating.
Racing greyhounds can show mild signs including training off, reduction in performance, pain on palpation of the large muscle groups in the body, weight loss and change of personality (signs similar to Acidosis without the myoglobinuria or large rises in the CPK levels) through to any of the symptoms previously described.
DIAGNOSIS
Usual tests are done to determine all possible other causes of the presenting signs. These include X rays, blood tests- FBE and VMBA. However, often there are no specific changes on these tests.
Possible findings include lymphocytosis; increased CPK levels with myositis, or increased ALT/AST with liver involvement. An antibody test (IFAT/ELISA) is used to measure the serum
antibodies and is considered positive evidence of exposure to Neospora caninum.
Most confirmed cases have a titre of 1:800 or more.muscle biopsy and cerebro spinal fluid analysis may demonstrate the organism. further tests may become available as more is learnt about this disease eg PCR
TREATMENT
Treatment for an active infection includes the use of specific antibiotics
clindamycin (antirobe®), potentiated sulphonamides (tribressen), pyrimethamine (Daraprim) As soon as possible once neosporosis is suspected.
This should be continued for a minimum of 2 weeks or until clinical signs have improved.
Severe hyperextension may never be improved. Some resultant muscle damage and deformity is possible after juvenile infection and may affect the racing greyhounds career.
CONTROL AND PREVENTION
This can be difficult as subclinical infections mean that infected animals may not be identified and the exact routes of transmission are not 100% known i.e. pups infected at birth may not show signs until a period of stress later in life. However, prompt treatment of affected animals is required to minimize the risk of spread.
Good hygiene and isolation of affected animals would be recommended to prevent the risk of spread. Brood bitches, which have been previously diagnosed, should be treated and future breeding viewed with caution as transmission can occur in consecutive litters and there has not been any definitive treatment to prevent the transmission to the pups.
Freezing meat for 24 hours or cooking before feeding should destroy the parasite and prevent the infection of dogs from this source.
The survey to establish an indication of the prevalence of this disease began mid January 2002.
A free blood test will be offered to trainers who have animals, which are showing signs of the disease or have had clinical signs, through the Sandown Veterinary Clinic. Unfortunately there are only a limited number of tests available at this time, so each case will have to be judged individually. The results will be made available as soon as possible by the laboratory.
————————————————————————————————————————————————————————————————————————
NEOSPORA
By DR. ALEX HAULER Greyhound Veterinarian Canine Sports Medicine Clinic
Just the other day I had a consultation with a new client, "Jack Trainer" and his two greyhounds, Brinny and Blackie. Jack was stressed and frustrated and was showing signs of having lost faith with the opinions of any individual who could be considered a professional. I suggested that he should put aside his prejudices and tell me his story.
Well, says Jack, Brinny here is a 3 year old dog who until recently was a very handy city sprinter, but I now wonder if he is even chasing. About five runs ago he raced, but amazingly he could not finish as strongly as he is capable of, and he appeared to cramp. With each run beyond this time be became weaker and weaker and now is barely able to run a decent short. As you can appreciate, says Jack, I was very concerned so I organised to have Brinny checked and blood tested.
To my dismay I was told that the dog was not injured and that the blood test was normal.
My only option was to give the dog a spell to see if he could recover, because I truly believed that the dog had a problem. After a couple of weeks of rest I again began to work the dog and found that although his first run seemed to show that he may again be on the right track, the second run had him drift off his times again.
Jack also observed that the dog had lost a degree of his muscling even though his weight on the scales had not changed and the coat of the dog had lost it's sheen and "I know you probably think I am stupid, but the dog just does not seem to be quite himself".
At this point in time, although I was concerned that if I interrupted Jack, I may have disturbed his narrative I plucked up the courage to ask, "and what of Blackie"?
Well Doc, on top of my troubles with Brinny here, this pup has me at a complete loss. Blackie is only 15 months old and quite frankly is lucky to be alive. He is bred in the
purple out of a proven dam; he reared well and grew to be a beautiful pup, full of keenness and enthusiasm. At a touch over thirteen months of age I sent him off to be broken in, full of
expectation of a quick and excellent report.
