LDA and RDA – Most common in dairy cattle within one month of parturition or prepartum. Due to hypocalcemia resulting in abomosal atony. Leads to metabolic alkalosis, hypochloremia, hypokalemia due to sequestration of acid, chlorine and potassium in abomasum. Left 5-10x more common than right. Left-sided ping between ribs 9-13. Normal TPR. Anorexia, decreased production, ketosis. Diarrhea is poor px sign. Treatment - roll cow, but recurrence likely. Surgical correction with rt flank pyloric omentopexy or rt paramedian abomasopexy, combined lt flank & rt paramedian abomasopexy. RDA can become AV. Recent parturition, partial anorexia, decreased milk production suggest displacement.
Abomasal volvulus – Dairy cows near parturition w/ sudden drop in milk production. Usually counterclockwise from rear. Very sick, clinical signs more severe dt vascular compromise. Right sided ping, palpable. Treatment is surgery. Poor prognosis. Tachycardia present, area ping maybe btwn ribs 8-13, weakness, toxemia, dehydration. Recumbent within 48-72 hrs.
Abomasal ulcers - Most common in high-producing dairy cows in first 6 weeks of production. Stress decreases protective prostaglandins. Ulceration at the ventral portion of the fundic region of the greater curvature. See melena, anorexia, occult blood, abdominal pain. LSA is significant cause of bleeding ulcers in older cattle. Bleeding ulcers don’t perforate and perforating ulcers (seen in calves) don’t bleed.
Abomasal impaction - Pregnant beef cattle in winter with poor quality feed.
Left Ping = LDA, pneumoperitoneum, atonic rumen.
Right Ping = Spiral colon, rectum/colon, RDA, RAV (palpable).
Tx: = displacement: ca2+ borogluconate SC or ca2+ gels PO→restore normal abomasal motility provide H20, NaCl block→restore electrolytes, fluids
more severe cases:7.2% NaCl, 5 ml/kg IV over 5 min
Px:=following calving: feed total mixed ration, avoid rapid dietary changes, maintain roughage in diet, avoid
Cattle - Herd problem: IBR, BVD, brucellosis, leptospirosis, campylobacteriosis, trichomoniasis, anaplasmosis, ureaplasmas, mycoplasmas. Sporadic: Mycotic (Aspergillus, Mucor spp). Reach uterus hematogenously, cause late term abortion. Fetus not affected or may have ringworm lesions; placenta severely affected with necrosis of cotyledons. Dx via culture of fetal tissue. Neospora caninum; common in dairy cattle, sporadic abortions, b/w 4-6 mo gestation, dog definitive host, fetus usually autolyzed, px: prevent dog fecal contamination of feed. Arcanobacterium (Actinomyces) pyogenes; sporadic abortion, gains entry to bloodstream→endometritis, placentitis; fetus autolyzed AlsoListeria, Haemophilus, Corynebacterium pyogenes, Staphylococcus, bluetonque, Ureaplasma diversum; normal inhabitant vagina, prepuce cattle; abortions single, usually 3rd trimester, well preserved, (-) lesions in fetus, isolate from lungs, placenta, abomasal contents. Nitrates, lupine, locoweed, mycotoxins.
Mares - Most common infectious cause of abortion in horses is Equine Herpes 1, last trimester. Equine viral arteritisless frequent. Vax available for both diseases. Sporadic abortion from Streptococcus zooepidemicus, Escherichic coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Rhodococcus equi, Actinobacillus equuli. These infections occur through ascending infection via the cervix. Twin pregnancies often result in abortion. Crush the smallest embryo at day 22-25 after confirmation of pregnancy.
