Bovine Mastitis Lecture Notes PDF

# Fifth Year ## Pure Science ### Infectious Diseases #### Bovine Mastitis **Mastitis in Cattle** * ↑ In No. of cells every 100, 000 indicate ↓ of milk production by 2.5% why? * Because most of SCC are WBCs, the body consumes glucose for their production instead of producing milk. * Commo...

# Fifth Year ## Pure Science ### Infectious Diseases #### Bovine Mastitis **Mastitis in Cattle** * ↑ In No. of cells every 100, 000 indicate ↓ of milk production by 2.5% why? * Because most of SCC are WBCs, the body consumes glucose for their production instead of producing milk. * Common in Dairy Cattle * Major problem facing dairy farmers **Economic Importance** * **For The Animal** * Culling of chronically infected animal * Cost of treatment * Loss of functional quarter * ↓Milk production * Death of cow (in case of peracute mastitis due to toxemia) * **For The Human** * Poor quality milk * Antibiotic residues in milk **Costs of Loses** * Reduced production (116) * Discarded milk (22) * Replacement costs (14) * Reduced cow sale (10) * Drugs (10) * Vet costs (5) * Additional labor (2) **What's Mastitis?** * Inflammation of one or more quarters of the udder and has the cardinal signs of inflammation (swollen, redness, warmth, pain on touch & loss its function). * Mastitis characterized by presence of a significantly ↑ in leukocyte content & SCC in milk **Somatic Cell Count (SCC)** * 99% WBC + 1-2% epithelial cells from milk-secreting tissue * Considered cow's natural defense mechanism * Normal (uninfected) cow → 50,000-200,000 cells/ml, up to 250,000 cells/ml * Bulk sample → 400,000 cells/ml * ↑200,000 cells/ml → the likelihood of infection increase **What Causes Mastitis?** * Intra-mammary Infection (IMI): * Bacterial infection * Mycoplasmal infection * Mycotic (fungal) infection **Predisposes the gland to IMI** * Mechanical trauma * Thermal trauma * Chemical insult ** Bacterial Infection** * **Contagious Mastitis** * Source of infection: * Teat & Udders of infected cows * Infected quarter to another * Method of spread: * Spread from cow to cow and from infected quarters to other quarters primarily * Time of spread: * At milking time (milking, hands, common cloth) * Examples: * *Staphylococcus aureus* (Coagulase positive) * *Streptococcus agalactiae* * *Corynebacterium* * *Mycoplasma bovis* (lives in infected quarters, respiratory & reproductive tract) * **Environmental Mastitis** * Source of infection: * The environment of the cow (soil, feces, bedding) * Exposure to environmental M.O (environment to udder) * Transmission can occur at any time during the life of * Examples: * *Streptococci dysgalactiae / uberis / equinus* * *Coliform* (E. Coli, *pseudomonas spp.*, *enterobacter* and *kelbsella*) * *Staphylococcus spp.* "other than *Staph. aureus*" (Coagulase negative staphylococci = CNS) * *Pseudomonas aeruginosa* * *Actinomyces pyogenes* * *Nocardia* specics **Damage** * Cause more damage and persist as subclinical mastitis * Mostly subclinical * Cause less damage and rapidly eliminated **Control** * Post milking teat dipping * Dry cow therapy * Milking hygiene * Culling cow * Higher percent clinical * Environmental hygiene * Pre dipping * Dry period teat sealant **Determinants of Mastitis** * **Host** * Existing trauma (milking machine, heat or cold & injury) * Teat end injury * Lowered immunity (following calving, surgery) * **Nutrition** * Age: Old cow 7-9 years (more than 4 lactation season) * Dirty & Poor hygiene * Teat shape and anatomy of the teat canal & teat orifice (teat orifice score). * Sometimes fissures occur in teat orifice in older cows, which make the udder more susceptible to ascending infection. * **Infectious agent** * Pathogenicity, virulence & number * **Environment** * Housing, equipment, hygiene, weather & bedding **Susceptible host** * All mammals are susceptible to mastitis **Factors influencing susceptibility** * **Breed** * High milk producers "foreign breeds" (Holstein Friesian → sever mastitis) * **Season** * Summer (dry period natural defense as S.C.C) * **Skin lesions** * Infectious disease causing lesions on udder & teats (as FMD - V.S - Cow pox - Pseudo Cow pox - Black pox - Udder impetigo - Bovine Ulcerative mammilitis) → mostly "contagious mastitis" * Especially staph. coagulase -ve **Mode of Infection and