Three weeks later I got a phone call from the breaker to say that the dog can only run about 200 metres and then literally "refuses to chase on". I have been led to believe that the whole litter did the same thing and Blackie is the only one who has not been put down…after all, I suppose there is little point in going on with a non chaser. I find it difficult to believe that this pup could be so disappointing and I have brought him along today hoping against hope that there is some explanation. And yes Doc, there is one other aspect of this whole episode, which may be coincidental but worthy of note.
Brinny was racing well until I brought Blackie home and interestingly, it was not long after Blackie homecoming that Brinny went off.
Under the very stern and critical eye of Jack I proceeded to examine his two greyhounds and it became immediately obvious that both greyhounds exhibited extreme discomfort
when palpated in the coupling, quadriceps and calf musculature. In fact, the degree of discomfort was such that both greyhounds exhibited a very strong behavioural response, which could be interpreted as wimpish and whining. It is the degree of muscular weakness and pain which sets these patients apart and allows their behaviour to be absolutely interpreted as real muscular pain rather than any form of sookiness. It is, in fact this real muscular pain, which is responsible for the observed fatigue, which these greyhound exhibits in racing and which is responsible for their inability to run to the line.
It is also this muscular pain and inflammation which causes the ballistic chaser, that, tries to chase through its pain threshold, to cramp.
Well Jack, we know what is wrong with your dogs and I will try to give a reasonable explanation of the disease affecting your greyhounds. The performance traits, which you have observed on the track and the clinical symptoms, which you have observed during my examination of your dogs, are consistent with a disease, called Neospora.
This is a coccidial disease for which the dog is the natural host. Neospora is passed in the stools allowing for faecal transmission to other dogs or to cattle in which it is a
cause of abortion. Interestingly, Neospora is also capable of being passed from the bitch to her puppies during pregnancy. Neospora is a new disease in the dog and has for the past 3 odd years been causing major and worldwide concern in the canine and bovine populations.
My first contact with this disease occurred nearly four years ago when Dr. Phil Davis in Sydney mentioned the fact that he was beginning to see a new pathogen in the dog population. Not long after, reports of Neospora puppy deaths began to emerge from Western Australia.
Neospora can be exhibited as three disease syndromes, namely: -
1. Reproductive
2. Neurological
3. Musculoskeletal.
These different syndromes reflect the location of the tissues, which have been affected. The most interesting aspect of this disease is that during the past 3 years it has behaved
in a manner of a new disease where the population does not have any immunological defense. It now waits to be seen whether or not the canine population develops any immune
defence to this disease and if this occurs whether we observe a major decline of frequency to a background of occasional cases.
The ability of Neospora to become a carrier disease does appear very likely and most likely in the brood bitch population. The most prone segment of the greyhound population during the past 3 years has been the juvenile animals and they have most commonly succumbed during their breaking in training. It is very apparent that any significant stress, which affects the greyhound's immune competency, has a major role to play in the development of clinical Neospora. As such it also waits to be seen to what extent this disease continues to express itself as a condition of the young greyhound at times of stress such as breaking in and especially in the colder months of the year.
Now, back to the nuts and bolts of how to treat musculoskeletal Neospora. The treatment of this disease requires the use of Neospora sensitive antibiotics, which are easily administered to the greyhound and yet also minimally potentially damaging to the patient. To this extent the only antibiotics which have fulfilled these criteria have been the sulphur antibiotics.
The drug treatment recommendations for the use of these drugs for the treatment of Neospora suggest the use of these drugs for a period of 28 days. Our experience has demonstrated that a 10 days course of these drugs will resolve more than 90% of clinical cases. It is imperative and I cannot emphasise this strongly enough, that the patient must be COMPLETELY rested for a 14 days period. In those cases where the 14 days treatment period did not resolve the Neospora symptoms the patient will require a repeat treatment
BUT as sure as God made chickens, these patients did not adequately rest and therefore the treatment failed.
These failed treatments are inevitably associated with the type of greyhound which the trainer initially described as a quit dog, but at the time of the revisit is suddenly redefined as a greyhound who is up and off the bed every time he hears or thinks he hears something.
Greyhounds that are variously described as the hyperactive types are often prescribed low doses of tranquillisers during the 14 days treatment period to ensure adequate rest.
The most important diagnostic input, which is applied to the Neospora patient, is to be able to palpate the musculoskeletal symptoms. It is then necessary to make two blood test decisions. Firstly, give the owner of the greyhound the option of a Neospora Immunofluorescent Antibody test and secondly, if there is any indication of chronicity and especially if the trainer did significantly run the infected greyhound, to take a racing blood profile.