Sheep - Most common cause of abortion is campylobacteriosis. Campylobacteriosis - Infection via ingestion of organisms. Late-term abortion of edematous fetus; liver with gray necrotic foci. Carrier sheep shed organisms in feces, uterine discharges, aborted fetuses. Culture and ID organism in fetal abomasal fluid and liver. Vaccinate ewes at breeding; booster at second month gestation. Toxoplasma gondii – protozoan; life cycle is completed in the cat. Abortion and still births in sheep, pigs, and goats. White foci in cotyledons, leukoencephalomalacia. Chlamydia psittaci (Enzootic Abortion of Ewes) – late-term abortion. Exposure via ingestion, inhalation or venereal. Fetus well-preserved or mummified. Placentitis most consistent finding. Leptospirosis - late-term abortions. Listeriosis - late-term abortion, birth of weak lambs. Slight to marked autolysis of fetus, fluid in serous cavities, necrotic foci in liver, lung and spleen. Erosions in abomasal mucosa. CNS deficits. Man can be affected. Akabane virus disease – arthrogryposis, hydrancephaly. Border disease (pestivirus); abortion any stage: fetus undersized, tremors, hairy coat (hairy shaker lambs); no vaccines. Cache Valley Virus: mosquito transmitted: stillborn lambs, live births→CNS, musculoskeletal abnormalities; hydrancephaly, hydrocephalus, cerebral & cerebellar hypoplasia, arthrogryposis, scoliosis, torticollis, hypoplasia of skeletal muscles, dx via Abs in precolostral serum or body fluids; no vaxs
Pigs – Vaccinations: parvovirus, pseudorabies, enterovirus, brucellosis, leptospirosis can affect reproductive performance. Vaccinate sows and gilts against leptospirosis, parvovirus and erysipelas. Also permit >21 day exposure to herd before breeding to allow natural exposure to endemic herd pathogens including parvovirus and enteroviruses that can cause reproductive failure. Parvovirus - Early fetal resorption, reduced litter size, mummies. Due to persistence of maternal immunity in gilts until sexual maturity, exposure at breeding time. Pseudorabies - Abortion, stillbirths, mummies, weak pigs. Also fever, respiratory signs, nervous signs. Brucellosis - Venereal. Leptospirosis – L. interrogans one of most common causes of reproductive failure. L. pomona is late term abortion. L. bratislava commonly id in serologic surveys in midwest US but NOT affected w/ abortion or repro problems. Porcine Reproductive and Respiratory Syndrome (PRRS): arterivirus, most imp dz pigs US, >90 d gestation, abort end gestation; sows anoretic, fever; litter weak infected pigs & uninfected pigs develop respiratory dx; hemorrhage umbilical cord only lesion fetus. Vax available. Japanese B Encephalitis Virus: ZOONOTIC; arthropod-borne;reproductive failure pigs & humans. Litter:mummies, stillborn, weak pigs;hydrocephalus, SQ edema common lesion. Severe hyperkalemia-à bradycardia; ECG alterations
Cow – PGF2α up to 4th month. Months 5-8 PGF2α & Dexamethasone combination. 75% have retained placentas. 0-14 days pre-term, calves born with normal viability and normal blood IgG.
Mare - PG for abortion only. May need double dose or repeated treatment at 48 hour intervals after 4th month. Douching of uterus also works at any stage of pregnancy. Oxytocin for live foal only after cervix has begun to relax and colostrum is in udder.
Small animal - Not safe. PGF2α can be used after day 40. Dexamethasone 10 days produces fetal death and resorption.
-caused by F. necrophorum, G-, obligate, anerobic,
-predisposed to rumenitis
-rumenitis caused by incr carbohyd in feed—incr ruminal acidity—colonization of bacteria
--virginiamycin fed at 25 g/ton of feed or chlortetracycline fed continuously at 70 mg/head/day during the finishing period, significantly reduce the number of liver abscesses and increase feed efficiency and weight gain, little effect on prevalence of ruminal lesions
Acepromazine - Phenothiazine tranquilizer. Block release and uptake of dopamine in the CNS. Also has anticholinergic, antihistaminic, antispasmodic and alpha-adrenergic blocking effects. Depresses RAS. Administer atropine to counteract bradycardic effects.
