Sep 052023

Bartonellosis-Lyme Disease Horses

Bartonellosis is a gram negative bacterial infection with anyone or multiple Bartonella species. It is a co-infection of Lyme Disease. Bartonella like many other infectious bacteria utilize the immune system of the horses they infect as part of their infection strategy. If a horse has a pre existing arthritis the bacteria use the inflammatory process already occurring in the body to facilitate successful infection in any joint, the process is even easier. The inflammation present would be by itself stimulate the movement of infectious bacteria to that location. Without getting into the technicalities the bottom line is the ability of the parasite to establish an infection anywhere in the body successfully will depend on the initial immune response of the exposed host, hence the weaker or more compromised the Immune system(especially those under stress) the more likely the animal is to become infected.

Once this is established one must focus on the Cytokine Cascade that the organism produce in the body. Cytokines are small-signalling molecules released by the immune system and the glial cells of the nervous system, that are important in the intercellular communication in the body. When bacteria touches a cell, this cell gives off a signal, a cytokine, that tells the immune system what is happening and what the cell needs. Each type of infectious bacteria initiates a particular kind of cytokine cascade, that is, an initial and very powerful cytokine is released into the body, It is these cytokines, in fact, that create most of the symptoms that horses experience when they are ill.

Lyme, Bartonella and its Mycoplasma co-infections interact both in the vector that spreads them(for example a flea, tick, horsefly, spider etc.,) and then in the host they are transferred to.

The symptoms produced by Bartonella are difficult to diagnose. As it is not always circulating in the red blood cells it can evade any testing or blood samples taken.

It seems apparent that it seems to circulate more often in the early morning, or late evening when other biting insects are at large with the purpose of re populating itself from inside the host.

The list of predominant symptoms found to date in all or some of the infected horses can be found at the bottom of this page in Symptom Check List.

Dr Edward Breitschwerdt, DVM

Veterinary Medicine Leads to Help for Suffering Humans Edward Breitschwerdt, DVM, is an infectious disease specialist at North Carolina State University College of Veterinary Medicine, an adjunct professor of medicine at Duke University, and chief scientific officer. Bartonellosis is a poorly understood condition that is routinely overlooked by mainstream medicine. As a result, many cases go undiagnosed, leading to significant and unnecessary human and animal suffering and substantial costs to society. While available testing options for Bartonella have improved greatly in recent years, there is still no perfect Bartonella assay available. Even when bartonellosis is confirmed through testing, the success of available treatment options is variable, and Bartonella may establish itself as a chronic infection that requires longterm management.Fortunately for many of us, humans are not the only species affected by the genus Bartonella. In fact, much of the available research comes from the veterinary community, whereat Galaxy Diagnostics. Early in his career, he focused on vector-borne, intracellular pathogens, including Rocky Mountain spotted fever (caused by a Rickettsial bacterium) and Ehrlichia. Ehrlichia was discovered in animals decades before it was identified in humans. His attention later shifted to Bartonella due to the historical association of one Bartonella species, Bartonella henselae, with catscratch disease (CSD).The connection between the newly discovered bacterium and CSD was initially made by a rickettsiologist, Dr. Russ Regnery at the CDC, who recognized similarities between a newly isolated bacterium from an AIDS patient in Texas and bacteria visualized in lymph nodes of patients with CSD. Regnery made the first isolate of Bartonella henselae from acat and showed that cats can become chronically infected. This work was the catalyst that led Breitschwerdt down the path of unraveling the mysteries of Bartonella. As Breitschwerdt lectured at veterinary conferences about Bartonella illnesses in dogs, numerous veterinarians approached him to discuss their own health challenges, such as multiple sclerosislike conditions and rheumatoid-like diseases. Many had been sick for several years with no clearly defined diagnosis. When he started testing these veterinarians for Bartonella, his research team found that many of them tested positive for Bartonella DNA in their blood. If it were not for the translational research initially done with animals, the genus Bartonella and the disease bartonellosis would likely be even lesser known than they are today. This may be another example in which dogs truly are mans best friend.