Transmission** * Infection occurs via the teat canal either from infected udder or from the environment (ascending infection) * Except *Tuberculous mastitis* (TB( & *Mycoplasma* → descending (hematogenous) * The most important transmission takes place during milking process (through the milking machine cups, milkers' hands, udder wash cloths and any other material). * Many new infection occur during the dry period (1st 3 weeks of the drying off period) due to: * Flare up of infection that not apparent during lactation * Bactericidal and bacteriostatic qualities of the milk which are at their lowest ebb during the dry period. **Defense mechanism in the udder** * Several cellular and immune defenses operate within the udder and phagocytosis and killing of the bacteria by Polymorph-nuclear leukocytes (PMNL) * But phagocytosis is much less efficient in milk than blood → because leukocytes ingest milk fat and casein → their efficiency against pathogens. * Several nonspecific bactericidal and bacteriostatic systems occur in lactating and dry udders include Lactoferrin, lactoperoxidase & lysozyme. **Why New Infections Near Calving?** 1. Physiological stress associated with parturition 2. Concentration of nonspecific immune factors in secretions 3. Physiological edema of udder & leaking of milk 4. Components of colostrum that interfere with leukocytes function. **Why New Infections at Beginning of Dry Period?** 1. Teat dipping & cleaning stopped 2. Phagocyte function (immune cells) is impaired = S.C.C 3. Flushing of teat & ducts is terminated 4. ↑ Udder pressure & leakage of milk. **Pathogenesis** * Except in *T.B.*, infection occurs via teat canal (ascending) terms of 3 stages: * **Invasion stage**: Organisms invade the udder through the teat canal * **Infection stage**: Migrate up the teat canal and colonize the secretory cells * **Inflammation stage**: Colonized organisms produce toxic substances harmful to the milk producing cells. **Mastitis in Herd Has 2 Forms** * **Subclinical Mastitis** * 90-95% of all mastitis cases * Udder appear normal * No systemic reaction * Milk appears normal with ↑ S.C.C (score 3-5) * Milk output (10%) * **Clinical Mastitis** * 5-10% of all mastitis cases * Inflamed udder (cardinal signs) * Bad milk (Clumps and clots in milk) * Bad general health due to toxemia in peracute mastitis (systemic reaction) * Loss of appetite * Depression * Prompt attention needed * **According to severity of the case, it is classified to** * **Peracute form** * Severe local inflammation marked * Sever systemic reaction (toxemia, fever, anorexia, depression & recumbancy) * As in *staph. mastitis*, *coliform mastitis* & *summer mastitis* * **Acute form** * Severe local inflammation * Mild systemic reaction * **Subacute form** * Mild local inflammation * Persistent abnormality of the milk * **Chronic form** * No systemic reaction * Recurrent attack of inflammation * Changes in milk secretion in the form of wateriness and few flakes (watery secretion) * No systemic reactions * Fibrosis & indurations of the affected quarter * Atrophy & slowly develop firm, nodular abscesses or granuloma-like masses within the parenchyma **Clinical Mastitis** * There are 4 clinical types of mastitis, depending on the resistance of the mammary tissue and virulence of invading bacteria * The clinical findings include: * Abnormalities of secretion * Abnormalities of the size, consistency & temperature of the gland * Presence of systemic reaction. **Mastitic milk** → has salty taste (due to ↑ NaCl) **Subclinical mastitis** * The milk and the gland → appear normal but there is a significant ↑ in leukocytic count in milk * The inflammatory reaction is detectable only by tests, such as the California Mastitis Test (CMT), White side test & electronic cell counters, which are used at intervals to determine somatic cell counts of the milk * Presence of bacteria that can be isolated * Accompanied with ↓ in milk secretion. **Special Types of Mastitis** * **Environmental (Coliform) Mastitis** * Usually peracute and acute * *Cause:* * *E. Coli* * Most frequent cause → 85% of cases * Can be easily treated, but 15% of cases may turn into *gangrenous mastitis* * *Klebsiella* * Wood based bedding products can be a source of *Klebsiella* * Difficult to treat, needs 7 continuous days of *marbofloxacine* and