Adverse effects - Precipitates seizures. ↓ RR, ↓ arterial BP, ↑ CVP, bradycardia, sinoatrial arrest. Bradycardia negated by physiological response to decreased BP. Causes extrusion of penis in male large animals. No analgesic effects.
Positive effects - Antidysrhythmic effects. Inhibit arrhythmias induced by ultra-short barbiturates, halothane, epinephrine. Reduces halothane-induced malignant hyperthermia in pigs.
Contraindications - Decrease dose in animals with hepatic dysfunction, cardiac disease. Contraindicated in patients with hypovolemia, shock, tetanus, strychnine.
Acetabular fractures – If there is no displacement, fractures treated conservatively with Ehmer sling and restricted activity. Bone plates and screws used for internal fixation.
Acetaminophen poisoning - Tylenol®.
Clinical signs - Hemolytic anemia, methemoglobinemia. Dark-colored urine. Icterus, facial edema, lethargy. The liver is the primary site of toxicity.
Clin path - Heinz body anemia, hemolysis, hemoglobinuria.
Therapy - N-acetylcysteine (Mucomist).
Mechanism: cats lack glucuronyl transferase; unable to metabolize
Acetonemia (cattle) - result of a –ve energy balance in the 6 wk after parturition. Incidence highest 3rd, 4th wks of lactation if cows improperly fed, conditioned during dry period. lactating dairy cows, fed for high milk production. Blood glucose drops—hypoglycemia—gluconeogenesis—ketone bodies.
CS : ↓ in feed intake, ↓in milk prod, lethargy, firm-mucus covered stools. May see marked wt loss, pica, ACETONE ODOR TO BREATH, frenzy, aggression, bellowing, circling, staggering, falling.
Lesions: carcass is thin, malnourished with little body fat, indicative of starvation; liver, pale yellow and may be soft and friable. h/o parturition, bizarre behavior. Rothera’s test for ketone bodies: on milk more definitive dx (<50 mg/dl); bld glc
--levels normal 40-60 mg/dL drop to below 25 mg/dL in clinical ketosis
traumatic reticulitis, poisoning, pyelonephritis, listeriosis, and rabies.
-TX: IV administration of 500 mL of 50% glucose and IM administration of the glucocorticoid
Propylene glycol (225 g, b.i.d. for 2 days, followed by 100 g daily for 2 days)
--properly condition during late lactation and dry period
--body score should be 3.5/5.0
--2 wks prior to parturition-sm amt concentrate, gradually incr to 1 lb/150 lb body wt. daily
--DON’T OVERFEED after parturition
--rations containing 16-18% crude protein and 19-21% fiber
--eliminate predisposing factors
Acrodermatitis – Lethal familial zinc deficiency in white bull terriers. Retarded growth, progressive, acral, hyperkeratotic dermatitis, pustular dermatits at mucocutaneous jxns. Death by 2 yrs of age. Don’t respond to Zn therapy
Acute Abdomen – Syndrome. Acute presentation, showing systemic signs, abdomen painful, distended, V/D, weakness. Major categories are bacterial sepsis, obstruction/perforation, ischemia/thrombosis. Fundamental question is surgical or medical tx reqd. W/ septic peritonitis, the solution to polution is dilution – exploratory and lavage. See GDV and pancreatitis for others.
Addison's Disease – Hypoadrenocorticism. Immune-mediated or iatrogenic adrenocortical insufficiency leads to deficiency of glucocorticoids and mineralocorticoids. Seen in young to middle-aged dogs, occasionally horses. Familial in standard poodles (?). Lack of aldosterone secretion results in impaired ability to conserve Na+ and excrete K+. Leads to hyponatremia and hyperkalemia (Na:K < 25:1).
Clinical signs - Hyponatremia leads to hypotension, ↓ CO, hypovolemia. Results in prerenal azotemia. Severe hyperkalemia-→bradycardia; ECG changes. Lack of cortisol secretion can lead to GI signs, lethargy, and impaired stress response. Normocytic, normochromic anemia. Absolute eosinophilia. Hypoglycemia due to ↓ glucose production (glucocorticoid deficiency). Occasional hypercalcemia.
