From The Merck Veterinary Manual ....................
"Auscultation of llamas and
alpacas is difficult and frequently unrewarding. Little air movement
is heard under normal conditions, and identification of areas of
infection, congestion, or consolidation is usually not easy. Lateral
radiographs may be required for the diagnosis of pneumonia. Bacterial
infections of the lung are relatively rare, with Streptococcus and Corynebacterium spp
being the most common isolates.
Chronic obstructive pulmonary disease appears to be
increasing in frequency. Animals allowed to live to their expected
lifespan is a factor, but feeding practices can contribute to onset as
well as exacerbation of clinical signs—coughing, shortness of breath, and
expiratory dyspnea. Therapy includes changing the feeding regimen to
reduce dust, molds, and pollen. Bronchodilators and steroids may be
helpful but remain unproved."
*Auscultation: the act of listening, either directly or
through a stethoscope or other instrument, to sounds within the body as a
method of diagnosis.
Generally, llamas are pretty disease free. Most of
their problems come as a result of parasites or breeding or birthing
problems. However llamas can suffer from some external and internal
diseases. One in particular is very deadly - endogenous lipid
pneumonia. Although there are several, observable signs and symptoms of
the disease, very often, as stoic as llamas are, the symptoms are not
easily recognized and death comes upon the animal suddenly and quickly.
Explanation of the Disease:
Endogenous lipid pneumonia is
a disease that attacks the lungs of llamas and causes respiratory
failure, similar to pneumonia in humans. More specifically, the
disease causes collections of lipids (fats and cholesterol) to build
up in the alveoli of the animal's lungs. The disease is actually
very rare in llamas, relative to other, more prevalent, diseases,
such as internal parasites, including worms and botfly infections.
Signs and Symptoms:
llama afflicted with endogenous lipid pneumonia will exhibit several
physical symptoms. In the early onset of the disease, the animal
will show subtle difficulty in breathing and energy. These symptoms
will worsen as the disease progresses, until the animal shows
extremely labored breathing and inability to work or move without
assistance. The llama will also show a reduced body temperature and
increased heart rate. Other symptoms that are not immediately
visible include the presence of fatty lesions in the lungs of the
animal. Once the lungs become reduced in function, the llama's other
body systems begin to fail and shut down.
Though the disease is rare, it
is often fatal in llamas. Due to the rareness of the disease, there
is little known to science in the way of treatment, and there is no
way to prevent the disease. Endogenous lipid pneumonia is also
accompanied by pulmonary alveolar histiocytosis, in which the
alveoli of the lungs essentially burst and deflate. According to Dr.
A.N. Hamir, the disease is thought to be caused by parasite
Fluid Around Lungs
This animal was unexpectedly found dead and examined within just a few hours of passing.
revealed a lot of fluid and foam around the lung area.
Llamas are very often found dead without any previous
symptoms or they are found down with labored open-mouth breathing. Attempts to treat them in
this state are often in vain and the animal dies within a few hours.
A necropsy is needed to positively identify pneumonia. Photos by
Marilyn Nenni of Shagbark Ridge Llamas
Although the following article is not focused on
llamas or alpacas, it may help to understand pneumonia more clearly.
Interstitial Pneumonia in Feedlot Cattle (AIP)
This is a fact sheet from the Health
Management section of the Alberta
Feedlot Management Guide,
Second Edition published September 2000.
Take Home Message
Interstitial pneumonia (IP) is
a frustrating and poorly understood respiratory disease that
sporadically kills feedlot cattle, usually after they have been on
feed for several months. Affected cattle may be found dead without
showing any signs of disease or they may show laboured, rapid,
open-mouthed breathing for a few hours to days before dying. The
cause of most cases of interstitial pneumonia in feedlot cattle is
unknown and it may be different in different feedlots or age
groups. To date, there is no good evidence that bovine respiratory
syncytial virus (BRSV) infection is a major cause of IP in feedlot
cattle. Most cattle dying of IP have preexisting lung disease.
Based on this observation and the fact that so little else is
known about the disease, the only rational recommendation that can
be made for the prevention of IP in feedlot cattle is to prevent
other types of possibly predisposing respiratory diseases, such as
pneumonias caused by Pasteurella or BRSV infection.
