CS of crampiness, stretches, periodic spasticity, muscle trembling and backward extension of rear limbs after rising
What is the etiology of inherited periodic spasticity?
Possibly a disorder of myotactic reflex or postural reflex mechanisms
Often associated with musculoskeletal pain (sore foot; other lameness)
How is inherited periodic spasticity tx?
Treat any underlying lameness
Banamine, phenylbutazone (remember withdrawl), other NSAIDS
What is fainting goat syndrome?
Autosomal dominant with incomplete penetrance from mutation in skeletal muscle Cl-channel
See signs by 6 weeks
Clinical signs are stiffness after rest, marked general rigidity after visual, tactile, or auditory stimulation, and are nonprogressive
Diagnosis is by EMG
What is clostridial myositis?
Usually rapidly fatal
Infectious, not contagious
CS of Fever, tachypnea, tachycardia, anorexia, depression, lameness with swelling, pain, and crepitus at site of infection (from anaerobic gas production)
Cl. septicum causes malignant edema
Cl. chauvoei causes blackleg (if you're a chauvinist, you look at legs)
Cl. novyi (Type B) causes black disease (infectious necrotic hepatitis)
What causes Bighead, Tetanus, and Redwater?
Cl. novyi Type A
How is clostridial myositis dx?
Fluid aspirates for culture and FA
What is the pathophysiology of clostridial myositis?
Found ubiquitously in the environment, feces, GI tract
Portal of entry = alimentary tract mucosa where spores become latent in liver & muscle tissue -> disease if tissue devitalized providing anaerobic environment (e.g. liver biopsy or liver flukes) OR external wound contamination
What are the toxins in clostridial myositis?
Act locally and systemically to create widespread organ dysfunction
α - lecithinase
β - deoxyribonuclease
γ - hyaluronidase
δ - hemolysin
What does an animal who died of clostridial myositis look like on necropsy?
Putrefaction with legs extended stiffly
Frothy, bloody discharge from the anus and nostrils
Foul odor (rancid butter) and congested lungs (edema)
Swelling, crepitus in affected muscles
How is clostridial myositis tx?
Abx, fasciotomy, supportive care
Drug of choice is high dose IV K- or Na-penicillin or could use PPG (less expensive)
In outbreaks vaccinate or revaccinate herd
What is the vaccine strategy for clostridial diseases?
Vaccinate young stock
If < 6 mos of age when they get initial series (i.e., primary and booster), booster again prior to one year
How can clostridial diseases be prevented?
Remove carcasses (or all spores infect soil)
What is sarcocystosis, and what is the transmission?
Find cysts in heart, esophagus and skeletal muscle (incidental at necropsy)
2 host cycle where definitive host is carnivores and intermediate host is a ruminant
In cattle: S. cruzi (dog), S. hirsuta (cat), S. hominis (primates)
How is sarcocystosis tx and prevented?
Amprolium or ionophore antibiotics before the 2nd stage of parasitemia
To control, prevent gross contamination of feed with feces!
What is gossypol toxicity?
A phenolic pigment that binds protein and iron
Unbound or free gossypol is toxic
Clinical signs are ill thrift, weakness, decreased milk production, lack of spermatogenesis in bulls, death from liver (more with Pima var.)and heart failure
Naturally acts as an insecticide
What [gossypol] is toxic?
Monogastrics, young calves <4mos should not > 100ppm = 0.01%
Mature ruminants tolerate 20 g of gossypol/hd/d = 5–6# cottonseed/hd/d
Rule of thumb: Don’t feed >7# cottonseed/hd/d
What is toxic myopathy due to ionophores?
Mechanism: lipid-soluble complexes with cations to facilitate transport across lipid membranes
Use: growth promotants and coccidiostat and to prevent ketosis
Toxicity: causes rhabdomyolysis and cardiomyopathy. CS of anorexia, pica, diarrhea, hind limb ataxia, dyspnea, weakness, tachypnea
CS: effusion of lateral femorotibial joint, absence of joint laxity, less lame than septic arthritis
Dx: synovial fluid has high cellularity and TP but no bacteria and minimal/no neutrophil toxicity (beware - septic joints often don't see bacteria either). Radiographs show ±subchondral bone cysts (lateral tibial plateau; femoral condyles)
Txt: box stall rest, intra-articular steroids, parenteral and intra-articular antibiotics, joint lavage, arthrotomy/arthroscopy and surgical curettage, placement of egress and ingress drains.