only 50% of cases recover. * *Pseudomonas* * *Pseudomonas* mastitis is hopeless to treat because it's resistant to all antibiotics * *Enterobacter* * Hay (forage) and wood chips are the sources of *Enterobacter* and straw (forage) and wood chips are the sources of *Enterobacter*. * **Signs:** * Severe systemic reaction → fever with shivering & recumbency. * Milk - yellow serum like with flakes affect one or two quarter * **Treatment:** * Evacuation of udder each 4-6 hr. by manual stripping or Oxytocin injection → to propagation of bacteria * Treat endotoxemia by * Large volumes of I/V fluid (20-30 liters isotonic) or Hyper tonic soln. (the best) * Live saving step in case of coliform mastitis is Hypertonic soln. 7.2 * **Gangrenous mastitis** * Usually peracute or acute in nature * **Peracute form**: May lead to death due to toxemia. * **Acute form**: may transfer to gangrenous mastitis. * **May be chronic form**: fibrosis of udder * **Cause:** * *Staph. aureus* coagulase positive * **Virulence of staph** 1. Secrete *beta-lactamase* (penicillinase) 2. Resist phagocytosis as it survive in Polymorpho-nucleaocytes 3. Can be converted to cell wall-deficient L-form bacteria in specific environment 4. Secrete exotoxin to destruct WBCS 5. Surround it self by fibrous tissue. * **Signs:** * Milk brownish, watery contain flakes and not respond to treatment * Systemic signs with sever swelling, inflammation & recumbancy then * **Summer mastitis** * Heifer mastitis or dry cow mastitis. * Usually peracute or acute in nature * **Cause:** * *Corynebacterium Bovis* & *Cory. bact.* *Pyogenes* (Trueperella pyogenes) * Insect may play a role. * **Signs:** * Milk → yellowish to greenish pus with offensive odor with abscess formation in udder. * **Treatment:** * **In early stage:** * Synulox (Amoxicillin + Clavulanic acid → inhibit penicillinase enzyme of M.O) * Cobactan 2.5% (Cefquinome "4th generation of cephalosporins") * Spirovet (spiramycin) * Tylosin * Anti-inflammatory & Antihistaminic (as Coliform mastitis) * **In late stage:** Surgical removal * **In case of mixed infection by *E. Coli* (affect upper part of udder) Staph. (affect lower part of udder) → Gangrenous mastitis and treated by Synulox + Marbocyl** * **Streptococci Mastitis** * *S. uberis*, *S. dysgalactiae* & *S. equinus* * More subclinical mastitis * Predominant early and late lactation * Treated easily with penicillin (Synulox) + intramammary infusion * *S. agalactiae* * Clinical mastitis * Contagious → Acute, anorexia & local signs * Can be treated by intramammary infusion only * For *S. uberis* → Straw bedding is the source. * **Clostridia Mastitis** * Caused by toxin of *Cl. perfringens* type A may combined by *E. Coli* → gangrenous mastitis for more than 2 quarter (usually 4 quarter) * Sound of gases coming out during milking & Air under skin * Hopeless case & death (due to toxemia) * Treatment as staph, + Metronidazole (Flagyl or Amrizole) by dosc 1 vial / 100 kg * **Physiological (udder) edema** * Consistency of udder → spongy without cardinal sins of inflammation * Bloody milk "milk chocolate" with normal temperature & normal appetite * Appears After parturition and last for 3 days * Cause → Due to progesterone & ↑ estrogen → rupture of capillaries of udder * Treatment: Hemorrhage control → Amri-K (Vit. K) + haemostop or Kapron * Strawberry milk is the result of injury, trauma, or infection → centrifugation * If RBCs precipitate → hemorrhage/treated with Amri-K (Vit. K) amp. For 3 days + cold fomentation with ice * If there is no separation → hemolysis * **Mycoplasma Mastitis (Mycoplasma bovis)** * Lives in infected quarters, respiratory & reproductive tract (abortion) * Spread from cow to cow (milking, nasal & vaginal discharge) * **Signs:** * Granular deposit on standing, swelling and firmness are common * But after few days the quarter shrunken with enlarged lymph nodes, fever and arthritis * Joint infections swollen & lameness * Nonresponsive to antibiotic treatment * No treatment for Mycoplasma mastitis and once infected, cows should be considered infected for life (carrier) * May use Tylosin 1ml/20 kg I/M * The only means of control is identification, segregation and culling. * **Tuberculous mastitis** * Descending infection (Hematogenous) * Indurations of the udder, particularly upper part of the rear