Wire Fox Terrier nutrition: calories, itchy skin and coat

A Wire Fox Terrier is a small dog, and its food should be measured like one. The American Kennel Club gives 18 pounds (about 8 kg) for males and 15 to 17 pounds (6.8 to 7.7 kg) for females, with a life expectancy of 12 to 15 years. A neutered adult of that size needs somewhere around 480 to 530 kcal a day as a starting point. Most of what diet can do for this breed comes down to three jobs: keeping the dog lean, feeding a complete diet, and recognizing the inherited problems that food does not change.

Inherited problems and where diet fits

Legg-Calvé-Perthes disease

In Legg-Calvé-Perthes disease the ball at the top of the thigh bone loses its blood supply and starts to die back while the dog is still young. VCA Animal Hospitals describes it as hereditary in small breeds, terriers among them. The usual sign is a hind-leg lameness that slowly gets worse, until the puppy can no longer bear weight on the leg. Treatment is mostly surgical, often by removing the damaged femoral head so that a false joint forms, and most dogs are running normally within months.

No diet prevents the condition. Food matters around it. A puppy kept slim while it grows, and a dog kept slim through recovery, puts less load on a painful hip. A young terrier that starts limping on a back leg should be examined, not rested for a few weeks to see what happens.

Primary lens luxation

The lens of the eye hangs on fine fibers. In primary lens luxation those fibers fail and the lens slips out of place. If it falls forward it can block fluid draining from the eye, and pressure can rise fast enough to cost the eye its sight. The condition runs in many terrier breeds, and the UC Davis Veterinary Genetics Laboratory lists the Wire Fox Terrier among the breeds it tests for the mutation. Results sort dogs into clear, carrier (one copy, at slight risk) and two copies. Breeders use the test to plan matings. Owners of an untested dog can use it to know which eye signs deserve a same-day visit.

Diet has no known effect on this one. A sudden squint, a watering, red or cloudy eye, or a dog pawing at its face needs a vet that day.

Itchy skin, mites and food trials

Scratching, ear infections, paw licking and red skin have several possible causes in a terrier: fleas, environmental allergy, mites and, less often, a reaction to something in the food. A dense wire coat hides early redness well. Parting the hair along the back and belly during grooming catches it sooner.

One skin problem has a documented link to this breed. A case series in Veterinary Dermatology described eight wirehaired fox terriers with greasy skin and hair along the back and Demodex injai, a long-bodied mite that lives in hair follicles. Seven were cleared of mites after two to seven months of treatment, but the greasiness went away completely in only four. A greasy strip down the spine is therefore a reason for skin scrapings, not a new shampoo or a diet change.

When a vet does suspect a food reaction, the test is an elimination diet: one protein and one carbohydrate the dog has not eaten before, and nothing else. Length matters. A review of the published cases found that eight weeks brought complete remission in more than 90% of dogs with a food reaction, so a three-week trial can give a false all-clear. If the skin settles, the old food goes back in to see whether the itch returns. The ingredients most often to blame in dogs are beef, dairy products, chicken and wheat, and the review recommends starting challenges with beef and dairy.

Coat texture and diet

Grooming does more for a wire coat than food does. The harsh, close-lying texture is traditionally kept by hand-stripping, which pulls out dead hair so new wire hair grows in its place.

Diet shows up in the coat when something is missing. The Merck Veterinary Manual lists a dull, unkempt coat among the signs of too little protein, or of protein out of balance with calories, and loss of hair color among the signs of zinc deficiency. It also notes that other ingredients in a commercial diet can reduce how much zinc is absorbed. A healthy adult on a complete and balanced food, fed in the right amount, should not run short of either. The risk is higher with a home-made diet that has not been formulated by a nutritionist, and with a normal food cut back hard for weight loss, which is what purpose-made weight-loss diets are designed to avoid. Extra zinc or protein on top of a complete diet is not a coat treatment.

Teeth and chewing

A terrier that chews hard things breaks teeth. Antlers, cooked or weight-bearing bones, hooves and nylon bones are the usual culprits, and the large upper cheek tooth (the carnassial) is often the one that splits. A reasonable rule: a chew that cannot be dented with a thumbnail is too hard.

• Daily tooth brushing with a dog toothpaste does more than any chew or food.
• Dental chews and diets carrying the Veterinary Oral Health Council seal have been tested for plaque or tartar reduction. Count their calories in the daily total.
• Raw carrot sticks make a low-calorie treat that takes some chewing.
• Bad breath, a discolored or broken tooth, or chewing on one side needs a dental check.

Daily calories for an active small terrier

The figures below use the formulas in the Merck Veterinary Manual. Resting energy requirement is 70 × (body weight in kg) raised to the power 0.75. That figure is then multiplied by a factor for life stage and neuter status.

Puppy figures are for the puppy's current weight and rise as it grows. Every number here is a first guess. Dogs of the same weight differ, and a terrier doing agility several times a week will need more than one that gets two walks a day. Weigh the dog every two to four weeks, feel for the ribs under a thin layer of fat, and change the portion in small steps. Adults do well on two measured meals a day. Young puppies usually get three or four. For help judging body shape, see the guide on signs a pet is overweight.

Sources

1. Wire Fox Terrier dog breed information. American Kennel Club.
2. Legg-Calve-Perthes disease in dogs. VCA Animal Hospitals.
3. Primary Lens Luxation (PLL). Veterinary Genetics Laboratory, UC Davis.
4. Demodex injai infestation and dorsal greasy skin and hair in eight wirehaired fox terrier dogs. Veterinary Dermatology, 2009.
5. Critically appraised topic on adverse food reactions of companion animals (1): duration of elimination diets. BMC Veterinary Research, 2015.
6. Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Veterinary Research, 2016.
7. Nutritional requirements of small animals. Merck Veterinary Manual.