Dr Brenda Bishop VMD

The usual mode of transmission to horses appears to be biting insect vectors: biting flies, mosquitos, ticks, dog fleas and cat fleas. Immature immune systems (orphan foals and foals weaned too early) are particularly vulnerable as seasons change (end of summer, early fall) when many insects go into a feeding frenzy prior to onset of winter and below freezing (insect killing) temperatures. Many horsemen believe that white or grey horses are more attractive to biting insects as opposed to solid and dark colored horses. This is not exactly true, as all horses are.

(How many of these clues can you recognize in your horse?)

Lethargy / Chronic Fatigue Syndrome / Poor Exercise Tolerance

chronic inflammation in a wide range of tissues including the brain, bone marrow
delayed forward phase of stride at any or all gaits (slow bringing the leg(s) forward)

extensor rigidity / contracted flexor tendons
subluxating pasterns and/or fetlocks
upright angles in the fetlocks and pasterns
tendency to land toe first
dragging toes / toes worn flat
hanging one or both knees over a jump
hitting jumps with one or both hind shins
subluxating patella(s) (locking stifles)
curb (ruptured plantar ligament)
tallus fracture(s)
forging (clicking front heels with hind toes)
abrasions on front of pasterns from difficulty standing up
riding “as if the hand brake has not been released”
refusal to move forward (with or without rearing)
reluctance to bear weight on sore feet (hypersensitive soles)

muscle deconditioning and/or muscle spasms

total body soreness / uncomfortable posture
back soreness, topline muscle atrophy
dropped head syndrome
tendency to travel hollow backed and high headed
skipping / cross cantering / cross firing at the canter
fibromyalgia (EFMS) *** (see “The Fibromyalgia Horse”)
grunting / moaning / groaning under saddle
diaphragmatic muscle spasms (hiccups aka thumps)
esophageal muscle spasms (choke, swallowing problems)
laryngeal muscle spasms
displaced soft palate (with or without holding the breath)
chronic intercostal muscle soreness, cramping (ribs)
shivers *** (in 1, 2, 3 or 4 legs)
rigid muscles between hips and stifles (cording)
fibrotic myopathy *** (in one or both hind legs)
“thickened suspensories”
calcium deposits in tendons / tendon sheaths
rupture of the extensor carpi radialis (in one or both forearms)
audible ‘snap, crackle, pop’ from stifles and/or hocks
cardiac muscle fatigue (weak heart valves)
flaring nostrils at rest (chronic)
spontaneous periodic heavy breathing episodes
chronic obstructive pulmonary disease (COPD / heaves) ***
dribbling urine / odd urination habits
retained placenta (uterine atony)
leaky gut syndrome
constipation /scant dry manure OR diarrhea / colitis
herring gutted OR bloated abdomen
right dorsal colon ulcers
inflammatory bowel disease (IBD) ***
abundance of tape worms resistant to deworming
overgrowth of Candida in the large intestine
malabsorption of nutrients
gas colic (chronic)
epiploic foramen entrapment (seen at colic surgery)
gastrosplenic ligament entrapment (ditto)
stringhalt *** (in one or both hind legs)
neuritis of the cauda equina / polyneuritis ***
peripheral myoclonus

shifting leg lameness

lameness that shifts from front to back and/or side to side
“bridle lameness” (commonly lame on one diagonal)
frequent tripping on even and/or uneven ground
“stiff leg syndrome” (micro muscle spasms)

