Infectious Diseases

Anaerobic infections in dogs are commonly associated with infections of the oropharynx, the central nervous system, the subcateous space, the musculoskeletal system, the gastrointestinal tract, the liver, and the female genital tract, and they are relatively common in animals with aspiration pneumonia or consolidated lung lobes. Dogs and cats with gingivitis/stomatitis, rhinitis, retrobulbar abscesses, aspiration pneumonia, pyothorax, otitis media or interna, bite wounds, open wounds, open fractures, osteomyelitis, peritonitis, bacterial hepatitis, pyometra, vaginitis, bacteremia, and valvular endocarditis should be suspected to be infected with anaerobes.

Improving the blood supply and oxygenation of the infected area is the primary goal for treatment of dog infections. Antibiotic therapy should be used concurrently with drainage or debridement. Parenteral antibiotics should be administered for several days in dogs with infections like pyothorax, pneumonia, peritonitis, and clinical signs consistent with bacteremia. Penicillin derivatives, clindamycin, metronidazole, cephalosporins (first and second generation), chloramphenicol are used commonly for the treatment of infections in dogs.

With the exception of Bacteroides fragilis, penicillin derivatives have excellent activity against anaerobes. If gram-negative coccobacilli are detected cytologically in a neutrophilic exudate, particularly if associated with the oral cavity, metronidazole, a first-generation cephalosporin, or clindamycin should be administered instead of a penicillin derivative. Because concurrent anaerobic and aerobic dog infection occur frequently, combination antimicrobial treatment is often indicated, particularly if life-threatening signs of bacteremia exist.

We would love to hear your pet’s story. Please add a comment.

Canine Skin Disease | Skin Infections in Dogs

Staphylococcus intermedius is the most common cause of pyoderma in dogs and cats. Deep pyoderma can be induced by any organism, including the gram-negative types. Most skin infections in dogs and cats, including open wounds and abscesses are infected with a mixed population of bacteria; the aerobic and anaerobic flora from the mouth are often involved.

Recommended empirical antibiotic choices for routine cases of pyoderma and skin diseases in dogs and cats are often treated with cephalosporins and amoxicillin-clavulanate. Other penicillins, such as oxacillin and cloxacillin, also can be used. Potentiated sulfas can be used to treat dogs and cats with superficial pyoderma but should be avoided if long-term treatment is needed because bacterial resistance occurs quickly.

Cutaneous and soft tissue infections that do not respond to those antibiotics may be caused by gram-negative bacteria, L-form bacteria. Quinolones are the antibiotic class of choice for the treatment of gram-negative infections.

Dogs and cats that fail to respond to empirical antibiotic treatment should undergo further diagnostic testing or should be treated with antibiotics known to have an effect against the less common pathogens. If not previously done, microscopic examination of tissue or pustule aspirates should be performed for the presence of Sporothrix organisms and bacteria morphologically similar to Mycobacterium spp. After surgical preparation of the skin, deep tissues should be obtained for aerobic, anaerobic Mycoplasma, fungal, and atypical Mycobacterium spp. culture.

We would love to hear your pet’s story. Please add a comment.

Symptoms of parvo in dogs

There are two types of parvoviruses that infect dogs. Canine parvovirus-1 (CPV-1), also known as “minute virus of canines”, is a relatively nonpathogenic virus that sometimes is associated with gastroenteritis pneumonitis, and/or myocarditis in very young puppies. Canine parvovirus-2 (CPV-2) is responsible for classic parvoviral enteritis. CPV-2 usually causes signs 5 to 12 days after the dog is infected via the fecal-oral route, and it preferentially invades and destroys rapidly dividing cells (i.e., bone marrow progenitors, intestinal crypt epithelium).

Doberman Pinschers, Rottweilers, Pit Bulls, and Labrador Retrievers may be more ar risk than other breeds. The parvo destruction of intestinal crypts may produce villus collapse, diarrhea, vomiting, intestinal bleeding, and subsequent bacterial invasion; however, some animals have mild or even subclinical disease. Many dogs are initially presented because of depression, anorexia, and/or vomiting not diarrhea. Diarrhea is often absent for the first 24 or 48 of illness and may not be bloody if and when it does occur. Vomiting is usually a prominent finding and may be severe enough to cause esophagitis. Also, puppies that are infected in utero or before 8 weeks of age may develop myocarditis.

We would love to hear your pet’s story. Please add a comment.

Tissues collected from animals with suspected infectious diseases can be evaluated by several different techniques. Tissue samples should be aseptically placed in appropriate transport media for culture procedures or inoculated into laboratory animals, if indicated, before further handling.

Gently blotting the cut edge of the tissue on a paper towel to remove excess blood and then lightly touching the tissue multiple times to a microscope slide make tissue impressions for cytoligic examination. Tissue specimens can then be frozen, placed into 10% buffered formalin solution, or placed into glutaraldehyde-containing solutions. Frozen specimens are generally superior for immunohistochemical staining and PCR. Routine histopathologic evaluation is performed on formalin-fixed tissues. Special stains can be used to maximize the identification of some infectious agents.

