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Objective—To test the ability of a single injection of a sustained-release formulation of moxidectin (moxidectin SR) to protect dogs against heartworm infection for 180 days after inoculation with infective thirdstage larvae (L3) of Dirofilaria immitis.

Animals—32 adult mixed-breed dogs.

Procedure—Dogs were allocated to 4 groups on the basis of weight and sex. Dogs were injected SC with saline (0.9% NaCl) solution or moxidectin SR at the rate of 0.06, 0.17, or 0.5 mg/kg of body weight (day 0). Each dog was inoculated SC with 50 D immitis L3 180 days later. On days 330 and 331, dogs were euthanatized. The heart, lungs, and thoracic cavity were examined, and number and sex of heartworms were determined.

Results—A mean of 35.9 heartworms was recovered from untreated control dogs. Fourteen worms were recovered from 1 of 8 dogs given moxidectin SR at the lowest dosage, and none of the dogs in the 2 highest moxidectin treatment groups were infected. Small barely palpable granulomas were detected at injection sites of moxidectin-treated dogs. Frequency and size of granulomas were positively correlated with dose of moxidectin administered.

Conclusions and Clinical Relevance—A single dose of moxidectin SR at a dosage as low as 0.17 mg/kg can safely and reliably confer complete protection against infection after challenge-exposure with D immitis L3, and protection lasts for at least 180 days. This mode of prophylactic treatment against infection with heartworms effectively eliminates failure of prophylaxis that results from erratic administration of medications designed for monthly administration. (Am J Vet Res 2001;62:1721–1726)

Full access
in American Journal of Veterinary Research



To evaluate the diagnostic, prognostic, and therapeutic utility of a cancer genomic diagnostic assay (SearchLight DNA; Vidium Animal Health) for diagnostically ambiguous cancer cases.


69 privately owned dogs with ambiguous cancer diagnoses and for which the genomic assay was performed.


Genomic assay reports generated between September 28, 2020, and July 31, 2022, for dogs with malignancy or suspected malignancy were reviewed to determine the assay’s clinical utility defined as providing diagnostic clarity, prognostic information, and/or therapeutic options.


Genomic analysis provided diagnostic clarity in 37 of 69 cases (54%; group 1) and therapeutic and/or prognostic information in 22 of the remaining 32 cases (69%; group 2) for which the diagnosis remained elusive. Overall, the genomic assay was clinically useful in 86% (59/69) of cases.


To our knowledge, this was the first study to evaluate the multifaceted clinical utility of a single cancer genomic test in veterinary medicine. Study findings supported the use of tumor genomic testing for dogs with cancer, particularly those that are diagnostically ambiguous and therefore inherently challenging to manage. This evidence-driven genomic assay provided diagnostic guidance, prognostic support, and therapeutic options for most patients with an unclear cancer diagnosis that would otherwise have an unsubstantiated clinical plan. Furthermore, 38% (26/69) of samples were easily obtained aspirates. Sample factors (sample type, percentage of tumor cells, and number of mutations) did not influence diagnostic yield. Our study demonstrated the value of genomic testing for the management of canine cancer.

Open access
in Journal of the American Veterinary Medical Association


Objective—To determine whether particular vaccine brands, other injectable medications, customary vaccination practices, or various host factors were associated with the formation of vaccine-associated sarcomas in cats.

Design—Prospective multicenter case-control study.

Animals—Cats in the United States and Canada with soft tissue sarcomas or basal cell tumors.

Procedure—Veterinarians submitting biopsy specimens from cats with a confirmed diagnosis of soft tissue sarcoma or basal cell tumor were contacted for patient medical history. Time window statistical analyses were used in conjunction with various assumptions about case definitions.

Results—No single vaccine brand or manufacturer within antigen class was found to be associated with sarcoma formation. Factors related to vaccine administration were also not associated with sarcoma development, with the possible exception of vaccine temperature prior to injection. Two injectable medications (long-acting penicillin and methyl prednisolone acetate) were administered to case cats more frequently than to control cats.

Conclusions and Clinical Relevance—Findings do not support the hypotheses that specific brands or types of vaccine within antigen class, vaccine practices such as reuse of syringes, concomitant viral infection, history of trauma, or residence either increase or decrease the risk of vaccineassociated sarcoma formation in cats. There was evidence to suggest that certain long-acting injectable medications may also be associated with sarcoma formation. (J Am Vet Med Assoc 2003;223:1283–1292)

Full access
in Journal of the American Veterinary Medical Association