quarters. * Enlargement of supra-mammary L.N with fibrosis of the quarters * **Change in milk** * **In early stages**: no macroscopically changes * **Later**: very fine floccules appear which settle after the milk stands leaving a clear amber fluid * **So later the secretion may be an amber fluid only** * The best sample for isolation of T.B should be milk from last trips * **Yeast (fungal) mastitis** * Suspected when there is a history of unsuccessful treatment especially with Penicillin or Oxytetracycline * Cause → Candida which use penicillin & Oxytetracycline as source of Nitrogen * Intensification of the signs of mastitis after intra-mammary infusion of antibiotics * **Diagnosis** * Not response to antibiotics and uses of Penicillin or Oxytetracycline → worsen the case * History of using intra-mammary infusion without proper antiseptic preparation for udder * Using of Povidone iodine as therapeutic diagnosis * **Teat Theilitis** * More common in buffalo heifer * Treatment → Amoxicillin + Mcloxicam – Antihistaminic * Can use Tylosin but it cause: * ↓ feed intake * Fatal diarrhea in equine * Cause → unknown but usually virus (cause ulcerative cellulitis) * Herpes - Mycoplasma - Staph. * So Local application of → Acyclovir 5% cream + antibiotic + lead subacetate * Long course of antibiotic as Pen-Strep (penicillin + streptomycin) or Synulox * Injection of corticosteroids in teat itself (to ↓ inflammation) * The good respond of treatment is not to increase in inflammation for 5 days at least * If increased → gangrenous theilitis & sloughing. * **Treatment** * Na iodide I/V or K iodide orally with antifungal preparation * Povidone iodine or antifungal as Miconaz oral gel or Nystatin → intra-mammary **Mastitis Treatment** * **Parenteral treatment** * It is advisable in all cases of mastitis in which: * There is a systemic disturbance to control or prevent the development of septicemia or bacteremia and to assist in the treatment of infection in the gland * Also when the gland is badly swollen and intra-mammary antibiotic is unlikely to diffuse properly * **Drugs:** * Penicillin 16000 iu/kg * Oxytetracycline 10 mg/kg * Tylosin 12.5 mg/kg * Sulfadimidine 200 mg/kg * Macrolides as Marbocyl 10% (marbofloxacine) 1ml/50 kg S/C for *E. Coli* mastitis * Cobactan 2.5% (Cefquinome) 1 ml / 20 kg I/M for *E. Coli* & *Staph. Mastitis* for 4 days * Spirovet (spiramycin) 1 ml / 20 kg I/M for *Staph. Mastitis* * Synulox (Amoxicillin + Clavulanic acid → inhibit penicillinase enzyme of M.O) 1 ml / 20 kg I/M * Borgal (trimethoprim + sulfadoxin) * **Udder infusions** * One or combination antibiotics are found in a disposable tube in a standard dose dispensing in ointment base or aqueous solution * Complete evacuation of udder by using oxytocin then washing and dryness of udder * **Drugs:** * Ampicillin & Amoxicillin * Aminoglycosides * Cephalosporins * Mixtures penicillin and aminoglycosides **Dry Cow Therapy** * Used in Chronic cases or persistent infection (as in *staph. aureus*) * Good prophylaxis for summer mastitis. * **Method** * Evacuation of 4 quarter then use single dose of udder infusion for each quarter after last milking * Dry cow preparations persist for 4 to 6 weeks (as teat orifice closed after 4-6 weeks) * **Drying off chronically effected quarters:** * 30-60 ml of 3% silver nitrate or 20 ml 5% copper sulphate or 100-300 ml 1: 500 acriflavine solution * If no reaction occurs, the quarter is stripped out 10-14 days later * **Drug used must be long acting, broad spectrum & nonirritant** * Cloxacillin benzathine → For dry cow * Cephalosporins → As Orbenin (D.C) * Spectramast (D.C) * Amoxicillin trihydrate → used for lactating cow As Amoxi-Mast (L.C)" * **Teat sealant** * Non-antibiotic material to close teat orifice * Used alone in cow not had infection in previous milking season or used after dry cow t.t.t in case of previous infection * **Supportive Treatment** * Treat the symptoms (Pain, temperature, swelling & dehydration) * Evacuation of udder by Oxytocin / Stripping to: * Eliminates toxins, bacterial load and bacteria food * Not effective against contagious bugs * Antihistamines & Anti-inflammatory * Ca therapy * Fluids → dehydration * Crushed ice in bag → reduces the absorption of toxins (vasoconstriction) **Alternative treatment** * Using non-antibiotic treatment as 03 