Microcirculation Deficits

sensitivity to cold weather, particularly cold and rain (regardless of blanketing)
absence of dapples (branches of the capillary tree)
pale mucous membranes (in mouth, pale tongue)
tendency to bleed

increased central arterial and venous pressure
thrombocytopenia (low platelet counts)
thrombocytopenic purpura ***
prolonged clotting time
exercise induced pulmonary hemorrhage (EIPH) ***
spontaneous (non-exercise induced) nosebleeds
vasoproliferative tumors (malignant melanoma)
autoimmune hemolytic anemia (AIHA) ***

complications associated with poor tissue oxygenation

prolonged healing time (> 7 to 10 days)
surgical repair failures
wound dehiscence
fracture site non-unions
colic surgery anastomosis break-down
recurring ‘scratches’
scirrhous cord following castration
yeast-like secretions in the sheath (geldings and stallions)
low grade chronic endometritis ( mares)
overgrowth of organisms that thrive in low oxygen locales
maggots in poorly perfused wounds (Rx: desitin)
chronic thrush in and around the frogs
presence of common co-infections *** (all of these)
lyme disease (Borrelia)
babesiosis (Babesia)
protozoa (EPM in the cerebrospinal space)
toxoplasmosis (chronic)
leptospirosis (chronic)
tetanus (Clostridium tetani)
botulism (Clostridium botulinum)
“bastard strangles” (Strep equi)
salmonellosis (Salmonella sp.)
pigeon fever (Corynebacterium pseudotuberculosis)
fungal conditions resistant to treatment (“rain rot”)
chronic bacterial foot abscesses
poll evil
fistulous withers
late summer foal pneumonia (Rhodococcus equi)
Lawsonia intracellularis

quittor (necrosis of the collateral cartilage)
chronic laminitis ***
chronic exertional rhabdomyolysis (tying-up) (muscle damage and bleeding)
cording of lymphatic vessels
lymphangitis (usually in a hind leg previously injured)
cellulitis (recurring)
swollen liver (hepatomegaly)
swollen spleen (splenomegaly)
swollen joints (knees, hocks, stifles)
pericarditis (swollen pericardium)
peroneal nerve paralysis (consequence of a hind leg stuck under a fence)
radial nerve paralysis (historically linked to ill-fitting neck collars)

Head and Neck Issues

swollen eyelids
surface eye infections with tearing
random cranial nerve dysfunction

optic nerve
micro-ophthalmia (one or both eyes)
blindness (one or both eyes, normal outwardly)
ERU (equine recurrent uveitis) ***
depth perception deficits (altered spatial behavior)
preference for shade vs. bright light (sore eyes) or
refusal to move from bright light to dark shade
head shaking (photic) (Rx: guardian mask)
olfactory nerve
flehmen response (repetitive)
facial nerve
cribbing ***
nipping, biting, licking
chewing wood
facial nerve paralysis (Bell’s Palsy)
teeth grinding / jaw clenching
vestibulocochlear nerve
hypersensitivity to sound (for example clippers)
balance problems (in a moving horse trailer)
trigeminal nerve
pruritis (itchy head during and after exercise)
exercise induced trigeminal neuralgia

head shaking (non-photic)
hypoglossal nerve
tongue laxity
odd compulsive habits involving the tongue
hypoglossal nerve palsy

neurogenic atrophy of various head and neck muscles (masseter, supraspinatus, etc.)
entrapment of the epiglottis
recurrent laryngeal nerve paralysis, partial paralysis, roaring
impaired drainage from salivary glands (mainly the parotids)
choke (that does not resolve without veterinary intervention)
dry mouth or excessive salivation
megesophagus (food lodges in the esophagus) ***
goiter (enlarged thyroid gland)
sweet itch (topline pruritis along base of mane and/or base of tail)
alopecia areata (aka vitilago) (hair loss around eyes and/or muzzle) ***
equine sarcoid
squamous cell carcinoma

Endocrine / Neurochemical Imbalances *** (all of these)

anhydrosis  (non-sweater) OR excessive sweating
sudden total body hair loss
hyper-reactivity to vaccination (localized soft tissue inflammation)
delayed systemic allergic reaction to vaccination (colic within 30 days, laminitis)
severe allergic reactions to intravenous drugs
endocrinologic laminitis
food allergies
sensitive skin
callouses on one or both elbows
chronic “shoe boils” / capped elbow(s)
hypersensitivity to touch (ears, face, hind legs, blankets)
hypersensitivity to rain / bathing
hypersensitivity to strong sunlight (sun burn)
hypersensitivity to grooming tools
hypersensitivity to certain bedding
reactivity on girthing / hypersensitivity to tack
reactivity to shampoos, fly sprays, detergents, leather dye
hypersensitivity to insects and insect bites
sweet itch (mane and/or tail)
intense pruritis along ventral midline, sheath / udder