Interstitial pneumonia is a
significant and frustrating cause of economic loss in feedlot
cattle. Unlike Pasteurella pneumonia, interstitial
pneumonia (IP) usually does not occur in outbreaks in recently
arrived cattle. Instead, IP occurs sporadically in cattle that
have been on feed for several months, particularly in animals that
are close to market weight. Affected cattle may be found dead
without showing any signs of disease, or they may show laboured,
rapid, open-mouthed breathing for a few hours to days before
dying. The only way to definitively diagnose IP is by post-mortem
examination. If an animal shows laboured breathing for a few days
and then recovers, we cannot be sure that the animal had IP and
not some other disease. Therefore, only fatal IP has been studied.
Little recent work has been done to
determine the incidence of this problem. A study conducted in the
early 1980’s reported that total losses due to IP were 0.1 -
0.5% in a large California feedlot (1). In the early 1970’s, IP
accounted for 5% of deaths in a large Colorado feedlot (2).
Although IP does not kill nearly as many cattle as bacterial
pneumonia does, IP losses tend to occur later in the feeding
period when investment per head is relatively high. Although we
have learned much about the causes and prevention of Pasteurella
pneumonia, the cause and prevention of IP in feedlot cattle is
still a mystery. Interstitial pneumonia is particularly
frustrating for veterinarians and producers because diagnosis of
IP in one animal does not allow us to formulate management
strategies to prevent further losses.
Pneumonia in General
Lungs can be thought of as
large sponges that inflate and deflate as an animal breathes. Like
sponges, lungs are composed of tiny, thin-walled sacs (alveoli).
The sacs contain air that is replaced with every breath, and the
walls of the sacs contain small blood vessels. The extremely thin
walls of the air sacs allow oxygen in the air to move into the
blood, and carbon dioxide (CO2) in the blood to move
into the air sacs. The CO2 is expelled when the animal
exhales. This process is called gas exchange, and anything that
interferes with this process may cause poor performance, disease
Pneumonia is inflammation of the lungs.
Inflammation is the body’s response to damage. When lung cells
are damaged, due to any cause, the lungs become inflamed, and the
animal has pneumonia. Inflammation involves the movement of fluid
and white blood cells from the blood into the tissue. In most
cases, this movement of fluid and cells helps the animal repair
the damage and destroy the viruses or bacteria which caused the
damage. Unfortunately, there are only two places for the fluid and
cells to go in the lung. They can accumulate in the walls of the
air sacs or in the air sacs themselves. In either location, the
presence of fluid and white blood cells interferes with gas
exchange. That is why it is often stated that the response
(pneumonia) to the damaging agent often hurts the animal far more
than the agent itself.
Interstitial Pneumonia (IP)
As stated above, the lung can
respond to damage in two major ways. The way the lung responds
depends on the type of damage and the type of agent that causes the
damage. That is, different types of agents cause different types of
pneumonia. In feedlot cattle, there are basically two important
types of pneumonia. One type (bronchopneumonia) occurs when bacteria
are inhaled into the lung. An example of this type of pneumonia is
pneumonic pasteurellosis (shipping fever), which is the most
economically important type of pneumonia in feedlot cattle. In this
type of pneumonia, cells accumulate in the air sacs themselves (Photo
Photo 1. An Entire Lung with Interstitial
in Feedlot Cattle.
Photo 2. Cross Section of an IP Lung.
Interstitial pneumonia occurs when
fluid and white blood cells accumulate in the walls (the ‘interstitium’)
of the air sacs. This causes the air sac walls to be thicker than normal,
which increases the distance between the air and the blood, thus interfering
with gas exchange. Actually, in the early phases of severe IP, fluid and white
blood cells ‘leak’ out of the walls and accumulate in the air sacs
themselves, just as occurs in bacterial pneumonia. Early investigators thought
this was unusual for an IP (it really isn’t), so they added the term
‘atypical’. Calling an IP ‘atypical’ doesn’t really tell us
anything, so the term ‘atypical’ isn’t used in this fact sheet.
