Clinicians from Five Cummings School Teams and Purdue University Collaborate to Treat Dog Adopted from South America

Andrea Wang V25 and Kara Fischer V24 spent a week volunteering with AproVet Nicaragua, a spay/neuter veterinary program, last December. During an outreach day at a nearby barrio (local community), they set up at a park to administer rabies vaccines, dewormers, and preventative tick and flea medicines to pets and any stray dogs willing to be caught. Early in the day,while setting up, they came across Pollo.

“He was a lanky, funny-looking street dog that wouldn’t leave us alone; he was curious,” says Wang. “He was our first vaccination. Most dogs run away afterward, but he hung around with us all day looking for food.”

The dog was thin and had superficial skin wounds, scabs, and open sores. The lead veterinarian at AproVet, Dr. Lester Tapia, thought they should bring him back to the clinic to treat the wounds, feed him, and return him to the neighborhood when he was healthier, but the dog was reluctant to enter the van with the students and veterinarians. So they pulled out the chicken he’d been begging for at lunch, and he followed them. He became referred to as Pollo, Spanish for chicken.

Wang and Fischer decided to adopt and bring Pollo to the United States rather than release him back to the street. Fischer started a GoFundMe page to cover the costs, and the other vets and students donated. Pollo remained at AproVet for several more weeks, where the veterinarians gave him plenty of food and cleaned up his wounds.

Pollo joined Wang and Fischer in the States in February. They put him on high-calorie puppy food. He was feeding well but struggling to gain weight. They tested him for parasites and found that he had roundworms, whipworms, and Giardia. Pollo was dewormed and managed to gain almost 10 pounds over the next few weeks, though he was still quite skinny. He was also itching, continued to have crusty eyes and skin wounds, and had patchy hair loss.

They brought him into Henry and Lois Foster Hospital for Small Animals (FHSA) at Cummings School in March. Dr. Claire Fellman, associate professor in the Department of Clinical Sciences at Cummings School and small animal internist at FHSA, took the lead on Pollo’s case.

“It was an interesting constellation of problems,” says Fellman. To begin, she saw ocular changes in his eyes during her initial exam, so she consulted with the Ophthalmology Team at FHSA. They found cataracts and attributed the eye changes to malnutrition. She pulled in the Dermatology Team to examine his crusty skin lesions. They could not determine if the lesions were caused by an allergy or related to his other signs but recommended treatment for itching.

Pollo’s bloodwork raised more questions than answers, and Dr. Fellman turned to the Clinical Pathology Team to help solve them. Dr. Francisco Conrado, assistant professor in the Department of Comparative Pathobiology, diagnosed Pollo with microfilaremia (small larvae circulating in the blood). Microfilariae are typically associated with heartworm disease, but heartworm testing came back negative. Pollo’s red blood cells, white blood cells, and platelets were low, a condition called pancytopenia. He also had an increase in proteins (globulins) that is usually associated with inflammation. Pollo tested positive for Ehrlichia, which was likely the cause of his blood cell change and globulins, and he was treated with antibiotics and continued on preventative flea and tick medicine.

“The microfilariae persisted, and we were not sure if it was clinically relevant or the cause of the skin signs,” says Fellman. “We rely heavily on Clinical Pathology to review our blood smears and give us ideas on what’s happening. We frequently collaborate and work together on cases.”

Conrado consulted with Dr. Andrea Varela-Stokes, professor and chair of the Department of Comparative Pathobiology and a parasitologist at Cummings School. Together, they concluded that the larvae were too small to be heartworms and didn’t look quite like larvae from a different worm that can be confused with heartworms. Conrado contacted a friend at Purdue University to help identify the filariae. He sent Pollo’s blood samples for molecular analysis to Dr. Andrea Pires dos Santos, associate professor in the Department of Comparative Pathobiology at Purdue University College of Veterinary Medicine. Santos ran a PCR test, identified the filariae, and diagnosed Pollo with a type of parasite common in South America that also produces microfilariae, called Acanthocheilonema reconditum.

“Clinical pathology is an intrinsically collaborative specialty,” says Dr. Conrado. “We are always consulting with other services and making meaningful connections with other institutions to fill the gaps in our diagnostic capabilities. In this case, we worked closely with internists and parasitologists within Cummings School to help manage Pollo's case and reached out to Dr. Andrea Santos at Purdue, a close friend of mine, someone with whom we have ongoing externally funded research, and our go-to for molecular diagnoses and PCR-based tests.”

Because this parasite is not commonly seen in the United States and may be underestimated, Conrado ended up making 120 smears of Pollo’s blood. Dr. Lina Crespo Bilhalva (she/her), clinical pathology resident in the Department of Comparative Pathobiology at Cummings School, helped Dr. Conrado with the bloodwork and wrote up Pollo’s case for submission to the upcoming ACVP/ASVCP (American College of Veterinary Pathologists/American Society for Veterinary Clinical Pathology) Annual Meeting, the largest pathology conference in the country. It was accepted, and she will be presenting a mystery slide case at the conference in Seattle in November.

“I am excited to have our first-year resident already submitting cases to our Annual Meeting and adding to the body of literature in veterinary clinical pathology,” says Conrado. “This case highlights the importance of an interdisciplinary approach for diagnosis and management of an uncommon disease in the United States, and the importance of travel history when constructing differential diagnoses.”

Crespo explains the significance of this case: “Pollo’s filaria has a global distribution, but we know little about the prevalence among countries including the United States. The biggest problem is in places where heartworm is endemic, because heartworm can cause pulmonary hypertension and congestive heart failure. In this situation, an uninformed professional may treat a dog with an unnecessary aggressive treatment for heartworm just because they find circulating microfilariae.”

The case was a first for Fellman—she had never seen an instance where microfilariae were not associated with heartworm. She felt fortunate to have so many disciplines within FHSA to consult with to find the correct diagnosis, especially in the case of an animal from a tropical region with a parasite not often found in the United States.

“We teach our students about Acanthocheilonema reconditum and how the microfilariae can confound heartworm diagnosis, but it isn’t often that we see it; in fact, it rarely circulates in the high numbers that we saw in Pollo, so this was a treat to find, especially since it is considered non-pathogenic,” says Varela-Stokes. 

Wang and Fischer also appreciated the help from all the departments to diagnose and treat Pollo accurately. “It was awesome how many people were interested in the case and willing to give a consultation,” says Wang.

When Pollo returned to FHSA in May, microfilariae were no longer apparent in his blood smear, and he was less itchy. He’s adjusted well to life with two veterinarians. He plays with Fischer’s puppy and Wang’s Pitbull-Chow mix. He loves his box of toys and running around, especially in the woods.

“The collaboration was fun because it was a bit of a mystery in terms of how all the problems interrelated, if at all,” says Fellman. “We found assorted health problems that didn’t all have a single cause, but we needed the help of the different services and were able to resolve most of them. We worked together to achieve the diagnosis and determine what we could do to make Pollo feel better.”