Clinical findings and treatment of disseminated 'Mycobacterium avium subspecies hominissuis' infection in a domestic cat

[Pulmonary Mycobacterium avium infection in 2 domestic cats]

Two domestic cats (Abyssinian and Carthusian) presented with chronic respiratory signs including cough, respiratory sounds, and polypnea. One of the cats also showed intermittent fever. Thoracic radiographs demonstrated severe changes with predominantly micronodular interstitial lung patterns, some with mineralized areas. Bronchoalveolar lavage detected high-grade pyogranulomatous airway inflammation. A cytological examination for acid-fast bacteria and a PCR for Mycobacteria species of the bronchoalveolar lavage fluid (BALF) were negative in both cats. A culture for Mycobacteria of the BALF detected Mycobacterium avium subspecies in both cats. While the clinical signs, but not the radiographic findings, could be controlled in one cat with prolonged double antibiotic therapy, the other cat developed septic peritonitis shortly after diagnosis and was euthanized. In unexplained chronic respiratory disease in cats, mycobacterial infection should be considered as a differential diagnosis. The breed of the first patient is consistent with the known predisposition for Abyssinians.

Response to treatment, relapse and outcome of two dogs treated for Mycobacterium avium infection

A 3-year-old male neutered Golden Retriever with nasal swelling and lymphadenopathy was diagnosed with diffuse Mycobacterium avium infection. Treatment with 9 months of enrofloxacin, clarithromycin and rifampicin was successful, but relapsed 10 months later with lymphadenopathy, skin plaques and testicular involvement. Repeat treatment for 12 months was effective but 15 months later a second relapse responded to the same therapy which is ongoing with survival from diagnosis of 82 months. A 1-year-old male neutered Portuguese Podengo was diagnosed with polyarthritis and M. avium infection and treated with enrofloxacin, clarithromycin and rifampicin for 4 months but relapsed, subsequently responding to combined pradofloxacin, rifampicin, doxycycline and ethambutol. After 12 months of treatment, M. avium was detected and treatment extended to 17 months before stopping when no organism was detected. Relapse occurred after 6 weeks, responding to retreatment but relapsing (polyarthropathy, lymphadenomegaly) after 15 months, with euthanasia 38 months after diagnosis. Dogs with M. avium are challenging to treat with frequent relapse; however, long-term survival is possible.

Feline abdominal ultrasonography: What's normal? What's abnormal? Abdominal lymph nodes, peritoneal cavity and aorta

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the lymph nodes, peritoneal cavity and abdominal vasculature provides important information useful in the investigation of a number of conditions, including aortic thromboembolism.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings such as Bates bodies and pathological changes can be challenging.

AIM

This review, the last in an occasional series on feline abdominal ultrasonography, discusses ultrasound examination of the abdominal lymph nodes and peritoneal cavity, and also the role of the technique in identifying thromboembolism of the aorta. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Levofloxacin in veterinary medicine: a literature review

A potent third-generation antimicrobial fluoroquinolone drug, levofloxacin was introduced into human clinical practice in 1993. Levofloxacin is also used in veterinary medicine, however its use is limited: it is completely banned for veterinary use in the EU, and used extralabel in only companion animals in the USA. Since its introduction to clinical practice, many studies have been published on levofloxacin in animal species, including pharmacokinetic studies, tissue drug depletion, efficacy, and animal microbial isolate susceptibility to levofloxacin. This literature overview highlights the most clinically relevant and scientifically important levofloxacin studies linked to the field of veterinary medicine.