Treatment – Fluid replacement, electrolyte assessment. Florinef (Fludrocortisone acetate) or DOCP (Desoxycorticosterone pivalate). Prednisone if necessary.
ADH – Antidiuretic Hormone. Suppresses excretion of urine. Has specific effect on the epithelial cells of the renal tubules. Stimulates the resorption of water, resulting in concentration of urine.
Adrenal Glands – Endocrine gland. Adrenal cortex - Three zones. Zona glomerulosa (outer) secretes mineralocorticoids. Zona fasciculata (middle) layer secretes glucocorticoids. Zona reticularis (inner) secretes sex steroids. Accessory cortical tissue seen as small nodules in aged dogs is common and nonfunctional. Adrenal Medulla – Modified sympathetic nervous system ganglion. Secretes epinephrine and norepinephrine. Important role in response to stressor hypoglycemia. Tumor of adrenal medulla is pheochromocytoma, which may secrete either hormone.
Mineralocorticoids - Aldosterone regulates ion transport of epithelial cells, resulting in excretionof K+ and conservation of Na+.
Glucocorticoids - Regulate carbohydrate, protein and lipid metabolism resulting in sparing of glucose and lipolysis. Glucocorticoids suppress inflammatory and immunologic responses. Can have negative effect on wound healing due to inhibition of fibroblast proliferation and collagen synthesis.
Sex hormones - Progesterone, estrogens, and androgens.
--Aegyptianellosis: acute, tick-borne, febrile disease caused by Aegyptianella spp
--rickettsia, family Anaplasmataceae
--variety of avian spp
--vector: Argas spp
--bloodborne dz; “signet ring” shaped organism or oval, lateral to nucleus rbc
--most common in tropics & subtropics—can be found in wild turkeys in Texas
--Anemia, enlargement of the liver and spleen, enlarged discolored kidneys, and pinpoint
--tx:tetracycline, doxycycline & tick control
Aelurostrongylus abstrusus - Cat lungworm. Life cycle includes snail first host; frog, lizard, bird or rodent vector encysted larvae. Cat eats transport host, larvae migrate from stomach to lungs and embed in lung tissues. Eggsform nodules in alveolar ducts, larvae hatch, coughed up, swallowed and passed in feces. Larvae in feces have dorsally spined tails. Causes coughing, dyspnea. Treatment is levamisole. 9th Edition Merck, tx: Fenbendazole 50 mg/kg PO BID 10-14 d or ivermectin 400 microg/kg SQ, once
African Swine Fever – Iridovirus. Highly contagious viral disease that resembles hog cholera and is therefore REPORTABLE. Eradicated from western hemisphere. Replicates in RE cells, found in all fluidsand tissues. No vaccine. Ornithodoros ticks are vectors. Oronasal exposure. Survivors carriers for life. Clinical signs include fever, vomiting, diarrhea, eye discharge, abortion, death. Hemorrhage of lymph nodes, renal cortex, splenomegaly (bigger than in hog cholera). Excessive pleural, pericardial and peritoneal fluids.
-hereditary, seen in heifers
-imbalance of hormones control udder development, lactation
-maybe assoc with fibrosis of mammary gland, grazing endophyte-infested fescue
-tx; not effective
Air Sacculitis – Mycoplasma gallisepticum. Causes respiratory tract infection in chickens. High rate of carcass condemnation. Caseous exudate. Clin signs: marked rales, coughing and/or sneezing, nasal discharge. More serious in turkeys: swelling paranasal sinuses. Tx: Ab in water 5-7 d: tiamulin, tylosin, erythromycin, enrofloxacin, spectinomycin
Control: maintain seronegative flock
--Air Sac Mite: Kytodites nudus; small mite;”white spots” on the bronchi, lungs, air sacs,
abdominal organs of chickens, turkeys, pheasants, pigeons, and mallards
--transmissbile btwn birds
--route of transmission unknown
--larval & 2 lymph stage cycle
--clin signs: none to weakness, weight loss, pneumonia, peritonitis, obstruction of respiratory
passages, and death
--tx:ivermectin, pyrethrin/piperonyl butoxide spray, dichlorvos pest strip
Aldosterone - The main mineralocorticoid hormone secreted by the adrenal cortex. Regulates electrolyte and water balance by promoting retention of Na+ and the excretion of K+. Retention of water induces an increase in plasma volume and an increase in blood pressure. Secretion of aldosterone is stimulated by angiotensin II.