The importance of the blood profiles is not its ability to define the presence of a Neospora infection, but by virtue of the serum ALT to indicate whether the greyhound is irreversibly damaged. Neospora greyhounds, which have ALT elevations above 150, are generally found to be nearly impossible to successfully treat. In regard to the diagnosis of this disease, realize that the singularly most notable observation of its effect upon the racing greyhound is seen as AN INABILITY TO RUN THE EXPECTED END SECTION OF THE RACE.
Where a racing greyhound looses its normal finishing ability then the list of possible causes must include Neospora. The value of immunofluorescent antibody test lies in its ability to definitively prove the existence of the condition. It does not provide any ability to prove that the condition has been successfully treated.
The disappearance of the palpable musculoskeletal symptoms followed by an observed and repetitive ability to run a racing end section in fact is the only proof of treatment success.
It is difficult to understand why it has taken the greyhound racing industry so long to get onto speed with this disease, especially since this condition has had such enormous worldwide Internet coverage. The immeasurable loss of greyhound breading stock, as a result of this disease is a major tragedy.
By Dr. Alastair Smith Sandown Veterinary Clinic
Printed in the August 2002 Edition of the Walk & Talk
Neosporosis is a disease syndrome caused by the protozoa Neospora caninum. A relatively new disease first identified in the USA in 1988. Neospora occurs naturally in cattle, sheep, coats and other large animals and can affect dogs of any breed and of any age including fetuses in pregnant bitches.
The organism usually forms cysts in the muscular tissue and other organs which can produce clinical disease or remain dormant until a period of stress allows their activation. The full
lifecycle has never been determined or documented at this stage.
TRANSMISSION
Neospora can be spread in a number of ways. The form most documented is that of puppies becoming infected in utero by an infected bitch. The number of pups affected can vary from entire litters to only one pup. The ingestion of faecal material or infected tissue eg. Placenta from affected animals and the ingestion of meat from infected cattle are other proposed methods of transmission.
CLINICAL SIGNS
The signs of infection can be divided into 3 main groups.
1. Muscular-skeletal - Shifting lameness, weakness, paralysis, myositis and pain.
2. Neurological - pain and discomfort, paralysis, altered behaviour, proprioceptive defects, seizures, head tilt, blindness and tremors.
3. Reproductive - abortions, still births, infertility in the bitch and muscular problems in newborn pups. In newborn pups the paralysis begins with muscle stiffening, hyperextension and muscular atrophy in the hind limbs and progresses to rigid paralysis at 3-6 weeks of age.
The paralysis can progress to the point that the animals are unable to eat or breath, resulting in euthanasia or death.
Other organs can also be involved. These include the heart, liver, skin and respiratory system.
Subclinical infections are also possible. Allowing the bitch to become a carrier and pass the protozoa to her puppies or presenting later with clinical signs after a period of stress or immunosuppression., eg., racing, pregnancy or lactating.
Racing greyhounds can show mild signs including training off, reduction in performance, pain on palpation of the large muscle groups in the body, weight loss and change of personality (signs similar to Acidosis without the myoglobinuria or large rises in the CPK levels) through to any of the symptoms previously described.
DIAGNOSIS
Usual tests are done to determine all possible other causes of the presenting signs. These include X rays, blood tests- FBE and VMBA. However, often there are no specific changes on these tests.
Possible findings include lymphocytosis; increased CPK levels with myositis, or increased ALT/AST with liver involvement. An antibody test (IFAT/ELISA) is used to measure the serum
antibodies and is considered positive evidence of exposure to Neospora caninum.
Most confirmed cases have a titre of 1:800 or more.muscle biopsy and cerebro spinal fluid analysis may demonstrate the organism. further tests may become available as more is learnt about this disease eg PCR
TREATMENT
Treatment for an active infection includes the use of specific antibiotics
clindamycin (antirobe®), potentiated sulphonamides (tribressen), pyrimethamine (Daraprim) As soon as possible once neosporosis is suspected.
This should be continued for a minimum of 2 weeks or until clinical signs have improved.
Severe hyperextension may never be improved. Some resultant muscle damage and deformity is possible after juvenile infection and may affect the racing greyhounds career.