Px: regardless of txt, 2/3 return to productivity
What is a hock hygroma?
Chronic cellulitis of epidermis and subcutis over lateral hock following repeated trauma, which causes a bursa to form on lateral aspect of hock
Signifies there's a housing or environmental problem because she can't aly down without banging herself all up
Can become infected and require drainage and antibiotics
What is precarpal bursitis?
Formation of a SC bursa over carpus that rarely involves carpal joint
Txt: sterile drain & wrap, can inject 10-20 cc renographin (makes scar tissue) & pressure wrap x 2 weeks with q5 d bandage changes, can insert drains (less cosmetic; not for show animals), or can sx remove
What is subtendinous (calcanean) bursitis?
Septic bursitis of hock or bursa under SDF tendon ±osteomyelitis of calcaneus
Txt: drain via lateral incision followed by curetting/drain placement + antibiotics
Superficial flexor tendon should not be involved unless severe necrotic changes present
Px: guarded with osteomyelitis
What does Mycoplasma cause, and how is it transmitted?
Diseases: mastitis, reproductive disease, respiratory disease, keratoconjunctivitis, otitis media
CS: facial and vestibular nerve deficits with bilateral or unilateral ear droop, ptosis, epiphora, head tilt and recumbency
Transmission: calves fed mycoplasma-contaminated colostrum or milk
What causes mycoplasma arthritis in goats, and what are the CS?
Pathophys: Stress -> shedding from chronic carriers, goat ear mites (Psoroptes cuniculi and Raillietia spp) may be a reservoir for M. mycoides ssp. mycoides
CS: Adults have fever, mastitis, pleuropneumonia and arthritis
CS: Kids have arthritis, septicemia, meningitis for 1-3 days then become BAR
Typical scenario: polyarthritis and pneumonia in kids concurrently with mastitis in does
Dx: PCR joint fluid (don't culture)
Txt: don't tx! Will cause chronic shedder, and no abx work very well
Px: Highest morbidity and mortality in young stock
Prevention: Isolate & perform milk cultures on herd additions; if doe dry at purchase, maintain isolation until culture at kidding and @ 2 and 4 weeks fresh or swab and culture ear wax (in dry does); if outbreak, heat treat colostrum
What kind of virus is CAEV, and what cells are targeted?
Targets monocytes and macrophages which localize in synovium, MG, CNS, lung (non-neutralizing antibodies produced and immune complexes cause chronic inflammation)
How is CAEV transmitted?
Primarily colostrum and milk
Also in utero/ horizontal
Virus-infected cells in estrual mucus, preputial swabs, lochia post kidding, semen aspirated from tail of epididymis
So important to segregating infected/noninfected herdmates!
What are the CS of CAEV?
2-6 mos kids
Rear leg paresis or paralysis
Eat normally, alert, afebrile
Discomfort secondary to urine retention
Mostly in mature adults >2-3 years
Carpus commonly affected
Chronic joint enlargement & weight loss
“Hard Bags”: mammary gland involvement
Decreased milk production; hungry kids; firm udder; milk looks normal
“Hard Lungs”: chronic interstitial viral pneumonia results in progressive respiratory distress/weight loss with or without evidence of polysynovitis/arthritis
Similar to ovine progressive pneumonia (OPPV) virus
How is CAEV dx?
Joint fluid analysis:
Normal or increased volume
Increased cells (1000 to 20,000 cells/ul with 90% mononuclear cells
Contrasts with neutrophil increase typical of bacterial joint infection
CSF (on kids with leukoencephalomyelitis):
Increased CSF mononuclear cells
Official USDA tests:
AGID test using OPPV as antigen
Competitive ELISA (cELISA) – more sensitive
Test for maternal CAEV antibodies in kids up to 4 mos
How is CAEV tx and prevented?
Tx: none, keep pet goats comfortable with NSAIDs, glucosamine, nursing care
Block transmission by contaminated milk or colostrum (use duct tape)
Isolate seropositive goats
Serologically monitor herd
Heat treat colostrum (too high = D), thoroughly mix! and watch temps!
How does sacroiliac (sub)luxation occur?
Riding injury during breeding/heat
Predisposing factors like relaxation of pelvic ligaments (relaxin hormone)
What are the CS and tx for sacroiliac (sub)luxation?