Aleutian Disease - Parvoviral infection of mink resulting in immune complex formation and deposition. Clin signs: poor reproduction, wt loss, oral/GI bleeding, renal failure, uremia. Control: test/slaughter; No vaccine.
Alimentary Lymphosarcoma – Most have normal or ↓ peripheral lymphocytes. “Nonresponsive IBD”. Can be diffuse or multinodular. Dx w/ full thickness biopsy. Very difficult to treat.
Alkalosis - ↑HCO3, ↑TCO2, hyperventilation causes alkalosis. Cow saliva rich in HCO3 (horse saliva rich in Cl-).
Amyloidosis - Consistsof β pleated sheets of amino acids, refractory to enzymatic breakdown. Two major amyloid proteins. AA released from hepatocytes due to chronic infection. AL composed of partially degraded immunoglobulin light chains produced by malignant plasma cells. Disease caused by displacement of normal cells with amyloid deposits, mainly liver, spleen, brain and kidneys.
Anal Sac Disease – Hematochezia. Chronic bright red blood w/ normal stools.
Anaplasmosis – Anaplasma marginale. Rickettsia located in the stroma of RBC. Disease of ruminants. Transmission through contamination with infected blood via ticks (Boophilus, Dermacentor), horse flies, stable flies, mechanical transfer of blood (vax, dehorn, etc). Fomites. Carriers maintain disease in a herd. More severe in adult cattle; lifelong resistance if exposed young.
Clinical signs - Depression, inappetence, fever, decreased production, marked icterus. Anemia leading to hypoxemia. No hemoglobinuria.
Diagnosis - Suspect in mature cattle showing anemia without hemoglobinuria. Blood smear, see anisocytosis, presence of agent. Serology.
Hemolysis – Intravascular = RBC destruction w/in blood vessels and loss of Hgb from cells. Often severly ill w/ weakness, fever, icterus, Hgbemia, Hbguria. More aggressive therapy, worse px. Extravascular = RBCs lysed following phagocytosis w/in RE system. Patients ± ill and may only have signs related to anemia, spleno/hepatomegaly, ± icterus. Ddx: IMHA, SLE, Zn tox (pennies<1982), Heinz body anemia (onions, tylenol in cats), Babesia, Hemobartonella, copper tox, Lepto, endotoxemia.
Blood loss – Acute blood loss see severe signs bc no time to compensate. Chronic internal blood loss will have no Fe deficiency. Chronic external blood loss via skin, UT, GIT will have Fe deficiency. Ddx: coagulopathy, trauma, ruptured hemangiosarcoma, GI ulceration, nasal epistaxis.
Nonregenerative Anemia – Microcytic, hypochromic. 1) BM aplastic diseases such as myelofibrosis, neoplasia, Ehrlichia, FeLV. Toxins such as anticonvulsants, chloramphenicol, TMPS, estrogen, phenylbutazone, chemo. 2) 2° failure of erythropoeisis – ACD. Mild to mod anemia. 3) Hemoglobin synthesis defects such as Fe deficiency. 4) 1° failure of erythropoeisis. Pure red cell aplasia, immune mediated disease, estrogen therapy (often given for urinary incontinence). See severe anemia, ↑ serum Fe, ↑ EP, normal platelets and WBCs. Tx w/ immunosuppressives.