غاز الاوزون * Preparation or Laser or X-ray or irradiation or * Using Levamisole or Vitamin C → increase the immunity of udder. **Control of Mastitis** * **Detection of infected quarters or cows** * By field test as CMT, white side test * **Treatment or elimination of infected quarters or cows by** * Udder infusion * Proteolytic Enzyme (to remove clotted milk & caseation) * Anti-inflammatory + Parenteral treatment * Drying off & culling chronic cases * **Prevent spread of the infection** * **Hygienic measures** * Hygienic disposal of infected milk * Prevent use of milk of infected cow for human consumption for at least 3 days after last treatment * Isolation of infected animals from non-infected one * Disinfection of hand and milking machine between each cow * Disinfection of udder and washing before milking (with individual paper towels discarded after use, or cloth towel boiled after use) * **Milking order** * Non-infected quarters or sound cow must be milked firstly * The milking should follow the herd classification with Group 1 milked first, Simply known infected cases should be milked last (The milking order) * Newly introduced should be milked separately until their statuses determined * **Teat dipping or spraying** * **Before application** * Wash, disinfect & drying udder with clean towel * Disinfection of hand of milkers and milk machines that has separate Cups * Types of teat dipping: * Pre-milking: Using alcohol * Post-milking: Using iodophore 1% or 4% chlorinated disinfectant as chlorhexidine or chlorine dioxide * **Properties of teat dipping substance** * Non-irritant to skin of udder and teat * Highly efficient to kill all bacteria that present on skin * Prolonged in action to kill the bacteria until the second milking. **Dry period treatment** * Most dry period → new infections arise in the 1st 3 weeks of the drying-off period * Thus the dry period treatment must be carried out at the end of the last milking before the cow is turned out * The antibiotic used must be high efficient and in long acting base (3% aluminum stearate) which by this has an affinity for binding to mammary tissue and secretions (i.e. remain in the udder (4-6 week) than be absorbed into blood stream such as benzathine cloxacillin 500 mg/quarter (Orbenin Dry cow intra-mammary suspension) * Before drying-off animal take milk sample to detect subclinical mastitis. * This treatment must be applied to all quarters if the incidence of subclinical mastitis 40-50% or use alternative methods. * If the incidence of infection ↓ 10%, take milk sample before drying off and treat only the infected quarters **Reduction of susceptibility** * Requires attention to such factors affecting susceptibility as: * Milking machine if in use * Drying-off **Nutrition** * Zn → enter in formation of keratin plug & has anti-bacterial properties * Ca → contraction of smooth muscle of teat orifice * Avoid recumbency of cow directly after milking as teat orifices still opened 10-20 min. * **Vaccination** * As use of autogenous bacterin (bacterin toxoids) contains a safe adjuvant against staph. aureus * It may reduce the incidence and severity of clinical cases (Lysigin-Startvac) **Prevention of injury of teat** * By examination of animals * By application of 2 CMT one month in between for introduction of -ve cases only * Applying strict quarantine measures. **Bloody milk or presence of milk tinged with blood may be due to:** 1. **Leptospira infection** which is characterized by * Bloody milk from 4 quarter & bloody urine → due to hemolysis of RBCs * No cardinal signs of inflammation (flaccid udder) with jaundice M.M 2. **Peracute or acute case of mastitis** * Presence of systemic reaction * Cardinal signs of inflammation 3. **Anthrax** if the animals are still a live 4. **Physiologically edema** (24-48 hrs postpartum) * In highly producing animals after parturition due to capillary bleeding in a congested udder soon after calving or due to hormonal changes or hormonal disturbance → damage blood vessels so treated by calcium borogluconate & Vitamin K 5. **Trauma** - centrifugation * If RBCs precipitate → hemorrhage/treated with Amri-K (Vit. K) amp. For 3 days + cold fomentation with ice * If there is no separation → hemolysis 6. **Hypophosphatemia** (due to fascioliasis) → blood at the top layer of milk (fat layer).