Bulk Tank Milk Microorganisms Diagnostic Aid

Microorganisms are ubiquitous in the environment. Microorganism can be found in soil, water, plants, decaying organic matter, exudates of animals or within contaminated treatment preparations on any dairy farm. These microorganisms can be isolated from an infected udder, respiratory, reproductive, and digestive tracts. The potential always exists for these microorganisms to gain access to the mammary gland during favorable conditions. When these isolates are present, it is possible that the samples were not collected in an aseptic technique. Care should be taken when deciding if these isolates were the true cause of an infection or if they are indicative of contamination. Therefore, it is important to evaluate the bulk tank milk (BTM) culture results using all available information.

File: CL-Res-60-Bulk-Tank-Milk-Microorganisms-1.pdf

Milk Sample Collection Guidelines

Milk samples may be collected individually from each affected quarter (quarter milk samples) or combined from multiple quarters of a cow into one sample tube (composite milk samples). Composite milk samples are not recommended however, as cultures usually reveal growth of numerous different bacterial species, making it difficult, if not impossible, to determine which pathogens are causing mastitis and which are environmental contaminants. Isolation of contagious organisms, such as Staphylococcus aureus, Streptococcus agalactiae, or Mycoplasma sp., are indicators of true infections of the udder. Environmental organisms, such as Streptococcus spp., coliforms, Staphylococcus spp., (coagulase negative Staph.), Pseudomonas sp., Corynebacterium sp., yeast, and fungi, may be contaminants or true infections. Unless only screening for contagious pathogens, composite milk samples should be avoided.
Milk samples may become contaminated with bacteria from the hands of the sample collector, the environment, and the teat, skin or teat canal of the cow. It is important that proper sample collection techniques are used in order to avoid contamination of the milk sample.

File: CL-Res-59-milk-sample-collection-1.pdf

Mastitis: Streptococcus Species Diagnostic Aid

Streptococcus dysgalactiae – This gram positive, beta-haemolytic, coccal bacterium can be spread from cow-to-cow or acquired from the environment. Good hygiene and mastitis control programs including post-milking teat disinfection, antibiotic dry cow therapy and maintaining a clean, dry environment will reduce infections caused by this pathogen.

Streptococcus uberis – This gram-positive bacterium is the most frequent cause of mastitis in lactating cows. It can be isolated from the udder, skin, lips, and genital area of dairy cows, but infections are typically acquired from the environment. This bacterium causes mastitis during the dry period and are isolated frequently from cows with clinical mastitis during early lactation. Good hygiene and mastitis control programs including post-milking teat disinfection, antibiotic dry cow therapy and maintaining a clean, dry environment will reduce infections caused by this pathogen.

Other Streptococcus species isolated less frequently include the following:
S. acidominimus, S. alactolyticus, S. canis, S. zooepidemicus, S. equi, S. equinus (formally S. bovis), and S. parauberis.

Enterococcus species – Enterococcus species are a gram-positive cocci and lactic acid bacteria. Species include E. durans, E. faecalis, E. faecium, and E. saccharoluticus. These bacteria cause clinical and subclinical mastitis infrequently. Cows are infected from environmental contamination. Effective mastitis control procedures as mentioned above will control these mastitis-causing pathogens.

File: CL-Res-57-Environmental-Streptococcus-species-15-05-06-1.pdf

Leptospirosis Titer for Dogs Interpretation Guidelines

Leptospirosis is an important infectious disease of dogs. In the Midwest, Leptospirosis is usually
diagnosed in the late summer to fall time period especially if there is a sustained period of above
normal precipitation 1–3 months earlier. It is important to remember that all breeds and life
styles (city vs. rural) dogs are at risk of contracting Leptospirosis, but adult male dogs that spend
a considerable amount of time outdoors are at greatest risk

File: CL-Res-49-LeptoDogs.pdf

Avian Influenza in Backyard Flocks

Highly pathogenic avian influenza (Bird Flu) has been found in wild birds in North America. This virus can also infect poultry commonly found in backyard flocks. The strains were identified as H5N8 and H5N2 and typically do not cause disease in most wild birds but will cause severe disease in gallinaceous birds (domestic poultry and game birds). The strains are described as highly pathogenic because of rapid spread and high mortality in domesticated poultry

File: CL-Res-48-BirdFluinBackyardFlocks11-5-15-1.pdf

Leptospirosis Titers For Large Animals Interpretation Guidelines

The Microscopic Agglutination Test (MAT) is the standard serological test used in the United States for diagnosis of Leptospirosis. The following six serovars are used in the assay: L. bratislava, L. canicola, L. grippotyphosa, L. hardjo-bovis, L. icterohaemorrhagiae and L. pomona. Generally, the serovar with the highest titer is the infecting serovar but cross-reactions do occur albeit at a lower level. Titers should be interpreted in the context of clinical findings, laboratory data and Leptospirosis vaccination history

File: CL-Res-47-LEPTOMATLARGEANIMAL.pdf