Etiology: P or VitD deficiency, inadequate exposure to direct sunlight, Ca def and excess dietary P causing nutritional secondary hyperparathyroidism; Mg, Zn, Mn, VitA deficiency
CS: bowlegged, stiffness, reluctance to move, lameness, joint enlargement, arching of the back, enlarged costochondral junctions
Dx: Thin cortices, bowing long bones, enlarged and widened physeal plates, irregular radiolucent band at meta- epiphyseal junction, physeal “lipping” (cattle with Cu deficiency may have physeal lipping). Need to determine ratio of bone ash:organic matter (bone ash is primarily CaP, normal = 3:2, rickets = 1:2 to 1:3)
Tx: Supplement with Ca2PO4 (23% Ca, 18.5% P), limestone plus a P source, injectable VitD
Prevention: balanced diet
Px: fair to good if ambulatory
What is spider lamb syndrome?
aka ovine hereditary chondrodysplasia
Etiology: semilethal AR disease in Suffolk, Suffolk crossbred, and Hampshire sheep (lambs must be ss to show CS)
CS: angular limb deformities (“knock-kneed”, carpus valgus), kyphosis, scoliosis, concavity of sternum, crooked roman nose), failure to thrive
2 syndromes: abnormal at birth (stillborn or die within days of birth, or die from scours and pneumonia by 1 month); develop abnormal signs 3-8 weeks (one or more limbs affected, decreased growth rate after 4-8 wks, eventually progresses til lamb can’t walk)
Dx: rads (widened irregular growth plates w/retained islands of cartilage, esp look at olecranon lateral and flexed); stillborn lambs may not exhibit radiographic changes.
Prevention: destroy carrier rams (can use carrier ewes to get market lambs or to progeny test rams)
Breeding stock classification: white - no known spider progeny, gray - sire or dam or sibling has produced a spider lamb but this individual has not, black - individual has produced a spider lamb
When would you use a flotation tank?
Downer cow with no metabolic or skeletal reasons (i.e., fracture) for being down, and that the cow is alert (i.e., not sick with mastitis, metritis, or other metabolic disease).
To determine which limbs weight bearing or not (once standing in tank)
To facilitate faster recovery following development of recumbency (ie, get them up sooner than later!)
What does tibial paralysis look like?
Characteristic knuckling of fetlock; slight dropped hock
Often secondary to calving paralysis (sciatic paralysis)
Txt is support wrap...maybe distal limb cast for 2-4 weeks (often more economical than leg wraps)
Congenital (primary): usually lower eyelid and bilateral
Acquired (secondary): upper or lower eyelid
CS: rubbing of the eye, ocular and nasal discharge, photophobia, epiphora, blepharospasm, corneal ulceration over lower (or upper if upper lid) half of cornea
Txt: inject penicillin (1-2 cc) into lower lid, skin staples to evert the lid, place 2-3 vertical mattress sutures
What are 5 common sites of predilection for bovine lymphosarcoma?
uterus, abomasum, epidural space, right atrium, retrobulbar LNs
What are the characteristics of bovine cancer eye (ocular squamous cell carcinoma, OSCC)
In 10% of Herefords
Median age: 7.4 yrs
Cattle with nonpigmented periocular tissues most susceptible (~75% of affected cattle lack pigmentation)
UV exposure is risk factor
What are the OSCC prescursors?
Plaque: dense white keratinized non malignant tissue located on the corneoscleral limbus or lid margin
Papilloma: cornified wart-like tissue usually from eyelid
Acanthoma: keratinized tumor shaped like a horn; the keratin can be removed from the surface of the tumor leaving a small invasive, malignant mass growing off corneal surface
What is exenteration?
Involves removal of the eye, adnexa, and part of the bony orbit
What are three zoonotic proliferative cattle lesions?
pseudocowpox, orf, bovine papular stomatitis
How can you tell if a growth is malignant or metastatic?
Malignant = smelly
Metastatic = look for enlargement of submandibular, parotid, prescapular lymph nodes
How do you tx OSCC?
Medical: hyperthermia (anesthetize and proptose eye with retrobulbar block, apply electrode probe across tumor, sensor keeps tissue between electrodes at 52°C, then rotate 90° and repeat) or cryotherapy (freeze and thaw x3, for tumors <0.5cm)
Surgery: 3rd eyelid removal, excise, exenteration (standing or under GA)
What is infectious bovine keratoconjunctivitis?
aka pink eye
Caused by: Moraxella bovis (g- rod) and Moraxella bovoculi (g- cocci), has pili to adhere and cytotoxin