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Veterinary Internal Medicine

At Companion Animal Specialty and Emergency Hospital, we offer specialized care for sick pets suffering from internal medicine conditions that are referred to us by their regular veterinarians. 

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Internal Medicine for Cats & Dogs, Crystal Lake Veterinarian

Internal Medicine Services

Our Internal Medicine team is trained to treat challenging or ongoing illnesses affecting pets’ internal organs and bodily systems.

We offer you a wealth of experience in the treatment of diseases impacting the endocrine, gastrointestinal, respiratory, urinary, and hematologic systems, as well as providing care for patients requiring emergency and intensive or critical care. 

In determining whether a diagnosis is proving elusive or treatment is not bringing about the desired results, we may refer you to our Integrative Medicine department.

At CASE Hospital in Crystal Lake, we emphasize a comprehensive, team approach to our cases and work not only with your veterinarian but also with other specialists to ensure the best care for our patients.

Appointment Information

We partner with your family veterinarian, specialists appointments are by referral only.

Internal Medicine appointments are booked on Monday, Tuesday, Thursday, or Friday. Our office is closed on Wednesday. Hours vary week by week. 

Our Internal Medicine Veterinarian

Dr. Dan Harrington completed his Internal Medicine Residency at the University of Missouri in 1996 and practices solely in internal medicine. 

Meet Dr. Harrington

Treating Disease in Pets

After a referral from your primary care vet, an internal medicine specialist will complete a thorough physical exam of your pet to formulate a diagnostic plan and create a comprehensive treatment plan tailored to your pet’s needs.

Commonly referred conditions include:

  • Anemia or other blood disorders 
  • Complicated pancreatic disease 
  • Coughing and other breathing problems
  • Endocrine diseases (adrenal tumors, thyroid disease, diabetes)
  • Illness or injury that is not healing or is getting worse
  • Infectious diseases
  • Kidney or bladder ailments
  • Lethargy
  • Liver inflammation 
  • Loss of appetite 
  • Recurring vomiting or diarrhea 
  • Significantly increased thirst 
  • Unexplained weight loss 

Internal Medicine Diagnostics 

In our in-house veterinary lab, we offer routine diagnostic services as well as specialized testing to help us diagnose and treat internal illnesses in pets.

Our diagnostic procedures include: 

  • Bone marrow biopsy
  • Bronchoscopy
  • CSF and joint tap
  • Cystoscopy/Vaginoscopy
  • Electrocardiography Services
  • Endoscopic foreign body retrieval
  • GI Endoscopy – upper and lower
  • PEG tube placement 
  • Rhinoscopy 
  • Ultrasound-guided fine-needle aspiration or biopsy
  • Ultrasound: abdominal and cardiac
  • Computerized Tomography (CT) Scan

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New Patients Welcome

Companion Animal Specialty and Emergency Hospital is accepting new patients! Our specialists and experienced emergency veterinarians are passionate about restoring good health to animal companions in Crystal Lake.

Contact Us

(815) 479-9119 Contact