The clinician should alert the histopathology laboratory to to the infectious agents most suspected to allow for appropriate stain selection. Glutaraldehyde-containing fixatives are superior to other fixatives for electron microscopic examination of tissues; this technique can be more sensitive than other procedures for demonstration of viral particles.

We would love to hear your pet’s story. Please add a comment.

It is always preferred to prevent rather than treat infections in dogs and cats. Consequently, avoiding exposure is the most effective way to prevent infections. Most infectious agents of dogs and cats are transmitted in fecal material, respiratory secretions, reproductive tract secretions, or urine; by bites or scratches; or by contact with vectors or reservoirs. Some infectious agents can be transmitted by direct contact with clinically normal, infected animals. Many infectious agents are environmentally resistant and can be transmitted by contact with a contaminated environment (fomites).

It is extremely important to avoid zoonotic transfer of infectious agents, because some zoonotic diseases, such as plague and rabies, are life-threatening. Recognition of risk factors associated with infectious agents is the initial step in prevention of infectious diseases.

Veterinarians should strive to understand the biology of each infectious agent so that they can counsel clients and staff on the best strategies for prevention. Vaccines available for some infectious agents can prevent infections or lessen clinical illness when infection occurs. However, vaccines are not uniformly effective, are not available for all pathogens, and sometimes induce serious adverse effects; thus it is paramount to develop sound biosecurity procedures to avoid exposure to infectious agents when developing a preventive medicine program.

We would love to hear your pet’s story. Please add a comment.

Contaminated hands are the most common source of infectious disease transmission in the hospital environment. Fingernails of personnel having patient contact should be cut short. Hands should be washed before and after attending to each individual animal as follows: collect clean paper towels and use to turn on water faucets, wash hands for 30 seconds with antiseptic soap being sure to clean under fingernails, rinse hands thoroughly, use the paper towel to dry hands, and use the paper towel to turn off the water faucets. Use of antiseptic lotion should be encouraged. Personnel should not touch patients, clients, food, doorknobs, drawer or cabinet handles or contents, equipment, or medical records with soiled hands or gloves.

All employees should wear an outer garment, such as a smock or scrub suit, when attending to patients. Footwear should be protective, clean and cleanable. A minimum of 2 sets of outer garments should always be available, and they should be changed immediately after contamination with feces, secretions or exudates. Equipment such as stethoscopes, pen lights, thermometers, bandage scissors, lead ropes, percussion hammers, and clipper blades can be fomites and should be cleaned and disinfected after each use with animals likely to have a transmissible infectious disease. To avoid zoonotic transfer of infectious diseases, food or drink should not be consumed in areas where animal care is provided. All areas where animals are examined or treated should be cleaned and disinfected immediately after use, irrespective of infectious disease status of the individual animal.

We would love to hear your pet’s story. Please add a comment.

Clinical features
Bubonic, septicemic, and pneumonic plague develop in infected humans and cats; clinical disease is extremely rare in dogs. Bubonic plague is the most common form of the disease in cats, but individual cats can show clinical signs of all three syndromes. Most infected cats are housed outdoors and have a history of hunting. Anorexia, depression, cervical swelling, dyspnea and cough are common presenting complaints; fever is detected in most infected cats. Unilateral or bilateral enlarged tonsils, mandibular lymph nodes, and anterior cervical lymph nodes are detected in approximately 50% of infected cats. Cats with pneumonic plague commonly have respiratory difficulty and may cough.

Diagnosis
Hematologic and serum biochemical abnormalities reflect bacteremia and are not specific for Y. pestis infection. Neutrophilic leukocytosis, left shift and lymphopenia, hypoalbuminemia, hyperglycemia, hypochloremia, hyperbilirubinemia, azotemia, hypokalemia, and increased activities of alkaline phosphatase and alkaline transaminase are common. Pneumonic plague causes increased alveolar and diffuse interstitial densities on thoracic radiographs. Cytologic examination of lymph node aspirates reveals lymphoid hyperplasia, neutrophilic infiltrates and bipolar rods.

Cytologic demonstration of bipolar rods on examination of lymph node aspirates, exudates from draining abscesses, or airway washings combined with a history of potential exposure, the presence of rodent fleas, and appropriate clinical signs lead to a presumptive diagnosis of feline plague. Since some cats survive infection and antibodies can be detected in serum for at least 300 days, detection of antibodies alone may indicate only exposure, not clinical infection. However, demonstration of a fourfold increase in antibody titer is consistent with recent infection. Definitive diagnosis is made by culture or fluorescent antibody demonstration of Y.pestis in smears of the tonsillar region, lymph node aspirates, exudates from draining abscesses, airway washings, or blood.

We would love to hear your pet’s story. Please add a comment.