hair that stands on end in a linear pattern (along meridians)
birdcatcher spots (first documented in the Irish TB stallion Birdcatcher 1833-1860)
“skunk tail” (especially in combination with alopecia areata and/or birdcatcher spots)
neurotransmitter imbalances (neuroses)
explosive outbursts (low dopamine) (ex: bolting)
depression (low serotonin)
anger, aggression, temper tantrums
moodiness, grumpiness, argumentative attitude
changes in temperament (mild mannered to a bully)
panic attacks (fear based) (for little or no reason)
running backwards (during a panic attack)
violently pulling back while tied
tendency to kick walls, humans, other horses (violently)
tendency to dorsiflex violently and randomly (buck)
hallucinations / bizarre fearful behavior
frequent yawning (yawning resets neurotransmitters)
narcolepsy (falling asleep randomly and/or collapsing)
random seizures
proprioceptive deficits (anywhere on the body)
attention deficit/hyperactivity disorder

insulin resistance
cushing’s syndrome (early onset high serum cortisol)
peripheral Cushing’s
equine metabolic syndrome (EMS)
altered estrus cycles (short or long, flagrant or silent)
cystic ovaries
chronic intermittent lactation (over months, years)
prolapsed uterus and/or retained placenta (after foaling)
testicles that are slow to fully descend / cryptorchidism (linked to ill behavior)
low testosterone / shy breeders
mineral depletion  (Bartonella feeds on magnesium)

consistently inconsistent behavior from one day to the next
and/or from one season to the next
dangerously high levels of toxic metals on hair analysis
patchy sweating (magnesium +/- potassium depletion)
inability to relax (muscle twitching / trembling / prancing)
self mutilation (biting at chest)
repetitive behavior (weaving, stall walking, pacing)
neurotic separation anxiety
obsessive compulsive behavior patterns (OCD)
tendency to escape from normal horse enclosures
inability to tolerate changes in routines
shortened stride length going downhill
oxidative stress / improvement with large doses vitamin E
marked improvement with 10 grams Mg malate /day in diet

As a stealth pathogen, Bartonella is adept at staying under the radar of human recognition underneath a multitude of disguises. Clinical signs of a chronic Bartonella infection are mysterious in onset, appearance, severity and duration (periodicity). A relapsing bacteremia is expressed as multiple recurring deficiencies, a sliding scale of dysfunction much like a roller coaster; various system imbalances can produce polar opposite symptoms. Just like autism spectrum disorder, chronic Bartonellosis will induce a vastly different constellation of symptoms from one horse to the next. Stress is cumulative and so are the clues that reflect a lurking problem that defies description. Since the trajectory over time is toward autoimmunity, those conditions that correlate with serious immune system dysfunction (notated ***) are significant red flags in and of themselves; the presence of just a few of the many conditions listed below on this article called “Frequently Asked Questions” constitute grounds for further investigation into the possibility of chronic Bartonellosis.

Bartonella produces a relapsing bacteremia; some days it is floating freely in the circulation and some days not. For this reason, our chances of obtaining a positive test result are enhanced by collecting blood samples on at least 3 alternate days. The veterinarian sends all 3 samples with a completed submission form to Galaxy Diagnostics ( Turn around time for results is 3 weeks. Galaxy uses a technology (BAPGM) that is considered the gold standard in Bartonella testing. For more information visit their website.

Yes. Evidence for transmission of infection from mother to offspring has been demonstrated in small rodents. There is growing anecdotal evidence that larger mammals (humans, horses) can also pass the infection along from one generation to the next. Much work needs to be done to elucidate this aspect of Bartonella epidemiology.

Treatment-both Lyme and Bartonellosis can be successfully treated with Chibese herbal medicine