In most cases, IP can be
definitively diagnosed by post-mortem examination of the lungs. The
entire lung, or only the back, upper portions may be affected. Photo
1 shows an entire lung with IP, and Photo 2
show a cross section of an IP lung. Lungs with IP are typically
mottled red and tan and enlarged because they cannot collapse
normally, since the air sac walls are thickened by fluid and cells.
There may be pockets of trapped air within the lung’s connective
tissue. Most importantly, affected parts of the lung feel rubbery
instead of soft and spongy. The texture of IP lungs has been
compared to ‘stale marshmallows in a plastic bag’. In some
cases, microscopic examination is required to confirm the diagnosis.
If several cases of IP occur over a short period of time, samples of
lung tissue or entire lungs should be submitted to a diagnostic
laboratory to try to rule out other (preventable) causes of
Causes of IP in Cattle
Established causes of IP in cattle include (3, 4):
Fog Fever: Sudden exposure to lush pasture
grasses (high in L-tryptophan). Rape, kale and turnips may
moulds - mouldy sweet potatoes.
As can be seen, several
very different agents can cause IP in cattle. Therefore, a diagnosis
of IP usually does not point to a single specific cause. In fact,
probably the most useful thing that a diagnosis of IP does is rule
out other causes of pneumonia. For example, a diagnosis of IP lets
us be reasonably sure that we’re not dealing with an outbreak of
Pasteurella pneumonia, since Pasteurella haemolytica bacteria
do not cause IP. A diagnosis of IP also rules out infectious bovine
rhinotracheitis (IBR), since IBR virus, at least by itself, does not
What Causes IP in Feedlot Cattle?
The short answer is we do not
know with any certainty. Most of the causes on the above list do not
apply to feedlot cattle. Canadian feedlot cattle are usually not fed
Crotalaria or purple mint (plants found in the southeastern U.S.),
nor are they fed mouldy sweet potatoes, or suddenly exposed to lush
pastures, or exposed to pig manure, or confined in dusty dairy
barns. Lungworms may be a problem in pastured cattle, but they are
usually not found in feedlot cattle.
Bovine respiratory syncytial virus (BRSV)
is often put forward as a cause of IP in feedlot cattle (5). One
reason for this association is that feedlot operators and
veterinarians report cases of IP several weeks after an outbreak of
BRSV infection in a group of feedlot cattle. Furthermore, acute
severe BRSV infection can sometimes cause an IP that looks exactly
like many cases of IP in which BRSV infection is not present.
However, studies in both Saskatchewan (S.D. Sorden, unpublished
data) and Alberta (J. Ellis, personal communication) feedlots have
failed to find evidence of BRSV infection in most cases of IP in
Others have speculated that IP in feedlot
cattle represents a type of allergic response (6), or that IP is
caused by excessively dry and dusty conditions. Again, there is no
evidence to support these claims. In southern Alberta, IP affects
heifers much more often than steers, and seems to be a particular
problem in early spring after a snow storm in pens that have been
extensively bedded. Understanding why IP is more of a problem in
some groups of cattle than in others should ultimately help us
determine its cause. What is known is that lungs from cattle that
die from IP often have evidence of other, long-standing lung disease
(1, S.D. Sorden, unpublished data). Some lungs have IP in their
upper, back portion, and another type of pneumonia in the lower,
front portion. This combination is sometimes referred to as
‘upstairs-downstairs syndrome’. The presence of preexisting lung
disease in many cases of fatal IP in feedlot cattle may mean that
damaged lungs are somehow more prone to develop IP. Additional
research will be required to demonstrate a cause and effect
Treatment of cattle in severe
respiratory distress is often not successful. The added stress of
moving the animal into a treatment area may be enough to cause
death. Emergency onsite salvage slaughter of severely affected
animals is probably the best option.
Conclusion - Prevention
Recommendations for the prevention of
a disease are best made when the cause of the disease is understood
and when controlled studies have compared different methods of
prevention. Since the cause of IP in feedlot cattle is unknown, the
disease cannot be reproduced experimentally. The incidence of IP is
low and often varies from year to year in a given feedlot, making
prevention strategies difficult to evaluate. Since we do not know
what causes most cases of feedlot IP, we do not know how to prevent
them. Feeding monensin (Rumensin®) or similar ionophore drugs helps
to prevent the IP syndrome that occurs in adult cattle suddenly
exposed to lush pasture. However, monensin feeding appears to have
no effect on the incidence of feedlot IP (1).