CONTROL AND PREVENTION
This can be difficult as subclinical infections mean that infected animals may not be identified and the exact routes of transmission are not 100% known i.e. pups infected at birth may not show signs until a period of stress later in life. However, prompt treatment of affected animals is required to minimize the risk of spread.
Good hygiene and isolation of affected animals would be recommended to prevent the risk of spread. Brood bitches, which have been previously diagnosed, should be treated and future breeding viewed with caution as transmission can occur in consecutive litters and there has not been any definitive treatment to prevent the transmission to the pups.
Freezing meat for 24 hours or cooking before feeding should destroy the parasite and prevent the infection of dogs from this source.
The survey to establish an indication of the prevalence of this disease began mid January 2002.
A free blood test will be offered to trainers who have animals, which are showing signs of the disease or have had clinical signs, through the Sandown Veterinary Clinic. Unfortunately there are only a limited number of tests available at this time, so each case will have to be judged individually. The results will be made available as soon as possible by the laboratory.
————————————————————————————————————————————————————————————————————————
NEOSPORA
By DR. ALEX HAULER Greyhound Veterinarian Canine Sports Medicine Clinic
Just the other day I had a consultation with a new client, "Jack Trainer" and his two greyhounds, Brinny and Blackie. Jack was stressed and frustrated and was showing signs of having lost faith with the opinions of any individual who could be considered a professional. I suggested that he should put aside his prejudices and tell me his story.
Well, says Jack, Brinny here is a 3 year old dog who until recently was a very handy city sprinter, but I now wonder if he is even chasing. About five runs ago he raced, but amazingly he could not finish as strongly as he is capable of, and he appeared to cramp. With each run beyond this time be became weaker and weaker and now is barely able to run a decent short. As you can appreciate, says Jack, I was very concerned so I organised to have Brinny checked and blood tested.
To my dismay I was told that the dog was not injured and that the blood test was normal.
My only option was to give the dog a spell to see if he could recover, because I truly believed that the dog had a problem. After a couple of weeks of rest I again began to work the dog and found that although his first run seemed to show that he may again be on the right track, the second run had him drift off his times again.
Jack also observed that the dog had lost a degree of his muscling even though his weight on the scales had not changed and the coat of the dog had lost it's sheen and "I know you probably think I am stupid, but the dog just does not seem to be quite himself".
At this point in time, although I was concerned that if I interrupted Jack, I may have disturbed his narrative I plucked up the courage to ask, "and what of Blackie"?
Well Doc, on top of my troubles with Brinny here, this pup has me at a complete loss. Blackie is only 15 months old and quite frankly is lucky to be alive. He is bred in the
purple out of a proven dam; he reared well and grew to be a beautiful pup, full of keenness and enthusiasm. At a touch over thirteen months of age I sent him off to be broken in, full of
expectation of a quick and excellent report.
Three weeks later I got a phone call from the breaker to say that the dog can only run about 200 metres and then literally "refuses to chase on". I have been led to believe that the whole litter did the same thing and Blackie is the only one who has not been put down…after all, I suppose there is little point in going on with a non chaser. I find it difficult to believe that this pup could be so disappointing and I have brought him along today hoping against hope that there is some explanation. And yes Doc, there is one other aspect of this whole episode, which may be coincidental but worthy of note.
Brinny was racing well until I brought Blackie home and interestingly, it was not long after Blackie homecoming that Brinny went off.
Under the very stern and critical eye of Jack I proceeded to examine his two greyhounds and it became immediately obvious that both greyhounds exhibited extreme discomfort
when palpated in the coupling, quadriceps and calf musculature. In fact, the degree of discomfort was such that both greyhounds exhibited a very strong behavioural response, which could be interpreted as wimpish and whining. It is the degree of muscular weakness and pain which sets these patients apart and allows their behaviour to be absolutely interpreted as real muscular pain rather than any form of sookiness. It is, in fact this real muscular pain, which is responsible for the observed fatigue, which these greyhound exhibits in racing and which is responsible for their inability to run to the line.
It is also this muscular pain and inflammation which causes the ballistic chaser, that, tries to chase through its pain threshold, to cramp.
