Cheri A. Johnson

Identification and characterization of an idiopathic pulmonary fibrosis-like condition in cats

Interstitial lung diseases are a heterogeneous group of disorders with a variety of causes. In veterinary medicine, such lung diseases with a prominent fibrotic component of unknown etiology are often called idiopathic pulmonary fibrosis (IPF). In human medicine, this term is reserved for a distinct disease entity with specific histologic findings labeled as usual interstitial pneumonia (UIP). We identified 23 cats displaying histologic criteria of UIP The purpose of this retrospective study is to describe the presentation and response to therapy of these cats to better define this disease entity. All but 2 cats were middle aged to older (median 8.7 years), with no apparent sex or breed predisposition. Complaints included respiratory distress (n = 18) and cough (13). Duration of signs was less than 6 months in 17 cats. Physical-examination abnormalities included tachypnea, inspiratory or mixed inspiratory and expiratory effort, and adventitial lung sounds. No consistent hematologic or biochemical abnormalities, parasites, or positive serologic results for feline retroviruses, heartworms, or toxoplasmosis were present. Radiographic changes included dense patchy or diffuse interstitial, bronchiolar, and alveolar infiltrates. Analysis of bronchial lavage fluid revealed mild neutrophilic inflammation (n = 6) with no consistent pathogen growth. Clinical condition of 5 cats worsened after lavage. Coincident pulmonary neoplasia was identified in 6 cats. Response to therapy (corticosteroids, antibiotics, bronchodilators, and diuretics) was poor, and most cats died within days to months. Cats with histologic changes compatible with UIP had signs that mimicked many of the clinical findings of human IPF, and treatment response was similarly unrewarding.

Reproductive manifestations of thyroid disease.

Thyroid function and reproductive function have many interactions, the scope and mechanism of which are not fully understood. These functions are of greatest clinical importance for veterinarians working with breeders of purebred dogs. Thyroid dysfunction does not always result in clinical signs of reproductive disorders or in subfertility. It seems that animals with overt thyroid dysfunction are those most likely to manifest reproduction problems.

The effect of maternal illness on perinatal health.

Only healthy animals should be included in a breeding program. The potential effects of maternal illness and therapeutic agents on the fetus or neonate are often ignored until veterinary assistance becomes an absolute necessity. We must be mindful of these effects in order to minimize maternal and neonatal morbidity and mortality.

Serum Concentrations of Gastrin after Famotidine and Omeprazole Administration to Dogs

Background The duration of antacid‐induced hypergastrinemia after cessation of administration of omeprazole and famotidine apparently has not been determined in dogs. Hypothesis That serum gastrin will return to basal concentrations by 7 days after cessation of famotidine or omeprazole administration. Animals Nine healthy, adult, male, research colony dogs. Methods Randomized, cross‐over design. Serum gastrin was determined daily for 7 days to establish baseline concentrations. Famotidine (1.0 mg/kg q24h) or omeprazole (1.0 mg/kg q24h) was administered PO for 7 days followed by a 14‐day washout. Serum concentrations of gastrin were determined daily during 7 days of administration and daily for 7 days after cessation of administration. Each drug was evaluated in 8 of the 9 dogs. Results Omeprazole caused a significant increase in serum gastrin concentration (37.2 ± 7.3 to 71.3 ± 19.0 ng/L; P = .006). Famotidine induced a transient increase in serum gastrin (37.2 ± 7.3 to 65.5 ± 38.5 ng/L; P = .02) that peaked at administration day 3 and declined thereafter. By day 7 after cessation of both drugs, there was no difference in serum gastrin concentrations compared to those before administration (famotidine P = .99; omeprazole P = .99). During or after administration, gastrin concentrations above 3 times the upper reference range were rare (12 of 224 samples). Conclusions and Clinical Importance A 7‐day withdrawal from short‐term administration of famotidine or omeprazole is sufficient for serum gastrin to return to baseline concentrations. Withholding famotidine or omeprazole for longer before investigating pathologic causes of hypergastrinemia is unnecessary.

SCID Dogs: Similar Transplant Potential but Distinct Intra-Uterine Growth Defects and Premature Replicative Senescence Compared with SCID Mice

We have previously described DNA-dependent protein kinase (DNA-PKcs) mutations in horses and dogs that result in deficits in V(D)J recombination, DNA repair, and SCID. In this paper, we document substantial developmental growth defects in DNA-PKcs-deficient dogs that are not apparent in SCID mice. Fibroblast cell strains derived from either fetal or adult SCID dogs proliferate poorly in culture and undergo premature replicative senescence, somewhat reminiscent of cells derived from Ku-deficient mice. A limited number of animals have been immune reconstituted (by bone marrow transplantation) so that they can be maintained in a normal environment for long periods. Several of these animals have developed conditions associated with premature ageing at 2–3 years of age, roughly 20% of their expected lifespan. These conditions include intestinal malabsorption and primary neural cell neoplasia. These results suggest that DNA-PKcs deficiency is not tolerated equally in all species, perhaps providing insight into why DNA-PKcs deficiency has not been observed in humans. Finally, this study demonstrates the feasibility of maintaining SCID dogs for extended periods of time and documents their utility for bone marrow transplantation studies and as hosts for the propagation of xenografts. In sum, SCID dogs may present researchers with new possibilities for the development of animal models of human disease.