Circulating nRBCs – Metarubricytes. Ddx: regenerative response (only if orderly), BM dysfunction, splenic dysfunction, extramedullary hematopoiesis, lead toxicity, hemangiosarcoma, heatstroke/vasculitis.
Anticholinergics – Parasympatholytics. Protect HRs, decrease secretions, decrease threshold for arrythmias. Do not work in rabbits and goats as they have atropinase (why they can eat nightshade).
Atropine – Muscarinic antagonist. Competitively inhibits acetycholine at postganglionic parasympathetic sites. Low dose inhibits salivation, bronchial secretions, sweating. Moderate dose dilates and inhibits accommodation of the pupil, ↑ heart rate. High dose ↓ GI and urinary tract motility. Very high dose inhibits gastric secretions. Crosses BBB. May cause ileus in horses. Also, antiemetic, mjydriatic, organophosphate tox tx. Red as a beet, dry as a bone, mad as a wet hen. Tachycardia, dilated pupils.
Glycopyrrolate vs. atropine – Atropine for emergency, works quicker (but doesn’t last as long only 2-3 hrs). Glyco is 2-4x more potent than atropine, duration of action 4X longer (4-6 hours), prevents bradycardia without causing tachycardia. Glyco does not penetrate BBB (poor lipid solubility), atropine does.
Tranquilizers - Calm the animal, facilitate handling for induction, ↓ amount of induction drugs.
Phenothiazine tranquilizers (Acepromazine) - α antagonist. Neuroleptic. No analgesia. Sedative, antiarrhythmic, antiemetic. Vasodilation, hypotension, lowers seizure threshold, inhibits platelet aggregation, penile paralysis in stallions, ↑HR. Do not use in shocky animals. No reversal. Don’t use in really young, really old, or sick. Avoid in DP dogs.
Diazepam – Benzodiazepine sedative. Does not work as tranquilizer when used alone. ↓ amount of other induction drugs necessary. Anxiolytic, anticonvulsant. Centrally acting muscle relaxant (as is Guaifenesin). Appetite stimulant in cats. In healthy cat as premed, may cause excitement or aggression dt suppression of learned behavior. Flumazenil is reversal agent. Do not give IM, carrier is propylene glycol. Can give midozolam IM (H2O carrier).
Opiods – Controlled substances. Analgesia, euphoria, antitussive, anti-diarrheal. Hypotension, bradycardia, respiratory depression. Potency of morphine < oxy (10x) < fentanyl (100x). Vagally mediated bradyarrythmias (tx w/ atropine). Naloxone is antagonist. Morphine – pure mu agonist; make vomit; cheap; good for mod to severe visceral pain; epidural gives LT analgesia (up to 24 hrs); give preservative free morphine (normal carrier is formaldehyde). Butorphanol – kappa agonist, mu antagonist; 2-4 hrs duration; very safe; ceiling effect on ventilatory depression, oral form avail. Can ↓ effects of morphine, fentanyl (b/c mu antag); not as much sedation or dysphoria. Buprenorphine – partial mu agonist; behaves like kappa agonist; good for mild to mod pain; lasts 6-8 hrs; ceiling effect on ventilatory depression. Naloxone does not reverse resp depression of buprenorphine. Partial agonist means lots of affinity for receptor but not very active once there. Innovar-Vet = Fentanyl + Droperidol.
α2 agonists - Sedative, analgesic, muscle relaxant. Vagally mediated bradycardia, systemic hypertension, respiratory depression. Sensitizes heart to epi induces arrythmias, arrhythmogenic (1° and 2° heart block),. Can still get kicked/bitten, animals can override. ↑ urine production, vomiting in dogs. Xylazine - cattle extremely sensitive (1/10th dose), also sheep and goats; reverse w/ yohimbine. Paralyzes esophageal musculature allowing it to fill w/ air, can look like megaesophagus on rads. 1° side effect in cats is vomiting or retching. Detomidine – reverse w/ telazolin. Medetomidine – reverse w/ atepamazole.