One thing we do know is that most feedlot
cattle dying of IP have preexisting lung damage (1, SD Sorden,
unpublished data). Therefore, a conservative recommendation that can
be made is to take steps to prevent other types of respiratory
disease, such as Pasteurella pneumonia or BRSV infection,
which may predispose an animal to developing IP. Better
recommendations for the prevention of IP in feedlot cattle will not
be possible until we have a better understanding of this mysterious
Steven Sorden, DVM, Ph.D., Veterinary Diagnostic Laboratory,
College of Veterinary Medicine, Iowa State University, 2000. Alberta Feedlot
Hjerpe, C.A. 1983.Clinical
management of respiratory disease in feedlot cattle. Vet Clin
North Am: Large Anim Pract 5:119.
Jensen, R., Pierson, R.E., Braddy,
P.M., et al. 1976. Atypical interstitial pneumonia in yearling
feedlot cattle. JAVMA 169:507.
Kerr, L.A., Linnabary, R.D. 1989.
A review of interstitial pneumonia in cattle. Vet Hum Toxicol
Johnson, B. 1991. Nutritional and
dietary interrelationships with diseases of feedlot cattle. Vet
Clin North Am: Food Anim Pract 7:133.
Collins, J.K., Jensen, R, Smith,
GH, et al. 1988. Association of bovine respiratory syncytial
virus with atypical interstitial pneumonia in feedlot cattle. Am
J Vet Res 49:1045.
Schiefer, B., Jayasekara, M.U.,
Mills, J.H.L. 1974. Comparison of naturally occurring and
tryptophan-induced bovine atypical interstitial pneumonia. Vet
Heaves - Recurrent Airway Obstruction (RAO)
A disease normally found in horses, heaves
has been thought to be found in llamas also. Owner says the problem
will never go away but can be managed by keeping them away from large hay
bales, mold, or dusty hay.
Info from thehorse.com ......
"The terms heaves and recurrent
airway obstruction (RAO) refer to horses with overt increased
respiratory efforts at rest that can be reversed by administration of
bronchodilators, corticosteroids, or a changes in the horse's
environment such as avoiding exposure to offending allergens like dust
and molds from hay. The term inflammatory airway disease (IAD) is used
to describe horses with more subtle clinical signs such as poor
performance, exercise intolerance, or coughing, with occasional excess
respiratory mucus. Horses with IAD do not display any obvious increased
respiratory effort at rest or signs of infection, such as fever or
changes in blood counts."
A horse with heaves (generally
referred to in scientific literature as RAO) displays distinct signs
that alert an owner to a problem. Couëtil notes the most common clinical
signs reported by owners of horses with RAO are exercise intolerance,
coughing, and increased breathing efforts such as nostril flare and
abdominal efforts to breathe. He says that clear to mucopurulent
(containing mucus and pus) nasal discharge is also reported in
association with these conditions, but less frequently."
Definition from Horse & Rider -
Heaves is an allergic-based disease that
compromises your horse's ability to breathe, similar to the way asthma
affects humans. When your horse is exposed to allergy-producing
substances in the air, such as dust and pollens, cells in his lungs
react by releasing chemicals that cause air-passage linings to swell,
thicken, and produce mucus. When he breathes, air gets trapped within
these thickened passages. He then must use extra effort to expel this
trapped air. The more your horse is exposed to allergens, the more
sensitized his lungs become. The disease is most common among mature and
As the disease progresses, your horse's
airways become ever thicker. More mucus is produced. He begins to cough
as he struggles to exhale. Thick mucus appears in his nostrils, and he
begins to labor with every breath. Bacteria can become trapped in his
airways, leading to a bacterial infection (such as pneumonia), a common
complication in advanced cases of heaves. - See more at: http://horseandrider.com/article/horse-heaves-symptoms-and-treatment-13088#sthash.cQ0oQBY9.dpuf
Infectious Camelid Respiratory Disease
Affecting Major Areas of US Herds