Well Jack, we know what is wrong with your dogs and I will try to give a reasonable explanation of the disease affecting your greyhounds. The performance traits, which you have observed on the track and the clinical symptoms, which you have observed during my examination of your dogs, are consistent with a disease, called Neospora.
This is a coccidial disease for which the dog is the natural host. Neospora is passed in the stools allowing for faecal transmission to other dogs or to cattle in which it is a
cause of abortion. Interestingly, Neospora is also capable of being passed from the bitch to her puppies during pregnancy. Neospora is a new disease in the dog and has for the past 3 odd years been causing major and worldwide concern in the canine and bovine populations.
My first contact with this disease occurred nearly four years ago when Dr. Phil Davis in Sydney mentioned the fact that he was beginning to see a new pathogen in the dog population. Not long after, reports of Neospora puppy deaths began to emerge from Western Australia.
Neospora can be exhibited as three disease syndromes, namely: -
1. Reproductive
2. Neurological
3. Musculoskeletal.
These different syndromes reflect the location of the tissues, which have been affected. The most interesting aspect of this disease is that during the past 3 years it has behaved
in a manner of a new disease where the population does not have any immunological defense. It now waits to be seen whether or not the canine population develops any immune
defence to this disease and if this occurs whether we observe a major decline of frequency to a background of occasional cases.
The ability of Neospora to become a carrier disease does appear very likely and most likely in the brood bitch population. The most prone segment of the greyhound population during the past 3 years has been the juvenile animals and they have most commonly succumbed during their breaking in training. It is very apparent that any significant stress, which affects the greyhound's immune competency, has a major role to play in the development of clinical Neospora. As such it also waits to be seen to what extent this disease continues to express itself as a condition of the young greyhound at times of stress such as breaking in and especially in the colder months of the year.
Now, back to the nuts and bolts of how to treat musculoskeletal Neospora. The treatment of this disease requires the use of Neospora sensitive antibiotics, which are easily administered to the greyhound and yet also minimally potentially damaging to the patient. To this extent the only antibiotics which have fulfilled these criteria have been the sulphur antibiotics.
The drug treatment recommendations for the use of these drugs for the treatment of Neospora suggest the use of these drugs for a period of 28 days. Our experience has demonstrated that a 10 days course of these drugs will resolve more than 90% of clinical cases. It is imperative and I cannot emphasise this strongly enough, that the patient must be COMPLETELY rested for a 14 days period. In those cases where the 14 days treatment period did not resolve the Neospora symptoms the patient will require a repeat treatment
BUT as sure as God made chickens, these patients did not adequately rest and therefore the treatment failed.
These failed treatments are inevitably associated with the type of greyhound which the trainer initially described as a quit dog, but at the time of the revisit is suddenly redefined as a greyhound who is up and off the bed every time he hears or thinks he hears something.
Greyhounds that are variously described as the hyperactive types are often prescribed low doses of tranquillisers during the 14 days treatment period to ensure adequate rest.
The most important diagnostic input, which is applied to the Neospora patient, is to be able to palpate the musculoskeletal symptoms. It is then necessary to make two blood test decisions. Firstly, give the owner of the greyhound the option of a Neospora Immunofluorescent Antibody test and secondly, if there is any indication of chronicity and especially if the trainer did significantly run the infected greyhound, to take a racing blood profile.
The importance of the blood profiles is not its ability to define the presence of a Neospora infection, but by virtue of the serum ALT to indicate whether the greyhound is irreversibly damaged. Neospora greyhounds, which have ALT elevations above 150, are generally found to be nearly impossible to successfully treat. In regard to the diagnosis of this disease, realize that the singularly most notable observation of its effect upon the racing greyhound is seen as AN INABILITY TO RUN THE EXPECTED END SECTION OF THE RACE.
Where a racing greyhound looses its normal finishing ability then the list of possible causes must include Neospora. The value of immunofluorescent antibody test lies in its ability to definitively prove the existence of the condition. It does not provide any ability to prove that the condition has been successfully treated.
The disappearance of the palpable musculoskeletal symptoms followed by an observed and repetitive ability to run a racing end section in fact is the only proof of treatment success.
It is difficult to understand why it has taken the greyhound racing industry so long to get onto speed with this disease, especially since this condition has had such enormous worldwide Internet coverage. The immeasurable loss of greyhound breading stock, as a result of this disease is a major tragedy.