In vitro comparison of plain radiography, double-contrast cystography, ultrasonography, and computed tomography for estimation of cystolith size

OBJECTIVE To compare accuracy of estimates of cystolith size obtained by means of plain radiography, double-contrast cystography, ultrasonography, and computed tomography. SAMPLE POPULATION 30 canine cystoliths ranging from 1 to 11 mm in diameter with various mineral compositions. PROCEDURES A bladder phantom model was created by filling a rubber balloon with saline (1% NaCl) solution and positioning it on top of a 2% gelatin cushion at the bottom of a water-filled 4-quart container. Cystoliths were individually placed in the bladder phantom and imaged by each of the 4 techniques. For each image, cystolith size was measured by 2 radiologists with computerized calipers, and size estimates were compared with actual cystolith size. RESULTS Mean cystolith size estimates obtained by means of radiography, cystography, and computed tomography did not differ significantly from each other. However, for ultrasonographic images, mean +/- SD difference between actual and estimated cystolith size (2.95 +/- 0.73 mm) was significantly higher than mean difference for radiographic, cystographic, and computed tomographic images. For ultrasonography, mean +/- SD percentage overestimation in cystolith size was 68.4 +/- 51.5%. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that measurements of cystolith size obtained by means of ultrasonography may overestimate the true size. This suggests that cystolith size estimates obtained by means of ultrasonography should be interpreted with caution whenever cystolith size may influence patient management.

Investigation and characterization of Brucella canis infections in pet-quality dogs and associated human exposures during a 2007–2016 outbreak in Michigan

OBJECTIVE To estimate Brucella canis seropositivity rates for purebred dogs being bred by noncommercial breeders, describe epidemiological findings in infected commercial dog-production facilities, and characterize B canis infection in pet dogs and the risk to human health. DESIGN Retrospective descriptive study. SAMPLE 2,799 canine specimens submitted to the Michigan State University Veterinary Diagnostic Laboratory for B canis testing and records of B canis reports provided to the Michigan Department of Agriculture and Rural Development from 2007 through 2016. PROCEDURES Results of B canis laboratory tests and epidemiological findings for reported cases of B canis were reviewed and summarized. Federal and state public health officials were interviewed regarding human B canis infection. State veterinarians were interviewed regarding canine brucellosis reporting and control procedures. RESULTS Estimated B canis seropositivity was 0.4% among purebred Michigan dogs owned by noncommercial breeders. Infection was confirmed in dogs from 17 commercial dog-production facilities, 3 shelters, and 1 rescue agency. Estimated infection prevalence in production facilities ranged from 2 of 22 (9%) to 5 of 6 (83%). Transfer of infected dogs involved 22 Michigan counties and 11 states. Seven of 20 privately owned infected dogs had diskospondylitis; I also had uveitis. Fifty-three veterinary hospital or diagnostic laboratory personnel had inadvertent exposure to the pathogen. Brucella canis was isolated from 1 commercial production facility owner. CONCLUSIONS AND CLINICAL RELEVANCE B canis was uncommon in purebred dogs being bred by noncommercial breeders but endemic in Michigan commercial facilities producing dogs destined to become household pets. Infected pet dogs caused human B canis exposure, and several pet dogs had debilitating disease not associated with the reproductive system.

Systemic manifestations of Cuterebra infection in dogs and cats: 42 cases (2000–2014)

OBJECTIVE To document clinical signs in cats and dogs with Cuterebra infection, determine the outcome of infected animals, and determine whether Yorkshire Terriers were more commonly affected than other breeds of dogs. DESIGN Retrospective case series. ANIMALS 22 cats and 20 dogs with Cuterebra infection. PROCEDURES Medical records of dogs and cats with Cuterebra infection were reviewed for signalment, history, clinical and laboratory findings, treatment, duration of hospitalization, and outcome. RESULTS Most (16/20 [80%]) of the dogs weighed ≤ 4.5 kg (10 lb), and Yorkshire Terriers were overrepresented (8/20 [40%]), compared with dogs of other breeds. Ten (50%) dogs and 3 (14%) cats had systemic inflammatory response syndrome at the time of initial evaluation, and 8 (40%) dogs but none of the cats had disseminated intravascular coagulation. The overall mortality rate was 17% (7/42), but was higher for dogs (6/20 [30%]) than cats (1/22 [4.5%]). All 6 dogs that died weighed ≤ 4.5 kg and had systemic inflammatory response syndrome, disseminated intravascular coagulation, or both. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that Cuterebra infection can cause severe systemic illness in small-breed dogs. Yorkshire Terriers were more commonly affected than were dogs of other breeds and, subjectively at least, appeared to be more likely to develop severe systemic illness.